Peripheral Neuropathy Can Persist in Cancer Patients Post-Treatment

A pair of new studies published by the Journal of the National Cancer Institute suggest that patients with early-stage breast cancer may be affected by peripheral neuropathy years after finishing treatment. Patients may experience pain, numbness, and tingling in the hands and feet, despite cessation of chemotherapy.

The authors also found few studies that tracked long-term peripheral neuropathy, which may leave physicians and patients uninformed about the condition, according to the study.

“Until recently, the really strong focus has been to identify treatments to reduce breast cancer recurrence and mortality,” said study co-author Joy Melnikow, MD, MPH. “I think we’ve reached the point now where we need to ask questions about the adverse effects that come along after curative treatments. We need to balance what are sometimes small therapeutic benefits with the risk of long-term adverse events.”

To determine how neuropathy affects patients years after treatment, the authors systemically reviewed previous studies. There were only 5 that followed patients for more than 1 year and produced variable results, according to the authors.

“The most striking finding from the review was how little data was out there,” Dr Melnikow said. “And these studies report a wide range of frequency for peripheral neuropathy, from as low as 11% to more than 80% of patients at 1 to 3 years after treatment.”

The novel study was started with the aim of filling the gap in information. Included in the study were 1512 patients with early-stage breast cancer included in the National Surgical Adjuvant Breast and Bowel Project Protocol B-30 (NSABP B-30), which explored the efficacy of chemotherapy combinations of doxorubicin, cyclophosphamide, and docetaxel.

The authors found that 2 years after starting treatment, 42% of patients experience neuropathy, with 10% reporting severe discomfort. Women who experienced severe neuropathy were more likely to report a worse quality of life, according to the study.

The authors noted that patients who received low-dose docetaxel combination therapy were less likely to experience long-term neuropathy. These results may help physicians chose more optimal treatments to reduce the risk of neuropathy.

Additionally, patients who had pre-existing neuropathy were likely to be older, obese, and had worse outcomes.

Oncologists may encourage patients to undergo adjuvant chemotherapy to protect against disease recurrence; however, the authors suggest that the choice of drugs or avoidance should also take neuropathy risks into consideration, according to the study.

“There is very little treatment for neuropathy, and there’s nothing that’s actually proven to work,” said senior study author Patricia Ganz, MD. “Since we don’t have an effective treatment, ideally it would be best to prevent it from happening by not administering chemotherapy if it is likely to have minimal additional benefit. Alternatively, this class of drugs could be avoided in patients who are at higher risk for persistent neuropathy. At the minimum, patients need to be informed about the likelihood of persistent symptoms.”

Additional studies are needed to explore peripheral neuropathy and other side effects for cancer treatment. The authors also note that more consistent metrics are needed to facilitate easier analyses of studies related to peripheral neuropathy.

“This is a call to action,” Dr Melnikow concluded. “We can’t definitively define the frequency of peripheral neuropathy or understand the differences between chemotherapy regimens with the data we have. This issue of adverse effects in survivors goes beyond peripheral neuropathy. There are other effects that need to be considered while women are making treatment decisions.”