(060) Genomic profiling and the need for immunotherapy in gastric cancer

Background: The use of monotherapy (aPD-L1 monoclonal antibody) is considered the standard treatment for advanced gastric cancer (AGC). However, immunotherapy drugs are not currently available for the Peruvian health system.

Objectives: Thus, this study aimed to describe the potential benefit of immunotherapy for patients with advanced gastric cancer based on real-world data.

Methods: We conducted a cross-sectional analysis of 30 patients with gastric adenocarcinoma treated at two public hospitals (Hospital Nacional Dos de Mayo in Lima and Hospital Regional de Ica in Ica) and one private clinic (Oncosalud – AUNA) during the period 2020-2022. Clinical records from each patient were reviewed to collect clinicopathological and genomic information.

Results: In our study, the median age was 62.5 years (42 to 89 years); 56.7% of the patients were male. Regarding clinicopathological features, 87% of patients had a III/IV clinical stage. Histologically, most of the patients presented the intestinal subtype (57%). Likewise, 80% of the tumors were located either on the antrum or the body of the stomach. Based on patient genomic profiling, 12% of the patients had a high microsatellite status, and 23% had a high TMB (≥10 Muts/Mb). Thirty percent of patients could benefit from therapies relevant to AGC in the literature, such as nivolumab, Dostarlimab, or Pembrolizumab. Similarly, 43% of patients would be good candidates for drugs with clinical relevance for other tumor types, and 70% of patients could potentially benefit from drugs tested in clinical trials.

Conclusions: In Peru, approximately 40% of patients with gastric tumors could benefit from potential immunotherapies with clinical relevance in AGC as well as other tumor types. Although immunotherapy is not covered by public or private insurance in Peru, it is important to know the extent of the potential demand in our country.