54P Fallopian tube cancer and ovarian cancer: A real-world comparison of epidemiological patterns, clinical outcomes, and mutational landscape

Abstract

Fallopian tube cancer is a rare tumor which accounts for only 1% of all gynaecological cancers. It is closely related and generally treated with a similar approach to ovarian cancer. We used the publicly available databases to provide a description of epidemiological patterns, clinical outcomes, and mutational landscape of fallopian tube cancer and compare it with that of ovarian cancer. We extracted clinical and epidemiological data of fallopian tube and ovarian cancers from the SEER database [13 reg; Nov 2020 Submission]. The average annual percentage change (AAPC) of incidence rates was calculated using The NIH’s Joinpoint Regression Program. Sequencing data were obtained through The American Association of Cancer Research (AACR) project GENIE database. We included 4,240 cases of fallopian tube cancer and 74,837 cases of ovarian cancer diagnosed between 1992 and 2018. The overall incidence of fallopian tube cancer was 0.39 [95% CI, 0.38-0.40], whereas the overall incidence of ovarian cancer was 6.97 [95% CI, 6.92-7.02]. Between 1992 and 2018, there was a significant increase in the incidence of fallopian tube cancer (AAPC = 6.1% 95% CI, [4.6, 7.9], p<0.001) and a decrease in the incidence of Ovarian cancer (AAPC = -1.7% 95% CI, [-2, -1.4], p<0.001). The median overall survival of fallopian tube cancer was significantly higher than ovarian cancer (80 months vs 43 months, P<0.001). A presentation with stage IV disease was significantly less frequent in fallopian tube cancer compared to ovarian cancer (50% vs 70%, P<0.001). In 166 patients with fallopian tube cancer and 5,303 patients with ovarian cancer in GENIE, the most frequently mutated genes were TP53, SPTA1, LRP1B, FAT3, and NF1; and TP53, CSMD3, DNAH9, ARID1A, and PDE4DIP; for fallopian tube cancer and ovarian cancer respectively. Fallopian tube cancer is a distinct disease entity different in genetic, epidemiological, and clinical characteristics from ovarian cancer. Cases with fallopian tube cancer are less likely to present with distant metastasis and have longer overall survival compared to cases with ovarian cancer. The most frequently mutated genes of both cancers are different.