Combination of BCL-2 and MYC protein expression improves high-risk stratification in diffuse large B-cell lymphoma

PURPOSE: To evaluate whether the addition of two biological markers (MYC and BCL-2 protein overexpression) improves the stratification of high-risk patients with diffuse large B-cell lymphoma (DLBCL). METHOD: Seven risk factors were identified at diagnosis, and a maximum of 7 points were assigned to each patient. The patients were classified according to four risk groups: low (0–1), low-intermediate (2–3), high-intermediate (4), and high (5–7). Only high-risk patients with DLBCL were included in this analysis. We retrospectively examined 20 cases from 2008 to 2013 at the Nanjing Drum Tower Hospital. RESULTS: The median expression of MYC protein was 60%, and 17 of 20 (65%) evaluable cases overexpressed MYC. The median expression of BCL-2 protein was also 60%. Eighteen of 20 (90%) evaluable cases showed BCL-2 overexpression. Additionally, 12 out of 20 cases (60%) demonstrated coexpression of MYC and BCL-2 proteins. The percentages of overall survival and progression-free survival at the median follow-up time (36 months) were 33.3%±16.1% and 16.9%±13.5%, respectively. By comparison, nine, four, and 20 patients were classified as high risk based on the International Prognostic Index (IPI), National Comprehensive Cancer Network(NCCN)-IPI, and revised IPI criteria, respectively. According to the IPI and NCCN-IPI stratification, the risk groups demonstrated closely overlapping survival curves. In addition, four out of 20 cases were identified as low-intermediate risk according to the NCCN-IPI criteria. CONCLUSION: The addition of MYC and BCL-2 protein expression to the IPI could identify a subset of DLBCL patients with high-risk clinicopathological characteristics and poor clinical outcome.