The hereditary cancer clinic nurse’s communication challenge
The hereditary cancer clinic nurse works at the intersection of genetics, oncology, and preventive medicine — a specialty whose communication challenges share a structural pattern that differs fundamentally from almost every other clinical field: the nurse is explaining risk that has not yet materialized, and explaining why risk that was present before a previous cancer remains fully present after it was treated. The families in these conversations are not confused because they are inattentive. They are confused because their mental model of disease — you have a disease, you treat it, the threat is resolved — does not map onto the molecular biology of germline pathogenic variants.
The first systematic failure is the BRCA1 post-treatment confusion. The patient completed breast cancer treatment eight months ago. The oncology follow-up is excellent. The genetics team is now recommending prophylactic bilateral salpingo-oophorectomy. The daughter cannot understand why more surgery is being planned when the cancer is already gone. What she is missing is the distinction between somatic and germline variants: treating the breast cancer removed the tumor, but the BRCA1 pathogenic variant is still present in every cell of the body, including every ovarian and fallopian tube epithelial cell. The BRCA1 variant confers 44–46% lifetime ovarian cancer risk. That risk was present before the breast cancer. It is still present after treatment. And ovarian cancer — unlike breast cancer — has no effective early detection method.
The second failure is the Lynch syndrome interval confusion. The sigmoid adenoma was removed fourteen months ago. The colonoscopy confirmed a clear colon. Why is another colonoscopy being scheduled for eighteen months from now? The son cannot understand why the interval is so short when the doctor just looked. What he is missing is that Lynch syndrome’s mismatch repair deficiency affects every colonic mucosal cell simultaneously, not just the cell that produced the removed polyp. New microsatellite-unstable adenomas form continuously throughout the entire colon, and MSI-H polyps in Lynch syndrome can progress from adenoma to invasive carcinoma in two to three years — not the ten or more years of average-risk adenoma progression. The colonoscopy interval corresponds to the biology, not to a calendar preference.
The third failure is the Li-Fraumeni surveillance resistance. The patient is 31 years old, has never had cancer, and feels completely well. Annual whole-body MRI, brain MRI, and breast MRI have been recommended indefinitely. The husband cannot understand why an asymptomatic healthy person needs annual full-body imaging. What he is missing is that a TP53 germline pathogenic variant eliminates the G1 cell cycle checkpoint from every cell of the body — not just cells in one organ. Li-Fraumeni syndrome confers approximately 90% lifetime cancer risk across more than twenty tumor types simultaneously. Early Li-Fraumeni tumors do not produce symptoms until they reach a size or location that disrupts function, by which point staging is often advanced. Annual whole-body MRI detects these tumors when they are small, localized, and surgically curable — before symptoms appear.
Three conversations from the hereditary cancer clinic:
Scenario 1: Viviana Reyes-Montoya — 44, physical therapist from Houston, Texas
Viviana Reyes-Montoya had spent eighteen years working as a physical therapist in a rehabilitation hospital in the Texas Medical Center, helping patients rebuild function after strokes, joint replacements, and trauma. She was comfortable with medical environments in a way that most patients are not, and she had navigated her breast cancer diagnosis the previous year with the organized practicality of a clinician: she had researched her options, attended every appointment, completed her treatment — lumpectomy followed by radiation and adjuvant letrozole — and returned to work eight months after diagnosis with clean margins and a favorable prognosis. Her oncologist had sent her for genetic testing as part of post-treatment workup. The result had come back three weeks later: BRCA1 pathogenic variant, c.5266dup, a well-characterized protein-truncating variant.
Her genetics appointment had covered the implications efficiently: elevated lifetime risk for contralateral breast cancer, and ovarian cancer risk of 44–46% across the lifetime. The genetics counselor had recommended prophylactic bilateral salpingo-oophorectomy — removal of both fallopian tubes and ovaries — ideally before age 45, along with annual breast MRI for surveillance of the contralateral breast. Viviana had absorbed the information professionally. Her daughter Ana-Sofía, a 24-year-old graduate student in public health at UTHealth, had called from Austin that evening with a question that was less clinical and more emotional.
“Mamá acabó el tratamiento del cáncer de mama. Le dijeron que el pronóstico es bueno. Está de vuelta en el trabajo. Y ahora le recomiendan una operación para quitarle los ovarios y las trompas. ¿Por qué más cirugía? ¿No se supone que el cáncer ya se trató?” (Mom just finished breast cancer treatment. They told her the prognosis is good. She is back at work. And now they are recommending surgery to remove the ovaries and fallopian tubes. Why more surgery? Wasn’t the cancer already treated?)
