Chemoresponse assays may markedly boost ovarian cancer survival

NEW YORK (Reuters Health) - Ovarian cancer patients lived 14 months longer, a 50% improvement, when their tumors were responsive to treatment in a new study - and a chemoresponse assay the researchers tested shows promise for predicting in advance which treatments would work best.

"Based on the results of this trial I would tell you that a patient with recurrent ovarian cancer would benefit from having a biopsy, it would improve their overall survival and decrease their toxicity," study leader Dr. Thomas Rutherford from Yale University School of Medicine in New Haven, Connecticut told Reuters Health.

Dr. Rutherford and his team presented their results March 9th at the Society of Gynecologic Oncology (SGO) Annual Meeting in Los Angeles.

The study included 283 women, of whom 262 has successful biopsies and testing in vitro. The ChemoFx assay tested up to 15 approved treatment regimens on the samples to identify those to which the tumor might be sensitive, and 12 were administered.

Precision Therapeutics, the maker of the assay, says a unique component of the company's patented five-step process "is the ability to keep the patient's tumor cells proliferating and behaving as if they were in the body while they are challenged with each chemotherapy."

The study was non-interventional, so that all treatment regimens were chosen by physicians who were unaware of the assay results. The researchers then evaluated the assay's results according to the actual clinical outcomes.

In 52% of patients, the assay identified at least one treatment to which the tumor would be sensitive.

For the cohort as a whole, the progression-free survival was 6.7 months and the overall survival was 26.5 months.

Patients who received treatment to which their tumors were sensitive had progression-free survival for 8.8 months, compared to 5.9 months for those who underwent treatment to which their tumors were resistant or intermediate (hazard ratio: 0.67; p=0.009).

The effect was roughly similar in both platinum-sensitive and platinum-resistant tumors.

The median overall survival was 37.5 months for patients with treatment-sensitive tumors, compared to 23.9 months for intermediate and resistant tumors (HR: 0.61; p=0.010).

Both overall and progression-free survival differences persisted after controlling for other factors through multivariate analysis.

Dr. Jubilee Brown, a gynecologic oncologist at the University of Texas MD Anderson Cancer Center in Houston who wasn't involved in the study, told Reuters Health in an email, "For a very long time, we have thought assay-directed therapy would be a good idea but have awaited data supporting the use of an assay like this. The choice of which treatment to use in a given person is a complicated decision, but this study may help to inform such choices moving forward."

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