Clear cell ovarian cancers with microsatellite instability: A unique subset of ovarian cancers with increased tumor-infiltrating lymphocytes and PD-1/PD-L1 expression.

Journal Article (Journal Article)

Clear cell ovarian carcinoma (CCOC) represents a distinct histologic subtype of ovarian cancer associated with significantly worse prognosis across all stages and no effective therapeutic options. Here, we report a rare but clinically important cohort of CCOCs with microsatellite instability (MSI) (MSI-CCOCs), which are highly immunogenic and may thus be very responsive to immune checkpoint blockade. CCOCs with MSI exhibit a significantly higher number of CD8+ TILs, higher CD8+/CD4+ ratio, and higher PD-1+ TILs compared with microsatellite stable (MSS) CCOCs and compared with high grade serous ovarian cancers, which are the most common histologic subtype of ovarian cancer. Of note, PD-L1 expression in tumor cells or immune cells was noted in all cases of CCOCs with MSI. These observations open an alternative therapeutic avenue for a fraction of patients with CCOC and argue for the routine testing of CCOCs for MSI, a test that is not currently routinely performed.

Full Text

Duke Authors

Cited Authors

  • Howitt, BE; Strickland, KC; Sholl, LM; Rodig, S; Ritterhouse, LL; Chowdhury, D; D'Andrea, AD; Matulonis, UA; Konstantinopoulos, PA

Published Date

  • 2017

Published In

Volume / Issue

  • 6 / 2

Start / End Page

  • e1277308 -

PubMed ID

  • 28344892

Pubmed Central ID

  • PMC5353914

International Standard Serial Number (ISSN)

  • 2162-4011

Digital Object Identifier (DOI)

  • 10.1080/2162402X.2016.1277308


  • eng

Conference Location

  • United States