Minimum resection length to ensure a pathologically negative distal margin and a larger remnant stomach for esophagogastric junction cancer.

Background: Ensuring a pathologically negative distal margin (DM) and preserving a larger remnant stomach is important for proximal gastrectomy (PG) in patients with esophagogastric junction (EGJ) cancer. However, the minimum DM length for ensuring negative margins has not been identified.

Methods: We enrolled patients undergoing PG or total gastrectomy for EGJ cancer. A parameter ΔDM, representing the pathological extension distally beyond the gross tumor boundary, was evaluated. The maximum ΔDM, which indicates the minimum length ensuring a pathologically negative DM, was determined in all patients. Subgroup analyses were performed according to factors associated with ΔDM > 10 mm. The possible incidences of pathologically positive DM based on gross DM length were also calculated.

Results: Among 253 eligible patients, the maximum ΔDM was 55 mm. Growth and pathological types were significantly associated with ΔDM > 10 mm. In subgroup analyses, the maximum ΔDM was 30/20/55 mm for the superficial/expansive/infiltrative growth types, and 55/40 mm for the differentiated/undifferentiated types. In the infiltrative growth type alone, the maximum ΔDM remained 55/40 mm for the differentiated/undifferentiated types. However, even if the gross DM length was reduced to 30 mm, the possible incidence of pathologically positive DM only increased to 2.6% in the infiltrative differentiated type.

Conclusion: We recommend a minimum DM length of 30/20/55 mm for the superficial/expansive/ infiltrative growth types. Specifically in the infiltrative growth type, we alternatively recommend 30/40 mm for the differentiated/undifferentiated types, with a mandatory intraoperative frozen section analysis. Mini-abstract This study proposes a distal margin length for safe resection of esophagogastric junction cancer, ensuring pathologically negative margins while preserving a larger remnant stomach, based on growth and pathological types.