Risk Factors Identified for Recurrence after NeoAdjuvant Therapy
Simple clinical score assists decision-making following neoadjuvant therapy
There is an increased use of neoadjuvant therapy (NAC) despite a lack of survival benefits. Why? Because there are several other benefits derived from NAC.
Neoadjuvant chemotherapy (NAC) is being used more frequently despite a lack of survival benefits. There are, however, benefits that reach beyond survival. Lumpectomy is facilitated in patients who would otherwise undergo mastectomy. There is a decrease in axillary positive nodes, potentially reducing the need for node dissection. NAC offers an in vitro method for evaluating chemotherapy response, providing the opportunity to change or discontinue drugs. Finally, response rates offer prognostic information not otherwise obtainable.
An international collaboration identified risk factors for local/loco-regional recurrence after neoadjuvant chemotherapy and breast conserving therapy.
The authors found 3075 relevant publications. Sixteen met inclusion criteria and 9 research groups agreed to share individual patient data. There were 4125 patients eligible for study. All patients had neoadjuvant chemotherapy as well as breast conserving therapy and radiation. LR was defined as recurrence in the ipsilateral breast where LRR was defined as recurrence in the ipsilateral breast or regional nodes. Within 10 years of diagnosis, 6.5% developed LR whereas 10.3% developed LRR.
Four clinical risk factors were found to be associated with LR. Six factors were associated with LRR. Using a point system, each risk factor was assigned points based on their importance in recurrence. The risk factors and point allocation can be seen below.
Less than or equal to 1 is considered low risk and is associated with a 10-year LR rate of 4%. Intermediate risk is 2-4 points with a 10-year LR rate of 7.9%. Five points defines high risk and carries a 10-year LR of 20.4%.
Low risk is defined by 0-2 points and associated with a 3.2% LRR. Three to six points is intermediate risk and has a 10.1% recurrence rate. Finally, high risk is defined has 7-10 points and has a 24.1% LRR.
Like all scoring systems, this is a tool that can assist the breast surgeon in making decisions as to whether breast conserving therapy is appropriate. The authors have attempted to include all previously identified risk factors into a simple clinical score. All factors are readily available to the clinician before and after surgery.
Since all patients had radiation therapy it may similarly assist the radiation oncologist in determining whether a more comprehensive radiation field may be appropriate.
The strengths of this study are its large sample size allowing for multivariate analysis of available predictive factors. However, there are several weaknesses; the most important of which is lacking data on surgical margin status and Her2 status , as well as information on targeted therapy. Nonetheless, this study, with its large sample size does give the surgeon another option in evaluating whether breast conserving therapy is a viable option for patients undergoing NAC.