%0 Journal Article %1 Schmidt.2007 %A Schmidt, M. %A Bremer, E. %A Hasenclever, Dirk %A Victor, A. %A Gehrmann, M. %A Steiner, E. %A Schiffer, I. B. %A Gebhardt, S. %A Lehr, H-A %A Mahlke, M. %A Hermes, M. %A Mustea, A. %A Tanner, B. %A Koelbl, H. %A Pilch, H. %A Hengstler, J. G. %D 2007 %J British journal of cancer %K IMISE-Publikationen %N 2 %P 241–247 %T Role of the progesterone receptor for paclitaxel resistance in primary breast cancer %V 96 %X Paclitaxel plays an important role in the treatment of primary breast cancer. However, a substantial proportion of patients treated with paclitaxel does not appear to derive any benefit from this therapy. We performed a prospective study using tumour cells isolated from 50 primary breast carcinomas. Sensitivity of primary tumour cells to paclitaxel was determined in a clinically relevant range of concentrations (0.85-27.2 microg ml(-1) paclitaxel) using an ATP assay. Chemosensitivity data were used to study a possible association with immunohistochemically determined oestrogen and progesterone receptor (ER and PR) status, as well as histopathological parameters. Progesterone receptor (PR) mRNA expression was also determined by quantitative RT-PCR. We observed a clear association of the PR status with chemosensitivity to paclitaxel. Higher levels of immunohistochemically detected PR expression correlated with decreased chemosensitivity (P=0.008). Similarly, high levels of PR mRNA expression were associated with decreased paclitaxel chemosensitivity (P=0.007). Cells from carcinomas with T-stages 3 and 4 were less sensitive compared to stages 1 and 2 (P=0.013). Multiple regression analysis identified PR receptor status and T-stage as independent predictors of paclitaxel chemosensitivity, whereas the ER, N-stage, grading and age were not influential. In conclusion, in vitro sensitivity to paclitaxel was higher for PR-negative compared with PR-positive breast carcinoma cells. Thus, PR status should be considered as a possible factor of influence when designing new trials and chemotherapy protocols.

@article{Schmidt.2007, abstract = {Paclitaxel plays an important role in the treatment of primary breast cancer. However, a substantial proportion of patients treated with paclitaxel does not appear to derive any benefit from this therapy. We performed a prospective study using tumour cells isolated from 50 primary breast carcinomas. Sensitivity of primary tumour cells to paclitaxel was determined in a clinically relevant range of concentrations (0.85-27.2 microg ml(-1) paclitaxel) using an ATP assay. Chemosensitivity data were used to study a possible association with immunohistochemically determined oestrogen and progesterone receptor (ER and PR) status, as well as histopathological parameters. Progesterone receptor (PR) mRNA expression was also determined by quantitative RT-PCR. We observed a clear association of the PR status with chemosensitivity to paclitaxel. Higher levels of immunohistochemically detected PR expression correlated with decreased chemosensitivity (P=0.008). Similarly, high levels of PR mRNA expression were associated with decreased paclitaxel chemosensitivity (P=0.007). Cells from carcinomas with T-stages 3 and 4 were less sensitive compared to stages 1 and 2 (P=0.013). Multiple regression analysis identified PR receptor status and T-stage as independent predictors of paclitaxel chemosensitivity, whereas the ER, N-stage, grading and age were not influential. In conclusion, in vitro sensitivity to paclitaxel was higher for PR-negative compared with PR-positive breast carcinoma cells. Thus, PR status should be considered as a possible factor of influence when designing new trials and chemotherapy protocols.}, added-at = {2014-10-15T15:04:22.000+0200}, author = {Schmidt, M. and Bremer, E. and Hasenclever, Dirk and Victor, A. and Gehrmann, M. and Steiner, E. and Schiffer, I. B. and Gebhardt, S. and Lehr, H-A and Mahlke, M. and Hermes, M. and Mustea, A. and Tanner, B. and Koelbl, H. and Pilch, H. and Hengstler, J. G.}, biburl = {https://www.bibsonomy.org/bibtex/21280ebba12e261143b6db6fbe46e7861/drtester}, interhash = {c4c6ebdb02ee2719b9f7749b1a60c136}, intrahash = {1280ebba12e261143b6db6fbe46e7861}, journal = {British journal of cancer}, keywords = {IMISE-Publikationen}, number = 2, pages = {241–247}, timestamp = {2014-12-03T00:00:16.000+0100}, title = {Role of the progesterone receptor for paclitaxel resistance in primary breast cancer}, volume = 96, year = 2007 }