title: Factors associated with response to methylphenidate in advanced cancer patients.
abstract: BACKGROUND
  There has been increasing interest in the use of methylphenidate for cancer-related fatigue (CRF) in patients with advanced cancer. However, there is limited literature on the specific patient characteristics associated with response to methylphenidate. Our objective of this study was to identify the specific patient characteristics associated with response to methylphenidate and to compare day 1 response with day 8 response.
  
  
  METHODS
  We retrospectively reviewed the records of patients in two prospective controlled clinical trials that we had conducted who had received methylphenidate for cancer-related fatigue. Baseline patient characteristics, symptoms (as assessed by the Edmonton Symptom Assessment System [ESAS] and Functional Assessment of Chronic Illness Therapy-Fatigue [FACIT-F]), and response (change in fatigue) at the end of day 1 treatment were analyzed to determine their association with response to methylphenidate on day 8.
  
  
  RESULTS
  A total of 82 patients with advanced cancer who received methylphenidate for CRF were included in our review. The median age was 55 years, 66% were female, 74% were white, and the most common cancer type was breast (37%). Fifty out of 82 patients (61%) responded to methylphenidate (≥ 7 points in FACIT-F). The intensity of baseline fatigue positively correlated with the response to methylphenidate (p < .001). Change in fatigue in response to methylphenidate was not associated with intensity of baseline depression, anxiety, drowsiness, or daily opioid dose. Better improvement of fatigue after treatment on day 1 was associated with more improvement with fatigue on day 8 as assessed by FACIT-F (p = .0004) and ESAS (p = .0001). Day 1 response as a predictor of day 8 response had a sensitivity of 0.84, a positive predictive value of 0.67, and specificity of 0.6.
  
  
  CONCLUSIONS
  Response to methylphenidate is associated with higher baseline fatigue but not with higher baseline depression or sedation. Additionally, day 1 improvement is highly sensitive as a predictor of long-term improvement.
authors.affiliation: Department of Palliative Care and Rehabilitation Medicine, Unit 008, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA. syennu@mdanderson.org
authors.forename: Sriram
authors.initials: S
authors.lastname: Yennurajalingam
authors.forename: J Lynn
authors.initials: JL
authors.lastname: Palmer
authors.forename: Ray
authors.initials: R
authors.lastname: Chacko
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bruera
mesh_terms: D000855:Anorexia / Q000188:drug therapy / Q000209:etiology; D001007:Anxiety / Q000188:drug therapy / Q000209:etiology; D000697:Central Nervous System Stimulants / Q000627:therapeutic use; D003863:Depression / Q000188:drug therapy / Q000209:etiology; D016903:Drug Monitoring; D004417:Dyspnea / Q000188:drug therapy / Q000209:etiology; D005221:Fatigue / Q000188:drug therapy* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D008875:Middle Aged; D009325:Nausea / Q000188:drug therapy / Q000209:etiology; D009367:Neoplasm Staging / Q000145:classification; D009369:Neoplasms / Q000150:complications* / Q000188:drug therapy / Q000473:pathology; D010146:Pain / Q000188:drug therapy / Q000209:etiology; D012189:Retrospective Studies; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy / Q000209:etiology; D012894:Sleep Stages; D016896:Treatment Outcome
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate