Abstract
BACKGROUND.
Over the past decade, a number of new therapeutic agents have become available in the treatment of metastatic breast cancer (MBC). This study characterized the use and assessed the impact on survival of populationโbased access to new agents for the treatment of MBC.
METHODS.
The dates of release in British Columbia of 7 new systemic agents for MBC during the 1990s were used to construct 4 time cohorts. All patients with a first diagnosis of distant metastases in each of the time cohorts were identified and characterized, and their survival was compared. Cox proportional regression modeling was used to assess for predictors of survival.
RESULTS.
In total, 2150 patients with a first distant metastases diagnosed during 1 of the 4 cohort intervals were identified. Baseline characteristics between cohorts were similar, except a greater proportion of the later cohorts received adjuvant chemotherapy (P < .001), had positive estrogen receptor status (P = .01), and had a longer median time from initial diagnosis to MBC (P < .001). Survival in Cohort 1 (1991โ1992) and Cohort 2 (1994โ1995; median, 438 days and 450 days, respectively) was similar. Survival was longer in Cohort 3 (1997โ1998; median, 564 days; P = .002) and improved further in Cohort 4 (1999โ2001; median, 667 days; P = .05). In multivariate analysis, the later cohorts were associated independently with improved survival (P = .01 and P < .001, respectively).
CONCLUSIONS.
Populationโbased access to new therapeutic agents for MBC appeared to be associated with improved survival. To the authors' knowledge, this is the first study to date that demonstrates, from a populationโbased perspective, improving survival over the past decade for women with MBC. Cancer 2007. ยฉ 2007 American Cancer Society.