London School of Hygiene & Tropical Medicine

While Sweden had the highest rate of one-year survival from the most common form of the disease (non-small cell lung cancer) at 46%, the UK ranked lowest at just 30%. Denmark also had a relatively low survival of 34%.

The research was carried out by the Cancer Research UK Survival Group at the London School of Hygiene & Tropical Medicine for the International Cancer Benchmarking Partnership. It included over 57,000 patients, looking at their stage at diagnosis and what proportion of them lived for more than a year.

The study suggests that late diagnosis does contribute to low survival - only one in seven patients were diagnosed at the earliest stage of the disease in both the UK and Denmark, compared with one in five elsewhere. However, wide disparities in stage-specific lung cancer survival indicate that other factors such as differences in treatment also play a key role. Out of the six countries studied, UK survival figures were among the lowest at all stages. For the earliest form of the disease survival rates in the UK were 16% lower than in Sweden, and similar patterns were found for small cell lung cancer.

Using population based data can cause comparability issues, as countries differ in how they collect information, but despite this there remains evidence of large international differences in lung cancer survival.

Dr Sarah Walters from the London School of Hygiene & Tropical Medicine, who was lead author on the paper, says: “This is the first international population-based study of lung cancer survival by stage at diagnosis, and it includes nearly 60,000 patients. We’ve shown that wide international inequalities in lung cancer survival occur, even between patients who were diagnosed at the same stage of disease. This indicates that the quality of stage-specific treatment may differ even between these six wealthy countries with universal access to health care.

“It is clearly important to include stage at diagnosis in future international studies of cancer survival. Such comparisons would be easier if stage data were systematically recorded in the medical records, and coded in the cancer registries using international standard classifications.”

Lung cancer remains the leading cause of cancer death worldwide, with around 35,000 people dying from the disease in the UK each year.

Publication

• Walters, S et al. Lung cancer survival and stage at diagnosis in Australia, Canada, Denmark, Norway, Sweden and the United Kingdom: a population-based study, 2004-2007. Thorax. DOI: 10.1136/thoraxjnl 2012-202297