The GOG-B21 trial found that while adding pembrolizumab to chemotherapy benefits the dMMR subgroup, it paradoxically leads to worse outcomes in the pMMR subgroup. This highlights the critical need for molecular testing to avoid potential harm.

Based on translational data from the RUBY trial, experts are most cautious about recommending frontline checkpoint inhibitors for patients in the "No Specific Molecular Profile" (NSMP) subgroup of pMMR endometrial cancer, suggesting this group may not benefit.

A study switching therapy based on ctDNA-detected ESR1 mutations revealed patients felt significantly better after the switch, even without visible tumor progression on scans. This counterintuitive finding suggests molecular progression has a subclinical impact on quality of life, supporting proactive, biomarker-driven treatment changes before patients clinically deteriorate.

The future of GYN oncology immunotherapy is diverging. For responsive cancers like endometrial, the focus is on refining biomarkers and overcoming resistance. For historically resistant cancers like ovarian, the strategy shifts to using combinatorial approaches (e.g., CAR-NKs, vaccines) to fundamentally alter the tumor microenvironment itself, making it more receptive to an immune response.

In a subset analysis of the high-risk MONARCH-E trial, an inferred Oncotype score did not identify which patients benefited from the CDK4/6 inhibitor abemaciclib. This indicates that while such scores assess prognostic risk and guide chemotherapy decisions, they are not predictive biomarkers for selecting patients for this targeted therapy.

The RAS/MAP kinase pathway is an "underrecognized" and "underutilized" therapeutic target in endometrial cancers. Despite up to a quarter of these cancers having mutations in pathway genes, clinical focus has often been elsewhere. This highlights a significant, overlooked opportunity for applying RAS-targeted therapies to a broader patient population.

Inconsistent methods for assessing biomarkers like PD-L1 (CPS vs. TAP scoring), p53 (IHC vs. sequencing), and HRR (different panels) across major clinical trials make it difficult to compare results and identify a reliable predictive marker for endometrial cancer.

The RSClin tool integrates a patient's Oncotype DX score with their unique clinical-pathologic features, such as tumor size and grade. This provides a more accurate and personalized risk assessment, as the same genomic score can represent significantly different prognoses for patients who have low versus high clinical risk factors.

Experts advise against using gene expression profiling to escalate care for CSCC (e.g., deciding to add systemic therapy). Its primary utility is in de-escalation: a low-risk profile can provide an additional data point to support a decision for observation in a borderline high-risk case, helping to avoid overtreatment.