Little data exist on whether efficacy benefits or side-effects persist after 5 years of adjuvant treatment with an aromatase inhibitor. We aimed to study long-term outcomes in the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial that compares anastrozole with tamoxifen after a median follow-up of 100 months. METHODS: We analysed postmenopausal women with localised invasive breast cancer. The primary endpoint disease-free survival (DFS), and the secondary endpoints time to recurrence (TTR), incidence of new contralateral breast cancer (CLBC), time to distant recurrence (TTDR), overall survival (OS), and death after recurrence were assessed in the total population (intention to treat; ITT: anastrozole, n=3125; tamoxifen, n=3116; total 6241) and the hormone-receptor-positive subpopulation, the clinically important subgroup for which endocrine treatment is now known to be effective (84% of ITT: anastrozole, n=2618; tamoxifen, n=2598; total 5216). After treatment completion, fractures and serious adverse events continued to be collected blindly (safety population: anastrozole, n=3092; tamoxifen, n=3094; total 6186). This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN18233230. FINDINGS: At a median follow-up of 100 months (range 0-126), DFS, TTR, TTDR, and CLBC were improved significantly in the ITT and hormone-receptor-positive populations. For hormone-receptor-positive patients: DFS hazard ratio (HR) 0.85 (95% CI 0.76-0.94), p=0.003; TTR HR 0.76 (0.67-0.87), p=0.0001; TTDR HR 0.84 (0.72-0.97), p=0.022; and CLBC HR 0.60 (0.42-0.85), p=0.004. Absolute differences in time to recurrence increased over time (TTR 2.8% [anastrozole 9.7%vs tamoxifen 12.5%] at 5 years and 4.8% [anastrozole 17.0%vs tamoxifen 21.8%] at 9 years) and recurrence rates remained significantly lower on anastrozole compared with tamoxifen after treatment completion (HR 0.75 [0.61-0.94], p=0.01). The fewer deaths after recurrence (anastrozole 245 vs tamoxifen 269) was not significant (HR 0.90 [0.75-1.07], p=0.2), and no effect was noted for OS (anastrozole 472 vs tamoxifen 477) HR 0.97 [0.86-1.11], p=0.7). Fracture rates were higher in patients receiving anastrozole than in those receiving tamoxifen during active treatment (number [annual rate]: 375 [2.93%] vs 234 [1.90%]; incidence rate ratio [IRR] 1.55 [1.31-1.83], p<0.0001), but were not different after treatment was completed (off treatment: 146 [1.56%] vs 143 [1.51%]; IRR 1.03 [0.81-1.31], p=0.79). We did not note any significant difference in risk of cardiovascular morbidity or mortality between anastrozole and tamoxifen treatment groups. INTERPRETATION: These data show long-term safety findings and establish clearly the long-term efficacy of anastrozole compared with tamoxifen as initial adjuvant treatment for postmenopausal women with hormone-sensitive, early breast cancer, and provide statistically significant evidence of a larger carryover effect after 5 years of adjuvant treatment with anastrozole compared with tamoxifen.
- MeSH
- alkylační protinádorové látky škodlivé účinky terapeutické užití MeSH
- časové faktory MeSH
- fraktury kostí chemicky indukované MeSH
- inhibitory aromatasy škodlivé účinky terapeutické užití MeSH
- lidé MeSH
- lokální recidiva nádoru MeSH
- nádory prsu farmakoterapie mortalita MeSH
- následné studie MeSH
- nitrily škodlivé účinky terapeutické užití MeSH
- postmenopauza MeSH
- přežití bez známek nemoci MeSH
- tamoxifen škodlivé účinky terapeutické užití MeSH
- triazoly škodlivé účinky terapeutické užití MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Klíčová slova
- Arimidex, Novaldex,
- MeSH
- adjuvantní chemoterapie metody škodlivé účinky využití MeSH
- finanční podpora výzkumu jako téma MeSH
- interpretace statistických dat MeSH
- karcinom terapie MeSH
- lidé MeSH
- nádory prsu diagnóza terapie MeSH
- nitrily aplikace a dávkování škodlivé účinky terapeutické užití MeSH
- tamoxifen aplikace a dávkování škodlivé účinky terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
British journal of cancer, ISSN 0007-0920 vol. 90, suppl. 1, March 2004
18 s. : tab., grafy ; 28 cm
- MeSH
- hormonální substituční terapie trendy MeSH
- nádory prsu MeSH
- receptory pro estrogeny antagonisté a inhibitory terapeutické užití MeSH
- Publikační typ
- sborníky MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- endokrinologie
- onkologie
- gynekologie a porodnictví
- MeSH
- cytodiagnostika diagnostické užití metody MeSH
- lidé MeSH
- nádory prsu diagnóza MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH