Nearly half of women with breast cancer report persistent pain, and 58% report sensory disturbances up to 3 years after surgery, according to Dr. Rune Gärtner of the University of Copenhagen and her associates.
In more than half of these cases, the women describe their pain as moderate to severe, Dr. Gärtner and her associates said (JAMA 2009;302:1985-92).
The researchers assessed persistent breast cancer pain in a nationwide study of 3,253 Danish women who underwent surgery for unilateral primary breast cancer in 2005-2006. They categorized the patients into 12 treatment groups according to the type of surgery, adjuvant radiotherapy, and adjuvant chemotherapy they received.
Surgeries included breast-conserving surgery with either sentinel node dissection or axillary node dissection and mastectomy.
The mean interval between the surgery and this pain assessment was 26 months (range, 13-41 months). Very few of these patients were receiving aromatase inhibitors when they were assessed, which are known to cause muscular and joint pain.
A total of 1,543 women (47%) reported pain in the area of the affected breast, the axilla, the arm, or the side of the body. Eighteen percent reported pain in one of these areas, 28% in two areas, 28% in three areas, and 26% in all four areas.
Thirteen percent of the women reported severe pain and 39% reported moderate pain, while 48% reported light pain. Among the women who reported severe pain, 77% had pain every day, Dr. Gärtner and her colleagues said.
One-fifth of the study subjects had consulted a physician about the pain during the preceding 3 months. A total of 28% had taken analgesics, and 26% had received other therapies, such as physiotherapy or massage.
Fifty-eight percent of women reported persistent sensory disturbances. The rate was lowest (31%) among women who had breast-conserving surgery with sentinel node dissection, and it was highest (85%) among women who had breast-conserving therapy with axillary node dissection and radiotherapy.
“The most important determinant of persistent pain and sensory disturbance was young age (less than 40 years),” they noted. Radiotherapy also was an independent and significant risk factor for persistent pain.
Taken together with the results of previous research, these findings indicate that “chronic pain after breast cancer surgery and adjuvant therapy may predominantly be characterized as a neuropathic pain state and [is] probably related to intraoperative injury of the intercostal-brachial nerve,” Dr. Gärtner and her colleagues said.
In the future, using nerve-sparing surgical and radiotherapy techniques may reduce the risk of persistent breast cancer pain, they added, but larger, more detailed studies are needed.
No conflicts of interest were reported. The work was supported by grants from the Danish Cancer Society, Breast Friends, and the Lundbeck Foundation.