Risk Scoring System for Predicting Axillary Response After Neoadjuvant Chemotherapy in Initially Node-positive Women with Breast Cancer

Background: One of the current therapeutic challenges for women with breast cancer receiving neoadjuvant chemotherapy (NAC) is distinguishing women with complete axillary nodal response from those with axillary residual disease to promote a personalized therapeutic strategy including sparing axillary surgery. This study set out to develop a risk scoring system (RSS) for predicting probability of nodal pathological complete response (pCR) in women presenting with cN1 breast cancer who received NAC.

Methods: Data of 116 women with cN1 breast cancer who received NAC between January 2009 and December 2013 were abstracted from our prospectively maintained database. A risk model based on factors impacting nodal axillary was developed.

Results: The overall nodal conversion rate was 36.2% (42/116). Axillary nodal response was associated with three variables: menopausal status [Odds ratio (OR) = 0.23; 95% confidence interval (CI) 0.09-0.60], the radiological % of breast tumour shrinkage ≥50% (OR = 3.71; 95% CI 1.51-9.10), and negative hormone receptors (ER-, PR-) (OR = 2.41; 95% CI 0.99-5.87). These variables were included in the RSS and assigned scores ranging from 0 to 2. The discrimination of the RSS was 0.78 [95% confidence interval (CI) 0.69-0.86]. A total score of 3 points corresponded to the optimal threshold of the RSS. The diagnostic accuracy was 74.1%.

Conclusions: This study shows that the probability of axillary nodal pCR after NAC can be accurately predicted so that women at high probability may be spared of axillary surgery.