Highlights in Breast Cancer from ASCO 2021: An Interview with Virginia Kaklamani, MD

Screening for mutations was recommended for all patients with breast cancer by the American Society of Breast Surgeons in 2019. Although most physicians do not screen all patients with breast cancer, it has been recommended that all HER-negative germline BRCA1/2 mutations be screened as well as patients in the adjuvant setting. Virginia Kaklamani, MD, DSc, Professor, Medicine, Division of Hematology/Oncology, and Leader, Breast Cancer Program, The University of Texas Health San Antonio MD Anderson Cancer Center, discussed breast cancer research insights at the 2021 American Society of Clinical Oncology Annual Meeting.¹

Three cyclin-dependent kinase (CDK)4/6 inhibitor trials (PALOMA-3, MONALEESA-3, DAWN-1) have shown expected results. Palbociclib and ribociclib showed improved overall survival. Dalpiciclib (SHR6390) showed progression-free survival with CDK4/6 inhibitors in metastatic disease. Some physicians are using CDK4/6 inhibitors as first-line treatment in patients with metastatic disease. The MONALEESA-3 trial results have also shown that once CDK4/6 inhibitors are stopped, there is no rebound effect and the CDK4/6 inhibitors have a prolonged benefit even once stopped. In the SOLAR-1 trial, more than 70% of patients showed long-term disease control, which is impressive.¹

Most trials are drug A versus drug B. There is no such thing as drug A followed by drug B versus drug B followed by drug A. There would be a lot of variables in those trials: the dropout rate would be high, and the studies would take longer to finish. As a result, in the past, head-to-head competitions were usually outlawed.¹ In the absence of head-to-head statistics, we normally use our most effective drug first, followed by our second- and third-line drugs, and so on, explained Dr Kaklamani. We do the same thing in the metastatic HER-positive scenario. In most situations, we start with a CDK4/6 inhibitor as a first-line treatment.¹

Last year, during COVID-19, women were afraid to have mammograms or mammography centers were closed for a few months. Even after the centers reopened, some patients were still hesitant to come in for a mammogram. This resulted in a delay in the diagnosis. We do not know how clinically significant this is and we will have to wait a long time to find out. Delays in diagnosis were seen. Fortunately, there were no negative effects in patients taking treatment for breast cancer in terms of the risk of COVID-19 infection. We did not have many of those patients, but we did not notice any negative consequences, said Dr Kaklamani.¹

Reference

1. The Oncologist. ASCO 2021 insights on breast cancer research: an interview with Dr. Virginia Kaklamani. Oncologist. 2021;26(suppl3):S1-S2.