Engaging Pathologists in a Peer-to-Peer Learning Collaborative on HER2-Low Breast Cancer

Abstract

Abstract Introduction/Objective Recent advances in research have shown clinical effectiveness when targeting the lower range of HER2 expression (ie, HER2-low) in patients with metastatic breast cancer. American Society for Clinical Pathology worked in collaboration with Q Synthesis to develop a peer-to-peer learning collaborative to proactively prepare pathologists for HER2-low. This CME project was supported by an educational grant from AstraZeneca Pharmaceuticals LP and Daiichi Sankyo Inc. Methods/Case Report 38 pathologists participated in the ASCP HER2 Breast Trailblazers. For foundational knowledge, learners completed online modules covering scientific updates on HER2-low. Through small-group, case- based discussions, learners reviewed operational challenges and opportunities to prepare for HER2-low. They applied this knowledge to lead projects at their own institutions focusing on the anticipated changes around HER2-low. Results (if a Case Study enter NA) The learners identified the following challenges and opportunities: Defining HER2-low: Several learners had heard misconceptions around the definition of HER2-low. Recent studies have defined HER2-low as IHC 1+ or IHC 2+ with ISH-negative. Interobserver concordance with IHC 0 vs 1+: Several learners discussed the challenges around interpreting IHC 0 vs 1+. They felt that some pathologists may need guided feedback to improve their diagnostic skills. Use of IHC vs. ISH: Several learners only performed ISH for HER2 testing on all breast cancer samples. If HER2-low emerges as a third category, they would need to return to IHC. Implications for non-metastatic breast cancer: Recent HER2-low studies have focused on patients with metastatic breast cancer. If HER2-low emerges as a third category, it is unclear whether this designation will also be used in patients who have early-stage breast cancer. Leadership As pathologists prepare for HER2-low, they have opportunities to lead projects to assess and improve IHC interobserver concordance, coach others on IHC interpretation, increase operational efficiency, strength communication skills, and build up the team by proactively anticipating challenges around HER2-low. Conclusion HER2-low breast cancer may be emerging as a new category. Through a peer-to-peer learning collaborative, pathologists identified ways to proactively prepare and demonstrate leadership so that cancer centers and laboratories may be ready to embrace a new paradigm of HER2 classification in breast cancer.