Genomic Profiling of Small Intestine Cancers From a Real-World Data Set Identifies Subgroups With Actionable Alterations.

PURPOSE

Panel-based comprehensive genomic profiling (CGP) is used in clinical practice worldwide; however, large real-world data (RWD) of patients with advanced small intestine cancer have not been characterized. We investigated differences in the prevalence of clinically relevant alterations across molecularly defined or age-stratified subgroups.

PATIENTS AND METHODS

This was a collaborative biomarker study of RWD from CGP testing (Foundation Medicine, Inc). Hybrid capture was conducted on at least 324 cancer-related genes and select introns from up to 31 genes frequently rearranged in cancer. Overall, 1,364 patients with advanced small intestine cancer were available for analyses and were stratified by age (≥40 years/<40 years), microsatellite instability (MSI) status, tumor mutational burden (TMB) status (high ≥10/low <10 Muts/Mb), and select gene alterations. The frequency of alterations was analyzed using a chi-square test with Yate's correction.

RESULTS

Genes with frequent alterations included (59.8%), (54.8%), (27.7%), and (22.4%). Frequent genes with amplifications were (6.7%), (5.9%), (5.5%), and (3.4%). Patients younger than 40 years had significantly lower frequency of mutations than those 40 years and older (10.4% 28.7%; = .0008). Druggable genomic alterations were detected in 22.3% of patients: V600E (1.2%), (1.8%), (3.2%), amplification (3.2%), G12C (3.3%), fusion (0.07%), MSI-high (7.0%), and TMB-high (12.2%), with no significant differences in the frequency according to age (<40 years ≥40 years; 22.1% 22.3%). TMB of 10-20 Mut/Mb was observed in 4.8% of patients, and TMB ≥20 Mut/Mb was seen in 7.3% of the cohort.

CONCLUSION

RWD from clinical panel testing revealed the genomic landscape in small intestine cancer by subgroup. These findings provide insights for the future development of treatments in advanced small intestine cancer.