Mortality of women with ductal carcinoma in situ of the breast: a population-based study from the Girona province, Spain (1994-2013).

ABSTRACT

PURPOSE: We aim to comprehensively describe the incidence and mortality trends of ductal carcinoma in situ (DCIS) in the Girona province, Spain (1994-2013) and to estimate the all-cause mortality excess risk of diagnosed women. METHODS: Age-standardized rates of DCIS were estimated between 1994 and 2013. Standard mortality ratios (SMR) and absolute excess mortality were calculated overall and by tumor and patient characteristics. A sensitivity analysis was conducted excluding cases with a subsequent invasive breast cancer (sIBC). RESULTS: Of the 641 women included, 56 died (follow-up time 8.4 person-years). Between 1994 and 2013, a significant increase in incidence and decrease in mortality was identified among women aged between 50 and 69 years old. Neoplasms and circulatory system disease were the most common causes of death. No excess risk of death was found overall, except for women aged < 50 years (SMR = 3.44, 95% CI 1.85; 6.40) and those with a sIBC (SMR = 2.51, 95% CI 1.26; 5.02), risk that lessened when cases with sIBC were excluded. Patients with sIBC also showed an excess risk (SMR = 2.29, 95% CI 1.03; 5.10). CONCLUSIONS: Among women aged 50-69 years old, incidence of DCIS has significantly increased yet mortality has decreased. Overall, the all-cause mortality risk of women diagnosed with DCIS remains similar to that of the general population except for women diagnosed before age 50 and those with sIBC, who showed a significant increased risk. Differential management of these patients should be considered.