6150 Background: Pain has been identified as an important factor for cancer fatigue. We studied the association between changes in pain, fatigue, satisfaction and identified independent predictors of worse fatigue outcome and of clinically relevant fatigue (CRF) (usual fatigue ≥ 3/10) after 1 wk of CPM. Methods: 141 pts with worst pain ≥ 4/10 completed the Brief Pain Inventory, Brief Fatigue Inventory, and satisfaction at day 1, wk 1 and were screened for laboratory abnormalities on day 1. The presence of other symptoms and self-rated perception of changes in pain severity (SRPC) were assessed at wk 1. Raw changes in pain severity (RCPS), fatigue severity (RCFS) and satisfaction (RCSAT) were calculated; Spearman correlation, oneway ANOVA and multivariate logistic analysis were performed. Results: The median (M) age was 68 (44–87) with M Hemoglobin 11.6 g/dL (6.5–16.3). By SRPC, worse pain was found in 13 pts (9%), no changes in 33 (23%) and better in 95 (68%), (a little bit in 38, moderate in 23 and very much in 34). SRPC correlated significantly with RCPS (p<0.0001), RCFS (p=0.03) and RCSAT (p<0.001). Pts with moderate and much better SRPC had M 3 points decrease in pain severity. Three fatigue outcome groups (FOGs) were defined based on RCFS: better in 64 (46%), no changes in 30 (21%) and worse in 47 (33%); CRF was present in 103 pts (73%). There were significant differences in pain severity (p=0.04), RCPS (p=0.004) and satisfaction (p=0.02) among 3 FOGs by oneway ANOVA. In a multivariate logistic model with known fatigue predictors and pain outcome (RCPS ≥ 3 vs < 3), independent predictors of worse fatigue outcome were presence of drowsiness, poor pain outcome (PPO) and older age (p= 0.006, 0.009 & 0.03 respectively). In addition to drowsiness (p=0.002) and PPO (p=0.05), feeling nervous (p=0.02), sedation (p=0.07) and feeling irritable (p=0.07) predicted CRF independently. Conclusions: Perceived better pain outcome was reported in 68% pts and SRPC correlated significantly with RCPS, RCFS and RCSAT. Although 45% had better RCFS, 73% of pts had CRF. The PPO was predictive of worse fatigue outcome and CRF. (VAHSR&D PCC98068). Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration VA HSR&D