SAN FRANCISCO, CA—Among women cancer survivors, 45% still experience symptoms of chemotherapy-induced peripheral neuropathy (CIPN) years after they have completed cancer treatment. These findings were reported at the 2016 Survivorship Symposium.
Peripheral neuropathy is a type of nerve damage that can cause numbness, tingling, pain, muscle weakness, and other changes. It is a relatively common side effect of specific types of chemotherapy, affecting an estimated 57% to 83% of patients during or after their treatment. Chemotherapy drugs known to injure peripheral nerves include bortezomib, platinums, taxanes, thalidomide, and vinca alkaloids.
The study found that CIPN was associated with worse physical functioning, poorer mobility, and a nearly 2-fold higher risk of falls. Rehabilitation and fall prevention interventions may be tailored to persons with CIPN, based on the study findings.
“We can’t dismiss neuropathy as a treatment side effect that goes away, because symptoms persist for years in nearly half of women,” said Kerri M. Winters-Stone, PhD, a research professor at Oregon Health and Science University in Portland, Oregon, and lead author of the study. “While there are no effective treatments for this side effect, rehabilitative exercise programs may preserve physical functioning and mobility in the presence of neuropathy to help prevent falls and resulting injuries.”
The authors explained that this study is one of the first to examine the relationship between CIPN and physical functioning, including the risk of falls.
The study analyzed 678 women cancer survivors, including 462 who self-reported symptoms of CIPN. The study participants had a mean age of 62 years and were approximately 6 years past their cancer diagnosis.
When the groups with and without self-reported peripheral neuropathy were compared, those with neuropathy had significantly worse physical function. Physical function measures included timed chair stand, physical performance battery, gait patterns, and falls in the past year.
The underlying impairments in the women with CIPN put these women at risk for falls. The difficulties from peripheral neuropathy differ from other conditions such as old age; peripheral neuropathy does not cause muscle weakness but rather has a distinct effect on movement and gait patterns.
In this study, women with CIPN had difficulty rising from a chair. The authors explained that this is possibly because their brain does not get enough information from their feet about how quickly or forcefully to stand up.
The authors argued that their study’s findings indicate that commonly recommended exercise, such as walking, may be safer for women with CIPN when performed on a treadmill with handrails instead of outdoors because their altered gait puts them at increased risk of falling.
Because neuropathy does not decrease leg strength, machine-based resistance training may also not be beneficial. The authors explained that, instead, rehabilitation efforts should focus on improving balance during upright movement and specific gait training.
Men experience CIPN at the same rate as women, but less research data is available on men.
This study was funded by the National Cancer Institute, American Cancer Society, and Susan G. Komen for a Cure Foundation.