May 19, 2010
May 2010: By Clement Adebamowo, MD, ScD; Institute of Human Virology, Abuja, Nigeria
Although HIV infection and AIDS were first clinically recognized in developed countries, the disease has become more prevalent and is a greater health burden in developing countries, particularly in Africa. In 2007, there were 2.7 million new infections and two million HIV-related deaths worldwide.1
Most (22.4 million [95% CI 20.8 – 24.1 million] of the 33.4 million (95% CI 31.1 – 35.8 million) people living with HIV in the world live in sub-Saharan Africa; this area also accounted for 75% of the deaths from the disease in 2007.1,2 Over the past decades, well-validated and effective treatment and prevention strategies have been introduced in developed countries, resulting in control of the epidemic. In contrast, sub-Saharan Africa with its poor health care infrastructure and limited resources has struggled to cope.
This unprecedented epidemic has elicited a remarkable and extensive global health response that has channeled billions of dollars in aid to the most affected countries. Initiatives such as the United States President’s Emergency Plan for AIDS Relief (PEPFAR), Clinton HIV/AIDS Initiative (CHAI), and The Global Fund to Fight AIDS, Tuberculosis and Malaria have provided training, awareness, prevention, and treatment programs in the most affected parts of the world. These interventions have saved millions of lives, prevented new infections, strengthened health care systems, trained thousands of health care workers, stimulated countless research programs and opportunities, and led to development of new treatment, interventions, and research methodologies. To illustrate, in 2004, only 50,000 Africans out of 4.4 million in need were receiving life-saving antiretroviral drugs (ART), but by the end of 2008, 2.9 million were on ART.3,4
Despite the success of these interventions, much still needs to be done. The proportion of people receiving ART compared to those needing it in low- and middle-income countries (LMIC) ranges from 14% in North Africa and the Middle East to 55% in Latin America, with an average of 44% for sub-Saharan Africa. In many of these countries, patients present with advanced disease, and the proportion of patients retained in care 24 months after diagnosis is approximately 67%.4 In this situation, opportunistic infections and tuberculosis continue to be the leading causes of death in the HIV-infected populations in low- and middle-income countries.
However, improved access to treatment is lowering the rates of HIV-associated mortality and morbidity. In high-income countries where antiretroviral drugs have been available the longest, the excess mortality associated with HIV has declined by 85%. A similar, but lower-percentage reduction in mortality has been found in low- and middle-income countries2; current estimates suggest that an almost similar number of deaths have been averted by antiretroviral drugs in Western Europe and North America (1.1 million) as in Sub-Saharan Africa (1.2 million). It must be noted, however, that the epidemic in Africa is substantially larger, and antiretroviral drugs have been available for only a comparatively shorter period of time.
Vulnerable Populations at Increased Risk of Malignancies
The overall population of individuals affected by AIDS, treated and untreated, are at increased risk of malignancies. The close relationship between HIV infection and certain malignancies was recognized very early in the course of the epidemic, leading the Centers for Disease Control and Prevention (CDC) to classify carcinoma of the uterine cervix, non-Hodgkin’s lymphoma and Kaposi sarcoma as AIDS-defining malignancies. It was recommended that individuals presenting with these cancers be tested for HIV. In addition, recent studies in populations of HIV-positive individuals who have been on ART for long duration show increased incidence of other types of cancer. These non-AIDS-defining cancers (NADC) include a wide range of tumor types, such as liver cancer, oropharyngeal and lung carcinoma, anorectal carcinoma, Hodgkin’s lymphoma, and skin cancers.5 Even where there is no increase in incidence of particular cancers due to HIV infection, the high prevalence of the infection means that it is increasingly seen as a co-morbid condition in cancer patients with impact on therapeutic options.
