Diagnostic profile characteristics of cancer patients with frequent consultations in primary care before diagnosis: a case-control study

Abstract

Many patients with common cancers are late diagnosed. Identify consultation profiles and clinical features in patients with the seven most common cancers, who had consulted a general practitioner (GP) frequently before their cancer diagnosis. A case-control study was conducted in Region Västra Götaland, Sweden. A total of 2570 patients, diagnosed in 2011 with prostate, breast, colorectal, lung, gynaecological and skin cancers including malignant melanoma, and 9424 controls were selected from the Swedish Cancer Register and a regional health care database. Diagnostic codes [International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10)] from primary care for patients with ≥4 GP consultations registered in the year before cancer diagnosis were collected. Likelihood ratios (LRs) were calculated for variables associated with the different cancers. Fifty-six percent of the patients had consulted a GP four or more times in the year before cancer diagnosis. Alarm symptoms or signs represented 60% of the codes with the highest LR, but only 40% of the 10 most prevalent codes. Breast lump had the highest LR, 11.9 [95% confidence interval (CI) 8.0-17.8]; abnormalities of plasma proteins had an LR of 5.0 (95% CI 3.0-8.2) and abnormal serum enzyme levels had an LR of 4.6 (95% CI 3.6-5.9). Early clinical features associated with cancer had been registered already at the first two GP consultations. One out of six clinical features associated with cancer were presented by cancer patients with four or more pre-referral consultations already at the two first consultations. These early clinical features that were focal and had benign characteristics might have been missed diagnostic opportunities.