Axillary lymph node dissection for breast cancer: a decision analysis of T1 lesions

The value of routine axillary dissection for patients with breast cancer is still being debated. The argument centers around whether the information gained by knowing the lymph node status, which aids in making the decision about adjuvant chemotherapy, justifies the morbidity. This study quantitatively analyzes the potential outcomes of routine, selective, and no axillary dissection.

A decision analysis was performed of the strategies of lumpectomy and radiation versus simple mastectomy followed by no dissection, selective dissection, or routine dissection. Factors included biologic markers to identify high-risk lesions, the morbidity of axillary dissection, the effects of adjuvant chemotherapy on lymph node-negative and lymph node-positive disease, and the life expectancy of patients with high-risk and low-risk node-negative and node-positive lesions. Sensitivity analysis was done to determine threshold levels of these factors in choosing an option.

We discovered an advantage in quality-adjusted life expectancy (QALE) for no axillary dissection until the probability of positive lymph nodes reaches >15%; after that, selective node dissection is superior. Selective dissection is superior for lower morbidity rates of axillary dissection. Routine dissection is never a superior strategy. The difference among these strategies is small, however, with no one strategy providing a QALE greater than 1 year longer than any other.

Axillary dissection can be avoided in patients with high-risk lesions who would be candidates for adjuvant chemotherapy regardless of lymph node status, and possibly in patients with low-risk T1a lesions, but it should be recommended for low-risk T1b and T1c lesions for which lymph node status may determine the need for adjuvant chemotherapy.