I'm hesitant to post this, because it is Mail Online and they have some sketchy reporting, but this one seems legit...
http://www.dailymail.co.uk/health/article-5393255/Ovarian-cancer-actually-begins-fallopian-tubes.htmlby Megan Sheets
February 14, 2018
Two studies identifying the fallopian tube as the source of the cancer were (released) six days apart in October, shedding some light on the disease that doctors know very little about compared to other cancers.
Both studies looked at high-grade serous ovarian carcinoma (HGSOC) is the most frequent type of ovarian cancer with only 15 percent of those diagnosed surviving beyond five years.
They also both concluded that the majority of ovarian cancer cases start in the fallopian tubes.
(excerpt)