Analysis of Metastatic Involvement of Interpectoral (Rotter's) Lymph Nodes Related to Tumor Location, Size, Grade and Hormone Receptor Status in Breast Cancer

Abstract

This study was aimed at analyzing metastatic involvement in interpectoral (Rotter's) lymph nodes in relation to tumor location, size, grade and hormone receptor status in primary breast cancer. The study included 172 female patients undergoing surgery for breast cancer at the University Hospital for Tumors, Zagreb, Croatia from November 2001 to August 2003. In addition to the standard surgical procedure, interpectoral (Rotter's) lymph nodes were removed in all of the patients. Serum levels of the tumor marker CA 15-3 were determined before surgery and hormone receptor status after surgery. Rotter's lymph nodes were identified in 67% of the patients, with metastatic involvement being found in 20% of the Rotter's nodes. Metastatic involvement of Rotter's nodes in patients with negative and positive axillary lymph nodes was 4% and 35%, respectively. When we looked at the location of the tumor in patients with metastatic involvement of Rotter's nodes, we found that tumors located in the upper quadrants were more prone to metastasis to Rotter's nodes; there was a significant positive correlation between tumor location and positive Rotter's nodes (r = 0.953, P = 0.012). As regards tumor size, Rotter's nodes were identified in 15%, 20% and 30% of stage T1 (< 2 cm), T2 (2-5 cm) and T3 (> 5 cm) tumors, respectively. Hormone receptor status showed no statistically significant difference in the expression of estrogen and progesterone receptors between patients with and those without positive Rotter's nodes. Of 35 Rotter's node-positive patients, 31.4% had elevated serum levels of CA 15-3; the level was significantly higher in Rotter's-positive patients compared to those with negative (or absent) Rotter's nodes. The results show that one-fifth of breast cancer patients, or even one-third of those with positive axillary lymph nodes, are discharged with positive interpectoral lymph nodes that remain undiagnosed. As the nodes can be surgically removed without additional mutilation, exploration of Rotter's lymph nodes should be introduced into routine clinical practice.