Innovative Solutions Required
Given the increasing population of people living with HIV in low- and middle-income countries and the increased proportion receiving ART, AIDS-associated cancers — AIDS defining and non-AIDS-defining — are poised to become the largest category of cancers in these regions in the near future. Some of these cancers are known to be associated with infections such as hepatitis viruses and human herpes virus type 8, while others are related to behavioral risk factors such as smoking and multiple sexual partners, which are relatively more prevalent in people living with HIV/AIDS.5
The prevalence and distribution of these risk factors vary in different parts of the world, and this will influence the relative distribution of the types of cancers that occur in different societies. It is, therefore, important to begin to lay the foundation for research into the relative distribution of these factors, their relative contribution to causation, cost-effective preventive interventions to reduce their prevalence, improved case finding and diagnosis, and efficacious treatment in low-resource settings.
Cancer prevention, diagnosis, and treatment are complex and expensive. Cancer-care delivery in many low- and middle-income countries is in a state similar to that of HIV/AIDS care in the 1990s; before the different interventions mentioned earlier. It is doubtful if the world — given the current social, political, and particularly economic climate — can mount a response to the challenge of cancer in developing countries similar to what was done for HIV infection. We have to be innovative in harnessing existing resources and use those resources to develop sustainable cancer-control programs to meet the needs of low- and middle-income countries (LMIC).
As it happens, there are already some positive elements that can be built upon. For example the HIV-positive population receiving ART has successfully overcome some of the barriers to accessing modern medicine that is otherwise prevalent in LMIC, such as alternative health belief models that often lead to delayed presentation.
Health care systems for HIV-positive populations are also better than what is generally available in these communities. These functional health systems represent platforms upon which additional care delivery can be built to meet the needs of cancer prevention, diagnosis, and management. Preventing Mother-to-Child Transmission (PMTCT) centers can add breast and cervical cancer screening and detection programs in a cost-effective manner. Clinical, adherence and counseling, and patient tracking and follow-up systems that are used to manage HIV-positive patients can be deployed in support of the management of AIDS-associated malignancies. This will reduce the appallingly high loss to follow up of cancer patients in LMIC.
The infrastructure for training HIV health care workers can be extended to support the training of cancer care professionals in cancer registration, epidemiology, biostatistics, clinical and pathological diagnosis, and management of the common cancers that are prevalent in this community. Clinical trials groups like the AIDS Malignancy Consortium (AMC) and AIDS Clinical Trials Group (ACTG) need to develop low-cost, efficacious treatment and prevention clinical trials in order to identify the best clinical management and prevention guidelines suitable for use in LMIC. There is already evidence that the improvements in health care systems and empowering of patients in HIV programs is spilling over to have a positive transformative effect on the rest of the health care systems in LMIC.
ASCO’s Leadership Role
As a world leader in improving cancer care and prevention, ASCO has a role to play in this emerging scenario. ASCO has the expertise and ability to bring human and material resources to contribute to efforts aimed at mounting a credible and sustainable response to this emerging epidemic. These resources include provision of general and targeted training in the diagnosis and management of AIDS-associated malignancies; development of treatment guidelines for the management of the common AIDS-associated malignancies and for the management of common malignancies that occur in patients living with HIV/AIDS; extension of current ASCO educational, leadership, and quality-improvement programs to LMIC countries tailored specifically for their needs; identification and mentoring of oncology leaders and cancer societies in LMIC to equip them to respond to the needs of their population in the areas of advocacy, policy development, and promotion of awareness; support for international oncology professional volunteering to provide expertise in LMIC; and support for efforts to improve cancer care internationally. Many existing ASCO programs are already suitable for the work that needs to be done.
- UNAIDS. UNAIDS 2008 Report on the global HIV/AIDS Epidemic. Geneva: UNAIDS; 2008.
- World Health Organization AIDS Epidemic update: November 2009. Geneva: World Health Organization; 2009.
- El-Sadr WM, Hoos D. The President’s Emergency Plan for AIDS Relief — Is the Emergency Over? N Engl J Med. 2008;359:553-555.
- World Health Organization. Towards universal access: Scaling up priority HIV/AIDS intervention in the health sector: Progress report 2009. Geneva: World Health Organization;2009.
- Pantanowitz L, Dezube BJ. Evolving spectrum and incidence of non-AIDS-defining malignancies. Curr Opin HIV AIDS. 2009;4:27-34.
Article originally printed as an Expert Editorial column in 2010 Annual Meeting Daily News