The hereditary cancer clinic nurse, Catalina Medina-Herrera, had been explaining BRCA1 ovarian cancer risk to families for nine years, and she had learned that the question “why more surgery when the cancer is treated” always contained the same conceptual gap: the assumption that treating the cancer removed the genetic risk. She scheduled a video call with Viviana and Ana-Sofía together.
“Ana-Sofía, tu pregunta tiene mucho sentido, y me alegra que la hayas hecho. Voy a explicar por qué el cáncer de mama de tu mamá y su riesgo de cáncer de ovario son dos cosas relacionadas pero distintas, y por qué tratar una no resuelve la otra.” (Ana-Sofía, your question makes a lot of sense, and I am glad you asked it. I am going to explain why your mother’s breast cancer and her ovarian cancer risk are two related but different things, and why treating one does not resolve the other.)
She began with the distinction between somatic and germline variants. Most cancers arise from somatic mutations — DNA changes that accumulate over a lifetime in a specific cell lineage. A somatic mutation occurs in one cell, is present only in that cell and its daughter cells, and is not present in any other tissue of the body. When a somatic-mutation-driven tumor is removed, the mutation is gone with it.
“Una variante germinal es diferente. Una variante germinal está en el ADN del óvulo o del espermatozoide que formó a la persona. Eso significa que está en cada célula del cuerpo desde el nacimiento — en las células del pecho, en las células de los ovarios, en las células del cerebro, en las células de la piel. En todas. La variante c.5266dup de BRCA1 que tiene tu mamá no está solo en el tumor que se quitó. Está en cada célula del ovario izquierdo, en cada célula del ovario derecho, en cada célula de las trompas de Falopio, en cada célula de la mama contralateral. Quitando el tumor del pecho se quita ese tumor. Pero la variante BRCA1 sigue estando en todas las demás células, exactamente igual que antes.” (A germline variant is different. A germline variant is in the DNA of the egg or sperm that formed the person. That means it is in every cell of the body from birth — in the breast cells, in the ovarian cells, in the brain cells, in the skin cells. In all of them. The c.5266dup BRCA1 variant your mother has is not only in the tumor that was removed. It is in every cell of the left ovary, in every cell of the right ovary, in every cell of the fallopian tubes, in every cell of the contralateral breast. Removing the breast tumor removes that tumor. But the BRCA1 variant is still present in all the other cells, exactly as before.)
Ana-Sofía was quiet for a moment. She was a public health graduate student; she knew what a population-level risk figure meant. “¿Y cuál es el riesgo de cáncer de ovario con BRCA1?” (And what is the ovarian cancer risk with BRCA1?)
“Para mujeres con una variante patogénica en BRCA1, el riesgo acumulado de cáncer de ovario a lo largo de la vida es de 44 a 46 por ciento. Comparado con el 1.3 por ciento de la población general. Ese riesgo existe independientemente del historial de cáncer de mama. Haber tenido cáncer de mama no cambia el riesgo de cáncer de ovario — la variante BRCA1 en las células ováricas sigue siendo la misma.” (For women with a pathogenic variant in BRCA1, the cumulative lifetime ovarian cancer risk is 44 to 46 percent. Compared to 1.3 percent in the general population. That risk exists independently of breast cancer history. Having had breast cancer does not change the ovarian cancer risk — the BRCA1 variant in the ovarian cells is still the same.)
Viviana, who had been listening in clinical mode, asked the question she had been formulating since the genetics appointment. “¿Y no se puede vigilar? Con una prueba de sangre o una ecografía, como hacen con la mama con la resonancia?” (And can it not be monitored? With a blood test or ultrasound, like they do with the breast with MRI?)
