Human development central to changing cancer burden
1 June 2012 in the Lancet Oncology(1). Strikingly the study demonstrates not only how an increasing cancer burden will fall predominantly on those countries that are in the process of social and economic transition but also that the type of cancers that are most common is changing.
Geographic differences by levels of human development in 2008
In regions with either high or very high levels on the Human Development Index (HDI)(2), four cancers (breast, lung, colorectal and
prostate) explain half the overall cancer incidence burden. In low HDI and medium HDI regions, oesophageal, stomach and liver cancers are also common, and taken together, these seven cancers explain 62% of the cancer incidence burden in low HDI and medium HDI regions. Specifically in low HDI regions, cervix cancer ranks as the most common cancer above breast and liver cancers, with Kaposi sarcoma ranking as 4th most frequent.
Geographic differences by country and sex in 2008
In men, nine different types of cancer represent the highest incidence rates in specific countries of the world, with prostate, lung and liver cancers leading, followed by cancers of the oesophagus, stomach and Kaposi sarcoma, which rank first in specific low and medium HDI countries. Among women, the highest incidence rates are either breast cancer or cervix cancer in almost all of the 184 countries studied.
Cancer in transition – a ‘westernization’ effect
In medium- and high-HDI settings, the observed declines in cervix and stomach cancer incidence rates appear to be offset by increasing incidence rates of female breast, prostate and colorectal cancers. This may be attributed to a “westernization” effect in countries in rapid societal and economic transition, with reductions in infection-related cancers, outweighed by an increasing burden of cancers more associated with reproductive, dietary and hormonal risk factors.
Cancer burden evolution
Cancer is already the leading cause of death(3) in many high-income countries and is set to become a major cause of morbidity and mortality in the next decades in every region of the world. Assuming the trends observed in medium- to very high HDI countries were seen globally, namely increasing rates of colorectal, female breast and prostate cancer incidence, decreasing cervix and stomach cancer rates, and respective increases and decreases in female and male lung cancer (in high and very high HDI areas only), the authors estimate there will be over 22 million new cancer cases annually by 2030. These analyses constitute the first global overview of the current and future patterns of cancer incidence and mortality in relation to predefined levels of HDI.
According to Dr Freddie Bray, the lead author of the report: “This study should serve as a catalyst for further work on human inequality and cancer from a global perspective, in order to better determine how and why macroeconomic determinants influence cancer incidence, mortality and survival.” He concluded: “It is imperative that public health clinicians and cancer control specialists are alerted to the increasing magnitude of cancer incidence and mortality worldwide; this analysis serves as an important reference point in highlighting the need for global action to reduce the increasing burden of cancer.”
Implications on public health actions
Dr Christopher Wild, IARC Director said: “This study reveals the dynamic nature of cancer patterns in a given region of the world over time. Countries must take account of the specific challenges they will face and prioritize targeted interventions to combat the projected increases in cancer burden via effective primary prevention strategies, early detection and effective treatment programmes”.
The Lancet Oncology, Early Online Publication, 1 June
Global cancer transitions according to the Human Development Index
(2008—2030): a population-based study
Dr Freddie Bray PhD a , Ahmedin Jemal PhD b, Nathan Grey PhD b, Jacques Ferlay ME a, David Forman PhD a
Cancer is set to become a major cause of morbidity and mortality in the coming decades in every region of the world. We aimed to assess the changing patterns of cancer according to varying levels of human development.
We used four levels (low, medium, high, and very high) of the Human Development Index (HDI), a composite indicator of life expectancy, education, and gross domestic product per head, to highlight cancer-specific patterns in 2008 (on the basis of GLOBOCAN estimates) and trends 1988—2002 (on the basis of the series in Cancer Incidence in Five Continents), and to produce future burden scenario for 2030 according to projected demographic changes alone and trends-based changes for selected cancer sites.
In the highest HDI regions in 2008, cancers of the female breast, lung, colorectum, and prostate accounted for half the overall cancer burden, whereas in medium HDI regions, cancers of the oesophagus, stomach, and liver were also common, and together these seven cancers comprised 62% of the total cancer burden in medium to very high HDI areas. In low HDI regions, cervical cancer was more common than both breast cancer and liver cancer. Nine different cancers were the most commonly diagnosed in men across 184 countries, with cancers of the prostate, lung, and liver being the most common. Breast and cervical cancers were the most common in women. In medium HDI and high HDI settings, decreases in cervical and stomach cancer incidence seem to be offset by increases in the incidence of cancers of the female breast, prostate, and colorectum. If the cancer-specific and sex-specific trends estimated in this study continue, we predict an increase in the incidence of all-cancer cases from 12·7 million new cases in 2008 to 22·2 million by 2030.
Our findings suggest that rapid societal and economic transition in many countries means that any reductions in infection-related cancers are offset by an increasing number of new cases that are more associated with reproductive, dietary, and hormonal factors. Targeted interventions can lead to a decrease in the projected increases in cancer burden through effective primary prevention strategies, alongside the implementation of vaccination, early detection, and effective treatment programmes.
a Section of Cancer Information, International Agency for Research on Cancer, Lyon, France b Department of Surveillance and Health Policy Research, American Cancer Society, Atlanta, GA, USA
Correspondence to: Dr Freddie Bray, Section of Cancer Information, International Agency for Research on Cancer, 150 cours Albert Thomas, 69372, Lyon Cedex 08, France
Andy Gray MSc(Pharm) FPS
* Senior Lecturer
Division of Pharmacology
Discipline of Pharmaceutical Sciences
School of Health Sciences
* Consultant Pharmacist
Centre for the AIDS Programme of Research in South Africa (CAPRISA) University of KwaZulu-Natal PBag 7 Congella 4013 South Africa