Investigators have addressed the need to improve access to oncology drugs designed to increase the survival and quality of life of patients in sub-Saharan Africa and combat the significant health-care disparities many of these patients continue to face, according to a new study published by Sharma et al in PLOS Global Public Health. The researchers reviewed selected oncology drug therapies for common malignancies in sub-Saharan Africa—including breast cancer, cervical cancer, Kaposi sarcoma, lung cancer, and prostate cancer.
Background
Cancer is one of the top three causes of premature death in sub-Saharan Africa—home to 14% (n = 1.1 billion) of the world’s population—and without significant interventions, experts expect the number of deaths per year to double to about 1 million by 2030.
“Cancer is threatening sub-Saharan African populations to a degree that demands a large-scale response,” stressed senior study author Richard Marlink, MD, the Henry Rutgers Professor of Global Health and Professor of Medicine in the Division of Medical Oncology at the Robert Wood Johnson Medical School as well as Director of the Rutgers Global Health Institute at Rutgers University. With these rising cancer rates, investigators from the Botswana-Rutgers Partnership for Health sought solutions to mitigate cancer incidence and mortality.
The Botswana-Rutgers Partnership for Health is a collaboration between the Ministry of Health in Botswana, the University of Botswana, and the Rutgers Global Health Institute. Because Botswana’s cancer mortality rate exceeds 63%, the partnership is engaged in efforts to strengthen the country’s health systems and provide comprehensive, patient-centered oncology care.
“Our review describes several specific means for advancing oncology drug therapies in a region where there are complex barriers to providing comprehensive cancer care,” highlighted lead study author Kirthana Sharma, MD, MPH, a senior research manager at the Rutgers Global Health Institute and Chair of the Cancer Pathology Working Group. “High drug costs are a major challenge to bridging the stark inequities in access to cancer treatments. To optimize … treatments in this region, diagnostic and laboratory infrastructure also needs to be strengthened, and the oncology workforce needs to be further trained and developed,” she emphasized.
Study Methods and Findings
In the new study, the investigators identified gaps in the access to oncology drugs and clinical trials in sub-Sahara Africa, provided insights into several common cancer types in the region, and called attention to cancer therapeutics that should be considered for the World Health Organization (WHO) Model Lists of Essential Medicines.
In sub-Saharan Africa, patients with breast cancer fail to receive routine testing to determine the status of their specific hormonal profiles. Consequently, treatments may not include precision targeting, which is available in high-income countries where profiling capabilities are more accessible. The investigators stressed that this limitation could impact treatment decisions and result in patients receiving treatments that expose them to potential harms without any therapeutic advantage.
For instance, hormone therapy with the drug tamoxifen may be initiated in the absence of patient-specific evidence supporting its use because this agent is often inexpensive or free in some countries. When hormonal profiling is available, however, the medications proven most effective—such as the human epidermal growth factor receptor 2 targeted drug trastuzumab—may be cost-prohibitive. Another barrier is that immunotherapy, for example, with atezolizumab and pembrolizumab, requires specialized monitoring and management protocols that may not be available in sub-Saharan Africa.
Cervical cancer is the leading cause of female cancer-related mortality in sub-Saharan Africa. For patients with locally advanced cervical cancer, the standard of care is chemotherapy in conjunction with radiation therapy. After reviewing 29 oncology treatment centers in 12 countries in sub-Saharan Africa, the investigators found inconsistencies in the supply of cisplatin, resulting in treatment delays or drug substitutions. Limited access to radiation therapy in the region further complicated this dynamic.
Kaposi sarcoma—characterized by patches of abnormal tissue growth in the lymph nodes; under the skin; and in the lining of the mouth, nose, and throat—is caused by a human herpesvirus-8 infection and typically occurs in patients with weakened immune systems, including those with the human immunodeficiency virus (HIV) or AIDS. Investigators found that the incidence of Kaposi sarcoma in sub-Saharan Africa has increased 20-fold since the onset of the HIV/AIDS epidemic in the early 1980s.
In 2020, the first large clinical trial in more than a decade comparing chemotherapy drug use to treat Kaposi sarcoma in patients in sub-Saharan Africa took place. Researchers in this study described a “paucity of clinical trials for Kaposi sarcoma in sub-Saharan Africa compared to the significant burden of disease in the region.”
Additionally, with the increased affordability and marketing of tobacco products in sub-Saharan Africa, the occurrence of lung cancer has increased. The investigators emphasized the need for more advanced pathology capabilities to improve precision diagnostics and therapeutics in the region and revealed that they identified discrepancies related to targeted therapies and the WHO’s Model Lists of Essential Medicines.
Prostate cancer—a leading cause of cancer mortality among male patients—is often treated with surgical castration in sub-Saharan Africa. However, newer-generation oral hormone therapy may have an expanded role in the region. The investigators reviewed the potential of abiraterone with prednisone therapy to improve patient outcomes. Abiraterone is expected to be available through multiple generic options at reduced pricing in the near future. The investigators also clarified the role of molecular profiling, which isn’t readily accessible in the region, in relation to drug therapies for patients with metastatic castration-resistant prostate cancer.
“This guidance provides a framework for how to improve access to the life-saving and life-altering medications that are proven to work. The high-impact treatments available elsewhere are needed in this region of our world,” Dr. Marlink concluded.
Disclosure: For full disclosures of the study authors, visit journals.plos.org.
