Disparities in stage at diagnosis for five common cancers in China: a multicentre, hospital-based, observational study

Background: Stage information is crucial for cancer care and essential to improve polices for cancer control. However, the distribution of stage at diagnosis for common cancers in China is not well known. We aimed to identify the distribution and factors associated with stage at diagnosis for five major cancers in China.

Methods: In this multicentre, hospital-based, observational study, we included 23 hospitals in 12 provinces from China. We focused on cancers of the lung, stomach, oesophagus, colorectum, and female breast, and using electronic medical records at the individual level from the local hospitals, and cancer registration records from population-based cancer registries, identified diagnoses made between Jan 1, 2016, and Dec 31, 2017. We collected information on sociodemographic characteristics, lifestyle factors, insurance types, and stage at diagnosis. We analysed the prevalence of late-stage (stages III-IV) cancer cases overall, by sex, and by geographical region. We used logistic regression to identify the factors that were associated with late stage at diagnosis. We further compared these estimates with data from the USA using the Surveillance, Epidemiology, and End Results database.

Findings: We included 52 103 eligible patients. Among 41 671 patients with known stage at diagnosis, 22 009 (52·8%) were diagnosed with late-stage cancer. The proportion of late-stage cases was higher in men and boys than in women and girls (14 084 [64·1%] of 21 973 vs 7925 [40·2%] of 19 698 patients; diagnosed at stages III-IV; adjusted odds ratio [OR] 1·3, 95% CI 1·2-1·5). There is a persistent diagnostic disparity between rural and urban areas (adjusted OR 1·2, 1·1-1·4). Patients with the new rural cooperative medical scheme insurance had a significantly higher risk of late-stage diagnosis compared with patients with urban insurance (adjusted OR 1·4, 1·1-1·9). By specific cancer type, sex and rural-urban disparities were the largest in lung cancer. Compared with the USA, our study patients had a higher percentage of stage II-IV breast cancer (72·4% in China vs 48·8% in the USA), lung cancer (82·7% in China vs 74·7% in the USA), and colorectal cancer (84·8% in China vs 75·9% in the USA).

Interpretation: The disparities of cancer diagnosis within China, and between China and the USA, indicate an urgent need for early detection of cancer in China.

Funding: National Key R&D Programme of China, Major State Basic Innovation Programme of the Chinese Academy of Medical Sciences, and National Natural Science Fund.