Antiangiogenic therapy for breast cancer.

Angiogenesis is an important component of cancer growth, invasion and metastasis. Therefore, inhibition of angiogenesis is an attractive strategy for treatment of cancer. We describe existing clinical trials of antiangiogenic agents and the challenges facing the clinical development and optimal use of these agents for the treatment of breast cancer. Currently, the most promising approach has been the use of bevacizumab, a humanized monoclonal antibody directed against the most potent pro-angiogenic factor, vascular endothelial growth factor (VEGF). Small molecular inhibitors of VEGF tyrosine kinase activity, such as sorafenib, appear promising. While, the role of sunitinib and inhibitors of mammalian target of rapamycin (mTOR) in breast cancer has to be defined. Several unanswered questions remain, such as choice of drug(s), optimal duration of therapy and patient selection criteria.

Cyclophosphamide, methotrexate, and fluorouracil; oral cyclophosphamide; levamisole; or no adjuvant therapy for patients with high-risk, premenopausal breast cancer.

BACKGROUND: The Danish Breast Cancer Cooperative Group (DBCG) 77B trial examined the relative efficacy of levamisole, single-agent oral cyclophosphamide, and the classic combination of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) against no adjuvant systemic therapy in high-risk breast cancer patients. The authors report the results from that trial after a potential follow-up of 25 years. METHODS: Between 1977 and 1983, 1146 premenopausal patients who had tumors >5 cm or positive axillary lymph nodes were assigned randomly to 1 of 4 options: no systemic therapy, levamisole 5 mg weekly for 48 weeks (the levamisole arm), oral cyclophosphamide 130 mg/m(2) on Days 1 through 14 every 4 weeks for 12 cycles (the C arm), or oral cyclophosphamide 80 mg/m(2) on Days 1 through 14 plus methotrexate 30 mg/m(2) and fluorouracil 500 mg/m(2) intravenously on Days 1 and 8 every 4 weeks for 12 cycles (the CMF arm). RESULTS: The 10-year invasive disease-free survival (IDFS) rate was 38.6% in the control arm compared with 55.5% in the C arm, 48.8% in the CMF arm, and 35.2% in the levamisole arm. Compared with the control arm, the hazard ratio for an IDFS event was 0.62 in the C arm (P = .001) and 0.70 in the CMF arm (P = .01). The hazard ratio for death was 0.70 in both the C arm (P = .02) and the CMF arm (P = .02) at 10 years, and the overall survival (OS) benefit was maintained during 25 years of follow-up. No significant differences were observed in IDFS or OS between the C arm and the CMF arm or between the levamisole arm and the control arm. CONCLUSIONS: Compared with controls, both cyclophosphamide and CMF significantly improved disease-free survival and OS, and the benefits persisted for at least 25 years in premenopausal patients who had high-risk breast cancer.

HER2-targeted therapy in breast cancer. Monoclonal antibodies and tyrosine kinase inhibitors.

There is strong clinical evidence that trastuzumab, a monoclonal antibody targeting the human epidermal growth factor receptor (HER) two tyrosine kinase receptor, is an important component of first-line treatment of patients with HER2-positive metastatic breast cancer. In particular the combination with taxanes and vinorelbine has been established. In the preoperative setting inclusion of trastuzumab has significantly increased the pathological complete response rate. Results from large phase III trials evaluating adjuvant therapy in HER2-positive early breast cancer indicate that the addition of trastuzumab to chemotherapy improves disease-free and overall survival. The use of lapatinib, a dual tyrosine kinase inhibitor of both HER1 and HER2, in combination with capecitabine in the second-line treatment of HER2-positive patients with metastatic breast cancer previously treated with trastuzumab has been established. There is modest, but still insufficient, support that the compound passes the blood-brain barrier. Several trials are ongoing both in the adjuvant and metastatic settings and we have to await the results of these to clarify the role of trastuzumab and lapatinib. The clinical problem of tumours developing resistance to HER2-directed therapy is becoming increasingly important. Several issues about optimal selection of patients, prevention of resistance and use of different treatment options are still unresolved. In this article, we summarise the current knowledge on clinical evidence of HER2-directed therapy and the potential mechanisms of underlying resistance, including the possible clinical implications and review new therapeutic options.

DBCG trial 89B comparing adjuvant CMF and ovarian ablation: similar outcome for eligible but non-enrolled and randomized breast cancer patients.

INTRODUCTION: A cohort of premenopausal patients with primary hormone receptor positive breast cancer was prospectively identified to be eligible for the DBCG 89B trial. We perform a long-term follow-up and evaluate the external validity of the trial. MATERIAL AND METHODS: Following registration in a population-based registry, patients were invited to be randomized to ovarian ablation (OA) versus nine courses of three-weekly cyclophosphamide, methotrexate and 5-fluorouracil (CMF). The same procedures were used in all patients, including report forms, central review, querying, and analysis of data. Multivariate analysis was used to adjust for differences in base-line characteristics. RESULTS: Participation in the randomization varied according to center and time period. One thousand six hundred and twenty eight eligible patients were registered and 525 randomized in the DBCG 89B trial. Median estimated follow-up was 9.5 years for disease-free survival and 12.1 years for overall survival. Non-enrolled patients had a disease-free and overall survival similar to randomized patients. Within 5 years of surgery, results were similar following OA and CMF, but disease-free survival was significant inferior with OA more than five years after surgery, adjusted hazard ratio 1.38 (95% CI 1.03 to 1.85; p=0.03). This convened ten years after surgery to an inferior survival with OA, and the adjusted hazard ratio was 2.37 (95% CI 1.43 to 3.91; p<0.01). DISCUSSION: This prospective cohort study indicates that eligible patients not participating in the DBCG 89B trial had a similar disease-free and overall survival as participants. Survival was similar after OA and CMF in the first ten years, but became inferior in the OA group 10 or more years after surgery.