“Esa es exactamente la pregunta clave, y la respuesta es una de las razones por las que la cirugía profílactica existe. El cáncer de ovario no tiene una prueba de detección temprana efectiva. El CA-125 — la proteína sanguínea que se usa como marcador — y el ultrasonido transvaginal son las dos pruebas que se han estudiado más. El ensayo clínico PLCO, que fue un ensayo randomizado grande en Estados Unidos, estudió el cribado anual con CA-125 más ultrasonido transvaginal comparado con atención habitual en más de setenta y ocho mil mujeres. El resultado: el cribado no redujo la mortalidad por cáncer de ovario. La sensibilidad combinada para detectar cáncer de ovario en etapa temprana — estadio I y II — es menor del 50 por ciento. Estos tumores no dan síntomas hasta que ya son grandes o han diseminado. Cuando se diagnostican de forma sintómatica — por distensión abdominal, saciedad precoz, presión pélvica — el 75 a 80 por ciento ya están en estadio III o IV. La supervivencia a cinco años en estadio III es del 30 al 40 por ciento. En estadio IV, del 15 al 20 por ciento.” (That is exactly the key question, and the answer is one of the reasons prophylactic surgery exists. Ovarian cancer does not have an effective early detection test. CA-125 — the blood protein used as a marker — and transvaginal ultrasound are the two tests that have been studied most. The PLCO randomized trial, a large randomized trial in the United States, studied annual screening with CA-125 plus transvaginal ultrasound versus usual care in more than seventy-eight thousand women. The result: screening did not reduce ovarian cancer mortality. Combined sensitivity for detecting early-stage ovarian cancer — stages I and II — is below 50 percent. These tumors do not produce symptoms until they are large or have spread. When they are diagnosed symptomatically — from abdominal bloating, early satiety, pelvic pressure — 75 to 80 percent are already stage III or IV. Five-year survival at stage III is 30 to 40 percent. At stage IV, 15 to 20 percent.)
Ana-Sofía processed this. As a public health student, the epidemiology was clear. “O sea, si esperamos síntomas, las probabilidades de que ya esté avanzado son muy altas.” (So if we wait for symptoms, the probability that it is already advanced is very high.)
“Exactamente. Y eso explica por qué la cirugía profílactica es la estrategia preferida para portadoras de BRCA1. La salpingooforectomia bilateral profílactica — quitando los dos ovarios y las dos trompas de Falopio — reduce el riesgo de cáncer de ovario en un 80 a 96 por ciento. No es una cirugía que trata un cáncer existente. Es una cirugía que elimina el tejido donde ese cáncer se formaría, antes de que se forme.” (Exactly. And that explains why prophylactic surgery is the preferred strategy for BRCA1 carriers. Prophylactic bilateral salpingo-oophorectomy — removing both ovaries and both fallopian tubes — reduces ovarian cancer risk by 80 to 96 percent. It is not a surgery that treats an existing cancer. It is a surgery that removes the tissue where that cancer would form, before it forms.)
Viviana asked about the additional benefit she had read about. “Me dijeron que también puede reducir el riesgo de cáncer de mama.” (They told me it may also reduce breast cancer risk.)
“Sí. En mujeres que aún tienen ovarios funcionando — premenopáusicas — la salpingooforectomia bilateral reduce el riesgo de cáncer de mama en un 40 a 70 por ciento. Eso es porque los ovarios producen estrógeno y progesterona, que son mitógenos para las células epiteliales de la mama. En pacientes con BRCA1 que tienen cáncer de mama con receptores hormonales positivos — que es el caso de tu mamá — eliminar la fuente ovárica de estrógenos también complementa el tratamiento hormonal y reduce el riesgo de recurrencia. La cirugía profílactica tiene en este caso un doble beneficio.” (Yes. In women who still have functioning ovaries — premenopausal — bilateral salpingo-oophorectomy reduces breast cancer risk by 40 to 70 percent. That is because the ovaries produce estrogen and progesterone, which are mitogens for breast epithelial cells. In patients with BRCA1 who have hormone receptor-positive breast cancer — which is your mother’s case — eliminating the ovarian estrogen source also complements hormonal treatment and reduces recurrence risk. Prophylactic surgery in this case has a double benefit.)
Ana-Sofía had one more question — the one the nurse could see forming throughout the call. “¿Y yo? ¿Debo hacerme la prueba genética?” (And me? Should I get genetic testing?)
“Cada hijo de una persona con una variante germinal tiene un 50 por ciento de probabilidad de haber heredado esa variante. La prueba genética está disponible cuando quieras, ahora que eres adulta. Te recomendaría hablar con un consejero genético que pueda explicar lo que significa saber o no saber, para que la decisión sea tuya con toda la información. No es urgente — a tu edad las recomendaciones de vigilancia de BRCA1 suelen comenzar antes de los 30 años — pero tampoco hay razón para esperar indefinidamente si quieres saber.” (Each child of a person with a germline variant has a 50 percent probability of having inherited that variant. Genetic testing is available whenever you want, now that you are an adult. I would recommend speaking with a genetic counselor who can explain what it means to know or not know, so that the decision is yours with full information. It is not urgent — at your age BRCA1 surveillance recommendations typically begin before age 30 — but there is also no reason to wait indefinitely if you want to know.)
