Ki-67 and subtype as prognostic and predictive markers of diffuse large B-Cell lymphoma

Govind Babu, KC Lakshmaiah, Loknatha Dasappa, Suresh Babu, Linu Jacob Abraham, CS Premalatha, Clementina Rama Rao, LK Rajeev, AH Rudresha, KN Lokesh, Sunny Garg, Ankit Agarwal

Clinical Cancer Investigation Journal 2017 6(1):97-102

Introduction: Since patients with similar International Prognostic Index (IPI) scores have varied outcomes, molecular signatures including Ki-67 overexpression have been studied to prognosticate diffuse large B-cell lymphoma (DLBCL), which have shown varied outcomes. Objective: To correlate Ki-67 expression with survival in two biologic subgroups of DLBCL. Materials and Methods: One hundred and twelve adults with DLBCL between 2008 and 2012 were identified. Ki-67 overexpression was determined using immunohistochemistry. Results: A total of 112 patients of DLBCL were identified and included in the study. The median age was 54 years (18–78 years), with a male/female ratio of 1.8:1. Median survival was greater in patients with low Ki-67 (n = 32) as compared to high Ki-67 (n = 44) (32 m vs. 21.5 m, P = 0.033). In the germinal center B-cell (GCB) subtype, low Ki-67 had a better survival as compared to high Ki-67 (35 m vs. 28 m, P = 0.044), whereas in the non-GCB (NGCB) subtype, the results were same but statistically insignificant (26.5 m vs. 18 m, P = 0.7). In the high IPI arm, low Ki-67 had a better survival (26.5 m vs. 17 m, P = 0.02), whereas in low IPI arm, the results were similar but statistically insignificant (39 m vs. 38 m, P = 0.837). Survival analysis was done in each treatment arm (CHOP and R-CHOP) based on Ki-67 expression (high or low) in GCB and NGCB arms. No statistically significant difference was noted in any of the four arms; 27.5 m versus 34 m (P = 0.738) in high versus low Ki-67 in CHOP-GCB arm, 15 m versus 22 m (P = 0.443) in high versus low Ki-67 in CHOP-NGCB arm, 27 m versus 44 m (P = 0.104) in high versus low Ki-67 in R-CHOP-GCB arm, and 31 m versus 35 m (P = 0.861) in high versus low Ki-67 in R-CHOP-NGCB arm. Conclusions: Ki-67 although an indicator of poor outcome, its use to predict outcomes alone in the absence of study of expression of concomitant markers such as myc/BCL6 would cause a bias in results. Furthermore, its relevance in the rituximab era needs further validation.

from # All Medicine by Alexandros G. Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2s8FU9z
via IFTTT