ESMO Asia Virtual Congress 2020

Abstract 133P

Background

The aim of this study was to compare the treatment failure patterns after laparoscopic (LG) and open gastrectomy (OG) in locally advanced gastric cancer (LAGC).

Methods

A total of 1792 LAGC patients who underwent radical resection between January 2010 and December 2016 were divided into an LG group (n=1557) and OG group (n=235). Propensity score matching was performed to balance the two groups. Dynamic hazard rates of failure were calculated using the hazard function.

Results

A total of 1175 LAGC patients were included after matching (LG group, n=940; OG, n=235). The treatment failure rate of the whole group was 43.23% (508/1175), accounting for 41.38% (389/940) and 50.64% (119/235) in the LG and OG groups, respectively. The static treatment failure pattern showed that only distant recurrence rate of the LG group was significantly lower than that of the OG group (22.02% vs. 28.94%, P=0.025). Landmark analysis showed a lower early treatment failure rate of the LG group in stage Ib-IIIb subgroup (P=0.004). Furthermore, dynamic hazard curve peaked at 9.4 months (Peak rate=0.0186) and then gradually declined. For stage Ⅰb to Ⅲb patients, time of peak failure hazard was 5.2 months earlier in the OG group (OG versus LG: 11.0 versus 16.2 months). Finally, LG was an independent protective factor associated with early treatment failure in stage Ib-IIIb patients (hazard ratio, 0.63; 95% CI, 0.43-0.93; P=0.019).

Conclusions

Given the differences in treatment failure patterns between LG and OG, shorter-interval surveillance for the first 2 years should be considered for stage Ib-IIIb patients after OG.