Lymphatic involvement in early gastric cancer: prevalence and prognosis in France.

BACKGROUND

The prognosis of early gastric cancer (EGC) is considered better than that of invasive gastric carcinoma, with a 5-year survival rate of more than 90% after surgery. The prevalence of lymph node metastasis in EGC ranges from 8% to 20% and is associated with a poor prognosis.

HYPOTHESIS

The main prognostic factor of EGC in patients in France is lymphatic involvement.

DESIGN, SETTING, AND PATIENTS: From January 1979 to December 1988, 332 patients with EGC were operated on in 23 centers of 2 of the French Associations for Surgical Research. Clinical, pathological, and therapeutic data were reviewed, and the reckoning point was in June 1996.

MAIN OUTCOME MEASURES

The cumulative 5- and 7-year specific survival rates of EGC with or without lymphatic involvement.

RESULTS

The cumulative 5- and 7-year specific survival rates of 332 patients with EGC (mean follow-up time, 80 months), excluding both operative and unrelated mortality, were 92% and 87.5%, respectively. Thirty-four patients (10.2%) had metastatic lymphatic spread: 13 exclusively in the lymphatic vessels close to the tumor, 17 in at least 1 lymph node, and 4 in both the lymphatic vessels and nodes. The rate of lymph node involvement (regardless of lymphatic vessel involvement) correlated significantly with submucosal invasion (P =. 05) and histologic undifferentiation (P =.03). Lymphatic vessel involvement correlated positively with lymph node involvement (P =. 003). Since 5- and 7-year survival rates of the 13 patients with EGC who had lymphatic vessel involvement without lymph node involvement did not differ significantly from those of patients who had EGC with lymph node involvement (85% and 84% vs 72% and 63%, respectively [P =.42]), all patients with lymph node and/or lymphatic vessel involvement were considered unique. Prognosis was poorest in these patients according to both univariate analysis (94% for 298 without node or vessel involvement vs 78% for 34 with node and/or vessel involvement; P =.006) and multivariate analysis (P =.01). Submucosal invasion was a prognostic factor independent of lymphatic involvement (P =.05). Five- and 7-year survival rates did not differ when the group of 211 patients for whom less than 15 lymph nodes were retrieved were compared with those (n = 51) for whom 15 or more lymph nodes were retrieved (95.5% vs 92% and 95.5% vs 88%, respectively), whether according to univariate (P =.21) or multivariate (P =.31) analysis.

CONCLUSIONS

Our results suggest that both lymph node and lymphatic vessel involvement are important prognostic factors in patients with EGC. Lymphadenectomy in EGC is important to identify the high-risk population for whom prognosis is worse. The extent of lymphadenectomy (at least 15 nodes) in these patients, however, does not alter prognosis.