Reviewing changes in adjuvant treatment algorithm over a decade: effects and impact on outcome in patients with newly diagnosed early-stage breast cancer in Mid-Western Ireland.

Breast cancer is a leading cause of morbidity and mortality amongst adult women in Western Europe and North America. Within the last decade our understanding of this condition has improved. This has led to the emergence of new treatment algorithms and prognostic instruments. Examples of the former include taxane-based therapy and trastuzumab; further examples of the latter are novel prognostic instruments such as Nottingham Prognostic Index (NPI) and Adjuvant! Online (AO). The aim of this thesis is to determine if the application of these is associated with improved cancer-specific outcomes. To this end, we conducted a retrospective population-based determination of cancer-specific outcomes associated with newer treatment algorithms. In addition we determined the correlation between prognosis and actual outcome for NPI and AO. These were compared with outcomes associated with prior treatment approaches. The thesis finishes with a comparison of both to determine the optimal treatment management paradigm. Adjuvant taxane therapy was not associated with improved cancer-specific outcome compared with non-taxane based therapy. However, third-generation (taxane-based) therapy was associated improved cancer-specific outcome compared with first- and second-generation (taxane- and non-taxane based) therapy. Adjuvant trastuzumab treatment was associated with improved cancer-specific outcome. Prognostic accuracy differed for NPI and AO. In conclusion, these practice changes have had a mixed effect on outcomes for patients with early-stage breast cancer (EBC).