Improved prognosis of young patients with breast cancer undergoing breast-conserving surgery

BackgroundThe aim of the present study was to evaluate how breast cancer prognosis has evolved over time in young women treated with breast-conserving surgery (BCS). MethodsData from patients younger than 40years who had BCS and whole-breast radiotherapy in a single cancer centre between 1997 and 2010 were analysed. The patients were followed until 2016. Endpoints were local recurrence, any breast cancer-related event and death from any cause. ResultsA total of 1331 patients were included in the study. After a median follow-up of 93years, 114 local recurrences, 289 breast cancer-related events and 138 deaths had occurred. Women were divided into three groups of similar size based on tertiles of the date of diagnosis: 1997-2002 (524 patients), 2003-2005 (350) and 2006-2010 (457). The risk of local recurrence was 142 per 100 person-years in women diagnosed in the first interval, 085 per 100 person-years in the second and 048 per 100 person-years in the third (P for trend=0028). The respective values were 301, 252 and 207 per 100 person-years for any breast cancer-related event (P=0004), and 159, 122 and 064 per 100 person-years for death (P=0003). Each passing year was associated with a decreasing risk of local recurrence (hazard ratio (HR) 093, 95 per cent c.i. 087 to 100), any breast cancer-related event (HR 094, 091 to 098) and death (HR 089, 083 to 094). A major improvement in prognosis was observed after 2005, when the classification of breast cancer molecular subtypes and use of trastuzumab were implemented in routine clinical practice. ConclusionIn the past two decades, both local control and overall prognosis have improved significantly in young women (aged less than 40years) with breast cancer who undergo BCS. Molecular subtype matters most