Gut feeling for the diagnosis of cancer in general practice: a diagnostic accuracy review.

Objectives: Diagnostic delay in cancer is a challenge in primary care. Although screening tests are effective in diagnosing some cancers such as breast, colorectal and cervical cancers, symptom-based cancer diagnosis is often difficult due to its low incidence in primary care and the influence of patient anxiety, doctor-patient relationship and psychosocial context. A general practitioner's gut feeling for cancer may play a role in the early diagnosis of cancer in primary care where diagnostic resources are limited. The aim of this study is to summarise existing evidence about the test accuracy of gut feeling (index test) in symptomatic adult patients presenting to general practice, compared with multidisciplinary team-confirmed diagnosis of cancer (reference standard).

Design: Diagnostic accuracy review following Cochrane methods was performed.

Data Sources: MEDLINE, EMBASE, Cochrane Library, the Database of Abstracts of Reviews of Effects and Medion databases.

Eligibility Criteria: Cross-sectional, cohort and randomised studies of test accuracy that compared gut feeling (index test) with an appropriate cancer diagnosis (reference standard). No language or publication status restrictions were applied. We included all studies published before 25 March 2022.

Data Extraction And Synthesis: Methodological quality was appraised, using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) criteria. Meta-analysis with hierarchical summary receiver operating characteristic (HSROC) models was used.

Results: Of 1286 potentially relevant studies identified, six met the inclusion criteria. For two of the six studies, data could not be extracted despite contacting authors. No studies satisfied all QUADAS-2 criteria. After meta-analysis of data from the remaining studies, the summary point of HSROC had a sensitivity of 0.40 (95% CI: 0.28, 0.53) and a specificity of 0.85 (95% CI: 0.75, 0.92).

Conclusions: Gut feeling for cancer when used in symptomatic adult patients in general practice has a relatively low sensitivity and high specificity. When the prevalence of cancer in the symptomatic population presenting in general practice exceeds 1.15%, the performance of gut feeling reaches the National Institute for Health and Care Excellence 3% positive predictive value threshold for action, which recommends urgent access to specialist care and further investigations. The findings support the continued and expanded use of gut feeling items in referral pathways.