Risk of Gynaecological Cancers as Second Primary in Non-gynaecological Cancer Survivors: A Retrospective Cohort Study.

Aims and Objectives: This study aims to explore the clinical-pathological profile of gynaecological malignancies occurring as a second cancer and identify their modifiable and non-modifiable risk factors. Methodology: This retrospective cohort study included women operated for gynaecological carcinoma following a previous treated malignancy, in the gynaecologic oncology department of a tertiary care hospital, between 1st January 2016 and 31st December 2021. Demographic details, clinical and pathological characteristics of the current malignancy and previous malignancy were obtained from medical records and analysed using descriptive statistics. Results: During this period, 2370 women with gynaecological malignancies were operated, of whom 27 (1.1%) patients had gynaecological malignancy as a second malignancy. This included 19 (70.3%) endometrial and 8 (29.6%) ovarian cancer patients following a median period of 48 (24-144 months) from the index malignancy. Their median age and BMI were 60 years (37-67) and 27 (17-39.1), respectively. Endometrioid endometrial cancer was most common and was preceded by breast carcinoma in 19 (70.37%) and colorectal in 5 (18.5%). Four patients had previous microsatellite unstable colorectal cancer. Two patients were found to have mismatch repair deficient endometrial cancer on somatic testing. High-grade serous carcinoma was the most common ovarian histology and was preceded by breast cancer in 6 (75%). Four patients underwent germline testing, and one was found to have a (breast cancer gene) BRCA pathogenic mutation. Conclusion: Breast cancer and colon cancer can precede gynaecologic cancer. Individualization of somatic and genetic testing in colorectal and breast cancers will allow screening and prevention of second gynaecologic malignancies.