Yonsei Med J. 1992 Jun;33(2):137-142. English.
Published online Feb 20, 2002.
Copyright © 1992 The Yonsei University College of Medicine
Original Article

The value of immunohistochemical detection of P-glycoprotein in breast cancer before and after induction chemotherapy

Eun Hee Koh, Hyun Cheol Chung, Kyi Beom Lee, Ho Young Lim, Joo Hang Kim, Jae Kyung Roh, Jin Sik Min, Kyung Sik Lee and Byung Soo Kim
    • Department of Internal Medicine1, Yonsei University College of Medicine, Seoul, Korea.
    • Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
    • Department of Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
    • Department of Pathology, Ajou University College of Medicine, Suwon, Korea.

Abstract

We have studied the patterns of P-glycoprotein expression before and after 3 cycles of induction chemotherapy (5-fluorouracil, adriamycin and cyclophosphamide) using immunohistochemically stained paraffin-embedded specimen of 28 patients with locally advanced breast cancer. The frequency of P-glycoprotein expression in untreated breast cancer turned out to be very low: only one out of 28 untreated, biopsy specimen at the time of diagnosis was positive. The frequency of P-glycoprotein expression was markedly increased from 9.1% before chemotherapy to 63.6% after induction chemotherapy (p = 0.006). After 3 cycles of induction chemotherapy, 25 patients had obtained clinical response to chemotherapy (4, CR; 21, PR). Eleven out of 25 tumors (44%) showing clinical response and all three tumors (100%) with minimal response have expressed P-glycoprotein. One out of 6 patients (16.7%) with microscopic residual tumor seen in mastectomy specimen expressed P-glycoprotein, whereas 13 of 22 patients (59.1%) with gross residual tumor showed the presence of P-glycoprotein (p = 0.08). The frequency of intrinsic P-glycoprotein expression in untreated breast cancer was quite low, but approximately half of the patients do acquire P-glycoprotein expression during the cycles of induction chemotherapy. Therefore, the results suggest that the immunohistochemical detection of P-glycoprotein on residual tumor cells after induction chemotherapy can predict acquired drug resistance in breast cancer.

Keywords
P-glycoprotein; immunohistochemical stain


Metrics
Share
PERMALINK