Viviana, who had been listening to the exchange between her daughter and the nurse with the professional attention of a clinician who recognized a well-conducted patient education session, summarized quietly. “El cáncer de mama se trató. La variante no. Los dos son cosas distintas.” (The breast cancer was treated. The variant was not. The two are different things.)
“Exactamente eso.”
Scenario 2: Aurelio Sandoval-Cruz — 56, retired firefighter from San Diego, California
Aurelio Sandoval-Cruz had retired from the San Diego Fire-Rescue Department after thirty-one years as a firefighter and paramedic. He had spent his career going toward danger and had a categorical attitude toward physical risk: if you identified the problem, you addressed it, and you did not dwell on it further. When his primary care physician had ordered a colonoscopy as part of routine screening at age 55, and the gastroenterologist had found and removed a 12-millimeter tubulovillous adenoma in the sigmoid colon, Aurelio had treated the news with the same equanimity. Problem identified. Problem addressed. Done.
The pathology report on the removed adenoma had triggered something Aurelio had not expected. The pathologist had performed reflexive mismatch repair immunohistochemistry — a standard test on colorectal polyps and cancers in the current era — and found loss of MLH1 protein expression. Germline genetic testing had followed, and three weeks later Aurelio had a diagnosis: Lynch syndrome, MLH1 pathogenic variant, c.1989-1G>A, a splice-site variant causing loss of function. The genetics team had explained the implications: elevated lifetime risk for colorectal cancer, endometrial cancer in female relatives, and other Lynch-associated cancers. Colonoscopy every one to two years going forward, beginning immediately. Aurelio’s son Roberto, a 32-year-old certified public accountant in Chula Vista who handled his father’s medical paperwork, had called the hereditary cancer clinic nurse to ask a question that he framed with the precision of someone accustomed to identifying unnecessary recurring expenses.
“Mi papá tuvo la colonoscopia hace catorce meses. Le quitaron el pólipo. El médico confirmó que el colon estaba limpio. Ahora le dicen que necesita otra colonoscopia en dieciocho meses. ¿No es demasiado pronto? En la mayoría de los casos no se repite la colonoscopia por diez años. ¿Por qué tan seguido para mi papá?” (My father had the colonoscopy fourteen months ago. They removed the polyp. The doctor confirmed the colon was clean. Now they are telling him he needs another colonoscopy in eighteen months. Is that not too soon? In most cases the colonoscopy is not repeated for ten years. Why so often for my father?)
The hereditary cancer clinic nurse, Jorge Ramírez-Vega, had worked in the hereditary cancer clinic for seven years and had fielded this question dozens of times from families of Lynch syndrome patients. He had found that the most efficient explanation was to teach the biology that made the interval biology, not bureaucracy.
“Roberto, la respuesta corta es que el colon de tu papá no sigue las mismas reglas biológicas que el de la mayoría de las personas. Los diez años que se recomienda para la población general están basados en cómo los adenomas normales se vuelven cáncer. El síndrome de Lynch tiene un mecanismo diferente que hace que ese proceso sea mucho más rápido. Deja que te explique.” (Roberto, the short answer is that your father’s colon does not follow the same biological rules as most people’s. The ten-year recommendation for the general population is based on how normal adenomas become cancer. Lynch syndrome has a different mechanism that makes that process much faster. Let me explain.)
Jorge began with the mismatch repair system. Every time a cell divides, it copies its 3.2 billion base pairs of DNA. DNA polymerase makes errors at a rate of approximately one error per 100,000 base pairs before proofreading. After proofreading, roughly one error per 100 million base pairs remains. The mismatch repair system — a team of protein heterodimers including MLH1/PMS2 and MSH2/MSH6 — scans the newly synthesized DNA strand and identifies mismatches: places where the new strand does not pair correctly with the template strand. When a mismatch is identified, the MMR complex recruits exonucleases to remove the incorrect segment and re-synthesizes it correctly. The result: final error rate approximately one per 10 billion base pairs per replication cycle.
