[Clinical and economic issues in adjuvant chemotherapy for HER-2 positive breast cancer].
OBJECTIVE
To examine efficacy figures and drug expenditure for adjuvant chemotherapy in human epidermal growth factor receptor 2 (HER-2) positive breast cancer, in the Brazilian supplemental health insurance market.


METHODS
We obtained efficacy data (disease free survival at 3-years) and drug cost estimate for current adjuvant strategies in HER-2 positive breast cancer: Finland Herceptin (FinHER), National Surgical Adjuvant Breast and Bowel Project (NSAPB-31), North Central Cancer Treatment Group (N9831), Herceptin Adjuvant (HERA) and Breast Cancer International Research Group (BCIRG-006). We estimated clinical impact measures--number needed to treat (NNT) and absolute risk reduction (ARR)--and total drug cost by protocol to avoid one single cancer recurrence.


RESULTS
The largest ARR was 11.7% (95% CI: 2.2% to 21.2%) in the FinHER study, and the smallest in the nonanthracycline arm of the BCIRG trial, 4.9% (95% CI: 1.8% to 8.1%). The NNT was 8 (95% CI: 3 to 28) in the FinHER, 8 (95% CI: 7 to 11) in the NSABP-31/N9831, 12 (95% CI: 9 to 18) in the HERA, 14 (95% CI: 11 to 24) in the BCIRG/Anthracycline, and 17 (CI 95% CI: 12 to 34) in the BCIRG/Nonanthracycline. Drug cost to avoid one single cancer recurrence would be R$ 418,285.44 with the FinHER regimen, R$ 1,716,789.44 with the NSABP-31/N9831, R$ 2,481,891.58 with the HERA, R$ 2,963,634.62 with the BCIRG/Anthracycline, and R$ 3,930,520.43 with the BCIRG/Nonanthracycline (exchange rate: R$ 1.00=USD 0.56).


CONCLUSIONS
From an economic viewpoint, four to seven times more patients could benefit by using a short-course of trastuzumab at the initial adjuvant chemotherapy cycles (FinHER regimen) than by the prolonged trastuzumab administration as used in other adjuvant schedules.
Martins
Sandro José
SJ
PLANSERV, Estado da Bahia, Salvador, BA. sandro.martins@gmail.com
Yamamoto
Crystina Aoki
CA
D000911:Antibodies, Monoclonal / Q000191:economics / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000191:economics / Q000627:therapeutic use; D001938:Brazil / Q000453:epidemiology; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000191:economics; D017024:Chemotherapy, Adjuvant; D017326:Clinical Trials, Phase III as Topic; D066246:ErbB Receptors; D005260:Female; D006801:Humans; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D066246:ErbB Receptors; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab