Primary Tumour Genomics May Predict Recurrence Patterns After Gastric Cancer Surgery: JAMA Surgery | August 2026

Introduction:

Despite curative-intent resection, gastric cancer carries a substantial risk of recurrence, commonly through hematogenous, peritoneal, or lymphatic spread. Current postoperative surveillance is largely guided by clinicopathological factors. This study investigated whether genomic profiling of the primary gastric tumor could predict both recurrence risk and the subsequent pattern of metastatic spread.

Why was this study needed?

Gastric cancer recurrence remains common despite curative surgery.

Current clinical and pathological factors provide incomplete risk prediction.

Different metastatic patterns may reflect distinct underlying tumor biology.

Genomic profiling could enable more personalized postoperative surveillance and therapy.

Results:

Among 438 patients with resected gastric cancer, KRAS and PIK3CA alterations independently predicted worse disease-free survival.

Tumors that subsequently developed hematogenous metastases showed greater genomic instability, whole-genome duplication, and alterations in cell-cycle regulatory genes.

Interestingly, bone metastases represented a distinct phenotype, arising from more genomically stable tumors and showing an association with diffuse-type histology.

Primary tumor genomics therefore provided information not only about whether recurrence may occur, but potentially where it may occur.

Clinical Impact:

Genomic profiling of resected gastric cancer could move postoperative management beyond conventional stage-based risk assessment. Identifying molecular signatures associated with recurrence and specific metastatic patterns may eventually enable risk-adapted surveillance and more personalized perioperative treatment. Prospective validation is required before these genomic findings can guide routine follow-up.

Bottom Line:

Primary gastric tumor genomics may predict both recurrence risk and metastatic pattern after curative surgery. KRAS and PIK3CA alterations identify higher-risk disease, while distinct genomic profiles may help anticipate hematogenous and site-specific recurrence, opening the door to more personalized postoperative surveillance.