Purpose: to evaluate the predictive capacity of the sentinel lymph node (SLN) in relation to the axillary lymph node status in patients with initial invasive breast carcinoma submitted or not to neoadjuvant chemotherapy. Method: a prospective study was performed in 112 patients divided into two groups. The first group comprised 70 patients who had not received previous chemotherapy (Group I) and the second consisted of 42 patients who were submitted to neoadjuvant chemotherapy in three cycles of AC (adriamycin + cyclophosphamide) (Group II). Regarding chemotherapy, we observed partial response >50% in 21 patients, being complete in three of them, and <50% in 19 patients; in two patients progression of the disease occurred. A peritumoral injection of 99mTc dextran was applied with the help of stereotaxy in 29 patients with nonpalpable tumors, 16 of Group I and 13 of Group II. The radioactive accumulation shown by scintigraphy guided the biopsy of the axillary SLN with the help of a probe. The anatomopathologic study of SLN was based initially on a single section. When the LSN was free, it was submitted to serial sections at 50 mum intervals, stained with HE. Results: SLN was identified in 108 patients. No identification has been obtained in four patients, all with nonpalpable lesions (3 patients of Group I and 1 of Group II). The method's accuracy in predicting the axillary lymph node status was 100% in patients who did not receive neoadjuvant chemotherapy and 93% in those to whom this kind of treatment was administered. This difference proved to be statistically significant. Conclusions: the present study allowed us to conclude that in all patients who did not receive previous chemotherapy treatment, the SLN study was effective in predicting the axillary lymph node status. The high rate of false-negative results in the group of patients submitted to neoadjuvant chemotherapy seems to invalidate the use of SLN study these patients.
Breast cancer; Sentinel lymph node; Neoadjuvant chemotherapy
