Wednesday February 13 2013
Women's smoking habits changed in the 1960s and 70s
The news that lung cancer is now the leading cause of cancer-related deaths in British women is being widely reported by the media. The stories are based on well conducted research that predicts cancer deaths in 2013.
The study estimated how many deaths there will be from all forms of cancer across the European Union. As per the headlines, it found that lung cancer now outstrips breast cancer as the main cause of cancer deaths among women in the UK.
The rise in lung cancer deaths may be caused by:
- the long-term effect of the greater number of women smokers during the 1960s and 70s
- the fact that lung cancer remains challenging to treat, as it is often not diagnosed until it is at an advanced stage
The study also had some good news: it found that between 2009 and 2013, overall death rates for most cancers look likely to decline in Europe, although this decline is only 1% for the UK.
This research reinforces the fact that the dangers associated with smoking often do not develop for many decades. But if women quit before they are 40, they can significantly reduce their risk of dying from causes related to smoking. Regardless of gender, quitting at any age will bring benefits.
Where did the story come from?
The study was carried out by researchers from a number of European centres in Italy and Switzerland, and was funded by the Swiss Cancer League and the Italian Association for Cancer Research.
It was published in the peer-reviewed journal, Annals of Oncology.
Understandably, the UK media mainly concentrated on the cancer figures for the UK, especially the lung and breast cancer death rates in women. While the reporting was generally accurate, other worrying trends predicted in the study – such as deaths from pancreatic cancer showing no signs of falling – were mostly unreported.
What kind of research was this?
This research was an estimate of predicted death rates from different cancers and cancer overall in the 27 EU countries for 2013. The study follows similar estimates for 2011 and 2012.
Researchers modelled their predictions on previous cancer mortality rates using data from the World Health Organization (WHO). In particular, the researchers carried out detailed analysis of gastrointestinal cancers.
What did the research involve?
The researchers obtained official data on deaths from cancer from the WHO mortality and population database. Using complex statistical methods, the researchers used this data to model predictions for cancer death rates across Europe in 2013.
They computed age-specific rates for each five-year age group (from 0-4 to 80 years plus) to compute age-standardised death rates across Europe. The figures for the EU were taken from the period 1970 to 2009.
The cancers they looked at were:
The researchers also looked at cancer rates in six individual countries, using the most recent data available to build their predictions. The countries included were France (2010), Germany (2010), Italy (2009), Poland (2010), Spain (2010) and the UK (2010).
Types of cancer were coded according to an international classification of disease. Estimates of each country's population size and age structure were obtained from the same WHO database or, in the case of the France and the UK, from a European database.
What were the basic results?
The study predicts that there will be 1,314,296 deaths from cancer in the EU in 2013 (737,747 men and 576,489 women). This is a slightly higher figure than that for 2009 as the population as a whole has grown slightly older.
However, the researchers found the actual rate of people who die from the disease continues to decline. Between 2009 and 2013, adjusted death rates from cancer are predicted to fall by 6% (to 140.1 per 100,000) in men, and by 4% (to 85.3 per 100,000) in women.
By 2013 the average EU adjusted death rates (per 100,000) from specific cancers are predicted to be:
- 6.6 in men and 2.9 in women for stomach cancer
- 16.7 in men and 9.5 in women for cancer of the intestines
- 8.0 in men and 5.5 in women for pancreatic cancer
- 37.1 in men and 13.9 in women for lung cancer
- 10.5 in men for prostate cancer
- 14.6 in women for breast cancer
- 4.7 in women for uterine cancer
- 4.2 in men and 2.6 in women for leukaemia
Across Europe, these figures represent a fall in death rates from all cancers, apart from lung cancer in women and pancreatic cancer.
In 2010, there were 19,447 deaths among UK women from lung cancer and 11,575 deaths from breast cancer. The prediction for 2013 is 19,535 deaths from lung cancer and 10,983 deaths from breast cancer. Among the six major countries for which the predictions are available, the UK is predicted to have the lowest overall cancer death rate for 2013, 10% lower than the average EU rate.
Across Europe, pancreatic cancer is the only cancer for which death rates are not predicted to decline in both sexes. For 2013 the death rate is predicted to be 8 per 100,000 in men and 5.5 per 100,000 in women, compared with 7.9 and 5.4 in 2009. At 6.6 per 100,000 among men, the UK has lower rates than the European average.
Despite the overall decline in cancer deaths, lung cancer rates continue to rise among women across Europe – by 7% since 2009 – while breast cancer rates fall. In 2013 there will be an estimated 88,886 deaths among women from breast cancer (a rate of 14.6 per 100,000) and 82,640 (14 per 100,000) from lung cancer.
How did the researchers interpret the results?
The researchers point out that although overall cancer death rates are predicted to decline, within the EU there are wide disparities in cancer mortality, showing there is still "large room for improvement".
On the positive side, a steady decline in mortality is predicted for all cancers, apart from pancreatic cancer and lung cancer in women. They say that the decline in cancer mortality is likely to be due to early diagnosis and screening as well as better treatment.
The researchers say that the steady increase across Europe in lung cancer mortality among women is expected to continue, and by 2015 it may become the leading cause of cancer deaths among women.
This is already the case in the UK and Poland, the countries with the two highest rates of lung cancer among women. They say that it is possible the recent increase in deaths from lung cancer among UK women may be transient, due to the rise in smoking among young women in the 1970s.
Death rates from this disease could level off and should decrease in future years as fewer people are now smoking, so future smoking-related deaths should eventually fall.
Although the figures given for 2013 in this study are estimates, they are likely to be close to the mark, reflecting the trends in cancer death rates seen since 2009.
In both Europe and the UK, the news that death rates from cancer are falling – and are predicted to continue to do so – is encouraging and reflects improved treatment, screening and earlier diagnosis for this disease.
Clearly, the increasing number of deaths from lung cancer among women is disturbing, as is the lack of improvement in mortality from pancreatic cancer.
Encouraging people to stop smoking and avoid being overweight, coupled with improved treatments, may help reduce the number of people who develop these diseases and improve death rates.
For advice on giving up smoking, visit smokefree.nhs.uk.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter.