Optimizing chemotherapy for patients with advanced breast cancer

Efficacy and toxicity of capecitabine-based chemotherapy in patients with metastatic or advanced breast cancer: results from ten randomized trials

OBJECTIVE

The efficacy and adverse effects of capecitabine-based chemotherapy versus other regimens reported in previous trials were discordant. The aim of the present study was to determine the efficacy and toxicity profiles of capecitabine-based chemotherapy versus capecitabine-free regimens in patients with metastatic and/or advanced breast cancer.

METHODS

Randomized trials in which capecitabine-based chemotherapy was compared with capecitabine-free chemotherapy were included by searching the PubMed database. Differences in efficacy and grade 3-4 toxicities between capecitabine-based chemotherapy and other chemotherapy were compared.

RESULTS

Ten randomized controlled trials were included in our meta-analysis. Compared to patients treated with capecitabine-free chemotherapy, patients treated with capecitabine-based chemotherapy did not have a significantly different complete response (odds ratio (OR): 1.25, 95% confidence interval (CI): 0.87-1.79, p = 0.231), partial response (OR: 1.16, 95% CI: 0.95-1.41, p = 0.147), and overall response (OR: 1.21, 95% CI: 1.00-1.47, p = 0.053). Compared to the capecitabine-free group, less hematological toxicity and more gastrointestinal toxicity occurred in patients treated with capecitabine-based chemotherapy, including neutropenia (OR: 0.34, 95% CI: 0.19-0.59, p <0.001), anemia (OR: 0.41, 95% CI: 0.20-0.85, p = 0.016), leukocytopenia (OR: 0.50, 95% CI: 0.32-0.78, p = 0.002), and diarrhea (OR: 2.35, 95% CI: 1.62-3.42, p < 0.001). Furthermore, patients in the capecitabine group exhibited a significantly higher rate of grade 3 hand-foot syndrome than the capecitabine-free group (OR: 25.16, 95% CI: 12.27-51.58, p < 0.001).

CONCLUSIONS

The present study suggests that capecitabine-based chemotherapy is as effective as capecitabine-free chemotherapy in patients with metastatic and/or advanced breast cancer with different toxicity profiles. Capecitabine-based chemotherapy may be better tolerated than capecitabine-free chemotherapy. Due to several limitations in our study, future large randomized trials are needed.

Favorable response to doxorubicin combination chemotherapy does not yield good clinical outcome in patients with metastatic breast cancer with triple-negative phenotype

BACKGROUND

We analyzed the responses to first line treatment and clinical outcomes of metastatic breast cancer patients treated with palliative doxorubicin/cyclophosphamide (AC) according to molecular cancer subtype.

METHODS

A retrospective analysis was performed for 110 metastatic breast cancer patients selected on the basis of palliative AC treatment and the availability of immunohistochemical data for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2/neu) status.

RESULTS

Of the 110 patients analyzed, 71 (64.5%) were hormone receptor positive (HR+), 14 (12.7%) were HER2+, and 25 (22.7%) were triple negative (TN). There were no differences in age, stage at diagnosis, total number of cycles of palliative chemotherapy, incidence of visceral metastasis, and metastatic sites with the exception of liver among breast cancer subtypes. The overall response rates to AC were 55.9% for the HR+ subgroup, 42.9% for the HER2+ subgroup, and 56.5% for the TN subgroup. The progression-free survival (PFS) in patients with HER2+ and TN were significantly shorter than in the HR+ (median PFS, 9.1 vs 8.1 vs 11.5 months, respectively; p = 0.0002). The overall survival (OS) was 25.4 months in the TN subgroup and 27.3 months in HER2+ subgroup. The median OS for these two groups was significantly shorter than for patients in the HR+ subgroup (median, 38.5 months; 95% CI, 30.1-46.9 months; p < 0.0001).

CONCLUSIONS

The response to palliative AC chemotherapy did not differ among breast cancer subtypes. Despite chemosensitivity for palliative AC, the TN subtype has a shorter overall survival than non-TN subtypes. Innovative treatment strategies should be developed to slow the course of disease.

