A study, published in JAMA Oncology, examined the genomic profile of small-bowel adenocarcinoma when compared to colorectal cancer and gastric carcinoma.
Alexa Schrock, PhD, of Foundation Medicine, and colleagues analyzed 7,559 patients. Of these patients, 317 had SBA, 6,353 had colorectal cancer and 889 had gastric carcinoma through hybrid-capture-based genomic profiling.
Of the patients, 4,138 were male and the median age was 56 years, with a range between 12 years and 101 years old.
Here's what they found:
1. Researchers found frequent genomic alterations in SBA patients when compared to colorectal cancer or gastric carcinoma.
The BRAF gene was mutated in 7.5 percent of cancer patients and in 9.1 percent of SBA samples. However V600E mutations were less common in SBA. They were present in three of 29 BRAF-mutated cases.
2. SBA patients all had "enriched" ERBB2/HER2 gene point mutations, microsatellite instability and higher tumor mutational burdens.
3. Researchers noted significant differences between unspecified SBA and duodenal adenocarcinoma, as well as inflammatory bowel disease-associated SBAs.
Researchers concluded, "This study presents to our knowledge the first large-scale genomic comparison of SBA with colorectal cancer and gastric carcinoma. The distinct genomic differences establish SBA as a molecularly unique intestinal cancer."
They added that genomic profiling could be used to identify identify targetable genomic in most SBA cases. They believe immunotherapy could impact SBA.