Impact of chemotherapy on medium-term physical function and activity of older breast cancer survivors, and associated biomarkers

Abstract

Objective: Chemotherapy is less often prescribed in older individuals due to concerns about post-treatment morbidity and quality of life. We evaluated the physical performance of breast cancer survivors treated with and without adjuvant chemotherapy.

Materials and methods: We conducted a case-control study in 56 estrogen receptor positive breast cancer survivors (BCS) on adjuvant aromatase inhibitors 1-2years after definitive surgery. Cases had received adjuvant chemotherapy (n=27; age 70.5±3.6years) versus age-matched controls who had not (n=29; age 70.0±4.3years). Measures of grip strength, physical activity and performance, walking speed, fatigue, and self-reported physical function were collected. Biological correlates of inflammation, frailty and markers of DNA and RNA oxidation were compared.

Results: Grip strength (controls: 21±7.4 vs.

Cases: 29.7±5.0kg, p=0.20), physical activity (5403±3204 vs. 6801±9320steps/day, p=0.45), physical performance (short physical performance battery score: 10.1±1.8 vs. 10.4±1.1, p=0.52) and long-distance walking speed (1.2±0.21 vs. 1.3±0.41m/s, p=0.17) were similar between the two groups. Self-reported physical function was marginally lower in cases than controls (controls: 72±24 vs.

Cases: 57±34AU, p=0.07). Fatigue disruptiveness was not different between groups (controls: 11.1±13.0 vs.

Cases: 15.7±16.2AU, p=0.24). Similarly, the inflammation, oxidation, and frailty markers did not present a significant difference between groups, except for vitamin D levels (p=0.04).

Conclusion: Older women who received chemotherapy reported having slightly lower physical function, but a similar physical performance compared to women who did not. These data suggest that older BCS treated with chemotherapy recover to an extent similar to survivors who only received hormonal therapy.

Keywords: Albumin; Breast cancer; Chemotherapy; DNA oxidation; Elderly; Functional status; IGF-1; IGFBP-3; IL-6; Inflammation; Physical function; RNA oxidation; Survivorship; TNF-alpha; Vitamin D; d-Dimers.