Current Treatments and Biomarker Testing in Extrapulmonary Neuroendocrine Carcinoma: Strengths, Limitations, and Clinical Relevance

In this episode, ‘Current Treatments and Biomarker Testing in Extrapulmonary Neuroendocrine Carcinoma: Strengths, Limitations, and Clinical Relevance,’ the expert oncologists explored the following questions:

What are the current treatments that are being utilized for extrapulmonary neuroendocrine carcinomas and what are the strengths and limitations associated with these therapies?

How are you deciding on which biomarkers are ordered for each patient with a neuroendocrine tumor?

Which biomarkers are clinically relevant for patients with extrapulmonary neuroendocrine tumors?

The panelists examined the current treatment landscape for extrapulmonary neuroendocrine carcinoma (epNEC), noting that platinum-based chemotherapy regimens such as carboplatin or cisplatin plus etoposide have remained the mainstay of treatment since the 1980s, with responses often seen but limited in durability as resistance develops early. Aman Chauhan, Namrata Vijayvergia, William Oh, and Sandy Kotiah discussed additional chemotherapy options including fluorouracil-based regimens and the role of immune checkpoint inhibitors such as nivolumab, while acknowledging that real-world response rates remain low and that no high-quality prospective randomized data exist to guide subsequent lines of therapy. The panelists then turned to biomarker testing, highlighting the diagnostic utility of markers such as chromogranin A, synaptophysin, and Ki-67, as well as the growing importance of next-generation sequencing (NGS) to identify novel targets including delta-like ligand 3 (DLL3), microsatellite instability-high (MSI-H), and tumor mutational burden (TMB). They also noted the prognostic significance of tumor suppressor loss — including RB, p53, and PTEN — and emphasized that identifying actionable biomarkers will be critical to moving beyond chemotherapy toward more targeted therapeutic approaches.

Throughout the conversation, the experts provided a comprehensive reflection on the field and the factors that may shape how clinicians approach care moving forward.

The next episode in this series, ‘Guidelines, Infrastructure, and Stakeholder Roles in Biomarker Testing for Extrapulmonary Neuroendocrine Carcinoma,’ features the panelists advancing their conversation on extrapulmonary neuroendocrine carcinoma and focusing on what current National Comprehensive Cancer Network (NCCN) guidelines recommend for biomarker testing, anticipated future guideline updates, and the key stakeholders involved in building an effective biomarker testing infrastructure.