Pathological axillary lymph node status in HER-2 receptor positive and negative breast cancers

Value of frozen section and primary tumor factors in determining sentinel lymph node spread in early breast carcinoma

INTRODUCTION

Sentinel lymph node biopsy (SLNB) is the standard of care to assess the metastasis in breast carcinoma. Accuracy of intraoperative frozen section examination to evaluate SLN in detecting metastasis is important as it determines the further management of axilla. Primary tumor characteristics determining the metastasis to the lymph node will help in predicting the probability of spread and to determine the nature of disease. It also helps in refining selection of patients for SLNB. We evaluated all these criteria on Indian patients for the better management.

MATERIALS AND METHODS

Between January 2005 and April 2009, 114 consecutive patients of all age group of both sex, with cytology or biopsy proven carcinoma breast, clinical stage T1/T2 N0 M0 at Manipal Comprehensive Cancer Center, Manipal Hospital, Bangalore were subjected to SLNB and introperative frozen examination. First 75 cases had complete axillary clearance irrespective of SLNB result and subsequently, positive cases underwent axillary lymph node dissection (ALND). Age of the patient and primary tumor characteristics like size, grade, lymphovascular invasion (LVI), perineural invasion, ER/PR status, Her2-neu status and histological sub-types were evaluated for predicting the SLN metastasis. Feasibility of SLNB in previously treated patient is also evaluated.

RESULTS

The age of the patient ranged from 23 to 87 years and its association with SLN spread is not significant. Frozen section examination had accuracy of 97.37% in determining metastatic sentinel node with sensitivity of 96.15% and specificity of 100% with value P < 0.001. SLN remained significant indicator of the status of rest of axilla with value P < 0.001. Primary tumor characteristics like histological subtypes, grade (P = 0.353), ER/PR status (P = 0.839), Her2-neu status (P =0.296) were not significantly associated with SLN metastasis. Size of the primary tumor (P = 0.002), LVI (P < 0.001), perineural invasion (P = 0.084+) were significant factors determining the SLN metastasis. SLNB evaluation had no false negative values in previously treated breast.

CONCLUSION

SLNB is a valuable method of determining the axillary nodal metastasis. Intraoperative frozen section examination is highly ac-curate in detecting nodal metastasis. Primary tumor characteristics like size, LVI and perineural invasion are significant in predicting SLN metastasis. SLNB remains an important method of predicting axillary metastasis even in previously treated breast carcinomas.