Past

For distal gastric cancer, surgical resection can be performed by either distal gastrectomy or total gastrectomy.1 The ability to preserve the proximal stomach is limited by the proximal tumor extent with international guidelines, such as the ESMO guidelines, which recommend a proximal margin distance (PMD) of 3 cm for intestinal-type and 8 cm for diffuse-type cancers, adding an additional safety distance.2 However, the integration of the PMD into guidelines is based on correlations with fewer R1 resections; but meanwhile, with reliable intraoperative frozen section, the PMD may be omitted when feasible.3

Present

In the present analysis, intraoperative frozen section was found to be reliable, with less than 1% of cases having a positive proximal margin regardless.4 While in patients with intestinal-type tumors, oncological outcomes were not impaired when the minimum PMD was not retained, an adequate PMD was associated with improved disease-specific and overall survival in patients with cancers with noncohesive growth patterns (diffuse and mixed type).4 The results were comparable to those of stage II and III gastric cancer in a study by Squires et al., who, however, found a benefit of a 3 cm PMD only in stage I tumors and adjusted for diffuse histology in their multivariable analysis, but did not perform a separate analysis in that subgroup.5

Future

These results may inform intraoperative decision-making in the event that the recommended PMD is not achieved. In patients with intestinal-type tumors, a completion gastrectomy may be omitted without compromising oncological outcomes. Conversely, in patients with diffuse-type cancers, associations of an inadequate PMD with worse oncological outcomes suggest the need for additional margin clearance up to a total gastrectomy. Future research should validate these findings with multi-institutional data from centers with different practices of margin handling.