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Cancer research

Gastric Cancer Research Reveals Insights into PD-L1 Expression and Treatment

Strategic Insights

— 1 min read

Researchers at the University of Genoa in Italy have made significant contributions to the understanding of PD-L1 expression in gastric cancer. A new report presents findings from a multicentric, real-world retrospective study that analyzed data from 28 Italian pathology centers, covering 1936 cases of esophageal, esophagogastric junction, and gastric carcinoma diagnosed between October 2023 and September 2024. The study aimed to evaluate the real-world assessment of PD-L1 immunohistochemistry (IHC) results compared with clinical trial data.

Key Takeaways:

  • The study confirmed that PD-L1 expression in gastric cancer in Italian real-world practice aligns with clinical trials, but inter-institutional variability and preanalytical factors, such as tissue aging and PD-L1 clone, significantly influence PD-L1 scores.
  • The study documented PD-L1 expression distribution via combined positive (CPS), tumor proportion (TPS), and tumor area positivity (TAP) scores, and investigated the impact of several factors on IHC results.
  • A total of 1936 cases were collected, consisting of 1802 adenocarcinomas (ADCA), 131 squamous carcinomas (SCC), and 3 carcinomas of non-specific histotype.
  • Inter-institutional heterogeneity was observed, with CPS, TPS, and TAP scores in line with literature and clinical trials for both ADCA and SCC.
  • Preanalytical factors, such as tissue block aging, were significantly associated with a lower PD-L1 score, with a critical time window at 24-60 months.
  • The study highlights the importance of addressing issues related to inter-institutional variability and preanalytical factors to enhance the reliability of PD-L1 IHC assessment and ensure optimal patient selection for immune checkpoint inhibitors in gastric cancer.

Statistical Analysis:

  • 1936 cases were analyzed in the multicentric, real-world retrospective study.
  • 1802 adenocarcinomas (ADCA) and 131 squamous carcinomas (SCC) were included in the study.
  • CPS, TPS, and TAP scores were in line with literature and clinical trials for both ADCA and SCC.
  • Inter-institutional variability was observed, with a range of CPS scores among institutions: 43.6%-100%.
  • A critical time window of 24-60 months was identified for tissue block aging to minimize PD-L1 score influence.

Sources:

  • ESMO Open: Critical insights on real-life PD-L1 histopathological workflow and assessment in esophageal, esophagogastric junction, and gastric carcinoma in Italy. (2025;10(10):105846)
  • University of Genoa: Pathology Unit, Dept. of Surgical Sciences and Integrated Diagnostics (DISC), Genoa, Italy.

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