Dr. Beltran on Use of ctDNA to Evaluate Treatment Resistance in Prostate Cancer

Himisha Beltran, MD, associate professor of medicine, Lank Center for Genitourinary Oncology, Division of Molecular and Cellular Oncology, Harvard Medical School, director of Translational Research, and physician, Dana-Farber Cancer Institute, discusses the potential use of circulating tumor DNA to detect castration-resistant neuroendocrine prostate cancer.

Patients with advanced prostate cancer can develop resistance through multiple mechanisms, including those that are independent of the androgen receptor, says Beltran. In some cases, these resistance mechanisms can lead to a histologic transformation from a prostate adenocarcinoma to a small cell neuroendocrine carcinoma. Typically, a tissue biopsy is performed to confirm diagnosis and to guide treatment decisions, says Beltran.

Historically, tissue biopsies have shown that neuroendocrine transformations retain prostate-specific alterations and acquire new alterations in DNA and DNA methylation which may have therapeutic implications. However, tissue biopsies are invasive. As such, investigators wanted to determine whether ctDNA could be useful in detecting molecular features of neuroendocrine tumors, concludes Beltran.