Does all ovarian cancer originate in fallopian tube? Increasing evidence suggests so!

John Hopkins Medicine

Most-and possibly all ovarian cancer originates not in ovaries, but instead in the distal end of fallopian tubes attached to them, reports the findings of multi-center ovarian cancer genetics study published October 17, 2017 in Journal Nature Communications.

Douglas A. Levine, MD, director of the Division of Gynecologic Oncology at Perlmutter and professor of Obstetrics and Gynecology at NYU School of Medicine said in a news release, "Based on a better understanding of its origins, our study suggests new strategies for the prevention and early detection of ovarian cancer."

Serous tubal intra-epithelial carcinoma (STIC) are identified as precursors in ~50% cases of advanced high-grade serous carcinomas (HGSCs) of the pelvis. STIC have helped us a lot in understanding the origin of ovarian malignancies. It was originally diagnosed in fimbrial part fallopian tube when researchers examined the serial sections of this area in tube samples in cases of women who underwent prophylactic bilateral salpingo-oophorectomy(BSO).

This discovery led researchers to identify many cases of presumed ovarian cancer to be of tubal origin because of presence of a STIC.

The researchers in this study identified a total of 96 bio specimens’ samples, with or without STIC. 

The median age of the women was 59 years, with majority being Caucasians, with nearly 50% of women in FIGO stage IIIC and all women had HGSCs. Presence or absence of STIC did not change the clinical features or median survival.

In depth a morphologic, immunohistochemical, and molecular analysis of the samples failed to identify any difference in genetic profile of cells from HGSCs vs those from STIC in fallopian tube.

"We found no differences in the 20,000 genes that we can identify," says Levine. "This leads us to believe that that these ovarian cancers all originate in the fallopian tubes."

In fact, HGSCs had molecular profiles more similar to normal fallopian tube epithelium than to ovarian surface epithelium or peritoneum.

This study findings have several implications for early diagnosis of ovarian malignancy. If biomarkers can be identified on these tubal cells, then one day we may be able to diagnose ovarian malignancy by blood test. Since the tube is connected to the uterus, direct tissue sampling can also be carried out in future.

If the study finding is confirmed, then only removing the tubes may reduce the women’s risk of ovarian malignancy in patients with BRCA1 and 2 mutations. In fact, the NYU Langone Health center is  currently participating in a study Women Choosing Surgical Prevention or WISP trial, which is comparing the quality of life in women who have undergo only  salpingectomy as compared to salpingo-oophorectomy.

The researchers believe that it may take years before the study findings are confirmed and translate into actual clinical practice. But, at this stage the study holds a lot of meaning for gynecological oncologists and the evidence is sufficient to support incidental salpingectomy in average-risk women.

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