PHILADELPHIA The presence of multiple ovarian cancer genomes in an individual patient and the absence or downregulation of the gene LRP1B are associated with the development of chemoresistance in women with the high-grade serous cancer subtype of ovarian cancer whose disease recurs after primary treatment. These study results are published in Cancer Research, a journal of the American Association for Cancer Research.
David Bowtell, Ph.D., head of the Cancer Genomics and Genetic Program at the Peter MacCallum Cancer Centre in Melbourne, Australia, and colleagues generated these data in one of the first studies to investigate using patient tumor samples as the mechanisms responsible for the emergence of chemotherapy resistance in high-grade serous ovarian cancer.
"High-grade serous cancers account for about two-thirds of deaths from epithelial invasive ovarian cancer," Bowtell said. "We were interested in identifying the molecular changes that occurred in a tumor between the time when a woman first presented for surgery and chemotherapy, and the time when the tumor recurred and eventually became resistant to chemotherapy."
To examine this, the researchers analyzed metastatic lesions from individual patients and 22 paired pretreatment and post-treatment tumor samples for spatial and temporal genomic variation.
"Spatial variation is a measure of genomic heterogeneity in different deposits of tumor present at primary surgery variation that the tumor could draw on to evolve over time, especially in the face of chemotherapy," Bowtell explained. "Temporal variation gives us an indication of how much the tumor changes over time, and after one or more lines of chemotherapy."
The researchers compared the level of genomic change among women who were initially chemosensitive and those who were resistant to primary chemotherapy. Tumors that were initially sensitive to chemotherapy but later became resistant evolved furt
|Contact: Jeremy Moore|
American Association for Cancer Research