“Microsatelites son secuencias repetidas cortas de ADN — por ejemplo, CACACACACA — distribuidas en miles de lugares del genoma. Son especialmente susceptibles a errores de replicación porque la polimerasa se puede deslizar sobre ellos. En una célula con reparación de errores intacta, esos errores se corrigen. En una célula con síndrome de Lynch — donde MLH1 no funciona — esos errores en los microsatelites no se reparan. Se acumulan con cada división. Eso se llama inestabilidad microsatelital. Y es una señal de que la célula está acumulando mutaciones mucho más rápido de lo normal.” (Microsatellites are short repetitive DNA sequences — for example, CACACACACA — distributed across thousands of locations in the genome. They are especially susceptible to replication errors because the polymerase can slip over them. In a cell with intact mismatch repair, those errors are corrected. In a cell with Lynch syndrome — where MLH1 is not functioning — those errors in the microsatellites are not repaired. They accumulate with each division. That is called microsatellite instability. And it is a signal that the cell is accumulating mutations much faster than normal.)
Roberto was tracking this carefully. “¿Y eso hace que los adenomas sean más peligrosos?” (And does that make the adenomas more dangerous?)
“Hace que se conviertan en cáncer más rápido. En una persona sin Lynch, la secuencia adenoma-carcinoma — desde que aparece un pólipo hasta que se convierte en cáncer invasivo — tarda típicamente diez o más años. Por eso la colonoscopia cada diez años funciona en la población general: si quitamos un pólipo una vez por década, interrumpimos esa secuencia antes de que llegue a cáncer. En el síndrome de Lynch, esa secuencia puede tardar dos a tres años en algunos adenomas. Un pólipo que no se detectó en dieciocho meses puede convertirse en cáncer invasivo antes de que llegue la colonoscopia de los diez años.” (It makes them convert to cancer faster. In a person without Lynch, the adenoma-to-carcinoma sequence — from when a polyp appears to when it becomes invasive cancer — typically takes ten or more years. That is why colonoscopy every ten years works in the general population: if we remove a polyp once per decade, we interrupt that sequence before it reaches cancer. In Lynch syndrome, that sequence can take two to three years in some adenomas. A polyp not detected in eighteen months can become invasive cancer before the ten-year colonoscopy arrives.)
Roberto was quiet for a moment. “¿Y el pólipo que le quitaron — ya no hay riesgo de ese?” (And the polyp that was removed — is there no longer risk from that one?)
“El pólipo especifico que se quitó ya no está — correcto. Pero el mecanismo que lo produjo sigue intacto. La deficiencia en MLH1 está en todas las células de la mucosa del colon — no solo en las células del sigmoide que produjeron ese pólipo, sino en las células del ciego, del colon ascendente, del transverso, del descendente, del recto. Cada división celular en cualquier parte del colon está ocurriendo con la misma inestabilidad microsatelital. Nuevos adenomas se están formando continuamente en todo el colon. Tu papá tendrá más pólipos. No porque algo haya salido mal ni porque no se cuide. Sino porque el síndrome de Lynch hace que la mucosa del colon produzca adenomas de forma continua, y esos adenomas en Lynch progresan más rápido de lo normal.” (The specific polyp that was removed is no longer there — correct. But the mechanism that produced it is still intact. The MLH1 deficiency is in every cell of the colonic mucosa — not only in the sigmoid cells that produced that polyp, but in the cells of the cecum, the ascending colon, the transverse colon, the descending colon, and the rectum. Every cell division anywhere in the colon is occurring with the same microsatellite instability. New adenomas are continuously forming throughout the entire colon. Your father will have more polyps. Not because something went wrong or because he is not taking care of himself. But because Lynch syndrome causes the colonic mucosa to produce adenomas continuously, and those adenomas in Lynch progress faster than normal.)
Roberto thought about this. He was an accountant — he understood recurrence intervals. “O sea que el intervalo de dieciocho meses no es arbitrario — es el intervalo que corresponde a la velocidad con la que progresan los adenomas en Lynch.” (So the eighteen-month interval is not arbitrary — it is the interval that corresponds to the speed at which adenomas progress in Lynch.)
