MDR1 single nucleotide polymorphism G2677T/A and haplotype are correlated with response to docetaxel-cisplatin chemotherapy in patients with non-small-cell lung cancer.

BACKGROUND: The multidrug resistance gene 1 (MDR1) encodes P-glycoprotein (P-gp), which plays an important role in mediating multidrug resistance to chemotherapeutic agents. MDR1 gene polymorphisms may have an impact on the expression and function of P-gp, thereby influencing the response to chemotherapy. OBJECTIVES: To investigate whether the MDR1 2677 and 3435 genotypes are associated with the sensitivity of non-small-cell lung cancer (NSCLC) to docetaxel. METHODS: In this study we investigated the potential association of MDR1 2677G>T at exon 21, 3435C>T at exon 26 and their haplotypes with chemotherapy response of 54 Han Chinese patients with NSCLC. The patients were treated with docetaxel-cisplatin. RESULTS: The 2677 GG genotype was associated with a significantly better response to chemotherapy compared with the combined 2677 GT and TT genotype (p = 0.035). The 3435 CC genotype was also associated with a better response to chemotherapy compared with the combined 3435 CT and TT genotypes although the difference was not statistically significant (p = 0.123). Moreover, patients harboring the 2677G-3435C haplotype had a statistically significant better response to chemotherapy compared with those with the other haplotypes combined (p = 0.015). CONCLUSION: Our findings suggest that the MDR1 2677G>T/A polymorphism and the 2677G-3435C haplotype are predictors of treatment response to docetaxel-cisplatin chemotherapy in NSCLC patients.

[A randomized phase II trial of docetaxel and doxorubicin in treatment for patients with non-small-cell lung cancer who have failed previous platinum-based chemotherapy].

OBJECTIVE: The aim of this study was to evaluate the efficacy, toxicity and safety of doxorubicin combined with domestically produced docetaxel versus with taxotere, and to investigate whether these two regimens result in similar outcomes in the treatment for non-small-cell lung cancer (NSCLC) patients who failed previous platinum-based chemotherapy. METHODS: Eighty-eight NSCLC patients were enrolled into this clinical phase II trial. The patients randomly received either domestic docetaxel (study arm) or taxotere (control arm) at a dose of 70 mg/m2 on D2, while doxorubicin at a dose of 40 mg/m2 on D1 was administered in both groups. It was repeated every 3 weeks, totally for three cycles. No granulocyte colony-stimulating factor was used to prevent granulocytopenia. The response rate and toxicity were evaluated using World Health Organization toxicity scale and Karnofsky performance status scale. RESULTS: Of the 88 patients, 81 were evaluable in terms of efficacy. There was no complete responder in this series. The response rate (RR) was 17.1% in the study arm versus 7.5% in the control arm, and the clinical benefit rate (CBR) was 80.5% in the study group versus 72.5% in the control group. The most frequent grade 3 or 4 toxicities were neutropenia, leucopenia and gastrointestinal symptoms. Other toxicities such as alopecia and vomiting were mild and generally well tolerated. No fluid retention was noticed. CONCLUSION: The administration of doxorubicin 40 mg/m2 on D1 combined with domestic docetaxel 70 mg/m2 on D2 is proved to be as effective and tolerable as with taxotere. The domestic drug docetaxel may be considered as an alternative for patients with non-small-cell lung cancer who failed previous platinum-based chemotherapy.

[Preliminary study of biweekly regimen of docetaxel, oxaliplatin, 5-fluorouracil and leucovorin for advanced gastric cancer].

OBJECTIVE: To evaluate the efficacy and toxicity of a biweekly DOF regimen consisting of docetaxel, oxaliplatin, 5-fluorouracil and leucovorin for advanced gastric cancer. METHODS: The biweekly DOF regimen was administered in 37 advanced gastric cancer patients. Docetaxel, oxaliplatin and leucovorin were given intravenously at a dose of 35 mg/m2, 85 mg/m2 and 200 mg/m2 for 1 h, 2 h and 2 h on D1, respectively, and 5-Fu was administered as continuous intravenous infusion for 48 h at a dose of 1500 mg/m2 on D1 and D2. This regimen was repeated every 2 weeks. The efficacy and toxicity were evaluated after completion of 3 cycles at least. RESULTS: The overall response rate (RR) of this series was 67.6%, complete response rate and partial response rate were 27.0% and 40.5%, respectively. The time to progression (TTP) was 9.2 months, and median survival time (MST) was 13.7 months. The RRs of 11 chemotherpy-naïve patients and 26 patients pre-treated with chemotherapy were 81.8% and 61.5%, respectively. CONCLUSION: Our preliminary results showed that this biweekly combination regimen of docetaxel, oxaliplatin, 5-fluorouracil and leucovorin is effective and tolerable for advanced gastric cancer. However, further investigation of this regimen is mandatory.

