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 19 74 to 1990, 77 patients with localized gastric lymphoma (38 Stage IE a nd 39 Stage IIE) were treated with radiation therapy, chemotherapy, su rgery, 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 occurre d at local sites. Smaller tumor size was most strongly associated with local control (p = .001) and relapse-free survival (p < .001). Patien ts with tumor sizes less-than-or-equal-to 5 cm had relapse-free surviv al 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 c ombined-modality therapy had a relapse-free survival of 65%, compared with 24% for the 30 who received single-modality therapy (p < .01). Al though patient age, stage, depth of penetration, and resective surgery affected the above endpoints, these factors were not independent pred ictors of outcome. Analysis of treatment subgroups showed that surgica l resection combined with postoperative irradiation was associated wit h highest local control (p = .002) and the best relapse-free survival (p = .004), when compared with other treatment modalities. In 27 patie nts with tumor sizes less-than-or-equal-to 5 cm, comparison of the 15 patients who had surgery with the 12 who did not failed to reveal a lo cal control benefit from the addition of surgery. Conclusion: These da ta demonstrate that tumor bulk is an important prognostic determinant of local control and relapse-free survival in localized gastric lympho ma patients. Stage IE and IIE lymphoma of the stomach can be selective ly treated with primary radiation, but surgical resection may be neces sary for large tumors (> 5 cm), followed by adjuvant radiation.