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Chapter 28 Radiation Oncology in the Developing World

B. Breast cancer Estimated age-standardized incidence rate per 100,000

A. Cervix cancer Estimated age-standardized incidence rate per 100,000

<21.3

<28.6

<38.7

<56.5

<109.2

<7.0

<12.9

<20.2

<29.6

<56.3

C. Lung cancer Estimated age-standardized incidence rate per 100,000

D. Gastric cancer Estimated age-standardized incidence rate per 100,000

Techniques, Modalities, and Modifiers in Radiation Oncology

<3.2

<8.1

<17.1

<26.1

<52.0

<3.8

<5.8

<8.2

<13.0

<41.4

Figure 28.2.  Global variation in estimated age-standardized cancer incidence per 10 5 in 2008 for specific cancers based on International Agency for Research on Cancer statistics. Incidence is grouped by country quintile with higher incidence indicated by darker color. Rates for both sexes are shown for lung and stomach cancer. A: Cervix cancer rates are highest in Latin America, Sub-Saharan Africa, and parts of Asia including India. B: Breast cancer rates are high among high-income countries. Among low- and middle-income countries, rates are high in parts of Latin America and lower in parts of Africa and Asia. C: Lung cancer rates are high in both developed and developing parts of the world, including China, Southeast Asian countries, and parts of South America. D: Rates of stomach cancer are highest in East Asia. High rates are found in Latin America, other parts of Asia, and Eastern Europe. (From Ferlay J, Shin HR, Bray F, et al. GLOBOCAN 2008 v1.2, cancer incidence and mortality worldwide. IARC CancerBase No. 10 [Internet]. Lyon, France: International Agency for Research on Cancer, 2010. Available at: http://globocan.iarc.fr, with permission.)

role of occupational and environmental exposures to cancer in developing countries requires continued exploration. 24 In many developing countries, cancer often presents in advanced stages, due to factors such as lack of comprehensive screening and poor access to effective treatments. 25 As a result, case fatality rates are much higher in developing countries, with rates for breast and cervical cancer in low-income coun- tries being more than double rates in high-income countries. 26 With cervical cancer being so common in developing countries and the high frequency of advanced cancer presentations requiring local therapy, radiation therapy has an extremely important role in developing countries. The following sections will describe radiation oncology in developing countries in terms of access, quality, and economics.

40-year delay between the peak in smoking rates in a popula- tion and the peak in tobacco-related mortality. 12 Thus, an increasing rate of tobacco-related malignancies is expected in LMCs during the next half century. 13,14 Over 26% of cancers in developing countries are attributed to infectious causes. 15 Hepatitis B is a major risk factor for hepatocellular carcinoma in developing countries. Other factors are hepatitis C 16 and aflatoxin produced from Aspergillus in cer- tain poorly preserved foods. 17 Human papillomavirus (HPV) and Helicobacter pylori are important etiologic agents, and there are numerous other infectious agents relevant to cancer in the developing world. These include Epstein-Barr virus, HIV, schisto- somiasis, human T-cell leukemia virus type 1 (HTLV-1), and human herpesvirus 8 (HHV-8). 15 ,18 The prevalence of infectious causes is notable given the preventability of many of these causes through public health measures (e.g., hepatitis B, HPV vaccines). There are a number of other factors that are relevant to pat- terns of global cancer incidence. Diet 19 and obesity are risk fac- tors for some cancers. 20 This is notable given increasing trends in unhealthy diet and sedentary lifestyle among developing countries. 21 The impact of genetic polymorphisms on patterns of global cancer incidence has not been fully elucidated, but there is some suggestion of their relevance. 22,23 Similarly, the

Global Status of Access to Radiation Therapy

Access to radiation therapy is a multifactorial issue. Availability of machines and personnel for treatment is a key part of access to care. Other considerations include spatial accessibility, acceptability, affordability, accommodation, and awareness. 27,28