T Reinert1,2,3, M Debiasi1,4, J Bines1,5, C H Barrios6,7. 1. Latin American Cooperative Oncology Group (LACOG), Porto Alegre, Brazil. 2. Hospital Do Câncer Mãe de Deus, Rua Costa, 40, 4 Andar, Porto Alegre, Brazil. 3. Post Graduate Program in Medical Sciences, Federal University of Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil. 4. PUCRS School of Medicine, Porto Alegre, Brazil. 5. Instituto Nacional Do Câncer José de Alencar Gomes Da Silva (INCA), Rio De Janeiro, Brazil. 6. Latin American Cooperative Oncology Group (LACOG), Porto Alegre, Brazil. chbe@via-rs.net. 7. Hospital Do Câncer Mãe de Deus, Rua Costa, 40, 4 Andar, Porto Alegre, Brazil. chbe@via-rs.net.
Abstract
BACKGROUND: Over the last 20 years, aromatase inhibitors (AI) have been tested in clinical trials as first-line therapy for hormone receptor-positive (HR-positive) advanced breast cancer (ABC), firstly as experimental arms, when they proved to be effective, and recently as control arms. This analysis aims to evaluate trends in progression-free survival (PFS) and time to progression (TTP) over time. PATIENTS AND METHODS: A literature review was conducted using the MEDLINE database to identify randomized controlled phase II or III trials which reported PFS or TTP of at least one arm using first-line AI HR-positive ABC patients. A linear correlation was used to access the association between the year of the first patient enrolled and the observed PFS/TTP. RESULTS: The search retrieved 19 trials, accounting for 4552 postmenopausal patients divided into 21 separate AI treatment arms. The PFS/TTP increased from 6 to 9 months in the earlier trials to 13-16 months in the current era, representing an absolute gain of approximately 7 months, without the addition of any other drug. Our analysis showed a positive correlation between the year of the first patient enrolled in these trials and median PFS/TTP reported (R 2 = 0.34; p < 0.01). No correlation was found between the year of the first patient included in these trials and other potential prognostic factors such as visceral metastasis at baseline (R 2 = 0.26; p = 0.20) or exposure to adjuvant therapy (R 2 = 0.05; p = 0.18). CONCLUSION: Patients treated with first-line AIs in the more recently conducted trials have longer PFS/TTP when compared to their counterparts treated with the same drugs in older studies. These findings have important implications for the estimation of sample size and follow-up periods for the planning of future trials as well as in the translation of the results into clinical practice decisions.
BACKGROUND: Over the last 20 years, aromatase inhibitors (AI) have been tested in clinical trials as first-line therapy for hormone receptor-positive (HR-positive) advanced breast cancer (ABC), firstly as experimental arms, when they proved to be effective, and recently as control arms. This analysis aims to evaluate trends in progression-free survival (PFS) and time to progression (TTP) over time. PATIENTS AND METHODS: A literature review was conducted using the MEDLINE database to identify randomized controlled phase II or III trials which reported PFS or TTP of at least one arm using first-line AI HR-positive ABC patients. A linear correlation was used to access the association between the year of the first patient enrolled and the observed PFS/TTP. RESULTS: The search retrieved 19 trials, accounting for 4552 postmenopausal patients divided into 21 separate AI treatment arms. The PFS/TTP increased from 6 to 9 months in the earlier trials to 13-16 months in the current era, representing an absolute gain of approximately 7 months, without the addition of any other drug. Our analysis showed a positive correlation between the year of the first patient enrolled in these trials and median PFS/TTP reported (R 2 = 0.34; p < 0.01). No correlation was found between the year of the first patient included in these trials and other potential prognostic factors such as visceral metastasis at baseline (R 2 = 0.26; p = 0.20) or exposure to adjuvant therapy (R 2 = 0.05; p = 0.18). CONCLUSION:Patients treated with first-line AIs in the more recently conducted trials have longer PFS/TTP when compared to their counterparts treated with the same drugs in older studies. These findings have important implications for the estimation of sample size and follow-up periods for the planning of future trials as well as in the translation of the results into clinical practice decisions.