Lung Cancer Rate In UK Women Continues To Rise Despite Falling Smoking Prevalence

The number of cases of lung cancer among women in the UK continues to rise steadily despite dramatic falls in smoking prevalence during the last half of the 20th century according to new data from Cancer Research UK.

In 2009, Cancer Research UK reports that 23,041 new lung cancer cases were diagnosed in men and 18,387 cases in women. This makes lung cancer the second most commonly diagnosed cancer in both men and women, behind prostate and breast cancer respectively. The age standardized lung cancer rate for the 2009 year was 39.4 per 100,000 for women, up from 35.4 per 100,000 in 1995 and just 22.7 per 100,000 in 1975. In contrast, the male rate has almost halved from 112.6 in to 58.8 per 100,000 over the same period.

Smoking remains the strongest risk factor for lung cancer and rates of lung cancer typically follow smoking prevalence with a lag period of 20-30 years. It is therefore somewhat surprising that female lung cancer rates have not started to drop given that both the female and male smoking rates have been falling since the early 1970s. The percentage of adults in the UK who are current smokers is 21% for men and 20% in women compared to 55% and 44% for men and women in 1970.

Average Number Of Cigarettes Smoked Per Day By UK Men And WomenA possible explanation for the rise in lung cancer rates is that women smoked more intensely during the 1970s and 1980s than they had in the past. Cigarette consumption for women smokers more than doubled from 6.8 cigarettes per day in 1949 to 16.6 cigarettes per day in 1979. Cigarette consumption also increased in men, but to a lesser extent.

Other risk factors for lung cancer such as radon exposure, working in the asbestos industry, low fruit and vegetable consumption, and exposure to coal and diesel combustion products may also play a role in the rising lung cancer rates however it is not clear why these factors would effect women more than men. Furthermore, the risk of lung cancer in lifelong non-smokers has remained relatively constant at 10-15 cases per 100,000 per year suggesting that changes in other risk factors have had little impact on lung cancer trends.

Most of the increase in lung cancer cases has occurred in older age groups, particularly women over 80 where the rate has sky-rocketed from 85.9 per 100,000 in 1975-77 to 281.0 in 2007-2009. This is not unexpected as these cancer rates are reflective of the high prevalence of smoking in the 1940s and 50s. It is somewhat concerning however to see that lung cancer rates in younger age groups are actually on the increase again after decades of decline.

UK Women Lung Cancer Rates By Age Group

As can be seen from the graph above, lung cancer rates in the 50-59 age group are up more than 10% in the 2007-2009 period compared to their lowest point in the early 1990s. Lung cancer rates in the 60-69 age group are around 20% higher now compared to 2001-2003.

More statistics on lung cancer incidence are available on the Cancer Research UK website.