The jury is still out on peri-operative vs. adjuvant chemotherapy for distal gastric cancer

Staging accuracy in patients with clinical T2N0 gastric cancer: Implications for treatment sequencing

BACKGROUND

Patients with clinical T2N0 (cT2N0) gastric adenocarcinoma are recommended to undergo either perioperative chemotherapy or upfront resection. If T2N0 disease is pathologically confirmed, patients may be observed without chemotherapy. These guidelines create the possibility of both systemic therapy overuse and underuse depending on clinical staging accuracy. Our objectives were to define factors associated with upstaging after upfront resection and describe the association between postoperative chemotherapy and survival.

METHODS

Patients with cT2N0 gastric adenocarcinoma were identified using the National Cancer Database. Factors associated with upstaging were assessed by logistic regression. Survival was assessed using Kaplan-Meier and Cox proportional hazard analyses.

RESULTS

Of 4,076 patients undergoing upfront resection for cT2N0 gastric cancer, 1,933 (47.4%) were pathologically upstaged. Patients were more likely to be upstaged if they had >3.0-cm (adjusted odds ratio [aOR] 2.31, 95% confidence interval [CI] 1.97-2.70; P < .001) or poorly differentiated tumors (aOR 2.22, 95% CI 1.89-2.60; P < .001). Patients were less likely to be upstaged if they had distal tumors (aOR 0.77, 95% CI 0.64-0.93; P = .006). Of those pathologically upstaged (n = 1,933), 1,111 (57.4%) received adjuvant chemotherapy that was associated with improved survival (HR 0.55, 95% CI 0.47-0.63; P < .001). Among those not upstaged (n = 2,143), 247 (11.5%) received adjuvant chemotherapy that was not associated with improved survival (HR 0.92, 95% CI 0.70-1.21; P = .54).

CONCLUSIONS

Pathologic upstaging after upfront resection in patients with cT2N0 gastric cancer is associated with patient and tumor characteristics. Adjuvant chemotherapy is associated with improved survival only in the patients upstaged at surgery. An upfront surgical approach may be preferred in select patients, especially if avoiding chemotherapy is desired.