Impact of next-generation sequencing in advanced gastrointestinal cancer.

Abstract

814 Background: Next-generation sequencing (NGS) is a cutting-edge technology that allows for rapid DNA and RNA sequencing, identifying key mutations in cancer patients. It provides both diagnostic and predictive data for treatment decisions. Approximately 75.6% of US oncologists use NGS testing for patients with advanced solid tumors.This study retrospectively evaluates the impact of NGS testing on treatment outcomes for advanced GI cancer patients at a community-based cancer center in Florida. Methods: Between March 2019 and September 2023, 267 patients with stage 3 or 4 solid malignancies underwent NGS testing. Of these, 77 patients with advanced GI cancer were included in the study. Nearly half (48%) of the patients were diagnosed with advanced-stage colon cancer.NGS testing was performed using tissue samples (79.22%), blood samples (16.88%), or both (3.90%). Demographic and clinical outcomes, including time to diagnosis, treatment initiation, and survival, were collected and analyzed. Results: The median age of the study population was 70, with 88.31% of patients insured through Medicare. The cohort was composed of 61.04% males. Targetable mutations were identified in 59.74% of patients, leading to FDA-approved targeted therapies for 44.16%, and clinical trial eligibility for 79.22%. 52 patients were alive at the time of this analysis; those with biomarkers identified through NGS testing had a median treatment duration of 11 months regardless of whether testing impacted choice of therapy; whereas, patients without identified biomarkers had a median duration of 7.5 months. NGS testing impacted first-line therapy in only 6.49% of all patients; however, 80% of those patients were alive at the time of this analysis with a median duration of response of 5 months. Conclusions: NGS testing has become a cornerstone of oncologic care for advanced solid tumors; however, in this cohort of advanced GI malignancies, NGS results influenced first-line treatment decisions in only 6.49% of cases. Although the study included a small sample size, it reflects a real-world community setting where access to therapies and insurance coverage varies. For example, though patients may have targetable novel therapies available for their disease, the indications for such therapies may not be in the first line setting or covered by insurance. Advancements in NGS targeted therapies has greatly impacted the care of other solid malignancies such as non-small cell lung cancer; however, this study highlights that in the field of GI oncology, there is a large clinically unmet need of identifying newer biomarkers that are clinically relevant and impactful in earlier lines of oncologic care.