Duloxetine shows efficacy for pain associated with breast cancer treatment

By Bruce Sylvester

Duloxetine (Cymbalta ®), a widely-used treatment for depression and anxiety, appears to reduce joint pain in postmenopausal women being treated for early stage breast cancer, researchers reported on Dec. 9, 2016 in a special plenary session at the San Antonio Breast Cancer Symposium.

As background, the investigators noted that joint pain in postmenopausal women is a common side-effect of breast cancer treatment with an aromatase inhibitor (AI). As many as 50 percent of such women report joint pain and stiffness as a side effect of AI therapy, and about 20 percent report significant pain. The condition is known as AI-Associated Musculoskeletal Syndrome (AIMSS).

“A lot of 60-year-old women report feeling like they’re 80,” said lead investigator N. Lynn Henry, M.D., Ph.D, associate professor in the University of Utah’s Division of Oncology in the Department of Medicine in Salt Lake City. “The pain can really interfere with daily life. And this is a big problem. The length of treatment with AIs can be five to 10 years, so we’re asking a lot of women to manage significant discomfort for a very long period of time.”

Investigators from SWOG (formerly the Southwest Oncology Group), an international cancer clinical trials network funded by the (US) National Cancer Institute (NCI), conducted the randomized, placebo-controlled trial. They enrolled 299 subjects at 43 institutions in the SWOG network. The subjects were randomized to treatment for 12 weeks with either receive duloxetine or a placebo.

Each subject completed a questionnaire at baseline and at weeks 2, 6, 12 and 24. Questions pertained to pain, which was rated on a 0-10 scale, depression and quality of life.

The investigators reported that subjects using duloxetine achieved an average pain level drop from 5.5 to about 3. They also noted that reduction in pain was rapid, and pain relief lasted through the end of the 12-week trial.

“We’ve shown that this treatment is a potential option for women,” Henry said. “Taking this drug may help them tolerate their breast cancer treatment. And it’s important for their health that they stick with their treatment.”

Duloxetine belongs to a class of selective serotonin and norepinephrine reuptake inhibitors that work by increasing levels of serotonin and norepinephrine. Serotonin and norepinephrine help to halt the movement of pain signals in the brain.