The impact of lymphoscintographic drainage to the internal mammary nodes on the management of invasive breast cancer

Abstract

869 Background: Management of the internal mammary lymph nodes for invasive breast cancer has often been a question of much debate. In this study, we sought to determine how frequently there was drainage to the IM nodes as evidenced by lymphoscintigraphy (LSG), and if there was any correlation with location of primary or failure pattern. Also, we sought to determine what proportion of patients who had pathologically positive nodes had evidence of drainage to the IM nodes on initial LSG. Methods: We retrospectively reviewed the data from a single surgeon at our institution from 1998 to 2003 who had breast cancer surgery followed by LSG mapping. Overall, a total of 325 patients were evaluated with stage I-III breast cancer who had surgery followed by sentinel lymph node mapping using LSG. Radiographic LSG reports were analyzed for each patient, and their drainage patterns were recorded, as well as follow-up. Results: There were a total of 325 total patients reviewed. The location of the primary lesions were broken down as follows: 216 in the upper outer quadrant (UOQ), 60 in the upper inner quadrant (UIQ), 14 in the lower outer quadrant (LOQ), 31 in the lower inner quadrant (LIQ). The lymphoscintographic distribution was broken down as follows: 25 had evidence of drainage to the IM nodes, 193 had drainage to the axillary nodes, 7 had drainage to the SC nodes, 2 had contralateral drainage and 98 revealed no SLN on radiographic report. Overall, a total of 61 patients had positive nodes on either SLN biopsy. Of the 25 patients that had drainage to the IM nodes, 12 had a primary located in the UOQ, 4 in the UIQ, 2 in the LOQ and 6 in the LIQ. Of all patients that had positive nodes pathologically, only 3 had evidence of drainage to the IM nodes. Only one patient with evidence of lLSG drainage to the IM nodes had disease progression on follow up. Conclusions: Evidence of LSG drainage to the IM nodes did not represent a large cohort of patients that have had SLN biopsy (7.7%). In addition, having positive nodes on pathologic analysis did not correlate with an increased likelihood of IM drainage. Of these patients, only one had evidence of disease progression. In addition, location of primary did not seem to predict likelihood of drainage to the IM’s. No significant financial relationships to disclose.