Multidrug resistance in mucoepidermoid carcinoma of the parotid gland--immunohistochemical investigations of P-glycoprotein expression.
Abstract Conclusion: P-glycoprotein is abundantly expressed in certain parotid mucoepidermoid carcinoma tissues, known historically to be multidrug resistant. This discovery may be important in incrementally advancing our ability to develop alternative pharmacologic strategies to improve multi-modality tumor control.


OBJECTIVE
P-glycoprotein plays a functional role in promoting the efflux of drug metabolites in certain malignant tumors. With this understanding we immunohistochemically investigated the expression of P-glycoprotein in parotid mucoepidermoid carcinoma tissues and examined prognostic factors that contribute to the treatment of parotid cancer.


METHODS
Thirteen patients with mucoepidermoid carcinoma of the parotid gland were included. P-glycoprotein expression was immunohistochemically investigated by a modified avidin-biotin-peroxidase complex method using four different antibodies.


RESULTS
P-glycoprotein expression was observed in a higher percentage of patients with higher grade malignancy. The tumor size-related difference in P-glycoprotein expression was only significant for staining with one antibody, and no significant differences were observed with or without induction chemotherapy.
Department of Otolaryngology-Head and Neck Surgery, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan. furusaka.tohru@nihon-u.ac.jp
Tohru
T
Furusaka
Clarence T
CT
Sasaki
Akira
A
Matsuda
Yasuhiko
Y
Susaki
Hiroshi
H
Matsuda
Minoru
M
Ikeda
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D018277:Carcinoma, Mucoepidermoid / Q000378:metabolism* / Q000473:pathology* / Q000628:therapy; D002648:Child; D015331:Cohort Studies; D018432:Drug Resistance, Multiple; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D010307:Parotid Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000628:therapy; D047368:Tumor Burden
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents