Treatment of metastatic breast cancer: a large observational study on adherence to French prescribing guidelines and financial cost of the anti-HER2 antibody trastuzumab.

OBJECTIVE: This observational study aimed at analyzing adherence to prescribing guidelines of anti-HER2 monoclonal antibody trastuzumab treatment for metastatic breast cancer. Efficacy and costs were also evaluated. METHODS: The adherence to the trastuzumab treatment plan was analyzed according to both the French postlicensing guidelines published in 2001 and clinical guidelines from the regional cancer network in a cohort of 131 consecutive patients. RESULTS: The level of appropriateness to the molecular target was very high (92% of the patients showed a positive HER2 status, defined as HER2 3+ confirmed by immunohistochemistry or 2+ confirmed by fluorescent in situ hybridization). The treatment plan was made according to the French postlicensing guidelines in 41 patients (31.3%) and to the regional clinical guidelines for 109 patients (83.2%). The main reason for the difference was the type of molecules authorized for combination to trastuzumab. The median overall survival of the studied population was 18.6 months and the median progression-free survival rate was 7.7 months. Up to death or end of the study, the overall cost for the treatment of breast cancer with trastuzumab per patient and per year was 47,832 euro. CONCLUSION: This quite low adherence of clinicians to the French postlicensing guidelines is in contrast with the high level of adherence to the regional clinical guidelines. The reason is that the latter are less rigid about previously received treatments and enlarge the potential associated cytotoxics to vinorelbine. This supports the French National Cancer Institute decision to get expert clinicians involved together with the French agency for sanitary security of health products and the high health authority in a common elaboration of guidelines.

Use of the monoclonal antibody anti-HER2 trastuzumab in the treatment of metastatic breast cancer: a cost-effectiveness analysis.

BACKGROUND: This open controlled prospective study aimed at evaluating the medical and economical impact of first line chemotherapy for metastatic breast cancer (MBC). PATIENTS AND METHODS: Two groups of HER +++ MBC patients were compared: 26 were treated by a combination of trastuzumab and paclitaxel in 4 "prescriber" centers (group A) and 19 patients were treated by any chemotherapy without addition of trastuzumab, in 6 control centers (group B). The cost of chemotherapy and related hospitalizations was taken into account during the first 8 cycles. RESULTS: Forty-five patients, mean age 51 years have been included. The objective response rate was significantly higher in group A (42% vs. 6%, P = 0.036). The median overall survival was 17 months longer in the group A (29 vs. 12 months). The median progression free survival rate was 12.2 months longer in the group A (19 vs. 7 months). The 1-year survival rate was 85% in the group A and 47% in the group B. The mean overall care cost was 33.271 euro per patient in group A versus 11.191 euro per patient in group B. The additional cost per saved year of life expressed as the incremental cost-effectiveness ratio is 15.370 euro 2002. CONCLUSION: The related additional cost seems affordable for an European health care system and justifies the recommendation for its use in the subpopulation overexpressing HER2.