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Menopause Live - IMS Updates
InFocus

Date of release: 23 March, 2015

Deadly forecast


Biblical Methuselah lived almost 1000 years, but current longevity is only in the range of 80–85 years. However, compared to the corresponding figures 100 years ago, people now live much longer and experience a better quality of life. But now, a study from the UK tells us that cancer is becoming a major component among the list of diseases we should expect during our lifetime [1]. In this study, the probability of being diagnosed with cancer was estimated for individuals born in a given year, by assessing future risks as the cohort ages. Lifetime risk of cancer was performed separately for men and women born in each year from 1930 to 1960. The investigators projected rates of all cancers (excluding non-melanoma skin cancer) and of all cancer deaths forwards using a flexible age-period-cohort model and backwards using age-specific extrapolation. The results showed that the lifetime risk of cancer increased from 38.5% for men born in 1930 to 53.5% for men born in 1960. For women, it increased from 36.7 to 47.5%.The lifetime risk of cancer for people born since 1960 is more than 50%. Over half of the people who are currently adults under the age of 65 years will be diagnosed with cancer at some point in their lifetime. Frightening, isn't it?

Comment

The above data from the UK are much like the figures presented by the American Cancer Society [2]. The lifetime risk for developing any cancer in women is 37.8%; the figure for dying from cancer is 19.3%. The corresponding percentages in men are 43.3% and 22.8%, accordingly. The British investigators published another study earlier, in which the absolute annual projected numbers of cancer patients for the year 2030 were compared to historical data in previous years [3]: for women, there were 107,658 patients in 1984, 148,716 in 2007, and 200,929 in 2030, pointing at a mean annual increase of 1.3%. The corresponding numbers in men were 108,556, 149,169, and 231,026, translating into a mean annual increase of 1.9%. 
 
In women, breast and lung cancers have increased substantially since the mid-1970s. The increase in breast cancer is related to lifetime changes, such as increasing obesity, women having fewer children, at later ages, and breast screening detecting more breast cancers at younger ages. In men, there has been an increase in the incidence of prostate and bowel cancer. A large proportion of the increase in prostate cancer diagnoses has been caused by the detection of cancers by prostate-specific antigen testing that would not otherwise have been diagnosed. The increase in bowel cancer rates is thought to be related to an increase in red meat consumption and obesity.
 
Reading the relevant epidemiological data may be misleading for the lay physician. On the one hand, there is a sustained decline in the overall age-standardized cancer incidence rate beginning in the early 1990s, largely because of a decrease in the incidence of lung and prostate cancer in men and a decrease in colorectal cancer incidence in both sexes. But, on the other hand, the actual number of cases diagnosed each year has increased. This increase reflects the finding that the risk of being diagnosed with cancer generally increases with age and, over the past several decades, the population has grown, particularly in the older age groups.
 
What steps should be taken based on these projections [4]? An increase in the number of incident cases of cancer has implications for the cancer surveillance and control community and for the health-care system. A greater emphasis on primary prevention and early detection is needed to counter the effect of an aging and growing population on the burden of cancer. Predicting future incident cases helps health planners and policy-makers to anticipate the resources needed to screen, diagnose, and treat patients newly diagnosed with cancer, while providing ongoing care to cancer survivors. For example, the infrastructure of the health services must be prepared to allow proper diagnosis and treatment of cancer in a growing population. Are there enough oncologists? Operating rooms? Imaging facilities? Pathology labs? Infusion centers? It is true that such predictions should be viewed with caution since they are based on assumptions and complicated models. Nevertheless, these data are vital for policy-makers and health authorities.

Comentario

Amos Pines
Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel

    References

  1. Ahmad AS, Ormiston-Smith N, Sasieni PD. Trends in the lifetime risk of developing cancer in Great Britain: comparison of risk for those born from 1930 to 1960. Br J Cancer 2015 Feb 3. Epub ahead of print
    http://www.nature.com/bjc/journal/vaop/ncurrent/full/bjc2014606a.html

  2. Mistry M, Parkin DM, Ahmad AS, Sasieni P. Cancer incidence in the United Kingdom: projections to the year 2030. Br J Cancer 2011;105:1795803
    http://www.ncbi.nlm.nih.gov/pubmed/22033277

  3. Weir HK, Thompson TD, Soman A, Møller B, Leadbetter S. The past, present, and future of cancer incidence in the United States: 1975 through 2020. Cancer 2015 Feb 3. Epub ahead of print
    http://www.ncbi.nlm.nih.gov/pubmed/25649671