Abdominal pain in primary care: establishing a clinical profile and diagnostic pathway for identifying cancer

Introduction

Abdominal pain (AP) is a symptom commonly reported to United Kingdom (UK) general practitioners (GPs). It can be a symptom of both transient illness and serious disease; often making its cause difficult for GPs to diagnose. This ambiguity influences GP decision making, such as where to refer the patient for further investigation – thus potentially causing delays in diagnosis. Existing research has shown abdominal pain to be a prior symptom of nine different cancers.

These patients currently do not have an effective diagnostic pathway, although the NHS’s Accelerate Coordinate Evaluate (ACE) programme is piloting new diagnostic pathways for patients with non-specific but concerning symptoms using multidisciplinary diagnostic centres (MDC).

Aims & objectives

Using Clinical Practice Research Datalink (CPRD) data to study a large dataset of patients aged ≥40 with new onset abdominal pain. We will identify diagnoses of cancer within 24 months of this abdominal pain episode. The objectives of the project are to:

• Identify which cancers are diagnosed within 24 months of a patient presenting to primary care with abdominal pain
• Establish a clinical profile of concordant features recorded with abdominal pain – what concordant clinical features increase/decrease the likelihood of cancer? What concordant clinical features point to specific cancers?
• Make recommendations on the optimal diagnostic strategy for patients with abdominal pain, based on their gender, age and any additional symptoms
• Indentify what other diagnoses occur within 24 months of presentation with abdominal pain

Methodology

This is a prospective cohort study of CPRD patients with new unexplained abdominal pain occurring between 1^st January 2009 and 31^st December 2013.

We will study 150,000 cases (75,000 males) with a new (no history of AP in last year) record of unexplained abdominal pain in primary care, aged 40 and over, between January 2009 and December 2013. 30,000 cases (15,000 males) will be recruited in each of the age bands: 40-49; 50-59; 60-69; 70-79; 80+. We estimate that this sample will include 4500 patients with cancer.

Outputs & impact

• To identify any new diagnosis of cancer in the two years (0-12 months and 13-24 months) following the first consultation with abdominal pain.
• To see which clinical features predict cancer in the abdominal pain group.
• In the cancer group: Which specific features predict certain cancers a) firstly single cancers and b) cancers grouped by the diagnostic test of choice?
• Alternative diagnoses. In patients investigated for cancer, alternative explanations for AP may be found.

The intended outcome of this research is to improve the diagnostic accuracy of patients in the UK with unexplained abdominal pain, thereby reducing diagnostic waiting times, reducing the number of unnecessary specialist referrals and therefore improving patient experience.

Next steps

The outcomes of this study will also inform potential future models of care/service options: would patients be best served by referral to a symptom-specific multi-disciplinary diagnostic clinic (MDDC) or by GPs within the general practice surgery?  New specialist clinics have been established, but have no relevant evidence to help them select the best sequence of tests for patients. The results are applicable to national and international service providers.

Publications

• Price S, Gibson N, Hamilton W, Bostock J, Shephard E. Diagnoses after newly-recorded abdominal pain in primary care: observational cohort study. British Journal of General Practice April 2022; BJGP.2021.0709. doi: 10.3399/BJGP.2021.0709