Improvements in breast cancer survival over time, related to adjuvant treatment and node status

Abstract 

Background

There has been an increase in the use and effectiveness of adjuvant treatment for operable breast cancer and the aim of this study was to examine whether this has resulted in improved survival for all prognostic groups.

Methods

A retrospective study of 1517 patients with invasive breast cancer treated between 1980 and 2002 was carried out. The use of adjuvant treatment was compared between two time periods in patients based on nodal status, and survival was calculated by Kaplan–Meier life table analysis. Independent predictors for recurrence-free survival (RFS) were determined by Cox regression analysis.

Results

The use of adjuvant therapy increased for all prognostic groups. On multivariate analysis the use of radiotherapy and endocrine therapy was positively associated with RFS which was significant in the second time period. Outcome in node positive patients improved: five-year RFS from 59% to 76%, p<0.01 and breast cancer specific survival (BCSS) from 70% to 83%, p<0.01. However, there was no survival improvement in the larger group of node negative patients; BCSS 93% versus 95%, p=0.99. Within the node negative group, patients with tumours≥2cm had an improved RFS from 80% to 88%, p=0.02.

Conclusion

The increased use of adjuvant therapy was associated with an improved outcome in node positive patients. For node negative patients with good prognostic features the evidence of benefit was marginal.

Keywords: Breast cancer survival, Lymph node status, Adjuvant treatment