Has lung cancer presentation changed?

Problem

Late diagnosis is likely to contribute to the poor lung cancer survival rate seen in the UK1. Lung cancer patients whose diagnosis is initiated in primary care have higher survival rates2. Understanding trends in pre-diagnostic lung cancer presentations in primary care could help enable earlier diagnosis.

Approach

We studied 27,795 lung cancer patients in the Clinical Practice Research Datalink from 2000-2017 inclusive, plus 34,930 colorectal and 5,655 ovarian cancer patients for comparison. We defined first presentation as the first recorded cancer symptom(s) in the year before diagnosis, using 2015 NICE suspected cancer guidelines3. We identified the proportion of patients with a first presentation for each pre-diagnostic symptom. For patients with lung cancer we identified the proportions who met NICE criteria for further investigations in the year before their diagnosis3. We used generalised linear models (with a binomial function) to test if the proportion of patients varied with year of diagnosis.

Findings

In patients with lung cancer, the proportion with no recorded pre-diagnostic cancer symptoms did not vary; the proportion with a first pre-diagnostic presentation of cough or dyspnoea increased and the proportion with a first pre-diagnostic presentation of any of haemoptysis, fatigue, appetite loss, weight loss or chest pain decreased year on year. The proportion of patients who met NICE criteria for offer of a chest X-ray and those with suspected cancer increased; the proportion of patients who met NICE criteria for referral due to haemoptysis, referral due to abnormal chest X-ray and consideration of a chest X-ray decreased progressively. The proportion of patients who progressed through NICE criteria for further investigation decreased year-on year. Odds ratio for cough 1.01(95% confidence interval 1.004,1.016) per year; dyspnoea 1.05(1.046,1.06); haemoptysis 0.93(0.92,0.945); fatigue 0.98(0.972,0.998); appetite loss 0.93(0.904,0.965); weight loss 0.98(0.964,0.993); chest pain 0.96(0.948,0.966); offer of a chest X-ray 1.05 (1.044,1.055); suspected cancer 1.08 (1.066,1.0985); haemoptysis referral 0.93(0.922,0.947); abnormal Chest X-ray referral 0.87 (0.847,0.905); consideration of a chest X-ray 0.98 (0.974,0.991); offer of a chest X-ray then referral 0.97 (0.959, 0.982); consideration of chest X-ray then referral (0.92 0.906 0.943), consideration then offer of chest X-ray (0.98 0.973 0.993): all p<0.0001, other than fatigue p=0.03, weight loss p=0.004 and consideration then offer of chest X-ray p=0.0007. In colorectal and ovarian cancers first symptom presentations did not change.

Consequences

The prevalence of pre-diagnostic symptoms of lung cancer appears to have changed, unlike for ovarian and colorectal cancer. Cough and dyspnoea increased, therefore more patients met NICE criteria for the offer of a chest X-ray. Decline in the proportions of patients who progress through NICE criteria for investigations may indicate an increased willingness of GPs to investigate symptoms earlier. Pre-diagnostic presentations with cough and dyspnoea represent a growing opportunity for early lung cancer diagnosis.1. Richards, The size of the prize for earlier diagnosis of cancer in England2. Richards, Thorlby, Fisher, & Turton Unfinished business3. NICE 2015 Suspected cancer: recognition and referral (NG12)