Cancer is the leading cause of death among people living with HIV in both high and low resource countries. And the treatment outcome for those patients is often less successful. With more than 20 years' experience in his field, Professor Hennie Botha, Associate Professor and Head of the Department of Obstetrics and Gynaecology in the Faculty of Medicine and Health Sciences at Stellenbosch University, and his team is at the forefront of research into cancers that affect people living with HIV. “We have extensive experience in the field of cervical cancer, but much less is known about other anatomical sites affected by human papillomavirus (HPV) related cancers like male genital cancers, anal carcinomas, and oropharyngeal cancer (back of the throat). We will now be studying those cancers in more detail," Botha says.
Their efforts recently received a significant boost when Botha, in collaboration with researchers in the United States, Zimbabwe and Germany, were awarded a grant from the National Cancer Institute in the USA to assist in their studies into virus-associated tumours that disproportionately impact people living with HIV in sub-Saharan Africa. “We know people with HIV, even with effective ARV therapy, have a lower immune response and cancers associated with HPV are more common and often has a poorer outcome when compared with HIV negative patients," Botha says.
The $5,5 million (R100 million) grant – which will be rolled out over the course of five years – will be an immense help. “Performing this research requires human resources, the use of specialist equipment and tests for viruses and immune markers, which are quite expensive. A grant like this makes it possible to use the best scientific methods available. Another important part of the grant mechanism is the development of young academics and researchers. A sizeable portion of the grant will be used for developmental projects under the supervision and mentorship of more experienced researchers."
The research performed at Stellenbosch University is mostly focussed on investigating the immune landscape of individuals living with HIV when they develop an HPV associated cancer. “It's important to understand underlying biological mechanisms that lead to the development of the cancer to try and find solutions in the form of new medicines or other preventative measures," he says.
“Most cancers are more common in people living with HIV due to impaired immune mechanisms, however cancers associated with infections are particularly likely to occur and specifically cervical cancer, anal carcinoma and oropharyngeal cancer which are associated with HPV. HPV is a common virus that is circulating in the general population, but certain cancer-causing strains can lead to abnormal cells which eventually will develop into cancer."
Botha says cancer associated with HIV are often diagnosed at an advanced stage because they tend to develop more rapidly. “They are more difficult to treat and, even if the patient receives effective and complete treatment, the long-term outcome is not equal to HIV negative people. We are aiming to determine the causes for this rapid development to cancer, the poor response to treatment and the poorer survival rate after successful treatment to try and find potential modifying factors or even potential interventions that can improve the treatment outcome of these cancers."
Botha lists factors that could help reduce the risk for HIV positive patients. “Reducing smoking habits, keeping a healthy weight, regular exercise, screening for cancer and a reduced risk for infections that may cause cancer through vaccination. HPV vaccines have been on the market for more than a decade now and should be widely used in the prevention of HPV related cancers. We encourage anybody diagnosed with HIV to receive three doses of the HPV vaccine to prevent new infections and as such reduce their risk of developing cancer."
