Prospectively performed modified D1 lymphadenectomy for clinically diagnosed mucosal, node negative gastric cancer:...

Based on retrospective analyses demonstrating the low probabilities of both lymph node metastasis and recurrence of curatively resected mucosal gastric cancer, we have established criteria for modified D1 lymphadenectomy (lymphadenectomy in the perigastric region as well as along the left gastric artery) and performed this in a prospective manner. In this study, we evaluate our treatment strategy by reviewing the patients prospectively undergoing modified D1 lymphadenectomy. The clinicopathological characteristics and survival data of 138 patients who underwent modified D1 lymphadenectomy between 1987--when we first introduced endoscopic ultrasonography--and 1996 were analyzed. The criteria for modified D1 lymphadenectomy were mucosal, node negative gastric cancer by pre-operative and intra-operative examinations. Depth of invasion was correctly diagnosed in 80% of the patients. Among the resultant submucosal gastric cancer patients, the incidence of slight submucosal invasion was increased in the second half-period (78%) as compared with that in the first half-period (44%). Nodal involvement was observed in 4 patients (2.9%); all of them exhibited the depressed type with ulceration and a histologically high grade of gastric cancer. Because their metastasized lymph nodes were all confined to the perigastric region, surgical treatment resulted in no residual cancer macroscopically. No patients succumbed to gastric cancer within the median and mean follow-up periods of over 6 years. These results suggest that our modified D1 lymphadenectomy is an effective option for the pre-operatively and intra-operatively diagnosed mucosal, node negative gastric cancer which meets our criteria.