UCSF

Objectives

We examined the impact of functional limitations and functional decline during the first year following breast cancer diagnosis on the risk of mortality from breast cancer and other causes among African-American and white women, respectively.

Design

The Health and Functioning in Women (HFW) cohort study.

Setting

Detroit, Michigan, USA.

Participants

A total of 162 African-American and 813 white women aged 40-84 years with newly diagnosed breast cancer identified through the Metropolitan Detroit Cancer Surveillance System over a 7-month period between 1984 and 1985 and followed for up to 28 years (median 11 years).

Outcome measures

Risk of mortality from breast cancer and other causes.

Results

Statistically significant increases in the risk of other-cause mortality were found for each unit increase in the number of self-reported functional limitations (HR=1.08, 95% CI 1.03 to 1.14), 0 vs ≥1 functional limitations (HR=1.47, 95% CI 1.13 to 1.91), difficulty in pushing or pulling large objects (HR=1.34, 95% CI 1.04 to 1.73), writing or handling small objects (HR=1.56, 95% CI 1.00 to 2.44), and walking half a mile (HR=1.60, 95% CI 1.19 to 2.14). Functional limitations and functional decline did not explain racial disparities in the survival of this cohort. Functional decline was associated with increased risk of other-cause mortality in women with regional and remote disease but not in women with localised disease. Whereas measures of functional limitation were not associated with breast cancer-specific mortality, each unit of functional decline (HR=1.17, 95% CI 1.05 to 1.31) and decline in the ability to sit ≥1 h (HR=2.06, 95% CI 1.13 to 3.76) were associated with increased risk of breast cancer-specific mortality. Measures of functional decline were associated with increased risk of breast cancer mortality in overweight and obese women, but not in women of normal weight.

Conclusions

Whereas functional limitations were associated with increased risk of other-cause mortality, functional decline was associated with increased risk of breast cancer mortality.