# The Concept of “Platinum Sensitivity” in Endometrial Cancer

## TL;DR

Platinum sensitivity, a concept from ovarian cancer, is relevant in endometrial cancer, with longer platinum-free intervals linked to better treatment outcomes.

## Contribution

The paper highlights key differences in platinum sensitivity between ovarian and endometrial cancers and its implications for treatment.

## Key findings

- In endometrial cancer, 30% of patients show sustained responses to platinum rechallenge beyond the platinum-free interval.
- Platinum-free interval is linearly correlated with response rates, progression-free survival, and overall survival in endometrial cancer.
- Unlike ovarian cancer, endometrial cancer patients often respond to platinum re-administration beyond the prior platinum-free interval.

## Abstract

The concept of “platinum sensitivity,” originally established in ovarian cancer, is increasingly recognized as relevant in recurrent endometrial cancer. In both malignancies, a longer platinum-free interval (PFI) is associated with improved efficacy of platinum rechallenge. However, notable differences exist; in ovarian cancer, durable responses extending beyond the PFI are rare (~3%), whereas in recurrent endometrial cancer, approximately 30% of patients exhibit sustained responses beyond this interval. With the recent incorporation of immune checkpoint inhibitors into the therapeutic landscape for endometrial cancer, the optimal integration of the platinum sensitivity concept into clinical decision-making—particularly regarding treatment sequencing and drug selection—remains an important and unresolved challenge. Further research is warranted to elucidate the mechanisms underlying platinum resistance and to inform the development of optimal therapeutic strategies.

The concept of “platinum sensitivity” has long guided prognostic assessment and treatment selection in recurrent ovarian cancer. However, the emergence of targeted agents, such as bevacizumab and poly (ADP-ribose) polymerase inhibitors, has complicated its clinical utility. In contrast, emerging evidence suggests that platinum sensitivity may also be applicable to recurrent endometrial cancer. As in ovarian cancer, a prolonged platinum-free interval (PFI) in recurrent endometrial cancer is associated with an improved efficacy of subsequent platinum-based chemotherapy. The PFI is linearly correlated with the response rate to platinum re-administration, progression-free survival, and overall survival. Patients are typically classified as having platinum-resistant or platinum-sensitive disease based on a PFI cutoff of 6 or 12 months. However, unlike in ovarian cancer—where the duration of response to second-line platinum-based chemotherapy rarely exceeds the prior PFI (~3%)—approximately 30% of patients with recurrent endometrial cancer exhibit a sustained response to platinum rechallenge that extends beyond their preceding PFI. Despite the incorporation of immune checkpoint inhibitors into the treatment landscape of endometrial cancer, the role of platinum sensitivity in clinical decision-making—particularly regarding treatment sequencing and drug selection—remains a critical and unresolved issue. Further research is warranted to elucidate the mechanisms underlying platinum resistance and to guide optimal therapeutic strategies.