Elapsed time from breast cancer detection to first adjuvant therapy in a Canadian province, 1999-2000

Abstract

Background: A number of studies have examined time intervals between care steps in breast cancer diagnosis and treatment. The objective of this study was to document the elapsed time from first clinical or mammographic detection of breast abnormality to initiation of first adjuvant therapy in women with invasive breast cancer in Nova Scotia and to examine the effect of age, disease stage and place of residence on these intervals.

Methods: All dates were abstracted from patient charts and the Oncology Patient Information System. Eligible women were those with invasive breast cancer detected by Sept. 1, 1999, who were referred to 1 of 2 provincial cancer treatment centres by Sept. 1, 2000. All time intervals were calculated in days, and only patients experiencing both care events defining an interval were included in the analysis of time to event for that interval. We used proportional hazards regression analysis to evaluate the influence of patient age, disease stage and place of residence on times between care events.

Results: A total of 776 new diagnoses of breast cancer were reported to the Nova Scotia Cancer Registry over the study period. Of the 776, 467 met the inclusion criteria, and 364 patients were eligible for analysis. The overall median time from clinical or mammographic detection of breast cancer to initiation of first adjuvant therapy was 91 days (interquartile range 72-123 days). Disease stage was the strongest predictor of elapsed time: the median interval from disease detection to initiation of first adjuvant therapy for patients with stage I disease was 118 days, as compared with 85 days for those with stage II disease and 75 days for those with stage III disease (adjusted hazard ratio [HR] 2.1, 95% confidence interval [CI] 1.6-2.8). Patients aged 70 years or more at diagnosis experienced longer elapsed times (median interval 98 days) than did younger patients (93 days for those aged 50-69 years and 82 days for those aged 49 years or less) (adjusted HR 1.6, 95% CI 1.1-2.4).

Interpretation: Women aged 70 or more and those with stage I breast cancer experienced longer elapsed times from disease detection to initiation of first adjuvant therapy than did younger women and those with more advanced disease. These findings may have implications for the design of interventions to minimize intervals between steps in breast cancer care and should be validated within the Canadian context. Future investigation exploring the full spectrum of breast cancer care may lead to a more complete understanding of processes and gaps in the current system.

Fig. 1: Subjects available for analysis and reasons for exclusion.