# Age- and Treatment-Related Patterns in Fatigue, Coping/Resilience, and Skeletal Muscle Bioenergetics (31P-MRS τPCr) in Cancer Survivors: Exploratory Pilot Analysis

## TL;DR

This pilot study explores how age and cancer treatments affect fatigue, resilience, and muscle mitochondrial function in cancer survivors.

## Contribution

The study introduces exploratory insights into age- and treatment-related differences in mitochondrial function and psychological factors among cancer survivors.

## Key findings

- Older survivors showed longer τPCr and higher fatigue compared to younger participants.
- Younger participants had negative correlations between τPCr and fatigue, and positive correlations with resilience and coping self-efficacy.

## Abstract

Background: Cancer-related health outcomes are shaped by the interplay of aging, complex treatment exposures, and individual psychological characteristics. Mitochondrial dysfunction has been implicated as an underlying biological process affecting cancer-related outcomes. This secondary, exploratory pilot analysis aimed to examine age- and treatment-related differences in fatigue, coping self-efficacy, resilience, and skeletal muscle mitochondrial oxidative capacity, measured via phosphorus-31 magnetic resonance spectroscopy (31P-MRS). Methods: Eleven cancer survivors (mean age 53.3 ± 12.7 years) were recruited from a larger symptom management trial. Participants underwent 31P-MRS to assess mitochondrial function via phosphocreatine recovery time constant (τPCr). Patient-reported outcome measures and physical function assessments were collected. Group comparisons and correlation analyses were conducted to evaluate differences and associations based on age (<65 vs. ≥65 years) and treatment. Because treatment categories were not mutually exclusive and the time since last treatment was not collected, treatment-related comparisons are descriptive only. Given the small available sample size, we conducted this study as exploratory and hypothesis-generating. Results: Older survivors (≥65) had longer τPCr (59.5 vs. 50.1 s), weaker grip strength, higher fatigue, and lower physical performance compared to younger participants, although differences were not statistically significant. Treatment-related patterns were descriptive; participants receiving multiple treatments had shorter τPCr but lower muscular strength, while immunotherapy recipients reported higher fatigue and lower physical activity. Among younger participants, a negative correlation was observed between τPCr and fatigue (ρ = −0.71), and positive correlations were observed with resilience (ρ = 0.61) and coping self-efficacy (ρ = 0.74), reflecting a pattern that warrants cautious interpretation in this small sample. Conclusions: These preliminary results suggest age- and treatment-related differences in fatigue, physical performance, psychological factors, and skeletal muscle mitochondrial bioenergetics. These signals warrant further testing in larger, adequately powered cohorts to clarify mechanisms and inform the development of personalized survivorship care strategies.