MDR1 single nucleotide polymorphisms predict response to vinorelbine-based chemotherapy in patients with non-small cell lung cancer.

BACKGROUND: The polymorphisms of genes participate in metabolism and transport, and therefore may have an impact on the response to vinorelbine. OBJECTIVES: To investigate whether genotypes of CYP3A5, MDR1 and cyclooxygenase-2 (COX-2) are associated with the response to vinorelbine in non-small cell lung cancers (NSCLC). METHODS: We determined the genotypes of CYP3A5(*3), MDR1 (2677G-->T at exon 21 and 3435C-->T at exon 26 and their haplotypes) and COX-2 (-1195G-->A) polymorphisms by PCR-RFLP and chemotherapy response in 69 Chinese Han patients with NSCLC who received a combination chemotherapy of vinorelbine-cisplatin (VC). The chi(2) test was used to investigate potential associations between genotypes and response to chemotherapy. Odds ratios and 95% confidence intervals were calculated. RESULTS: The 3435 CC genotype was associated with a significantly better chemotherapy response compared with the combined 3435 CT and TT genotypes (p = 0.025). The 2677 GG genotype was also associated with a better chemotherapy response compared with the combined 2677 GT and TT genotype, although it was not statistically significant. Moreover, we analyzed the haplotypes of MDR1 3435-2677: patients harboring the 2677G-3435C haplotype had a statistically significantly better response to chemotherapy compared with those with the other haplotypes combined (p = 0.015). CYP3A5*3 is not likely to correlate with sensitivity to vinorelbine in NSCLC. COX-2 (-1195G) is likely to result in a better response to vinorelbine (nonsignificant). CONCLUSIONS: Our findings suggest that MDR1 2677G-->T/A and 3435C-->T polymorphisms can be used to predict treatment response to VC chemotherapy in NSCLC patients.

CYP450 polymorphisms predict clinic outcomes to vinorelbine-based chemotherapy in patients with non-small-cell lung cancer.

CYP2C19*2(G681A), CYP2C19*3(G636A), CYP2D6*4(C188T), CYP2D6*2(C2938T, G4268C), CYP3AP1*3- G44A and CYP3A5*3(A22893G) are the most common polymorphisms detected among Chinese that may influence the efficacy of vinorelbine-based therapies to treat non-small-cell lung cancer (NSCLC). We detected the genotypes of these polymorphisms by PCR-RFLP in 59 patients with NSCLC and assessed their responses to vinorelbine. CYP2D6*4(C188T), CYP3AP1*3 (G -44 A) and CYP3A5*3 were found to be associated with response to vinorelbine. For the 2D6*4 polymorphism, the 18 of 32 (56.25%) patients with homozygous (C/C) responded to this therapy, while 6 of 27 (22.22%) of those heterozygous (C/T) at this site responded. (chi2=5.68, p < 0.05) For the 3AP1*1/*3 polymorphism, 12 of 42 (28.57%) patients with homozygous (A/A) responded, while 12 of 17 (70.59%) with heterozygous (A/G) and homozygous (G/G) responded (chi2=7.19, p < 0.01). CYP3A5*3 polymorphism has a result corresponding to 3AP1*3 polymorphism. Other polymorphisms were not associated with response to vinorelbine. No significant difference in toxicity and survival was observed according to SNP genotype.

[Docetaxel in the treatment of advanced breast cancer ].

OBJECTIVE: To evaluate the efficacy, toxicity and safety of an new domestic docetaxel in the treatment of pretreated advanced breast cancer. METHODS: Fourty-four breast cancer patients who had failed in first-line chemotherapy were included in this trial. They received docetaxel as the second-line chemotherapy. Docetaxel was administered alone at a dose of 70 mg/m2 every 3 weeks. The use of granulocyte colony-stimulating factor to prevent granulocytopenia was not permitted. The response rate and toxicity were evaluated by World Health Organization toxicity scale and performance status by Karnofsky scale. RESULTS: Of the 41 evaluable patients, 4 achieved complete response and 14 partial remission, with a response rate and clinical benefit rate of 43.9% and 85.4%, respectively. Grade 3 or grade 4 neutropenia developed in 42.9%, alopecia in 7.1% and vomiting in 4.8% of these patients. Fluid retention was not observed in this series. CONCLUSION: Three-week administration of docetaxel alone at a dose of 70 mg/m2 is effective and tolerable. It provides an alternative for the pretreated advanced breast cancer patients.