Clinicopathologic characteristics and novel biomarkers of aggressive B-cell lymphomas in the nasopharynx

Abstract Background The most common nasopharyngeal lymphoma in the United States are B-cell non-Hodgkin lymphomas (B-NHL). Relatively little is known about the clinicopathologic features of these cases. In this study, we characterize a bi-institutional cohort of aggressive B-NHL primary to the nasopharyngeal area. We compare and contrast EBV positive versus EBV negative cases and evaluate expression of SSTR2, CD30, and PD-L1, potential markers for targeted therapeutics. Methods and results We retrieved 53 cases of aggressive B-NHL from the two institutions. Staining was performed for in situ EBV (EBER), CD30, SSTR2 and PD-L1. The response to initial therapy, disease-free interval, and survival at two- and five-year following initial diagnosis were used as primary clinical outcome. Overall, 13 out of 53 cases (23%) were EBV positive. CD30 expression was more frequent in EBV+ than in EBV− cases (4/6 vs 1/17). Seven of 14 (50%) cases tested demonstrated expression of PD-L1 within tumor cells; the two EBV+ DLBCL tested showed substantial PD-L1 reactivity. Six of 15 (40%) cases tested were positive for SSTR2. The three EBV+ patients with available outcome data died within one year of diagnosis; in contrast, the EBV− cases show survival rate of 100% (8/8) and 83% (5/6) at two- and five-year follow-up, respectively. Discussion The aggressive B-NHLs of the nasopharynx show differences between EBV+ versus EBV− cases. The association of EBV+ cases with expression of CD30 and PD-L1 may be particularly informative for targeted therapies. A significant number of cases express SSTR2, which could render them susceptible to somatostatin analogue and peptide receptor radionuclide therapies. Finally, our limited case series suggest that EBV negativity may be associated with a better prognosis.