High TIL Levels Predict Positive Outcomes in HER-2–Positive Breast Cancer

“High levels of tumor-infiltrating lymphocytes served as an independent positive predictive marker for EFS and pathological complete response in HER-2–positive early breast cancer treated with chemotherapy and anti-HER–2 agents, according a secondary analysis of the NeoALTTO trial.

“ ‘Increasingly, oncogenic addiction, in which tumors become dependent on a sole oncogenic pathway for growth, is thought to promote a tumor microenvironment conducive to immune escape,’ Sherene Loi, MD, PhD, of the Peter MacCallum Cancer Centre at the University of Melbourne, and colleagues wrote. ‘Although this had not been shown yet for HER-2 oncogenic signaling, one could speculate that anti-HER–2 therapy may not only work in a cell-intrinsic manner but may also reserve HER-2–induced immunosuppression as a mechanism for action.’

“The NeoALTTO trial included 455 women with HER-2–positive early-stage breast cancer between 2008 and 2010. The researchers randomly assigned patients to neoadjuvant treatment with trastuzumab (Herceptin, Genentech), lapatinib (Tykerb, GlaxoSmithKline) or both.

“Patients received the initial treatment for 6 weeks, followed by weekly paclitaxel for 12 weeks and three treatment cycles of fluorouracil, epirubicin and cyclophosphamide after surgery.”