Authors: N Bouganim E Tsvetkova M Clemons E Amir
Publish Date: 2013/05/17
Volume: 139, Issue: 2, Pages: 603-606
Abstract
Improvements in adjuvant therapy have led to a sustained fall in recurrences after early breast cancer The differential reduction in local and systemic recurrences is poorly understood This study aimed to explore changes in the distribution of locoregional and distant recurrences in clinical trials reported over the last 20 years We also aimed to determine the relative impact of adjuvant chemotherapy and endocrine therapy MEDLINE search for adjuvant phase III randomized breast cancer clinical studies between January 1990 and March 2011 was performed Neoadjuvant single agent biologics and studies that did not report the proportion of locoregional and distant recurrences were excluded The change in the frequency of recurrences was assessed as the nonparametric correlation between the number of locoregional recurrences as a proportion of all recurrences and time Studies were weighted by sample size The differential effect of chemotherapy and endocrine therapy was also assessed Fiftythree randomized clinical trials with a total of 86598 patients were included in the analysis Between 1990 and 2011 the proportion of locoregional recurrences has decreased from approximately 30 to 15 Spearman’s ρ = −040 p 0001 There was no interaction between type of surgery mastectomy vs lumpectomy administration of adjuvant radiation therapy and menopausal status and the correlation of locoregional recurrences and time Chemotherapy regimen showed a larger negative correlation compared with endocrine therapy ρ = 049 vs ρ = 024 Advances in treatment of early breast cancer have differentially reduced the proportion of locoregional recurrences compared with distant recurrences In recent trials locoregional recurrences account for less than 10–15 of all recurrences These falling event rates may affect patient care especially when deciding on treatments influencing locoregional control This change may also impact on the design of clinical trials assessing locoregional therapy such as surgery and/or local radiation therapy
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