Mutation in Fallopian Tubes May Help Catch Ovarian Cancer Early
Ovarian cancer is one of the most deadly cancers in women. According to the American Cancer Society, about 22,400 women will be diagnosed in 2017 and more than 14,000 will die from ovarian cancer. It ranks fifth in cancer deaths in women, accounting for more deaths than any other gynecologic cancer. About 1 in 75 women will develop ovarian cancer.
There are several known risk factors for ovarian cancer including:
First pregnancy after 35 years of age or nulliparous
Oral contraceptives appear to decrease the risk
Some fertility drugs
Unopposed estrogen therapy
Familial cancer syndromes
There is no know way to prevent ovarian cancer. The main reason for the high mortality rate is the lack of reliable methods for early detection. However, this may change with recent research that is shattering the concept of what ovarian cancer is and how it develops.
Traditionally ovarian cancer was thought to develop from the cells lining the ovary. Researchers have now shown that it occurs from cells within the fallopian tube that are then shed and adhere to the ovary and/or disseminate throughout the abdomen. Using sophisticated molecular methods they demonstrated a unique genetic signature within cells of the fallopian tube that herald the develop of the most common type of ovarian cancer, serous carcinoma. This is termed a “p53 signature” because it involves a mutation in the p53 gene, an important oncogene required for cancer development.
As genetic mutations accumulate in the fallopian tube, the resulting changes can then be seen under the microscope as an early noninvasive cancer called a serous tubal intraepithelial carcinoma (STIC). These cells can then be shed down the tube and onto the ovary where the cancer further grows. It is typically later that the cancer comes to attention, only after it has further spread. The study found that on average it took 6.5 years for a STIC to progress to ovarian cancer.
The implications of the study are redefining our view of ovarian cancer. Recognizing that most cancers begin in the fallopian tubes will allow new approaches to the prevention, early detection and treatment. It indicates that there is a window in which intervention is possible. The study also supports the recommendation for removal of the tubes in BRCA carriers.
According to lead researcher Dr. Ronny Drapkin, “these results represent an important step forward that helps fills a knowledge gap on the evolution of this cancer. More studies with a larger cohort of patients are needed to better understand these lesions and the progression into ovarian cancer, but this latest one suggests that examination of the fallopian tubes should become common practice in pathology, and not confined to just academic centers.”