The role of axillary dissection in mammographically detected carcinoma

Axillary dissection remains a standard component of the treatment of invasive carcinoma of the breast. The presence of metastases to the regional lymph nodes guides adjuvant therapy and aids in determining prognosis. Mammography results in the discovery of small and often node-negative carcinomas of the breast.

This 15-year, retrospective analysis investigated whether certain patients with small tumors could be spared the morbidity of axillary dissection.

Medical records showed that from January 1980 to May 1995, 4,543 needle localization biopsies were done at York Hospital because of abnormalities detected on mammograms. Of these, 703 (15.5 percent) proved to be carcinoma. Of the carcinomas, 68 percent were infiltrating ductal carcinoma, 26 percent were ductal carcinoma in situ, and 5.4 percent were infiltrating lobular carcinoma. Axillary dissection was done on 588 patients, and 88.1 percent of the patients had no metastases to axillary lymph nodes. No axillary metastases were present in 109 patients with ductal carcinoma in situ who underwent axillary lymph node dissection or in 21 patients with microscopic invasive tumors. Only two of 54 patients with a T1a tumor (tumor [T], < or = 0.5 cm) had positive axillary nodes. Only one of 29 patients with a well-differentiated T1b tumor (T, > 0.5 to < or = 1 cm) had metastatic axillary nodes. In the presence of negative axillary lymph nodes, 19.2 percent of patients with a T1a tumor, 33.7 percent of patients with a T1b tumor, 60 percent of patients with a T1c tumor (T, > 1 to < or = 2 cm), and 78.9 percent of patients with a T2 tumor (T, > 2 cm) were given adjuvant chemotherapy or hormonal therapy.

Patients with ductal carcinoma in situ and microscopic invasive tumors do not require node dissections. Possibly patients with T1a tumors and patients with well-differentiated, estrogen-receptor positive, progesterone-receptor positive, T1b tumors can also be spared axillary node dissection. By following this approach on occasion, patients with positive nodes might not undergo axillary lymph node dissection, but they may still be offered adjuvant therapy.