Prognostic value of flow cytometry in surgically treated primary gastric lymphoma.

ABSTRACT

AIM: To investigate whether flow cytometry could help to define the optimal therapeutic strategy of primary gastric lymphomas. MATERIAL AND METHOD: Retrospective study of 46 patients having primary gastric lymphoma--according to Dawson criteria--in Ann Arbor stage IE and IIE, who were surgically treated. From selected paraffin-embedded tissue blocks of the tumor, DNA content was studied by flow cytometry (FC). Other pathological tumor features were analysed by hematoxiline-eosine and Giemsa stains as well as immunohistochemical study; any possible influence on postoperative survival was investigated through statistical analysis. RESULTS: The DNA ploidy pattern was diploid in 40 cases (87%) and aneuploid (hyperdiploid) in 6 (13%). Postoperative survival probability (PSP) was 62.7% at 5 years. Statistical analysis showed significant prognostic value for Ann Arbor classification--with higher PSP for stage IE (p = 0.009)--and FC parameters diploid tumors had higher PSP than aneuploid tumors. Also tumors having S-phase (p = 0.044) or G2-M phase values (p = 0.023) under the respective mean values had higher PSP. No influence on PSP was found for wall invasion, Helicobacter pylori infection, Isaacson's histologic type or resection margin involvement. No significant relationship was appreciated between Isaacson's histologic type and DNA ploidy patterns. CONCLUSION: FC could be useful in assessing gastric lymphoma prognosis.