title: Understanding weight loss in patients with colorectal cancer: a human response to illness.
abstract: OBJECTIVE
  To provide a comprehensive overview of weight loss in patients with colorectal cancer (CRC) within the context of the Human Response to Illness (HRTI) model.
  
  
  METHODS
  Research from 1990-2008 and classic research from the 1980s were included. PubMed, CINAHL(R), and Google Scholar were searched for the terms cancer, CRC, weight loss, and cancer cachexia.
  
  
  RESULTS
  Progressive, unintentional weight loss is a common issue in patients with CRC that has a devastating effect on patients' self-image, quality of life, and survival. Physiologic abnormalities, responses to the tumor, and treatments contribute to weight loss in these patients. In addition, cancer cachexia is an end-stage wasting syndrome and a major cause of morbidity and mortality in this population.
  
  
  CONCLUSIONS
  The HRTI model provides an appropriate framework to gain a comprehensive understanding of the physiologic, pathophysiologic, behavioral, and experiential perspectives of weight loss and cancer cachexia in patients with CRC.
  
  
  CONCLUSIONS
  By examining weight loss in patients with CRC within the context of the four perspectives of the HRTI model, oncology and gastroenterology nurses can gain insight into optimal, evidence-based assessment and management of this patient population. In addition, current gaps in knowledge can be identified and provide guidance for future nursing research.
authors.affiliation: Research and Evaluation Unit, Winnipeg Regional Health Authority, Manitoba, Canada. sunita_hb@yahoo.co.in
authors.forename: Sunita Bayyavarapu
authors.initials: SB
authors.lastname: Bapuji
authors.forename: Jo-Ann V
authors.initials: JA
authors.lastname: Sawatzky
mesh_terms: D000223:Adaptation, Psychological; D001294:Attitude to Health; D002100:Cachexia / Q000209:etiology*; D015984:Causality; D015179:Colorectal Neoplasms / Q000150:complications* / Q000378:metabolism / Q000523:psychology; D006801:Humans; D008016:Life Change Events; D008954:Models, Biological; D016294:Models, Nursing; D008960:Models, Psychological; D009730:Nursing Assessment; D009859:Oncology Nursing; D011788:Quality of Life; D013315:Stress, Psychological / Q000209:etiology; D015431:Weight Loss / Q000502:physiology*