Second primary cancer after primary peritoneal, epithelial ovarian, and fallopian tubal cancer: a retrospective study.

BACKGROUND: In this retrospective study, data from patients listed in the Korea Central Cancer Registry during 1993-2014 were analysed, to investigate the incidence and survival of second primary cancers (SPCs) after a diagnosis of primary peritoneal, epithelial ovarian, and fallopian tubal (POFT) cancer. METHODS: The standardised incidence ratio (SIR) and survival outcomes of patients with SPCs among POFT cancer survivors were analysed. RESULTS: Among 20,738 POFT cancer survivors, 798 (3.84%) developed SPCs, at an average interval of 5.50 years. SPC risk in POFT survivors (SIR, 1.29) was higher compared to the general population. The most high-risk type of SPC was leukaemia (3.07) followed by the lung and bronchus (1.80), colon (1.58), rectum and rectosigmoid junction (1.42), thyroid (1.34), and breast (1.26). In women aged < 60 years, cancer of the breast (1.30), ascending colon (2.26), and transverse colon (4.07) as SPCs increased. Up to 10 years after POFT cancer treatment, leukaemia risk increased, especially in those < 60 years, with serous histology, and with distant stage, which required aggressive chemotherapy. The median overall survival time was 12.8 years and 14.3 years in women with POFT cancer and SPCs, respectively. Thyroid and breast cancers were favourable prognostic markers among SPCs. CONCLUSIONS: The overall SPC risk increases in POFT cancer survivors, especially in those < 60 years. The cancer risk of breast and the proximal colon increase based on hereditary predisposition, while leukaemia likely develops from aggressive treatment. The median overall survival is favourable in POFT cancer survivors with SPCs.