Abstract
Although sentinel lymph node biopsy (SLNB) has become a standard of care for management of axilla in breast cancer patients, the technique of SLNB is still not well defined. Unlike radioactive sulfur colloid which requires nuclear medicine facilities, methylene blue dye is readily available. The purpose of this study is to validate the use of methylene blue dye alone for SLNB in early breast cancer patients. 60 patients of early breast cancer were randomized to receive either methylene blue alone (Group A-30 patients) or a combination of both methylene blue and radioactive colloid (Group B-30 patients) for detection of sentinel lymph nodes. Sentinel lymph node biopsy was done followed by complete axillary dissection in all patients. In both Groups A and B, sentinel node was identified in all 30 patients, giving identification rate of 100%. In group A, sentinel node was the only positive node in 1 patient, with a false-positive rate of 14.2%. The negative predictive value was 91.3%. The sensitivity of the procedure in predicting further axillary disease was 75% with a specificity of 95.45%. The overall accuracy was 90%. In group B, sentinel node was the only positive node in 2 cases, giving a false-positive rate of 28.7%. The negative predictive value was 95.65%. The sensitivity of the procedure in predicting further axillary disease was 83.33% with a specificity of 91.67%. The overall accuracy was 90%. Although the false-negative rate was slightly higher with methylene blue alone than that using combination (8.6%-4.3%), it was statistically insignificant. Similarly the sensitivity (75%-83.33%), specificity (95.45-91.67%), and negative predictive value (91.3%-95.67%) were also comparable between groups A and B, respectively. Negative predictive value and false-negative rates are comparable, whether blue dye is used alone or a combination of blue dye and radioactive colloid is used. Sentinel lymph node biopsy with blue dye alone is reliable and can be put to clinical practice more widely, even if nuclear medicine facilities are not available in resource constrained centers, so as to reduce long-term morbidity of axillary dissection, with similar oncological outcomes.