“Exactamente. El intervalo está calibrado a la biología del síndrome, no a una preferencia de calendario. En muchos centros se recomienda colonoscopia anual para Lynch, especialmente en los primeros años después del diagnóstico. Lo que sabemos con certeza es que los intervalos de diez años, que son adecuados para la población general, son insuficientes para tu papá. La colonoscopia frecuente es lo que ha demostrado reducir significativamente la incidencia de cáncer colorrectal en pacientes con Lynch — no porque se haga más de lo necesario, sino porque corresponde a lo que la enfermedad requiere.” (Exactly. The interval is calibrated to the biology of the syndrome, not to a calendar preference. At many centers, annual colonoscopy is recommended for Lynch, especially in the first years after diagnosis. What we know with certainty is that ten-year intervals, which are appropriate for the general population, are insufficient for your father. Frequent colonoscopy is what has been shown to significantly reduce colorectal cancer incidence in Lynch patients — not because it is being done more than necessary, but because it corresponds to what the disease requires.)
Aurelio had been listening with the quiet attention of someone who had spent three decades assessing situations before acting. “¿Y además del colon?” (And beyond the colon?)
“El síndrome de Lynch aumenta el riesgo en varios tipos de cáncer además del colorrectal: endometrio, ovario, vías urinarias, estómago, entre otros. Para hombres con MLH1 la mayor parte del riesgo aumentado está en el colon y el recto. Sus familiares directos — hijos, hermanos — tienen un 50 por ciento de probabilidad de haber heredado la misma variante. Para ellos también hay pruebas genéticas disponibles y, si las llevan, las guías de vigilancia aplican también.” (Lynch syndrome increases risk in several cancer types beyond colorectal: endometrium, ovary, urinary tract, stomach, among others. For men with MLH1 most of the elevated risk is in the colon and rectum. His direct relatives — children, siblings — have a 50 percent probability of having inherited the same variant. For them also genetic testing is available, and if they carry it, the surveillance guidelines apply as well.)
Roberto noted this down carefully. Aurelio put on his jacket with the purposeful manner of a firefighter who had received his orders. “Cada año y medio. Entendido.” (Every year and a half. Understood.)
Scenario 3: Claudia Estrada-Figueroa — 31, middle school art teacher from San Antonio, Texas
Claudia Estrada-Figueroa had grown up watching her family fight cancer. Her mother, Elena, had been diagnosed with adrenocortical carcinoma at age 42 — a rare tumor that her oncologist had described as “unusual for someone your age.” Two years later, her older brother Daniel had developed an osteosarcoma of the distal femur at age 34, requiring limb-salvage surgery followed by chemotherapy. After Daniel’s diagnosis, the oncologist at UT Health San Antonio had ordered germline genetic testing for the family. The result: TP53 germline pathogenic variant, c.817C>T (p.Arg273Cys), a missense variant in the DNA-binding domain of p53 with well-established loss-of-function evidence. Elena, Daniel, and Claudia all tested positive. Their father tested negative — the variant had arisen de novo in Elena and was transmitted to her children.
The genetics team had explained Li-Fraumeni syndrome to Claudia in detail. Annual whole-body MRI, brain MRI, and breast MRI. Annual dermatology exam and colonoscopy starting at age 25. Aggressive evaluation of any symptom that could represent a new malignancy. Avoidance of unnecessary radiation exposure. Claudia had absorbed the surveillance protocol with the careful attention of someone who had watched what happened when tumors were found late. But her husband Miguel, a 33-year-old construction project supervisor who had married Claudia the previous year, was struggling with a different question. He had asked Claudia to schedule a meeting with the genetics team, and the hereditary cancer clinic nurse had taken that appointment.
“Claudia se siente completamente bien. No tiene cáncer. Nunca ha tenido cáncer. Es joven, está sana, hace ejercicio. Y me dicen que necesita una resonancia magnética de cuerpo entero, una de cabeza y una de mama, todos los años, de por vida. No lo entiendo. ¿Por qué tanto exámen para alguien que está bien?” (Claudia feels completely well. She has no cancer. She has never had cancer. She is young, she is healthy, she exercises. And they are telling me she needs a whole-body MRI, a brain MRI, and a breast MRI, every year, for the rest of her life. I do not understand it. Why so much examination for someone who is well?)
The hereditary cancer clinic nurse, Patricia Delgado-Ramos, had been expecting this question. It was the question that separated Li-Fraumeni syndrome surveillance from almost every other medical intervention — because in most medicine, surveillance is triggered by symptoms, history, or a known active disease. Li-Fraumeni surveillance was triggered by a molecular fact: the absence of a functional tumor suppressor in every cell of the body.
