By Lilian Anekwe
UK primary care researchers have identified a hit-list of signs and symptoms indicative of at least a one in twenty chance of cancer which they say should be built into practice software systems.
GPs should also audit practice records to identify patients with one of the ‘red flag’ symptoms and ‘reflect upon these cases as part of their appraisal to improve quality of care’, the researchers concluded.
A team from Keele University conducted a systematic review of 25 papers to identify the symptoms, signs, and non-diagnostic test results in people routinely consulting a GP that have a positive predictive value (PPV) of 5% or more for different cancers and would ‘require action by a GP’.
For colorectal cancer, 12 studies were identified that have a predictive value of 5% or more. In 11 of them, rectal bleeding had a predictive value of 5% or more in both men and women aged 75 and older.
Three studies of the symptoms of urological cancer found haematuria had PPVs of 5% and more in men aged 55 and older and women aged 65 and older, and macroscopic haematuria had a PPV of 5% or more in men over 60 and women over 40.
Haemoptysis had a PPV of 5% or more for lung cancer, according to one study, and an abnormal rectal examination was predictive of prostate cancer in men of all ages.
Two studies included in the analysis revealed one in twenty women who consulted their GP with a palpable breast lump had breast cancer. One study showed bleeding in women aged 75 to 84 had a PPV for gynaecological cancer of 5.4%.
The research team said the study, published in the September issue of the British Journal of General Practice, showed ‘that robust evidence exists for a PPV of 5% or more in specific age and sex groups’.
Lead researcher Dr Mark Shapley, a GP in Stoke on Trent and senior research fellow at Keele University, said: ‘While these symptoms, signs and non-diagnostic test results occur in the minority of patients with cancer, when they do occur, exclusion of cancer is obligatory unless exceptional circumstances exist.’
He said: ‘We recommend research and development of general practice computer systems to produce effective warning flags when the symptoms, signs or test results with a risk of 5% or more from unselected primary care populations are entered for patients within the specified sex and age groups.’
‘GPs should audit their management and reflect upon these cases as part of their appraisal to improve quality of care. There should be more open public debate on the level of risk that triggers a recommendation for referral by a GP.’
Dr Kevin Barraclough, a GP from Stroud with a research interest in cancer, said: ‘Age ranges are critical to positive predictive values. Iron deficiency anaemia in a 21-year old female is extremely unlikely to be due to colorectal cancer, whereas in a 60-year old male, cancer is likely.’
He added: ‘What we really need are numbers from good primary care studies. These are surprisingly few and far between. This paper is very useful but it does highlight the pressing need for symptom-based research in primary care to inform cancer referral guidelines.’
British Journal of General Practice 2010; 60: 681-688.
A palpable breast lump may be a sign of breast cancer The eight cancer red flags (*where evidence exists for a PPV for ≥5%)
Anaemia – in men with Hb ≤ 12g/dl aged 20 and older and women with Hb ≤11 g/dl aged 50 and over
Blood in urine – in men and women aged 60 and over
Coughing up blood – in men over 55 and women over 65
Difficulty swallowing – men over 55
Breast lump or mass – in women aged 20 and older
Post-menopausal bleeding – in women aged 75-84
Abnormal rectal examination – in men 40 and older
Rectal bleeding – in men and women aged 75 and older
Source: British Journal of General Practice, September 2010