title: Clinical features of metastatic cancer in primary care: a case-control study using medical records.
abstract: BACKGROUND
  How metastatic cancer initially presents is largely unknown.
  
  
  OBJECTIVE
  To identify clinical features of metastatic cancer in primary care.
  
  
  METHODS
  Case-control study in 11 general practices in Devon, UK.
  
  
  METHODS
  Cases of patients who had died with metastatic breast, colorectal, or prostate cancer were selected. In addition, two control groups were formed of patients with the same primary cancer but without metastases ('cancer controls') and patients without cancer ('healthy controls'), matched for age, sex, and practice. All symptoms, signs, and laboratory test abnormalities in the year before metastasis were identified. The primary analysis used conditional logistic regression.
  
  
  RESULTS
  In total, 162 cases, 152 cancer controls, and 145 healthy controls were studied. Common symptoms associated with cancer were: vomiting, 40 (25%) cases and 13 (9%) cancer controls (multivariable odds ratio [OR] 3.5, 95% confidence interval [CI] = 1.3 to 9.4, P = 0.011); low back pain, 38 (24%) cases and 17 (11%) cancer controls (OR 2.5, 95% CI = 1.1 to 5.6, P = 0.032); loss of appetite, 32 (20%) cases and nine (6%) cancer controls (OR 4.0, 95% CI = 1.2 to 13.2, P = 0.021); and shoulder pain, 27 (17%) cases and eight (5%) cancer controls (OR 5.3, 95% CI = 1.6 to 18, P = 0.007). Groin pain was uncommon, but strongly associated (16 [10%] cases and one [1%] cancer control [OR 10, 95% CI = 1.2 to 82, P = 0.032]), as was pleural disease (nine [6%] cases and one [1%] cancer control [OR 10, 95% CI = 1.1 to 92, P = 0.038]).
  
  
  CONCLUSIONS
  These features of disseminated cancer have been reported before in studies from secondary care, but the scarcity of specific symptoms (such as local pain) and the fairly common occurrence of non-specific symptoms (vomiting and loss of appetite) is important and may explain delays in the diagnosis of metastases.
authors.affiliation: University of Exeter Medical School, Exeter.
authors.forename: William
authors.initials: W
authors.lastname: Hamilton
authors.affiliation: University of Exeter Medical School, Exeter.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Barrett
authors.affiliation: University of Exeter Medical School, Exeter.
authors.forename: Sally
authors.initials: S
authors.lastname: Stapley
authors.affiliation: Centre for Academic Primary Care, University of Bristol, Bristol.
authors.forename: Debbie
authors.initials: D
authors.lastname: Sharp
authors.affiliation: Department of Primary Care Health Sciences, University of Oxford, Oxford.
authors.forename: Peter
authors.initials: P
authors.lastname: Rose
mesh_terms: D001066:Appetite; D001859:Bone Neoplasms / Q000556:secondary*; D001932:Brain Neoplasms / Q000556:secondary*; D001943:Breast Neoplasms / Q000150:complications / Q000473:pathology*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000150:complications / Q000473:pathology*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary*; D016015:Logistic Models; D017116:Low Back Pain / Q000209:etiology; D008175:Lung Neoplasms / Q000556:secondary*; D008297:Male; D008499:Medical Records; D016017:Odds Ratio; D017410:Practice Guidelines as Topic; D011320:Primary Health Care; D011471:Prostatic Neoplasms / Q000150:complications / Q000473:pathology*; D020069:Shoulder Pain / Q000209:etiology; D006113:United Kingdom / Q000453:epidemiology; D014839:Vomiting / Q000209:etiology
keywords: cancer; diagnosis; metastasis; primary health care