Objective: Gastric cancer confined to the muscularis propria (mp) has a favorable prognosis, but still belongs to the advanced category. Many oncologists have difficulties in selecting treatment modalities owing to the confused situation of mp cancer. To clarify the therapeutic strategy, the clinicopathological characteristics were investigated, and the risk factors, of this intermediate-stage gastric cancer, evaluated.
Material and methods: A total of 155 patients who underwent curative resection for primary gastric cancer between 1993 and 2001 were diagnosed with mp cancer. The patients were divided into recurrent and non-recurrent groups and analyzed clinicopathologically.
Results: The rate of recurrence was 20%. A multivariate analysis disclosed only lymphatic metastasis as an independent risk factor for recurrence of mp cancer. Hematogenous metastasis accounted for 37% of the recurrent patterns, and the liver (83.3%) was the most common organ. The 5-year survival rate of all mp cancer patients was 80.9%, but that of patients with recurrent disease was 19.2%. The median survival time of the recurred patients was 24 months, and 74% of those patients died within 3 years.
Conclusions: Lymph node metastasis is the only significant risk factor of mp cancer. Patients with lymphatic metastasis should undergo postoperative adjuvant therapy. On the other hand, patients with mp cancer without lymph node involvement have an excellent prognosis and could be candidates for laparoscopic gastric surgery.