Implications of enzymatic, acidic and thermal hydrolysis of DNA on the occurrence of cross-linked melphalan DNA adducts

Calf thymus DNA was treated with melphalan, a nitrogen mustard, and the formation of melphalan cross-linked DNA adducts was investigated. These cross-linked adducts could not be detected either in the enzymatically or in the thermally generated DNA hydrolysates. However, a search for DNA cross-linked adducts in the hydrolysates obtained under acidic conditions revealed the presence of different types of cross-links, mainly containing an adenine moiety. These results are very important because they show that the detection of cross-links is dependent on the hydrolytic procedure used and that these cross-linked adducts are formed under totally different reaction conditions from those in in vivo situations. This can explain the very low abundance or even the absence of cross-linked adducts in nitrogen mustard treated animals. The generally accepted theory that the anti-cancer activity of bifunctional mustards such as melphalan is due to cross-linking of DNA strands remains therefore from our point of view questionable.

Randomised, phase II trial comparing oral capecitabine (Xeloda) with paclitaxel in patients with metastatic/advanced breast cancer pretreated with anthracyclines

Capecitabine, an oral fluoropyrimidine carbamate, was designed to generate 5-fluorouracil preferentially at the tumour site. This randomised, phase II trial evaluated the efficacy and safety of capecitabine or paclitaxel in patients with anthracycline-pretreated metastatic breast cancer. Outpatients with locally advanced and/or metastatic breast cancer whose disease was unresponsive or resistant to anthracycline therapy were randomised to 3-week cycles of intermittent oral capecitabine (1255 mg m(-2) twice daily, days 1-14, (22 patients)) or a reference arm of i.v. paclitaxel (175 mg m(-2), (20 patients)). Two additional patients were initially randomised to continuous capecitabine 666 mg m(-2) twice daily, but this arm was closed following selection of the intermittent schedule for further development. Overall response rate was 36% (95% CI 17-59%) with capecitabine (including three complete responses) and 26% (95% CI 9-51%) with paclitaxel (no complete responses). Median time to disease progression was similar in the two treatment groups (3.0 months with capecitabine, 3.1 months with paclitaxel), as was overall survival (7.6 and 9.4 months, respectively). Paclitaxel was associated with more alopecia, peripheral neuropathy, myalgia and neutropenia, whereas typical capecitabine-related adverse events were diarrhoea, vomiting and hand-foot syndrome. Twenty-three per cent of capecitabine-treated patients and 16% of paclitaxel-treated patients achieved a > or =10% improvement in Karnofsky Performance Status. Oral capecitabine is active in anthracycline-pretreated advanced/metastatic breast cancer and has a favourable safety profile. Furthermore, capecitabine provides a convenient, patient-orientated therapy.

Long-term follow-up of a phase II trial studying a weekly doxorubicin-based multiple drug adjuvant therapy for stage II node-positive carcinoma of the breast

BACKGROUND

Combination chemotherapy improves outcomes in women with breast cancer (BC) that involves axillary nodes. This single-arm study aimed to evaluate the effectiveness of an intensive doxorubicin-based multidrug regimen as adjuvant therapy in women with stage II, node positive breast cancer.

PATIENTS AND METHODS

Between 7/80 and 8/85, 654 women, aged 25-73, who had a mastectomy for stage IIB BC were accrued. Patients with prior RT, chemotherapy, or surgical or radiation castration within 1 year of diagnosis were excluded. Treatment consisted of: 6 weekly courses of IV cyclophosphamide (C) 400 mg/m2, doxorubicin (A) 10 mg/m2, vincristine (V) I mg/m2, fluorouracil (F) 400 mg/m2, and a tapering course of prednisone followed by 12 courses of C 400 mg/m2, A 20mg/m2, V 1 mg/m2, F 400 mg/m2 given every 2 weeks. Patients with estrogen receptor positive tumors received Tamoxifen 10 mg bid between weeks 8 and 30. Treatment did not exceed 8 months. Median follow-up is 13.1 years.

