Introduction The purpose of this study was to leverage a large population database to analyze trends in the incidence of carcinosarcoma of the ovary, fallopian tube, and peritoneum.

Methods Data were obtained from the United States Cancer Statistics (USCS) database from 2001 to 2016. Age-adjusted incidence per 100,000 women and annual percent change (APC) in incidence were calculated using SEER*Stat and Joinpoint Software.

Results 9,675, 658, and 745 women had carcinosarcoma of the ovary, fallopian tube, and peritoneum with an age-adjusted incidence of 0.33, 0.04, and 0.03 in 2016 respectively. Over a sixteen-year period, the incidence of ovarian carcinosarcoma increased 0.53% per year (95% CI 0.13, 0.94; P = 0.014), and the incidence of tubal carcinosarcoma increased 4.85% per year (95% CI 2.32, 7.43; P = 0.001). The incidence of local disease decreased 3.53% per year (95% CI -5.78, -1.23; p = 0.006) in contrast to significant increases in both regional and distant disease. The incidence of carcinosarcoma increased only in the Middle Atlantic and East North Central regions [APC 1.36%, (95% CI 0.36, 2.38), p = 0.011; APC 1.71%, (95% CI 0.60, 2.38), p = 0.005]. Non-Hispanic Blacks had the highest incidence (0.35) of carcinosarcoma and highest increase in incidence per year (1.59%).

Conclusions Although rare, the incidence of carcinosarcoma of the ovary and fallopian tube is significantly increasing in the United States, particularly for Non-Hispanic Blacks.