Scientists at Dana-Farber Cancer Institute in Boston, Massachusetts, have identified 3 subtypes of high-grade serous ovarian cancer (HGSOC) that may soon help physicians determine which patients will benefit from a certain class of drugs.1 Researchers sorted tumor samples from HGSOC into 3 subtypes, according to the extent of a certain type of genetic damage in the cells. Patients in the subtype with the highest levels of damage were the slowest to develop resistance to platinum chemotherapy treatment such as carboplatin.
Investigators in the study used single-nucleotide polymorphism arrays to read elements of the genetic code one by one. They were probing HGSOC tissue samples for instances of loss of heterozygosity (LOH), which involves having a normal and mutant copy of certain genes. The 3 subtypes were based on the patterns of LOH within them.
One group had a high level of LOH and a deleted segment of chromosome 13. Researchers observed that this group of patients was slow to develop resistance to chemotherapy drugs and had the longest progression-free survival. LOH hampers cancer cells' ability to survive as the cells become dependent on proteins that repair damaged chromosomes. Drugs that target such repair proteins may be very effective against HGSOC cells with high levels of LOH, the authors say.
In addition, researchers found that LOH patterns in HGSOC were similar to those in triple-negative breast cancer, which also has a high level of chromosomal instability. As a result, agents that work well against HGSOC also may be effective in treating this type of breast cancer, the authors say.