Role of ultrasonography to detect axillary node involvement in operable breast cancer

Prompted by the concern about unnecessary axillary dissections, we prospectively studied the accuracy of clinical examination (CE) and conventional ultrasonography (USG, 7.5 MHz), to diagnose pre-operatively metastatic axillary lymph nodes in 200 operable breast cancer patients. USG had higher specificity (90% vs 77%, P = 0.025) and higher positive predictive value (ppv = 90% vs 76%, P = 0.02) than CE. Together, CE + USG had higher sensitivity (82% vs 58%, P = 0.00005) and higher negative predictive value (npv = 76% vs 58%, P = 0.008) than CE alone. In women < 45 years, CE + USG had higher sensitivity (91% vs 76%, P = 0.037) and npv (89% vs 67%, P = 0.018) than in older women. The sensitivity and npv of CE + USG to detect > 1 positive node were 97% (for both) in women < 45 years compared to 81% and 79% in older women. The high sensitivity of CE + USG (82% for the whole group) is probably due to the higher proportion of young women (median age = 45) in our population. It suggests that using CE + USG to avoid axillary dissection in some patients is feasible.