U-M researcher studying new ways to fight cancer pain
Written by Nicole Fawcett
ANN ARBOR, Mich. - For many women, breast cancer leaves behind more than just a scar.
About a quarter of women experience moderate to severe pain for many years after their treatment ends. In many cases, it's a type of pain that is challenging to treat, with few or no effective options.
"Pain affects many breast cancer survivors and can be a long-term effect of treatment. We are trying to understand who is most likely to get pain and how we can best treat it to improve the quality of life for these patients," says N. Lynn Henry, M.D., Ph.D., assistant professor of internal medicine at the University of Michigan Medical School and a breast cancer specialist at the U-M Comprehensive Cancer Center.
Henry is leading several clinical trials related to breast cancer pain. One will look at whether the antidepressant duloxetine, or Cymbalta, is more effective than placebo at managing pain. In another study, participants will undergo an MRI of their brain as well as a special test in which pressure is applied to the thumbnail. This will help researchers understand differences in peoples' sensitivity to pain by seeing what parts of the brain are more active when they have pain.
Other studies have looked at whether women who undergo multiple types of treatment are more likely to have pain. For example, one study found that women who have had chemotherapy were more likely to experience pain from aromatase inhibitors, an anti-hormone treatment.
"We know peripheral nerve damage is common with chemotherapy, and can cause numbness, tingling and pain. But maybe chemotherapy affects the nerves in the brain and spinal column, not just the peripheral nerves in the hands and feet," Henry says.
Several aspects of breast cancer treatment can cause pain:
- Pain can occur in the area where a woman had surgery, including the underarm if lymph nodes were removed.
- Women who had lymph nodes removed are also at risk of swelling in the arm, a condition called lymphedema, which can cause chronic pain.
- Some patients experience joint pain and achiness or a painful tingling called peripheral neuropathy during chemotherapy. This may linger even after the treatment is over.
- Another class of drugs called aromatase inhibitors also frequently cause joint pain and muscle aches.
It's about more than just pain, too. Because few treatments are effective, many women are just living with pain. And that makes some think twice about continuing with therapies that may reduce their risk of cancer returning. A study that Henry published in 2012 found that almost one in four women stopped taking aromatase inhibitors because of joint and muscle pain.
"Some women do well with their treatments but others have a really hard time with pain and they are miserable," Henry says. "We have to find better ways to predict who might be at risk of pain and then prevent or successfully treat it."
For information on any of Henry's pain studies, call the U-M Cancer AnswerLine at 800-865-1125.
Breast cancer statistics: 234,580 Americans will be diagnosed with breast cancer this year and 40,030 will die from the disease, according to the American Cancer Society.
Funding: Henry receives research funding from the American Cancer Society, the Damon Runyon Cancer Research Foundation, and the National Institutes of Health.