Prognosis in patients diagnosed with loco-regional failure of breast cancer: 34 years longitudinal data from the Stockholm-Gotland cancer registry

Rationale: Survival after loco-regional failure (LRF) of breast cancer was investigated at the population level.

Methods: Using the Stockholm cancer registry, 2698 patients diagnosed with LRF between 1980 and 2014 were identified and divided into three cohorts by year of LRF diagnosis. Post-relapse event-free survival (EFS) and overall survival (OS) were analyzed separately in local and loco-regional relapses and compared across the cohorts by Kaplan-Meier method. Relative survival was estimated and Poisson regression models, adjusted for clinically relevant prognostic factors, were fitted for excess mortality ratio calculation. Age-related survival trends were also explored.

Results: Among 1922 patients diagnosed with local relapse, 1032 (54%) EFS events and 931 (48%) deaths were registered. A significant improvement in EFS (p < 0.001) and OS (p < 0.001) was demonstrated in tumors that recurred locally in the years 1990-1999 and 2000-2014 compared with 1980-1989, regardless of age at relapse (≤ 60 years; > 60 years). In women with loco-regional relapse, 557 out of 776 (72%) experienced a post-relapse event and 522 (67%) died. Significantly longer EFS and OS were seen over time in the whole group (p < 0.001 and p = 0.003, respectively) and in younger (p < 0.001; p < 0.001) but not in older women (p = 0.55; p = 0.80). Relative survival was consistent with OS and a statistically significant decrease in mortality after loco-regional recurrence over time was seen only in women aged ≤ 60 years.

Conclusions: Survival after loco-regional failure of breast cancer has improved over time, especially in younger women.