Herceptin (trastuzumab) and similar drugs have greatly improved the outcomes of women with HER2/neu overexpressing (HER2+) breast cancer. However, swift and appropriate treatment is important once breast cancer, especially aggressive forms such as HER2+ disease, is diagnosed. While it might take years for some breast tumors to develop, once surgery occurs, it appears to be followed by accelerated growth of both local tumors and distant micrometastases. In other words, the process of tumor removal appears to potentiate the resurgent growth of residual cancer tissue. This suggests that surgery should be followed quickly by systemic treatment, if possible, to extinguish any new or residual tumors or micrometastases. Now a new study has reported that a delay of six months or longer in starting Herceptin after surgery could significantly reduce survival in women with HER2+ breast cancer.

Latest research finds six-month delay in starting Herceptin could reduce survival

The study referenced at the beginning of this news article was designed to investigate the impact of delaying the start of Herceptin treatment for more than six months after breast cancer diagnosis on (1) time to relapse; (2) overall survival; and (3) relapse-free survival among women with non-metastatic HER2+ breast cancer. To conduct the study, the authors identified women in the U.S. Department of Defense health claims database who were treated between 2003 and 2012 with Herceptin after breast cancer surgery without having received any systemic therapy before surgery. The 2,749 women were divided into two groups based on time from breast cancer diagnosis to beginning of Herceptin treatment: up to six months (79.9% of the women) and greater than six months (20.1%).

Women who began taking Herceptin at least six months after diagnosis were found to have approximately 50% higher risk of relapse and 43% higher risk of death compared to those who started Herceptin within six months of diagnosis. The authors conclude that delays of over six months in the initiation of Herceptin among HER2+ Stage 1-III breast cancer patients are associated with a higher risk of relapse and shorter overall and relapse-free survival.

Please click on the tag treatmentDelays for more information on the impact of treatment delays on prognosis.