Higher incidence of Simian virus 40 in primary gastric diffuse large B cell lymphoma (DLBCL) than primary nodal disease in Chinese patients, but of no prognostic implication

Abstract

6671 Background: Studies have reported the detection of simian polyomavirus SV40 DNA sequence in 10–40% of non-Hodgkin's lymphoma patients and there is compelling evidence that SV40 may contribute to the oncogenesis in human. However, its incidence in Chinese patients, prognostic implication and site predilection are largely unknown. Methods: We analysed the diagnostic histological specimens from 49 Chinese patients with diffuse large B cell lymphoma diagnosed from 1989 to 1996. PCR followed by Southern blot hybridization were performed and SV 40 specific DNA was confirmed by DNA sequencing. Results: Among the 49 patients (M:F=28:21; mean age=58 years, range 22–83), there were 7 cases (14%) positive for SV 40 by PCR and 6 of them were confirmed to be SV 40 specific DNA, giving an incidence of 12%. Primary sites were peripheral lymph node (n=30, 61%), gastric (n=18, 37%) and sternal soft tissue (n=1, 2%). Primary gastric lymphoma had a significantly higher SV40 positivity rate than the nodal disease (5/18, 28% versus 1/30, 3.3%; p=0.02) There was no difference between the SV40 positive and SV 40 negative patients in terms of mean age (51 versus 59), IPI score (2.5 versus 1.9), LDH level (565 versus 675), no. of chemotherapy regimens (6.17 versus 6.3) and first complete remission (CR) rate (67% versus 58%). With a median follow up of 3 years, 31 (63%) patients died (4/6 in SV40 positive versus 27/43 in negative, p=not significant). The overall median survival was 51 months with no difference between SV40 positive and negative cases (53 versus 39 months). Conclusions: SV40 was found at low incidence rate of 12% in Chinese DLBCL patients and it had no prognostic values. However, there was a significant association with gastric lymphoma. Further investigations should be done to study its possible etiological role. No significant financial relationships to disclose.