RESULTS

Six hundred thirty six patients are eligible. Fewer positive (+) nodes, premenopausal status, and positive progesterone receptor status are significantly (p < 0.05) associated with longer survival. At 10 years, 61% were relapse-free in the 1-3 +node group compared to 37 and 21% in the 4-9 and > or = 10 +node groups, respectively (p = 0.0001). Relapse-free survival at 10 years is 50% for premenopausal and 45% for postmenopausal patients. Severe or life-threatening hematological toxicity was seen in 6/630 (< 1%) patients. Four patients had severe (grade 3) neurotoxicity which resolved. No cardiac toxicity was observed.

CONCLUSION

This adjuvant regimen compares favorably to other published adjuvant treatments with similar length of follow-up.

Randomized, open-label, phase II trial of oral capecitabine (Xeloda) vs. a reference arm of intravenous CMF (cyclophosphamide, methotrexate and 5-fluorouracil) as first-line therapy for advanced/metastatic breast cancer

BACKGROUND

Oral capecitabine was evaluated in terms of overall response rate, safety, and tolerability as first-line therapy in women aged > or = 55 years with advanced/metastatic breast cancer.

PATIENTS AND METHODS

Ninety-five patients were randomized (2:1) to either intermittent oral capecitabine 1,255 mg/m2 twice daily (two weeks' treatment followed by a one-week rest period) or intravenous CMF (cyclophosphamide. methotrexate, 5-fluorouracil [5-FU]) administered every three weeks.

RESULTS

The overall response rate in the capecitabine group was 30% (95% confidence interval (95% CI): 19%-43%), including three complete responses (5%). The response rate observed in the CMF group was 16% (95% CI: 5%-33%), with no complete responses. Median time to disease progression was 4.1 months with capecitabine and 3.0 months with CME. Survival was similar in the two treatment groups (median 19.6 months with capecitabine. 17.2 months with CMF). The safety profiles were different for capecitabine and CMF. However, both regimens were generally well tolerated and treatment interruption and/or dose modification was effective in managing toxicities associated with capecitabine. Alopecia and myelosuppression were rare in patients receiving capecitabine while diarrhea and hand-foot syndrome were more common. Treatment interruption and/or individual dose adjustment of capecitabine was required in 34% of patients and was generally effective in managing adverse events. Treatment was stopped owing to toxicity in 16% of patients in the capecitabine arm. The incidence of deaths during or within 28 days of stopping study treatment was 8% and 6% in the capecitabine and CMF arms, respectively.

CONCLUSIONS

An oral, twice-daily regimen of capecitabine is effective and well tolerated when used as first-line chemotherapy in older patients (> or = 55 years) with advanced/metastatic breast cancer, and is suitable for outpatient therapy.

A cost--utility analysis comparing second-line chemotherapy schemes in patients with metastatic breast cancer

A cost-utility analysis has been performed comparing taxanes, vinorelbine and standard therapy for metastatic breast cancer considering clinical efficacy, quality-adjusted-life-years (QALYs) and costs. A decision model has been built. Clinical efficacy data were collected by literature review. Utility data and cost data were collected from previous studies and Dutch wholesale prices. Except for the MV standard therapy, VM has the lowest C/E ratio of $17,114/QALY, followed by paclitaxel ($30,270/QALY) and docetaxel ($49,739/QALY). VM yields the highest number of QALYs (0.47), compared to paclitaxel (0.35), docetaxel (0.34) and MV (0.29). Compared to the MV standard therapy, the incremental C/E of VM is $23,046/QALY, which is the lowest of all alternatives. We conclude that compared to paclitaxel, docetaxel and MV standard chemotherapy, VM is the most cost-effective second-line chemotherapy for metastatic breast cancer patients. There is a considerable variation in utility scores, depending on the methods or the data sources used. The C/E ratios were influenced most strongly by drug prices, utility and efficacy (in descending order of importance).