Introduction/Background The prolongation of life expectancy in gynecological cancer and the increase in advanced diagnostic techniques cause an increase in the frequency of diagnosis of multiple primary malignant cancers. In this study, it is aimed to examine the synchronous or metachronous tumor types and number of gynecological tumors diagnosed and treated, and to determine the prognostic factors in developing secondary malignancies.

Methodology Patients who applied with the diagnosis of 21,348 gynecological tumors from 9 centers in Turkey between 2000 and 2020 and received radiotherapy and/or radio-chemotherapy were retrospectively analyzed. 227 cases with metachronous and/or synchronous tumors were identified. In this study, the most common synchronous and metachronous tumors in all gynecological tumors were examined and their prognostic variables and survival rates were evaluated.

Results All patients treated with a diagnosis of gynecological tumor had 1.06% metachronous and/or synchronous tumors. Gynecological tumor rates were 152 (66.9%) endometrial cancer, 55 (24.2%) cervical cancer, 17 (7,5%) ovarian tumor and 3 (1.4%) vulvar cancer, respectively. Primary tumor histology is; endometroid tumor was 108 (47.6%) and squamous tumor was 52 (22.9%). Primary gynecological tumor treatment; Pelvic radio-chemotherapy and intracavitary treatment were composed of 29.9%, 22.2% intracavitary treatment, and 21.1% pelvic radiotherapy and intracavitary treatment. Metachronous, synchronous, and metachronous and synchronous tumor association rates were 48% (109), 47.6% (108) and 4.4% (10), respectively.

Conclusion The incidence of multiple primary cancers is not very low. Survival rates can be increased by detecting cancers associated with screening procedures at an early stage.

Disclosures The most common secondary tumors among 108 synchronous tumors were 51 (22.4%) ovarian cancer, 14 (6.2%) breast cancer and 10 (4.4%) endometrial cancer. Among 109 metachronous tumors, the most common secondary tumors were 49 (21.5%) breast cancer, 19 (8.3%) lung cancer and 11 (4.8%) colon cancer.

The 3- and 5-year overall survival rates of patients with synchronous tumors were 91.9% and 87.9%, respectively, and 3- and 5-year survival rates for gynecological tumors with metachronous tumors were 89.3% and 81.9%, respectively. The 3- and 5-year survival rates of patients with both synchronous and metachronous tumors were 85.7% and 64.3%, respectively. No statistical significance was found between all these rates.

Ovarian cancer, which is the most common synchronous tumor with gynecological tumors, was diagnosed in IA stage with a rate of 31.8%. The most common breast cancer detected in patients with metachronous tumors was stage I. and II.