The clinical utility of molecular residual disease testing in early-stage breast cancer

Breast cancer is the most commonly-diagnosed malignancy among women. Currently, radiologic imaging is indicated for defined surveillance periods and to assess or corroborate patient symptomatology. More recently, the advent of circulating tumor DNA (ctDNA) assays has conferred a potential enhancement in disease monitoring via the evaluation of molecular residual disease (MRD).

Studies have shown that MRD testing reportedly eventuates in a lead-time predictive benefit in diagnosing progressive disease compared to traditional assessment. In particular, the Signatera test has compelling advantages compared to many of the available MRD tests, especially given the reported clinical data with MRD testing in early-stage breast cancer. In the current review, we recount the results from several studies on the topic of MRD testing in the treatment and surveillance of breast cancer.

MRD testing in early-stage breast cancer theoretically confers a significant clinical benefit with adjuvant therapy and during patient surveillance. However, there are concerns with the potential for aggressive or prolonged treatment, not to mention the specific approach to managing patients who are ctDNA positive but remain asymptomatic.