Pain catastrophizing as a longitudinal correlate of shoulder dysfunction and lymphedema in geriatric breast cancer survivors.

BACKGROUND

Modified radical mastectomy (MRM) is associated with persistent psychological and physical sequelae in geriatric breast cancer survivors. This study examines the 60-month longitudinal associations between pain catastrophizing, depression, pain interference, shoulder dysfunction, and lymphedema.

METHODS

In this retrospective cohort study, 89 geriatric women (median age = 72, IQR = 69-76, range = 65-88) who underwent MRM were assessed at baseline (pre-surgery), 1, 3, and 2 months after completion of radiotherapy (median 5 months post-surgery, IQR 4.5-5.5), and 12, 24, 36, 48, and 60 months post-surgery. Pain Catastrophizing Scale (PCS), Geriatric Depression Scale (GDS), Brief Pain Inventory (BPI) interference, shoulder range of motion (ROM) differences (flexion and abduction), and lymphedema severity (Frustum formula, ISL staging) were measured. Lymphedema was defined using a primary threshold of ≥ 5% inter-limb volume difference and a sensitivity analysis threshold of ≥ 10% or ≥ 200 mL. Patients were stratified by baseline PCS median (high: ≥25; low: <25). Spearman correlations, Wilcoxon signed-rank tests, Mann-Whitney U tests, and Fisher's exact tests were used. All statistical tests were two-tailed, and p-values were adjusted for multiple comparisons using the false discovery rate (FDR) method.

RESULTS

Strong correlations were observed between PCS, GDS, and BPI across all time points (ρ = 0.911-0.994, q < 0.001). Shoulder ROM differences correlated significantly with PCS, GDS, and BPI from 1 month onward (ρ = 0.864-0.939, q < 0.001), peaking at 24 months. Lymphedema (≥ 5% threshold ) showed moderate correlations at 3 months (ρ = 0.443-0.516, q < 0.001), strengthening by 24-36 months (ρ = 0.687-0.803, q < 0.001). High PCS patients had significantly worse GDS, BPI, ROM differences, and lymphedema incidence (see Table 3).

CONCLUSIONS

Pain catastrophizing is strongly and persistently associated with shoulder dysfunction and lymphedema in geriatric breast cancer survivors. Early PCS-based risk stratification is recommended to guide targeted interventions.