“Miguel, para responder esa pregunta necesito explicar qué hace normalmente el gen TP53 y qué pasa cuando no funciona. Porque cuando entiendas eso, la resonancia anual va a parecer no solo razonable sino completamente necesaria.” (Miguel, to answer that question I need to explain what the TP53 gene normally does and what happens when it does not function. Because when you understand that, the annual MRI is going to seem not only reasonable but completely necessary.)
She began with the basic biology of cell division. Every cell in the body divides regularly — skin cells, bone marrow cells, gut lining cells, breast cells, muscle cells. Each division requires copying 3.2 billion base pairs of DNA. Errors happen. Sometimes those errors occur in important genes — oncogenes that drive cell growth, or tumor suppressor genes that limit it. A cell that accumulates too many of these errors becomes cancerous. The reason most cells do not become cancerous, despite decades of dividing with regular replication errors, is that the cell has quality-control mechanisms that prevent a damaged cell from continuing to divide.
“El más importante de esos mecanismos de control de calidad es la proteína p53, codificada por TP53. Cuando una célula sufre daño en el ADN — una ruptura de doble cadena, un error de replicación severo, daño por radiación — p53 se estabiliza y activa dos respuestas críticas. Primero, activa una proteína llamada p21 que bloquea el ciclo celular en el punto de control G1: detiene la célula antes de que empiece a copiar su ADN dañado, dando tiempo a la maquinaria de reparación para corregir el error. Si el daño es demasiado grande para reparar, p53 activa el segundo mecanismo: apoptosis. La célula con ADN irreparablemente dañado se destruye a sí misma antes de poder dividirse. Esto es lo que se llama la función de guardian del genoma: p53 detiene o elimina las células con ADN peligrosamente dañado, antes de que esas células acumulen las mutaciones que las vuelven cancerosas.” (The most important of those quality-control mechanisms is the p53 protein, encoded by TP53. When a cell sustains DNA damage — a double-strand break, a severe replication error, radiation damage — p53 is stabilized and activates two critical responses. First, it activates a protein called p21 that blocks the cell cycle at the G1 checkpoint: it stops the cell before it starts copying its damaged DNA, giving the repair machinery time to correct the error. If the damage is too great to repair, p53 activates the second mechanism: apoptosis. The cell with irreparably damaged DNA destroys itself before it can divide. This is called the guardian of the genome function: p53 stops or eliminates cells with dangerously damaged DNA, before those cells can accumulate the mutations that make them cancerous.)
Miguel was listening intently. “¿Y con el síndrome de Li-Fraumeni?” (And with Li-Fraumeni syndrome?)
“Con la variante germinal en TP53 que tiene Claudia, cada célula de su cuerpo ya tiene una copia de TP53 que no funciona correctamente — desde que nació. No en una célula específica. En todas. En las células del hueso, del músculo, del cerebro, de la mama, de la glándula suprarrenal, de la sangre. En cada una de ellas. Cuando una mutación somática inactiva la segunda copia de TP53 en cualquiera de esas células — que es un evento que ocurre al azar, en cualquier tejido, en cualquier momento — esa célula pierde completamente el punto de control G1 y la capacidad de apoptosis por daño de ADN. Una célula sin ese freno puede acumular mutaciones oncogénicas con cada división y eventualmente volverse cancerosa.” (With the TP53 germline variant Claudia has, every cell of her body already has one copy of TP53 that does not function correctly — since she was born. Not in a specific cell. In all of them. In bone cells, muscle cells, brain cells, breast cells, adrenal cells, blood cells. In each one. When a somatic mutation inactivates the second copy of TP53 in any of those cells — an event that occurs randomly, in any tissue, at any moment — that cell completely loses the G1 checkpoint and the ability to undergo apoptosis from DNA damage. A cell without that brake can accumulate oncogenic mutations with each division and eventually become cancerous.)
Miguel was very still. “¿En cualquier órgano?” (In any organ?)
