OncoImmunology (Jan 2021)

Association of PIK3CA mutation and PTEN loss with expression of CD274 (PD-L1) in colorectal carcinoma

  • Tomotaka Ugai,
  • Melissa Zhao,
  • Takashi Shimizu,
  • Naohiko Akimoto,
  • Shanshan Shi,
  • Yasutoshi Takashima,
  • Rong Zhong,
  • Mai Chan Lau,
  • Koichiro Haruki,
  • Kota Arima,
  • Kenji Fujiyoshi,
  • Benjamin Langworthy,
  • Yohei Masugi,
  • Annacarolina da Silva,
  • Katsuhiko Nosho,
  • Yoshifumi Baba,
  • Mingyang Song,
  • Andrew T. Chan,
  • Molin Wang,
  • Jeffrey A. Meyerhardt,
  • Marios Giannakis,
  • Juha P. Väyrynen,
  • Jonathan A. Nowak,
  • Shuji Ogino

DOI
https://doi.org/10.1080/2162402X.2021.1956173
Journal volume & issue
Vol. 10, no. 1

Abstract

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Immunotherapy targeting the CD274 (PD-L1)/PDCD1 (PD-1) immune checkpoint axis has emerged as a promising treatment strategy for various cancers. Experimental evidence suggests that phosphatidylinositol-4,5-bisphosphonate 3-kinase (PI3K) signaling may upregulate CD274 expression. Thus, we hypothesized that PIK3CA mutation, PTEN loss, or their combined status might be associated with CD274 overexpression in colorectal carcinoma. We assessed tumor CD274 and PTEN expression by immunohistochemistry and assessed PIK3CA mutation by pyrosequencing in 753 patients among 4,465 incident rectal and colon cancer cases that had occurred in two U.S.-wide prospective cohort studies. To adjust for potential confounders and selection bias due to tissue availability, inverse probability weighted multivariable ordinal logistic regression analyses used the 4,465 cases and tumoral data including microsatellite instability, CpG island methylator phenotype, KRAS and BRAF mutations. PIK3CA mutation and loss of PTEN expression were detected in 111 of 753 cases (15%) and 342 of 585 cases (58%), respectively. Tumor CD274 expression was negative in 306 (41%), low in 195 (26%), and high in 252 (33%) of 753 cases. PTEN loss was associated with CD274 overexpression [multivariable odds ratio (OR) 1.83; 95% confidence interval (CI), 1.22–2.75; P = .004]. PIK3CA mutation was statistically-insignificantly (P = .036 with the stringent alpha level of 0.005) associated with CD274 overexpression (multivariable OR, 1.54; 95% CI, 1.03–2.31). PIK3CA-mutated PTEN-lost tumors (n = 33) showed higher prevalence of CD274-positivity (82%) than PIK3CA-wild-type PTEN-lost tumors (n = 204; 70% CD274-positivity) and PTEN-expressed tumors (n = 147; 50% CD274-positivity) (P = .003). Our findings support the role of PI3K signaling in the CD274/PDCD1 pathway.

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