There are many different types of ovarian cancers and recent research is suggesting that most, if not all start in the fallopian tubes. This is an important breakthrough. By understanding more about how and where ovarian cancers start, clinicians and researchers can work on new prevention and detection methods as well as treatments.
The findings come from a few different sources. Researchers from the Perlmutter Cancer Center at NYU Langone Health published a multicenter study of ovarian cancer genetics on October 17th in Nature Communications. This was not, however, the first time that this information was brought to the public eye. In 2011 the Dana-Farber Cancer Institute in Boston showed in the lab how cancer cells can progress from fallopian tubes. Around this time researchers in Canada began encouraging providers to remove the fallopian tubes in women who wanted to permanently prevent pregnancy rather than just tying the tubes as a means of prophylaxis.
Future implications of this research
Douglas A. Levine, MD, director of the Division of Gynecologic Oncology at Perlmutter, professor of Obstetrics and Gynecology at NYU School of Medicine and author of the multicenter study says that “Based on a better understanding of its origins, our study suggests new strategies for the prevention and early detection of ovarian cancer.”
The fallopian tubes are the tubal structures in the body that transport the egg to the uterus and provide the place for fertilization if sperm is present. This latest study has found that ovarian cancer cells have a lot in common with cells that cover the surface of the fallopian tubes and have less in common with the cells on the surface of the ovaries. The implications here are huge.
Moving forward, the authors hope to find biomarkers on these tubal cells that can be used for detection purposes. Hopefully, blood tests, advanced Pap smears, or testing the tubal tissue directly will help providers detect ovarian cancer earlier. The research team is currently planning to investigate how to apply the current findings to clinical practice, but they are also realistic. While promising, this type of work takes time. It may be years before they are able to prove that they can use this information to detect ovarian cancer earlier on, prevent it from spreading, or increase survivorship in patients with ovarian cancer.
Preventive care for ovarian cancer
In agreement with what Canadian researchers have been saying, these new findings suggest that removing fallopian tubes, but not ovaries may reduce the risk of ovarian cancer in women who are high risk due to genetic mutations such as BRCA. Levine says, “We are one of several centers taking part in Women Choosing Surgical Prevention or WISP trial, which seeks to determine whether removing the tubes improves the quality of life, compared to removing both the tubes and ovaries.”
There are still many points that require clarification. All of this may not be helpful if the cells that turn into ovarian cancer do not become malignant until they have spread to other parts of the body. If this turns out to be the case, preemptively removing fallopian tubes would be pointless. The authors also acknowledge that ovarian cancer could originate from other sources as well, so this should also be investigated.
Researchers are on the right track though. This is hardly the first study to suggest that ovarian cancer originates from the fallopian tubes. Previous research has indicated that many high-grade and serious cancers that are rooted in the pelvis come after there are already lesions in the fallopian tubes that are called serous tubal intraepithelial carcinoma (STIC).
Genetics has changed the face of cancer understanding, prevention, detection, and treatment. Studies have revealed that in many different cancer types, cells of different origins have different genetic profiles. These genetic profiles are what tell us exactly where the tissue came from. This is important because it allows us to compare STIC cells to ovarian cancer cells and know that if they have different genetic profiles they must have originated in different tissue types. This information would provide greater insight into helping us look at preventative measures and detection. However, a molecular analysis of cells from 96 women with high-grade serous carcinoma showed that there were no genetic differences between ovarian cancer cells in the pelvis and cells that came from the tubes. Levine reported, “We found no differences in the 20,000 genes that we can identify. This leads us to believe that these ovarian cancers all originate in the fallopian tubes.”
Research is advancing every day
Every year we are learning more and more about how genetics plays a key role in cancer development, detection, prevention, and treatment. We already know that high-grade serous carcinoma (HGSC) is the most common and aggressive type of epithelial ovarian cancer (EOC) and that this is associated with hereditary breast and ovarian cancer syndrome (HBOC). We also know that BRCA1 and BRCA2 mutations are responsible for most cases of HBOC. For women with stage one EOC, the 5-year survival rate is greater than 90 percent. Unfortunately, as we previously pointed out, most women are not diagnosed until cancer has progressed to stage III or IV, at which time the survival rate is between 20 and 40 percent. Numerous studies have been done or are currently underway. One study used mice and manipulated the BRCA and TP53 genes in the fallopian tube cells showing that mutations in these can give rise to HGSC. Tubal ligation has also been shown to reduce the risk of ovarian cancer, further supporting the hypothesis that ovarian cancer cells originate from the fallopian tubes.
While there is still a long way to go to individuals and families affected by ovarian cancer can rest assured that progress is being made. This information is promising for the future and can offer hope to future generations. The next steps are to further prove this correlation and then look at how we can use it to potentially screen women for ovarian cancer.