Lung cancer survival in China and world-wide: results from CONCORD-3

Abstract

Background

In 2015, the CONCORD programme initiated global surveillance of trends in population-based cancer survival as an indicator of health system performance and to support the formulation of global cancer control policies. In 2018, the third cycle of the programme, CONCORD-3, extended the worldwide monitoring of cancer survival trends to include data up to 2014. CONCORD-3 analysed survival data for over 37 million adults (15-99 years) who were diagnosed with one of 18 common cancers between 2000 and 2014, including 6.1 million individuals diagnosed with lung cancer. Anonymised individual patient records were contributed by 290 population-based cancer registries in 61 countries, including 21 in China.

Methods

Tumours were classified into three major groups based on ICD-O-3 morphology codes: small-cell lung cancer (SCLC), non-small cell lung cancer (NSCLC) (comprising adenocarcinoma, large cell carcinoma, and squamous cell carcinoma), and lung cancer not otherwise specified (NOS). Trends in 5-year net survival in each morphology group were estimated for patients diagnosed during 2000-2004, 2005-2009 and 2010-2014, using the non-parametric Pohar Perme estimator. Background mortality was adjusted using life tables of all-cause mortality rates by single year of age, sex, single calendar year and, where available, race/ethnicity, for each country or region. All-ages survival estimates were standardised using the International Cancer Survival Standard weights. Survival trends have also been compared between China, the Western Pacific region and other countries.

Findings

The proportion of non-small cell lung cancers ranged from 36% in China to over 80% in Guadeloupe, Martinique and Taiwan. Small-cell lung cancers accounted for 13% overall, with an international range from 3% to 17%. Almost one-fifth (19%) of lung cancers tumours were assigned a non-specific morphology (NOS), with the proportion varying from 8% in Belgium to over 50% in China, India, and Thailand. For patients diagnosed during 2010-2014, age-standardised 5-year net survival for NSCLC was below 10% in Bulgaria, Chile and Guadeloupe, but reached 39% in Japan. Age-standardized 5-year net survival for SCLC was consistently below 15% in all countries. Between 2000-2004 and 2010-2014, 5-year survival changed very little in each morphology group and in most countries. However, 5-year survival for NSCLC improved by 10% or more in Korea (from 16% in 2000–2004 to 29% in 2010–2014) and Taiwan (from 13% to 23%).

Interpretation

These findings provide a global overview of lung cancer survival trends by morphology, derived from population-based cancer registries. They can inform public health strategies aimed at reducing disparities in outcomes. Lung cancer survival varies widely between China and other Western-Pacific countries. Accurate pathological classification is critical for improved analysis of international inequalities in lung cancer survival. We encourage population-based cancer registries with high-quality data in China and other Western Pacific countries to join the global effort, including the ongoing CONCORD-4 study.