Immunohistochemical expression of multidrug resistance proteins as a predictor of poor response to chemotherapy and prognosis in patients with nodal diffuse large B-cell lymphoma.
OBJECTIVE
The aim of this study was to determine whether expression of P-glycoprotein (P-gp), multidrug-resistance-related protein 1 (MRP1), and lung resistance protein (LRP) was related to the response to induction chemotherapy and prognosis in untreated diffuse large B-cell lymphoma (DLBCL).


METHODS
We assessed immunohistochemical expression of P-gp, MRP1 and LRP, using formalin-fixed and paraffin-embedded specimens of lymph node in 41 patients with DLBCL. Association between expression of these three proteins and their impact on clinical outcome and prognosis was statistically evaluated.


RESULTS
P-gp was positive in 37% of subjects, MRP1 in 63%, and LRP in 68%. The complete remission rates achieved in the group expressing these multidrug resistance (MDR) proteins was significantly lower than in the group not expressing them (20 versus 58%; p = 0.025 in P-gp, 23 versus 80%; p < 0.001 in MRP1 and 32 versus 69%, p = 0.043 in LRP, respectively). Furthermore, the patients expressing LRP had a shorter overall survival rate than those that did not (median of 26 months versus median not reached; p = 0.013).


CONCLUSIONS
These findings suggest that the three MDR proteins are important predictive factors for the clinical outcome and prognosis in patients with DLBCL.
Ohsawa
Masahiko
M
Department of Pathology, Osaka City University, Graduate School of Medicine, Osaka, Japan. m-ohsawa@med.osaka-cu.ac.jp
Ikura
Yoshihiro
Y
Fukushima
Hiroko
H
Shirai
Nobuyuki
N
Sugama
Yoshimi
Y
Suekane
Takehisa
T
Hirayama
Michihiko
M
Hino
Masayuki
M
Ueda
Makiko
M
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000188:drug therapy* / Q000378:metabolism*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000188:drug therapy / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D011237:Predictive Value of Tests; D011379:Prognosis; D015996:Survival Rate; D016896:Treatment Outcome; D020394:Vault Ribonucleoprotein Particles / Q000378:metabolism*; D000099187:Major Vault Protein
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D009363:Neoplasm Proteins; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein