Analysis of prognostic factors in localized gastric lymphoma: the importance of bulk of disease

PURPOSE: To identify prognostic factors in localized gastric lymphoma patients for optimal therapy selection. METHODS AND MATERIALS: From 1974 to 1990, 77 patients with localized gastric lymphoma (38 Stage IE and 39 Stage IIE) were treated with radiation therapy, chemotherapy, surgery, or a combination. Univariate and multivariate local control and survival analyses were performed on possible prognostic factors, such as patient age, gender, histologic subtype, stage, tumor size, depth of penetration, multicentricity, and treatment modality. RESULTS: At 5 years, the relapse-free survival was 52%; 74% of the relapses occurred at local sites. Smaller tumor size was most strongly associated with local control (p = .001) and relapse-free survival (p < .001). Patients with tumor sizes < or = 5 cm had relapse-free survival of 87%, compared with 41% and 15% for those with tumor sizes of 5.1 cm to 10 cm and > 10 cm, respectively. The 47 patients who received combined-modality therapy had a relapse-free survival of 65%, compared with 24% for the 30 who received single-modality therapy (p < .01). Although patient age, stage, depth of penetration, and resective surgery affected the above endpoints, these factors were not independent predictors of outcome. Analysis of treatment subgroups showed that surgical resection combined with postoperative irradiation was associated with highest local control (p = .002) and the best relapse-free survival (p = .004), when compared with other treatment modalities. In 27 patients with tumor sizes < or = 5 cm, comparison of the 15 patients who had surgery with the 12 who did not failed to reveal a local control benefit from the addition of surgery. CONCLUSION: These data demonstrate that tumor bulk is an important prognostic determinant of local control and relapse-free survival in localized gastric lymphoma patients. Stage IE and IIE lymphoma of the stomach can be selectively treated with primary radiation, but surgical resection may be necessary for large tumors (> 5 cm), followed by adjuvant radiation.