Colombian Study Tracks Ten-Year Survival in Breast Cancer Patients Carrying Inherited Risk Variants

In the rolling hills of Medellín, Colombia, a team of oncologists and geneticists has quietly assembled one of the most detailed pictures yet of how hereditary breast cancer unfolds in a Latin American population. Their new study, published in BMC Cancer, followed 259 women with breast cancer who carried pathogenic or likely pathogenic germline variants — inherited changes in their DNA that substantially raise cancer risk — and estimated their ten-year overall survival. The headline finding: roughly three out of four of these women were still alive a decade after diagnosis, a figure that both reassures and challenges assumptions about hereditary cancer in the region.

The research matters because the vast majority of survival data on hereditary breast cancer comes from North American and European cohorts, populations whose genetic ancestry and variant spectrums can differ markedly from those of Latin America. Germline pathogenic or likely pathogenic variants, abbreviated P/LPVs in the clinical literature, are present in approximately ten percent of all breast cancer cases. When a woman carries one of these inherited variants, her tumor biology, treatment options, and even her family’s screening needs can change dramatically. Yet for Latin American patients, clinicians have long had to extrapolate from studies conducted elsewhere, a practice that obscures potentially important population-specific differences in which genes are mutated and how those mutations influence outcomes.

To fill that gap, the researchers conducted a retrospective cohort study at Fundación Colombiana de Cancerología Clínica Vida, an oncology center in Medellín, in collaboration with Universidad CES. They identified women with breast cancer and confirmed germline P/LPVs detected through multigene panel testing between 2018 and 2024. Multigene panel testing, which became widely available only in the last decade, sequences dozens of cancer-associated genes simultaneously, replacing the older approach of testing only BRCA1 and BRCA2. The 259 women in the cohort had their demographic characteristics, clinical presentations, tumor features, and treatments systematically recorded, allowing the team to ask which factors predicted who lived and who died.

The genetic landscape they uncovered was striking. BRCA2 variants dominated, accounting for 40.9 percent of the pathogenic variants in the cohort, while BRCA1 variants made up 13.5 percent. That distribution is notable because in many published cohorts BRCA1 and BRCA2 are closer to parity, and the predominance of BRCA2 in this Colombian population adds to a growing body of evidence that hereditary cancer genetics varies substantially across ancestries. The remaining cases were distributed across other genes in the panel, including less frequently altered genes such as TP53, CHEK2, and PALB2, each of which carries its own implications for tumor behavior and clinical management.

Survival analysis relied on two complementary statistical tools. Kaplan-Meier estimation, the workhorse of survival statistics, allowed the team to calculate the probability of surviving over time while accounting for patients whose follow-up ended before death or before the ten-year mark — a process called censoring. Cox regression models then allowed the researchers to isolate the independent effect of individual variables, such as gene variant or disease stage, while statistically adjusting for all the others. The median follow-up in the cohort was 45 months, with an interquartile range of 40 to 55 months, and administrative censoring was applied at 120 months. That relatively short follow-up is an important caveat: the ten-year survival estimate of 75 percent, with a 95 percent confidence interval of 70 to 80 percent, is partly extrapolated from the observed data, and the authors are explicit that the figure should be interpreted with that limitation in mind.

Within the cohort, survival differed meaningfully by which gene carried the pathogenic variant. Patients with TP53 and CHEK2 variants showed higher overall survival estimates, whereas those with BRCA1 and PALB2 variants fared worse. This pattern is biologically plausible. BRCA1-associated breast cancers are frequently triple-negative — lacking estrogen receptors, progesterone receptors, and HER2 amplification — a subtype with historically poorer prognosis and fewer targeted treatment options. PALB2, which encodes a protein that partners with BRCA2 in the DNA repair machinery, is also associated with aggressive disease in some studies. TP53 variants, despite causing Li-Fraumeni syndrome, a condition notorious for early-onset cancers, appeared in this cohort alongside better survival, a finding the authors flag as exploratory given the small numbers of patients carrying rarer variants.

