(RxWiki News) Cancer is a tricky disease. Researchers now believe that one form of ovarian cancer may start as a fallopian tube tumor. Findings from this new study may offer new hope in treating the disease.
High-grade serous ovarian cancer (HGSOC) is the fifth-deadliest cancer among American women. There have been theories that HGSOC starts in the fallopian tubes for some time, but there's been no proof up until now.
In a new study at the Dana-Farber Cancer Institute, researchers have developed a laboratory model that demonstrates how cells in the fallopian tubes may morph into cancer cells that appear to come from the ovaries.
"Ovarian cancer may start in the fallopian tubes."
Scientists were able to show this process in the laboratory and demonstrate powerful evidence that it can happen in patients. So this discovery throws new weight behind the theory that HGSOC begins, in fact, in the fallopian tubes.
"Such studies will help us identify different types of high-grade serous ovarian cancer, as well as possibly discover biomarkers — proteins in the blood — that signal the presence of the disease," said Dana-Farber's Ronny Drapkin, M.D., Ph.D., senior author of the new study being published in the Proceedings of the National Academy of Sciences.
"Ultimately, the model will enable us to test potential therapies to determine which work best in each type of the disease," he continued.
The origins of HGSOC have been so difficult to track down because of the insidious nature of the disease. Ovarian tumors often begin and grow in the body without producing any warning symptoms.
By the time the disease is discovered, the ovaries can be so overrun with cancer that nearby sections of the fallopian tube are hard to see, making them difficult to examine under a microscope.
Late detection is one reason why ovarian cancer is so difficult to treat.
- In a study last year, Dana-Farber researchers were able to create a laboratory model that mirrors the structure and function of normal fallopian tube tissue in the body
- For the new study, researchers removed secretory cells from this model and "immortalized" them - the genetic programming of the cells was altered so they would behave like cancer cells do
- The Cancer Genome Atlas Project has shown that ovarian cancers don't have a consistent pattern of gene mutations (other than in the p53 tumor suppressor gene)
- Instead, ovarian cancer cells have broad irregularities in the number of copies of key genes — too many, too few, or none at all.
- The gene most commonly missing from ovarian cancer cells is hRb, the one most often overduplicated is c-Myc
- The Dana-Farber researchers made the immortalized cells mimic those abnormalities by shutting down hRb and sending c-Myc into overdrive
- Like true tumor cells, these "artificial" cancer cells proliferated rapidly and were able to leave their home tissue and grow elsewhere
- When implanted in laboratory animals, these cells also developed tumors that were structurally, behaviorally, and genomically similar to human HGSOC
The American Cancer Society estimates that 22,000 women in the United States are diagnosed with HGSOC each year, and 14,000 die of it. Worldwide, the incidence approaches 200,000 women with 115,000 deaths each year.