Multiple primary cancers of the breast and endometrium: clinical and morphological features

Introduction. Over the past decade, there has been an increase in the number of multiple primary malignant tumors. The incidence of multiple primary cancers in the world ranges from 2% to 17%, with a synchronous cancer incidence of approximately 6%. Among patients with multiple primary cancers, the majority have two tumors. The most common gynecological diseases associated with breast cancer are ovarian cancer, endometrial cancer and cervical cancer.
Aim: to study the clinical and morphological characteristics of patients with multiple primary breast and endometrial cancer.
Material and methods. A retrospective analysis of patients with multiple primary cancers registered at the Moscow S.P. Botkin multidisciplinary research and clinical center was conducted.
Results. 35,0% of patients were diagnosed with SMPC, with a median time interval of 2,0 months between tumors detection (Q1-Q3 1,0–1,3), 65,0% had MMPC with a median time between tumor detection of 90,0 months (Q1-Q3 37,5–179,5). The age of patients with SMPC at the time of diagnosis of the first tumor was 38-78 years, with an average of 61,7±11,4 years, and the age of patients with MMPC at the time of diagnosis of the first tumor was 33-83 years, with an average of 57,9±11,1 years (p > 0,05). IA stage of breast cancer and endometrial cancer prevailed – 46,3% and 53,8% of cases, respectively; as well as breast ductal carcinoma – 87,5%, luminal B HER2 negative – 37,5% of cases and endometrial cancer – 85,0% of cases.
Conclusions. In patients with multiple primary breast and endometrial cancer, tumors are predominantly detected at stage I, with a less aggressive histological type and the most favorable molecular type of breast cancer. In most cases, surgery is the treatment of choice. Radiation therapy for breast cancer increased the risk of developing endometrial cancer by 2,6 times.

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