Serous Tubal Carcinogenesis: The Recent Concept of Origin of Ovarian, Primary Peritoneal and Fallopian Tube High-Grade Serous Carcinoma.

Background: Pelvic (non-uterine) high-grade serous carcinomas (PHGSC) including ovarian, tubal and primary peritoneal serous carcinomas have increased death: incidence ratio due to presentation at advanced stage, rapid progression, poor prognosis and high morbidity. Ambiguity regarding their pathogenesis and lack of a proper screening method is the cause of their late detection and high fatality rate. This study was undertaken to assess the fallopian tube for the presence of precursor lesions in pelvic serous carcinoma.

Methods: This was a prospective case-control study carried out in a tertiary care center. Consecutive specimens of 55 cases of pelvic high-grade serous carcinoma and 41 controls inclusive of 21 low-grade serous carcinoma, 10 benign adnexal masses and 10 normal adnexa were included in the study. Both side fallopian tubes in each case were subjected to histopathological examination and p53, Ki67 immunohistochemistry.

Results: There were 55 cases of PHGSC comprising of 50 cases of ovarian HGSC, two cases of primary peritoneal carcinoma (PPC) and three cases of tubal carcinoma. Serous tubal intraepithelial carcinoma (STIC) was detected in 14 cases (28%), p53 signature in 13 cases (26%) and tubal intraepithelial lesion in transition in 10 cases (20%) of ovarian HGSC. One case (50%) of PPC and one (33%) case of tubal carcinoma revealed the presence of STIC. None of the controls exhibited any precursor lesion except ovarian low-grade serous carcinoma where p53 was detected in 20% of cases.

Conclusion: This revelation concludes that fallopian tubes are the sites of precursors of PHGSC to a large extent. In the absence of a proper screening method of HGSC, prophylactic bilateral salpingectomy at hysterectomy for benign diseases can achieve ultimate goal of reduction in incidence of PHGSC.