Breast cancers observed in transplant patients in a single institution

Objective: Document occurrence of breast cancer in females after liver, kidney, or pancreas transplantation seen at a tertiary medical center. Methods: Medical records of adult female patients with liver, kidney, or pancreas transplants from 1/1/1995 to 4/4/2014 were retrospectively reviewed. Patients with a history of breast cancer, no mammogram post-transplant, or no research authorization were excluded. Mammogram findings and pathology results were reviewed and recorded. Cancer rates could not be measured in patients followed up outside the institution. Descriptive statistics summarized the cohort. Occurrence rates were estimated using Poisson regression. Results: 1095 women were included and 33 were diagnosed with breast cancer post-transplant. Median age at diagnosis was 58 years. Average interval from transplant to cancer diagnosis was 82.6 months. Observed occurrence of invasive and in-situ breast cancer (reported as per 100,000 person-years [95% confidence interval]) was 353 [243–496]. Liver transplant patients showed the lowest rate (181 [95% CI 73–372]), vs. kidney (476 [305–708]) or pancreas (467 [57–1688]). Patients with the highest breast density showed increased occurrence despite younger age (1001 [367–2178]) compared to those with lower breast density (range 239 [109–454] to 372 [186–666]). Conclusions: Female patients after organ transplant experienced increased breast cancer occurrence in this observational study. Those who developed breast cancer also had increased breast density. The findings underscore the importance of breast cancer screening in this population.