The multivariate analysis sharpened the picture considerably. Two factors remained statistically significant predictors of death after adjustment for other variables: metastatic stage at diagnosis, which carried a hazard ratio of 8.16 with a 95 percent confidence interval of 2.39 to 27.9, and the presence of a BRCA1 variant, with a hazard ratio of 1.55 and a confidence interval of 1.30 to 5.97. In plain terms, women whose cancer had already spread to distant organs at diagnosis faced roughly eight times the hazard of death compared with those diagnosed at earlier stages, and carrying a BRCA1 variant independently increased the risk of death by about 55 percent. The dominance of stage at diagnosis is a familiar refrain in oncology, but its magnitude here underscores a persistent challenge: hereditary cancer patients benefit most when their risk is identified before the disease advances.

One of the most clinically provocative results concerned risk-reducing surgery. Prophylactic mastectomy and salpingo-oophorectomy — surgical removal of healthy breast tissue or ovaries and fallopian tubes — are standard recommendations for carriers of BRCA1 and BRCA2 variants precisely because they dramatically lower the risk of future cancers. In this cohort, however, the researchers found no statistically significant survival differences between patients who underwent risk-reducing surgeries and those who did not. The authors are careful not to overinterpret this null result; the study was not designed or powered to test the efficacy of these procedures, and the follow-up period may be too short for prevention benefits to translate into measurable survival gains. Still, the finding highlights how much remains unknown about the real-world impact of preventive strategies in diverse populations.

The study’s design carries inherent limitations that the authors acknowledge candidly. Retrospective cohorts depend on medical records, which can vary in completeness, and the cohort was drawn from a single oncology center, which may not represent all Colombian women with hereditary breast cancer. The limited duration of follow-up means the ten-year survival figure rests on statistical extrapolation, and findings related to less frequent variants — TP53, CHEK2, PALB2 — are explicitly exploratory and should be interpreted with caution. No specific external funding supported the work, and the study used anonymized records with ethics approval from Universidad CES and Clínica Vida, waiving individual informed consent under Colombian regulatory standards.

Despite those caveats, the implications are clear and actionable. The results lend strong support to integrating germline testing into routine oncologic care in Colombia and across Latin America, ensuring that the roughly one in ten breast cancer patients who carry inherited pathogenic variants are identified and offered tailored surveillance, treatment, and family counseling. They also establish a baseline of population-specific survival data that clinicians in the region have lacked. The authors call for larger, prospective studies to validate long-term outcomes, and such efforts are essential: as multigene panel testing becomes more affordable and widespread, the number of identified carriers will grow, and the question of how best to care for them — which genes demand which interventions, and when — will only become more pressing. For now, the Medellín cohort offers a rare and valuable window into hereditary breast cancer as it actually unfolds in Latin America, and a reminder that precision oncology must be built on data from the populations it serves.

Subject of Research: Ten-year overall survival and prognostic factors in Colombian breast cancer patients carrying germline pathogenic or likely pathogenic variants

Article Title: Ten-year overall survival in patients with breast cancer and pathogenic/probably pathogenic germ line variants who attend genetic consultation at an oncology center in the city of Medellín

Article References: López – Torres, N. A., Grajales, D., Vásquez – Trespalacios, E. M., Naranjo, A. M., & Montoya, M. E. (2026). Ten-year overall survival in patients with breast cancer and pathogenic/probably pathogenic germ line variants who attend genetic consultation at an oncology center in the city of Medellín. BMC Cancer. https://doi.org/10.1186/s12885-026-16898-z

Image Credits: AI Generated

DOI: 10.1186/s12885-026-16898-z

Keywords: breast cancer, germline variants, BRCA1, BRCA2, overall survival, genetic counseling, PALB2, TP53, CHEK2, multigene panel testing, Colombia, prognosis