Efficacy of gemcitabine-based chemotherapy in metastatic breast cancer: a meta-analysis of randomized controlled trials.
OBJECTIVE
To compare the effects of gemcitabine-based chemotherapy and gemcitabine-free regimens, a meta-analysis of all relevant randomized controlled trials was performed to investigate the improvement in overall response rate (ORR), time to progression (TTP), and overall survival (OS). A subgroup of gemcitabine-based doublet compared with single agent was also analyzed.


METHODS
The PubMed and Embase databases were searched for relevant publications reporting randomized controlled trials comparing gemcitabine-based chemotherapy and gemcitabine-free regimens between January 1990 and December 2012. Hazard ratios (HRs) with their 95% confidence intervals (CIs), or data for calculating HRs with 95% CI were derived.


RESULTS
Nine trials with a total of 2651 patients were included in this meta-analysis. Compared with gemcitabine-free chemotherapy, gemcitabine-based therapy demonstrated no improvement in terms of ORR (HR 1.09, 95% CI 0.73-1.62; P = 0.67), TTP (HR 0.91, 95% CI 0.72-1.15; P = 0.44) and OS (HR 1.05, 95% CI 0.88-1.25; P = 0.60). In a subgroup including patients who received adjuvant chemotherapy containing anthracyclines or taxanes, sub-analysis assessment revealed that gemcitabine-based doublets were superior to monotherapy in ORR (HR 1.64, 95% CI 1.26-2.12; P = 0.0002) and TTP (HR 0.71, 95% CI 0.62-0.81; P < 0.00001), but no benefit was observed for OS (HR 0.90, 95% CI 0.79-1.03; P = 0.14). The rates of grade 3 and 4 anemia (HR 2.02, 95% CI 1.35-3.02; P = 0.006), neutropenia (HR 2.33, 95% CI 1.37-3.63; P = 0.01), and thrombocytopenia (HR 8.31, 95% CI 5.00-13.82; P < 0.0001) were significantly higher in the gemcitabine-based arm.


CONCLUSIONS
The present study suggests that gemcitabine-based chemotherapy was as effective as gemcitabine-free chemotherapy in patients with metastatic breast cancer with increased hematological toxicity. Subgroup analysis indicated that adding gemcitabine to monotherapy might be more effective.
Department of Internal Medicine, Affiliated Shantou Hospital of Sun Yat-sen University , Shantou, Guangdong , China.
Weibing
W
Li
Hongbiao
H
Wang
Xuyuan
X
Li
D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects* / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D003841:Deoxycytidine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D016896:Treatment Outcome; D000093542:Gemcitabine
D000964:Antimetabolites, Antineoplastic; D003841:Deoxycytidine; D000093542:Gemcitabine