“En cualquier órgano. El síndrome de Li-Fraumeni no es un síndrome de cáncer de un solo órgano. Los tumores más comunes incluyen sarcomas de hueso y tejido blando, cáncer de mama de inicio joven, tumores cerebrales — generalmente gliomas de alto grado — carcinoma adrenocortical — que es lo que tuvo la madre de Claudia — y cáncer hematológico. Pero hay más de veinte tipos de tumores documentados en familias con síndrome de Li-Fraumeni. El riesgo acumulado de cáncer a lo largo de la vida es de aproximadamente 90 por ciento para las mujeres y 73 por ciento para los hombres. Eso no significa que Claudia vaya a tener cáncer mañana. Significa que a lo largo de su vida, sin vigilancia activa, la probabilidad de que un tumor se desarrolle en algún lugar del cuerpo es muy alta.” (In any organ. Li-Fraumeni syndrome is not a single-organ cancer syndrome. The most common tumors include bone and soft tissue sarcomas, young-onset breast cancer, brain tumors — typically high-grade gliomas — adrenocortical carcinoma — which is what Claudia’s mother had — and hematological cancer. But there are more than twenty documented tumor types in Li-Fraumeni syndrome families. The cumulative lifetime cancer risk is approximately 90 percent for women and 73 percent for men. That does not mean Claudia will have cancer tomorrow. It means that over her lifetime, without active surveillance, the probability that a tumor will develop somewhere in the body is very high.)
Miguel had been sitting with his hands on the table. “¿Y cómo ayuda la resonancia?” (And how does the MRI help?)
“Un sarcoma en los músculos paraespinales de cuatro centímetros, una masa suprarrenal en crecimiento, un tumor cerebeloso pequeño — ninguno de estos da síntomas mientras es pequeño. Los síntomas aparecen cuando el tumor ya tiene un tamaño suficiente para comprimir o desplazar estructuras adyacentes, o cuando ya ha diseminado. Si esperamos síntomas, a menudo estamos esperando un estadio avanzado. La resonancia magnética de cuerpo entero puede detectar esos tumores cuando tienen dos o tres centímetros — cuando todavía son operables, cuando el tratamiento es curativo. El protocolo de Toronto modificado, publicado por Kim y colaboradores, mostró que la vigilancia con resonancia magnética de cuerpo entero en pacientes con síndrome de Li-Fraumeni detectó tumores en estadios tempranos con mejores resultados que el diagnóstico impulsado por síntomas. Claudia tiene 31 años y está bien ahora. El objetivo de la vigilancia es que siga bien — con tumores detectados cuando todavía son curables, no cuando ya son avanzados.” (A 4-centimeter sarcoma in the paraspinal muscles, a growing adrenal mass, a small cerebellar tumor — none of these produce symptoms while they are small. Symptoms appear when the tumor is large enough to compress or displace adjacent structures, or when it has already spread. If we wait for symptoms, we are often waiting for an advanced stage. Whole-body MRI can detect those tumors when they are two or three centimeters — when they are still operable, when treatment is curative. The modified Toronto protocol, published by Kim and colleagues, showed that whole-body MRI surveillance in Li-Fraumeni syndrome patients detected tumors at early stages with better outcomes than symptom-driven diagnosis. Claudia is 31 and well now. The goal of surveillance is for her to remain well — with tumors detected when they are still curable, not when they are already advanced.)
Miguel was quiet for a long time. When he spoke, his voice was steadier. “¿El primer candidato fue el de la madre y el hermano — los dos con tumores extraños en el momento equivocado. Eso es lo que la variante hace.” (The first candidates were her mother and brother — both with unusual tumors at the wrong time. That is what the variant does.)
“Sí. El carcinoma adrenocortical de la madre de Claudia a los 42 años y el osteosarcoma del hermano a los 34 son exactamente el patrón clínico del síndrome de Li-Fraumeni: tumores raros, de inicio joven, en múltiples familiares de primer grado. La vigilancia anual existe porque la familia ya sabe lo que pasa cuando no se detecta a tiempo.” (Yes. Claudia’s mother’s adrenocortical carcinoma at age 42 and her brother’s osteosarcoma at age 34 are exactly the clinical pattern of Li-Fraumeni syndrome: rare tumors, young onset, in multiple first-degree family members. Annual surveillance exists because the family already knows what happens when it is not detected in time.)
Claudia had been listening to the conversation quietly. She had known everything the nurse said — had researched it thoroughly after her own test result — but she had not been able to explain it to Miguel in a way that landed. “La resonancia no es para buscar cáncer que ya tengo. Es para encontrarlo cuando todavía es pequeño, si se forma. Esa es la diferencia.” (The MRI is not to look for cancer I already have. It is to find it when it is still small, if it forms. That is the difference.)
Miguel nodded slowly and picked up his jacket. “Entendido. Dónde firmo para la primera cita.” (Understood. Where do I sign for the first appointment.)