The diagnostic value of symptoms for colorectal cancer in primary care: a systematic review

Abstract

BackgroundOver 37 000 new colorectal cancers are diagnosed in the UK each year. Most present symptomatically to primary care. AimTo conduct a systematic review of the diagnostic value of symptoms associated with colorectal cancer. DesignSystematic review. MethodMEDLINE, Embase, Cochrane Library, and CINAHL were searched to February 2010, for diagnostic studies of symptomatic adult patients in primary care. Studies of asymptomatic patients, screening, referred populations, or patients with colorectal cancer recurrences, or with fewer than 100 participants were excluded. The target condition was colorectal cancer. Data were extracted to estimate the diagnostic performance of each symptom or pair of symptoms. Data were pooled in a meta-analysis. The quality of studies was assessed with the QUADAS tool. ResultsTwenty-three studies were included. Positive predictive values (PPVs) for rectal bleeding from 13 papers ranged from 2.2% to 16%, with a pooled estimate of 8.1% (95% confidence interval [CI] = 6.0% to 11%) in those aged ≥50 years. Pooled PPV estimates for other symptoms were: abdominal pain (three studies) 3.3% (95% CI = 0.7% to 16%); and anaemia (four studies) 9.7% (95% CI = 3.5% to 27%). For rectal bleeding accompanied by weight loss or change in bowel habit, pooled positive likelihood ratios (PLRs) were 1.9 (95% CI = 1.3 to 2.8) and 1.8 (95% CI = 1.3 to 2.5) respectively, suggesting higher risk when both symptoms were present. Conversely, the PLR was one or less for abdominal pain, diarrhoea, or constipation accompanying rectal bleeding. ConclusionThe findings suggest that investigation of rectal bleeding or anaemia in primary care patients is warranted, irrespective of whether other symptoms are present. The risks from other single symptoms are lower, though multiple symptoms also warrant investigation.

Predictive values of GPs’ suspicion of serious disease: a population-based follow-up study

“…7 A specific level of PPV prompting referral cannot be established, but studies indicate that levels above 1% should prompt investigation. 4,7 As in the study by Scheel et al, 9 6.2% (279 of 4518) of the patients in the current study were diagnosed with a serious disease without the GP having a suspicion of one being present after the index consultation.…”

“…1 When patients present with symptoms and signs in general practice, the positive predictive values (PPVs) of serious disease are low (often <5%), whereas the frequency of 'low-risk-but-not-no-risk' symptoms and signs is high. [2][3][4][5][6][7] This fundamental conflict constitutes a major clinical challenge for GPs and for the organisation of the entire healthcare system.…”

Lifestyle and Sporadic Colorectal Cancer in India

“…The authors clearly stated that the physicians should continue to rely on the clinical findings for detecting this cancer. Studies have reported the presence of rectal bleeding as a single symptom or it may also present in conjunction with other symptoms (Astin et al, 2011). Most of the symptoms present more rampantly in higher stage tumors as an indicator of the aggressive nature of this disease, however, this may not always be true.…”

Effects of Dietary Counseling on Patients with Colorectal Cancer

“…Exophytic tumors are most often located in the right half of the colon, while stenosing tumors are mostly found in its left half. The majority (up to 75%) of colorectal cancer occur within the descending colon, sigmoid colon and rectum, 15% of cases are located in the cecum and ascending colon, and only 10% in the transverse colon (13,14,15). Adenocarcinoma accounts for more than 95% of colorectal cancer cases.…”