Last month the European Society of Medical Oncology held its summit in Cape Town where global experts, including South Africans, shared the latest therapeutic advances in cancer care.
Globally, one in six people currently die of cancer, with the incidence growing faster in developing countries through ageing and rapidly growing populations which are increasingly adopting unhealthy Western lifestyles. By 2030 an estimated 70% of cancers will be in developing countries. This has prompted urgent global scientific collaboration on therapies and drugs.
The advances in immunotherapy – a modality that reduces cancer’s insidious ability to block the body’s natural immune defences – emerged from such collaboration. Immunotherapy drugs help the body fight the disease naturally without incurring some of the debilitating side-effects that arise from other treatments.
Two cancers where immunotherapy excels at, or dramatically boosts more traditional treatments thereby possibly prolonging more lives, are advanced lung and skin cancer (melanomas). World-wide, lung cancer is the leading cause of cancer death. Each year, more people die of lung cancer than of colon, breast, and prostate cancers combined. Also, one in every three cancers diagnosed is a skin cancer.
Medical Oncologist and Extraordinary Professor of Immunology at the University of Pretoria, Professor Bernardo Rapoport, says that by using immunotherapy drugs, up to 25% to 30% more of selected melanoma patients are now surviving up to eight years longer than with traditional treatments alone.
“With immunotherapy drugs, one in four melanoma patients survives. Additionally, half of non-small cell lung cancer patients with a PD-L1 expression on at least 50% of tumor cells (a pathology test that predicts response to immunotherapy treatment) survives at least two years,” said Professor Rapoport.
Founder of the Sandton Oncology Centre, Dr Daniel Vorobiof, said that in a trial of one immunotherapy drug registered in South Africa two years ago, a full 20% of patients with advanced malignant melanoma continued living for longer than five years.
“The median survival rate for patients with identical advanced disease using chemotherapy or radiation was less than 18 months. I have three or four (immunotherapy-treated) patients still alive after 10 years,” said Dr Vorobiof.
A principal clinical investigator at the Mayo Clinic, Professor Alex Adjei, said that in a five-year study of advanced lung cancer using immunotherapy, 16% of patients were still alive after five years.
“With the best existing chemotherapy, almost all of them could be dead within five years,” said Professor Adjei.
The trio of oncology experts say that immunotherapy has the potential to cure cancer, but caution that current research is focussed on understanding why some patients have dramatic benefits and others none. Immunotherapy candidates are assessed using biomarkers which reveal an individual’s built-in propensity to respond favourably or not.
Asked to roughly quantify how widely immunotherapy is being used, either in clinical trials or expanded access programmes, Rapoport puts it at roughly 95% chemotherapy, radiation or surgery, versus 5% Immunotherapy. However, he believes that within 15 years, this equation will be reversed.