Anesthetics during breast cancer surgery may affect development of chronic pain

In women with breast cancer, the choice of anesthetic used for mastectomy may affect the risk of developing long-term pain after surgery, according to a study in the March issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).

In particular, women who undergo mastectomy with the anesthetic drug propofol are one-half as likely to have chronic pain in the years after surgery, compared to those receiving a different anesthetic called sevoflurane, according to the report by Dr Ah-Reum Cho of Pusan National University, Busan, Korea.

With Propofol, Lower Rate of Chronic Pain after Mastectomy
The researchers assessed chronic (long-term) pain after mastectomy for breast cancer in 175 women. Chronic pain was compared for women receiving two different types of general anesthetics commonly used for surgery: propofol and sevoflurane.

When assessed up to four years after breast cancer surgery, 56 percent of the women said they had chronic pain. Chronic pain was less common for women who received propofol anesthesia: 44 percent, compared to 67 percent for those receiving sevoflurane anesthesia.

On analysis adjusting for other factors, women receiving sevoflurane were about 50 percent more likely to develop chronic pain after mastectomy. Among women with chronic pain, there was no difference in pain severity or duration between the propofol and sevoflurane groups.

Other factors associated with an increased risk of chronic pain after mastectomy were younger age, more extensive surgery (axillary lymph node dissection), and need for more morphine for pain relief after surgery. Higher use of morphine after surgery was a risk factor for more severe chronic pain.

Chronic pain after breast cancer surgery is a common problem that can have a major impact on the patient's life. Anesthesiologists are interested in identifying factors during and after surgery that may influence the risk of developing chronic pain. Recent studies have suggested that the choice of anesthesia during surgery may affect the risk of "central sensitization" to pain.

More Study Needed to Confirm 'Provocative' Findings
"This study suggests that anesthetics during breast cancer surgery may affect the development of chronic pain," Dr Cho and coauthors write. In particular, women receiving propofol anesthesia for mastectomy are about half as likely to develop chronic pain, compared to those receiving sevoflurane.

Dr Cho and colleagues emphasize that chronic pain risk is also influenced by other factors, and that their study cannot prove any cause-and-effect relationship. They call for further research to confirm the "provocative" finding that choosing propofol for anesthesia may lower the risk of chronic pain in women undergoing mastectomy for breast cancer.