Chemotherapy response assay test and prognosis for breast cancer patients who have undergone anthracycline- and taxane-based chemotherapy.
OBJECTIVE
A chemotherapy response assay test is performed to evaluate the degree of tumor growth inhibition by a chemotherapeutic agent. Several studies have been done on its usefulness; however, to the best of our knowledge, only a few studies concerning the relationship between chemotherapy response assay test results and breast cancer patients' prognoses have been conducted. Thus, we performed this study to analyze this relationship.


METHODS
Among breast cancer patients who underwent curative surgery and neoadjuvant or adjuvant chemotherapy between August 2004 and December 2009, 102 were enrolled in this study. Chemotherapeutic regimens for patients were doxorubicin plus taxane or doxorubicin plus cyclophosphamide followed by taxane. We divided these patients into two groups (sensitive group [n=19] and resistant group [n=83]) and analyzed the relationship between chemosensitivity results and patient prognosis.


RESULTS
The sensitive group was associated with poor disease-free survival (DFS) (p=0.003) and overall survival (OS) (p<0.001). No significant differences were observed in tumor histology (p=0.548), tumor size (p=0.479), number of metastatic lymph nodes (p=0.326), histologic grade (p=0.077), or nuclear grade (p=0.216) between the two groups. However, in respect to molecular subtype, the HER2-positive type and triple negative breast cancer were more frequently observed in the sensitive group (p=0.001). In a univariate and multivariate analysis for DFS, doxorubicin sensitivity was significantly associated with a poor prognosis (p<0.05).


CONCLUSIONS
Better chemosensitivity results are associated with a poor prognosis in breast cancer patients who have undergone anthracycline- and taxane-based chemotherapy, however, examination of additional cases and the use of a longer study period are needed.
Department of Medicine, Kyung Hee University Graduate School, Seoul, Korea.
Anbok
A
Lee
Woosung
W
Lim
Byung-In
BI
Moon
Nam-Sun
NS
Paik
Suck-Hwan
SH
Koh
Jeong-Yoon
JY
Song