Ki-67 expression as a prognostic factor in diffuse large B-cell lymphoma patients treated with rituximab plus CHOP.
BACKGROUND
Assessment of tumor cell proliferation based on Ki-67 expression yielded conflicting prognostic predictions of patients with diffuse large B-cell lymphoma (DLBCL). The introduction of rituximab to the DLBCL treatment regime has led to alterations in the significance of previous prognostic factors.


METHODS
We analyzed Ki-67 expression and its correlation with prognosis in 144 patients with DLBCL treated with rituximab plus CHOP (R-CHOP) between July 2003 and January 2008.


RESULTS
The complete response (CR) rates following R-CHOP administration were not significantly different, based on Ki-67 expression status (P = 0.104). However, higher rates of relapse were observed in the high Ki-67 expression group (Ki-67 >or= 85%, n = 46) with 25.0%, compared to 10.0% in the low Ki-67 expression group (Ki-67 < 85%, n = 88) (P = 0.040). The 2-yr event-free survival (EFS) rates were 44.3% and 74.1% in the high and low Ki-67 expression groups, respectively (P = 0.011). The 2-yr overall survival (OS) rate was 66.4% in the high Ki-67 expression group and 82.2% in the low Ki-67 expression group (P = 0.016). In multivariate analysis, Ki-67 expression was a significant prognostic factor for EFS [hazard ratio (HR) = 2.909; 95% confidence interval (CI) 1.261-6.708; P = 0.012]. Ki-67 was associated with OS but with borderline significance (HR = 2.876; 95% CI, 0.972-8.508; P = 0.056).


CONCLUSIONS
Elevated Ki-67 expression seems to be associated with higher relapse after CR and inferior EFS in patients with DLBCL treated with R-CHOP.
Yoon
Dok Hyun
DH
Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Choi
Dae Ro
DR
Ahn
Heui June
HJ
Kim
Shin
S
Lee
Dae Ho
DH
Kim
Sang-We
SW
Park
Bong-Hee
BH
Yoon
Sun Och
SO
Huh
Jooryung
J
Lee
Sang-Wook
SW
Suh
Cheolwon
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D058846:Antibodies, Monoclonal, Murine-Derived; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D049109:Cell Proliferation / Q000187:drug effects; D003520:Cyclophosphamide / Q000008:administration & dosage; D004317:Doxorubicin / Q000008:administration & dosage; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality*; D008875:Middle Aged; D011241:Prednisone / Q000008:administration & dosage; D011379:Prognosis; D012008:Recurrence; D000069283:Rituximab; D016019:Survival Analysis; D014750:Vincristine / Q000008:administration & dosage; D055815:Young Adult
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D019394:Ki-67 Antigen; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone