title: Prognostic relevance of prediagnostic weight loss and overweight at diagnosis in patients with colorectal cancer.
abstract: Studies on the association between body mass index (BMI) and colorectal cancer (CRC) prognosis after diagnosis have yielded inconsistent results. Few studies have investigated associations between prediagnostic BMI change and CRC prognosis.
  
  
  
  The associations of BMI at diagnosis and prediagnostic BMI change with relevant prognostic outcomes were evaluated in a large population-based cohort of CRC patients.
  
  
  
  A total of 3130 patients diagnosed with CRC between 2003 and 2010 were interviewed on sociodemographic and lifestyle factors, medication, and comorbidities. Cancer recurrence, vital status, and cause of death were documented for a median follow-up time of 4.9 y. With the use of Cox proportional hazards regression, associations between BMI at diagnosis and BMI change (difference between 1-10 y before diagnosis and at diagnosis) and overall, CRC-specific, recurrence-free, and disease-free survival were analyzed.
  
  
  
  Compared with normal weight, overweight [BMI (in kg/m2): 25 to <30] and obesity (BMI: ≥30) were associated with improved overall [adjusted HR (aHR): 0.82; 95% CI: 0.70, 0.95 and aHR: 0.80; 95% CI: 0.66, 0.98, respectively] and CRC-specific (aHR: 0.84; 95% CI: 0.71, 1.01 and aHR: 0.78; 95% CI: 0.62, 0.99, respectively) survival, with associations being even stronger when the analysis was restricted to nonmetastatic disease. Compared with stable BMI, a strong prediagnostic BMI decrease of >5 was associated with poorer prognosis for all survival outcomes (overall survival-aHR: 1.83; 95% CI: 1.43, 2.34; CRC-specific survival-aHR: 1.78; 95% CI: 1.33, 2.39), and associations were particularly pronounced in men (overall survival-aHR: 2.31; 95% CI: 1.65, 3.22; CRC-specific survival-aHR: 2.56; 95% CI: 1.72, 3.81; P-interaction = 0.08).
  
  
  
  Overweight and obesity are associated with enhanced survival after a CRC diagnosis. A major decrease in BMI in the years before diagnosis is a strong independent predictor of decreased survival. This trial was registered at www.studybox.de as ST-D066.
authors: Division of Clinical Epidemiology and Aging Research, v.walter@dkfz.de.
authors: Viola
authors: V
authors: Walter
authors: Division of Clinical Epidemiology and Aging Research.
authors: Lina
authors: L
authors: Jansen
authors: Division of Clinical Epidemiology and Aging Research.
authors: Michael
authors: M
authors: Hoffmeister
authors: Department of General, Visceral, and Transplantation Surgery and.
authors: Alexis
authors: A
authors: Ulrich
authors: Unit of Molecular Tumor Pathology, Department of Pathology, Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.
authors: Wilfried
authors: W
authors: Roth
authors: Institute of Pathology, Charité University Medicine, Berlin, Germany; and.
authors: Hendrik
authors: H
authors: Bläker
authors: Division of Cancer Epidemiology, and.
authors: Jenny
authors: J
authors: Chang-Claude
authors: Division of Clinical Epidemiology and Aging Research, German Cancer Consortium, German Cancer Research Center, Heidelberg, Germany; Division of Preventive Oncology, German Cancer Research Center and National Center for Tumor Diseases, Heidelberg, Germany.
authors: Hermann
authors: H
authors: Brenner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity; D050177:Overweight; D011379:Prognosis; D016016:Proportional Hazards Models; D012008:Recurrence; D015431:Weight Loss
keywords: body composition; body weight changes; colorectal neoplasms; prognosis; recurrence