Results from an international clinical trial suggest that avoiding surgical removal of axillary lymph nodes in older women with clinically node-negative breast cancer may improve short-term quality of life without adversely affecting survival. These results were published in the Journal of Clinical Oncology.
Surgical removal of axillary (under the arm) lymph nodes, also called axillary lymph node dissection, provides information about whether breast cancer has spread beyond the breast. Although accurately determining the extent of cancer is an important part of treatment planning, axillary lymph node dissection can cause chronic side-effects, including pain, limited shoulder motion, numbness, and swelling.
Researchers affiliated with the International Breast Cancer Study Group Trial 10-93 speculated that older women with early breast cancer may be less likely to benefit from axillary surgery than younger women. There is some evidence that older women tend to have less aggressive breast cancer than younger women.
To evaluate the effects of axillary lymph node dissection in older women with no evidence of lymph node metastases (clinically node-negative breast cancer) before surgery, an international group of researchers conducted a clinical trial in 473 women age 60 years or older.
Women were randomly assigned to receive breast surgery with or without axillary lymph node dissection. Women in both study groups received five years of tamoxifen as adjuvant therapy.
The initial primary objective of the study was to assess the effect of axillary lymph node surgery on disease-free survival (survival without new or recurrent cancer). Too few subjects were enrolled, however, to provide adequate statistics to address this question. In response, researchers redesigned the study to make quality of life the primary study outcome.
Average patient age was 74 years and 80% of patients had estrogen receptor-positive breast cancer. Forty-five percent of patients were treated with mastectomy, 33% had breast conserving surgery with radiation therapy, and 23% had breast conserving surgery without radiation therapy.
- Among women who underwent axillary lymph node dissection, 28% were found to have cancer in at least one lymph node.
- At the time of the first post-operative assessment, quality of life was worse in the women who had undergone axillary surgery than in those who had not. Women who had axillary surgery were more likely to report being bothered by hand, arm, or chest problems shortly after surgery.
- The difference between study groups in quality of life tended to disappear by 6 to 12 months after surgery.
- After a median of 6.6 years of follow-up, disease-free survival (survival without new or recurrent cancer) and overall survival were similar across the two study groups: Disease-free survival was 67% in women who had undergone axillary surgery and 66% in women who had not. Overall survival was 75% in women who had undergone axillary surgery and 73% in women who had not.
Although the study enrolled too few patients to make definitive statements about the effect of axillary surgery on survival, the researchers attempted to estimate the likelihood that an effect on survival would emerge in a larger study. They concluded that the likelihood was low and that even a larger study would most likely show that survival was similar in the two study groups.
The researchers conclude that in older women treated with tamoxifen for estrogen receptor-positive, clinically node-negative breast cancer, avoiding surgical removal of axillary lymph nodes may improve short-term quality of life without compromising survival. Due to the small sample size however, firm conclusions about the effect on survival cannot be drawn.
Reference: International Breast Cancer Study Group. Randomized Trial Comparing Axillary Clearance Versus No Axillary Clearance in Older Patients with Breast Cancer: The First Results of International Breast Cancer Study Group Trial 10-93. Journal of Clinical Oncology. 24:337-344.