Association of fall rate and functional status by genotype in cancer survivors after exercise intervention.

Purpose/objectives: Cancer treatment survivors often report impaired functioning and increased falls. Not all survivors experience the same symptom burden, suggesting individual susceptibilities. genotype is a potential genetic risk factor for cancer treatment related side effects. Lifestyle factors such as physical activity can mitigate the effect of genotype on measures of clinical interest in individuals without a history of cancer. We tested the hypothesis that genotype influences cancer treatment related side effects and symptoms as well as response to exercise intervention.

Materials And Methods: Data from a subsample of a study of fall prevention exercise in post-treatment female cancer survivors aged 50-75 years old (https://clinicaltrials.gov NCT01635413) were used to conduct a secondary data analysis. ApoE genotype was determined by serum sampling. Physical functioning, frequency of falls, and symptom burden were assessed using survey instruments.

Results: Data from 126 female cancer survivors a median of 49 months out from cancer diagnosis were analyzed. ApoE4 carriers trended toward a higher fall rate at baseline ( = 0.059), but after exercise intervention had a fall rate lower than E4 non-carriers both immediately after structured intervention ( = 0.013) and after 6 months of follow up ( = 0.002). E2 carriers did not show improved measures of depressive symptoms and self-report disability after exercise intervention. E3 homozygotes showed increased self report physical activity after the 6 month exercise intervention, but E4 and E2 carriers did not.

Conclusions: genotype may modulate cancer treatment related side effects and symptoms and response to exercise intervention.