To assess influence of stage at breast cancer diagnosis, tumour biology, and therapy on survival in contemporary times of better (neo) adjuvant systemic therapy. Design Prospective nationwide population based study. Method Female primary breast cancer patients diagnosed between 1999 and 2012 (173,797). Participants were subdivided into two time cohorts on the basis of breast cancer diagnosis; 1999 through 2005 (n = 80,228) and 2006 through 2012 (n = 93,569). Main outcome measures were relative survival, compared between both cohorts, and the influence of traditional prognostic factors on overall mortality, analyzed with Cox regression for both cohorts separately. Results Compared to 19992005 patients from 20062012 had smaller ( = T1 65 vs. 60%; p < 0.001), more often lymph node negative (N0 68 vs. 65%; p < 0.001) tumours, but they received more chemotherapy, hormonal therapy, and targeted therapy (neoadjuvant/ adjuvant systemic therapy 60 vs. 53%; p < 0.001). Median followup was 9.8 years for 19992005 and 3.9 years for 20062012. Relative 5years survival rate was 96% in 20062012, improved in all tumour and nodal stages compared to 19992005, and 100% in tumours ≤ 1 cm. With multivariable analyses, adjusted for age and tumour type, overall mortality decreased by surgery (especially breast conserving), radiotherapy and systemic therapies. Mortality increased with progressing tumour size in both cohorts (20062012 T1c vs. T1a HR 1.54, 95% CI 1.33 to 1.78), but without significant difference in invasive breast cancers until 1 cm (20062012 T1b vs. T1a HR 1.04, 95% CI 0.88 to 1.22), and independently with progressing number of positive lymph nodes (20062012 N1 vs. N0 HR 1.25, 95% CI 1.17 to 1.32). Conclusion Tumour stage at breast cancer diagnosis influences overall survival significantly also in the current era of effective systemic therapy. Early tumour stage at breast cancer diagnosis remains vital.
|Journal||Nederlands tijdschrift voor geneeskunde|
|Publication status||Published - 1 Jan 2016|