Is there any role for super-extended limphadenectomy in advanced gastric cancer? results of an observational study from a western high volume center

Background: Although the Japan Clinical Oncology Group (JCOG) 9501 trial did not find that prophylactic D3 lymphadenectomy led to any survival advantage over D2 lymphadenectomy, it did find that the prognosis of subserosal and N0 gastric cancer patients improved. The aim of this retrospective observational study was to compare survival after D2 or D3 lymphadenectomy in different patient subgroups. Methods: The study considered all of the patients who underwent D2 or D3 lymphadenectomy at a high-volume center in Verona (Italy) between 1992 and 2011. After excluding patients with Bormann IV or neuroendocrine tumors, early gastric cancers, or non-curative resections, the analysis involved 301 R0 patients: 100 who underwent D2, and 201 who underwent D3 lymphadenectomy. Post-operative deaths and deaths due to recurrences were considered as terminal events in the survival analysis. Results: The D2 patients were significantly older than the D3 patients at baseline (69.8 +/- 2.3 vs. 62.2 +/- 10.7 years). The median number of retrieved nodes was 29 (interquartile range: 24.5-39) after D2, and 43 (34-52) after D3. The five-year disease-related survival rate was similar after D2 (44%, 95% confidence interval (CI) 34-54%) and D3 (41%, 34-48%) (p = 0.766). A Cox model controlling for sex, age, tumor site, Lauren histology, and T and N stages showed that the risk of cancer-related death after D3 was similar to that recorded after D2 (hazard ratio 0.97, 95% CI 0.67-1.42). There was a significant interaction between the T status and the extension of the lymphadenectomy (p = 0.012), with the prognosis being better after D2 in T2 and T4b patients, and after D3 in T3 patients. Conclusions: The findings of this study suggest that D3 lymphadenectomy is not routinely indicated for patients with advanced gastric cancer, although differences in survival after D3 across T tiers deserve further consideration