Study Reveals Hidden Cancer Cells After Ovarian Treatment

A multi-institutional research effort led by Break Through Cancer has found that nearly half of ovarian cancer patients who show no visible signs of disease on scans after treatment may still harbor residual cancer cells. The findings, published in Clinical Cancer Research, offer new insight into why recurrence remains high and how it may be addressed more effectively.

The study was conducted by the Targeting Minimal Residual Disease (MRD) in Ovarian Cancer TeamLab, which includes researchers from The University of Texas MD Anderson Cancer Center, Dana-Farber Cancer Institute, Memorial Sloan Kettering Cancer Center, the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, and MIT’s Koch Institute for Integrative Cancer Research.

While advanced ovarian cancer patients often respond well to initial surgery and chemotherapy, recurrence occurs in about 80% of cases. Using a minimally invasive procedure known as second-look laparoscopy (SLL), researchers found that 42% of patients deemed cancer-free by imaging still had MRD, microscopic cancer cells undetectable by traditional methods.

“SLL allows us to identify diseases that would otherwise be missed,” says Amir Jazaeri, co-senior author of the study. “More importantly, it gives us the opportunity to analyze and target that disease.”

Using spatial transcriptomic and proteomic profiling, the team identified potential druggable targets and observed biological mechanisms such as hypoxia signaling, immune evasion, and epithelial-mesenchymal transition. These insights help explain how cancer cells survive treatment and inform future therapeutic strategies.

The study also evaluated the use of circulating tumor DNA (ctDNA), fragments of cancer DNA found in the bloodstream, as a non-invasive method to detect MRD. Initial results suggest ctDNA could help identify patients at higher risk of recurrence and track disease progression over time, potentially reducing the need for surgical procedures.

The findings are part of Break Through Cancer’s larger effort to understand MRD across several hard-to-treat cancers, including acute myeloid leukemia and ALK-positive lung cancer. Ongoing trials are using MRD status to test new therapies, including immunotherapy, with the aim of enabling earlier evaluation of treatment efficacy and more efficient clinical trials.