Bisphosphonate treatment in primary breast cancer: results from a randomised comparison of oral pamidronate versus no pamidronate in patients with primary breast cancer.

PURPOSE AND PATIENTS: During the period from January 1990 to January 1996 a total of 953 patients with lymph node negative primary breast cancer were randomised to oral pamidronate (n=460) 150 mg twice daily for 4 years or no adjuvant pamidronate (n=493) in order to investigate whether oral pamidronate can prevent the occurrence of bone metastases and fractures. The patients received adjuvant chemotherapy, loco-regional radiation therapy, but no endocrine treatment. RESULTS: During the follow-up period the number of patients with pure bone metastases was 35 in the control group and 31 in the pamidronate group. The number of patients with a combination of bone and other distant metastases were 22 in the control group and 20 in the pamidronate group. The hazard rate ratio for recurrence in bone in the pamidronate group compared to the control group was 1.03 (95% confidence interval 0.75-1.40) and p=0.86. No effect was observed on overall survival. In a small subgroup of 27 patients from the study, 12 of whom were treated with pamidronate a significant bone preserving effect was observed on bone mineral density in the lumbar spine, but not in the proximal femur. CONCLUSION: The results from the trial do not support a beneficial effect of oral pamidronate on the occurrence of bone metastases or fractures in patients with primary breast cancer receiving adjuvant chemotherapy.

Similar efficacy for ovarian ablation compared with cyclophosphamide, methotrexate, and fluorouracil: from a randomized comparison of premenopausal patients with node-positive, hormone receptor-positive breast cancer.

PURPOSE: To compare the efficacy of ovarian ablation versus chemotherapy in early breast cancer patients with hormone receptor-positive disease. PATIENTS AND METHODS: We conducted an open, randomized, multicenter trial including premenopausal breast cancer patients with hormone receptor-positive tumors and either axillary lymph node metastases or tumors with a size of 5 cm or more. Patients were randomly assigned to ovarian ablation by irradiation or to nine courses of chemotherapy with intravenous cyclophosphamide, methotrexate, and fluorouracil (CMF) administered every 3 weeks. RESULTS: Between 1990 and May 1998, 762 patients were randomly assigned, and the present analysis is based on 358 first events. After a median follow-up time of 8.5 years, the unadjusted hazard ratio for disease-free survival in the ovarian ablation group compared with the CMF group was 0.99 (95% CI, 0.81 to 1.22). After a median follow-up time of 10.5 years, overall survival (OS) was similar in the two groups, with a hazard ratio of 1.11 (95% CI, 0.88 to 1.42) for the ovarian ablation group compared with the CMF group. CONCLUSION: In this study, ablation of ovarian function in premenopausal women with hormone receptor-positive breast cancer had a similar effect to CMF on disease-free and OS. No significant interactions were demonstrated between treatment modality and hormone receptor content, age, or any of the well-known prognostic factors.

Acute and late toxicity following adjuvant high-dose chemotherapy for high-risk primary operable breast cancer--a quality assessment study.

From 1996 to 2000, high-dose chemotherapy with haematopoietic stem-cell support was used as an adjuvant treatment strategy for management of primary high-risk breast cancer patients with more than five positive nodes. This single institution study included 52 women aged < or = 56 years with primary operable breast cancer and > or = 6 tumour-positive axillary lymph nodes. The treatment regimen consisted of at least three initial courses of FEC (5-fluorouracil, epirubicin, cyclophosphamide) followed by high-dose chemotherapy (cyclophosphamide, thiotepa, carboplatin) supported by autologous peripheral blood stem-cell reinfusion. This study focuses on quality control including evaluation of toxicity, supportive therapy and assessment of the stem-cell products. Cytokeratin 19 positive cells were found in the stem-cell product from 3/37 patients. Data regarding organ toxicity were used for evaluation of short- and long-term side effects. Substantial acute toxicity and frequent catheter-related infections were found. Long-term toxicities included reduced lung diffusion capacity (n = 36), fatigue (n = 14), arthralgia/myalgia (n = 10), neurotoxicity (n = 9) and memory loss (n = 4). However, most toxicities were grade 1-2 and reversible within two years. No treatment-related death occurred. Within a median follow-up of 30 months (range, 11-57), 25% of the patients had relapsed. Recurrence-free survival was 75% and overall survival was 88% three years after the start of treatment. Overall, high-dose chemotherapy was relatively well tolerated, with manageable toxicity and an acceptable requirement of supportive therapy. Until now, high-dose chemotherapy has not proven superior to conventional-dose adjuvant chemotherapy, therefore it is necessary in the future to focus on well-designed randomized studies.