VARIATION IN NSCLC SURVIVAL 

After a diagnosis of lung cancer, there is a wide variation in survival, according to the first international population-based study, which involved nearly 60,000 patients.

The United Kingdom had the worst survival; Sweden had the best. The other countries for which data were analyzed were Australia, Canada, Denmark, and Norway.

The study, published online February 11 in Thorax, took stage at diagnosis into account. It has often been suggested that stage at diagnosis is one of the primary reasons that lung cancer survival is low in certain countries, such the United Kingdom, where patients go to see their doctors too late for treatment to be effective.

However, this study found that stage at diagnosis only partly explained the wide variation in survival rates.

Other factors, such differences in treatment, likely play a key role, say the authors, headed by Sarah Walters, MSc, PhD, from the Cancer Research UK Cancer Survival Group at the London School of Hygiene and Tropical Medicine.

Lowest Survival in the United Kingdom

After adjustment for differences in age and death from other causes, 1-year survival rates after a diagnosis of lung cancer ranged from 46% in Sweden, 42% in Australia and Canada, 39% in Norway, 34% in Denmark, to 30% in the United Kingdom.

The United Kingdom had the lowest survival rates for both nonsmall-cell lung (NSCLC) and small-cell lung cancer (SCLC).

For SCLC, 1-year survival was 12% to 16% lower in the United Kingdom than in Australia and Sweden. One-year survival in Canada, Denmark, and Norway were between these rates.

Fewer patients were diagnosed with NSCLC at an earlier stage in Denmark and the United Kingdom than in the other countries. This pattern of distribution could be the result of faster disease progression (related to a higher incidence of smoking) or of delays in diagnosis. Policies are now in place in both Denmark and the United Kingdom to shorten the time to diagnosis, the authors note.

However, they also note that survival was "comparatively low" at each stage of the disease in the United Kingdom. The 1-year survival rates for NSCLC in the United Kingdom were 10% to 16% lower than those in Sweden at each tumor, node, metastases stage (I to IV); this was statistically significant, they note. In the United Kingdom, the 1-year survival rates were 9% to 19% lower than in Canada for stages I to III (but survival at stage IV was low in Canada, too).

A similar pattern was seen for SCLC. In general, survival rates in the United Kingdom at each stage were lower than elsewhere.

Examining Reasons for the Variation

Dr. Walters and colleagues note that low stage-specific survival could indicate poorer levels of stage-specific treatment.

Previous studies have reported that surgery for lung cancer is carried out less frequently in the United Kingdom than in Canada or elsewhere in Europe, and that there is less use of chemotherapy and radiotherapy for lung cancer in the United Kingdom than in Australia, Canada, and Sweden. Although the data from these studies are not directly comparable, the overall pattern is "suggestive of the need for wider access to optimal treatment."

Clinical choices "may be more conservative" in some countries than in others, the authors explain.

The Cancer Survival Group is supported by Cancer Research UK. Coauthor Michael Richards, MD, is the National Cancer director for England (a position funded by the Department of Health).

Thorax. Published online February 11, 2013. Abstract