Thursday (4 February) is World Cancer Day. In an opinion piece for Health24, Prof Anna-Mart Engelbrecht (Department of Physiological Sciences) writes about how advances in personalised medicine and biotechnology offer new hope for cancer patients.
- Read the article below or click here for the piece as published.
Anna-Mart Engelbrecht*
Each year on February 4th, World Cancer Day raises awareness about cancer as a critical health issue that we cannot dare to neglect. The global cancer burden is increasing rapidly in developing countries as population numbers continue to grow and life expectancies rise. In low-income countries, poor patients receive only affordable or available treatments, rather than optimal ones. Other concerns regarding conventional cancer treatment are the many adverse side effects, the high rates of treatment resistance, and the rising cost of medical care to both patients and healthcare systems. The economic burden of cancer is substantial due to both healthcare expenditure, as well as lost productivity due to morbidity and premature death.
In 2003, scientists mapped out the human genome, or DNA, for the first time. This project meant that better understanding of genetics was possible and led to the discovery of many different genetic diseases. While this project initially cost R41 billion and took 10 years to complete, the cost to sequence a human genome has dropped to under R10 000 less than two decades later. It is predicted to reduce even further to approximately R1500 in the next five years. Because of its affordability, this technique has become so much more accessible to the medical world and may help advance personalised medicine. This helps doctors and clinicians to choose therapies and treatments that are more likely to work – treatments that are more personalised to individual patients and their specific disease.
Cancer occurs when mutations, or accidental changes, take place in the DNA of specific cells or tissue within the body. These cells then continue to grow excessively, forming a tumour, which then pushes into the surrounding body tissues, and may spread to other parts of the body. The same type of tumour, e.g. a lung tumour from different patients can have different mutations, and the primary tumour can also have different mutations compared to tumours which have spread to other organs in the same patient. However, understanding exactly where the DNA is mutated could help oncologists to choose more effective therapies for each specific type of cancer. This is known as precision oncology, and would aim to improve treatment efficacy, while reducing adverse effects.
Considering the need to understand the genetic mutations within cancer, there has been much research done in this field over the past few years. Some of the biggest breakthroughs include the discovery of both CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and circulating tumour DNA.
While it may sound unusual, bacteria can also get infected by viruses which are over a hundred times smaller than bacteria. To protect themselves against viruses and other invaders, some bacteria have “anti-virus DNA" called CRISPR which they use to edit the genes within the virus and render it powerless. After scientists discovered this, they realized that this could be used to edit DNA in other settings too. Considering the powerful role played by mutated or “broken" DNA in the development of cancer, it was hoped that CRISPR, along with an intracellular pair of “scissors" called Cas9, could be used to edit these damaged genes within cancer cells.
Several methods of gene-editing have been developed over the years, but CRISPR could alter the DNA of human cells in a precise, simple and affordable manner. CRISPR has taken the research world by storm and has shifted the border between the possible and impossible. It has become the major gene-editing technology in many research labs all over the world where it is now moving out of petri dishes and into clinical trials with cancer patients. CRISPR is an extremely useful tool in the bioengineering space which accelerated innovation in basic research, drug discovery, diagnostics and therapeutics. In a small study, CRISPR was able to successfully edit immune cells which were then injected into cancer patients. Immune cells can fight and kill cancer cells, and these CRISPR-edited immune cells became more successful at hunting down and attacking cancer cells within the body. However, CRISPR technology is still in its infancy, and many scientists are still cautious about its use in people.
Another advancement in the field of oncology was the discovery that tumours deposit fragments of mutated DNA into the blood stream, known as circulating tumour DNA. This can be identified in blood samples by cancer biomarker tests, leading to the earlier detection of cancer. This would also enable doctors to better guide therapy and monitor patients' progress after therapy. With the recent advances in research and biotechnology, early-stage cancer detection tests will soon become commercially available and will most likely decrease cancer mortality rates drastically.
Cancer therapy has evolved from radical surgery, radiotherapy and chemotherapy to personalised medicine and targeted biological therapies, which harness the body's biological processes, such as the immune system. Personalised medicine can lead to more effective healthcare as a precise diagnosis is provided. This will cost the patient less in the long term as it avoids unnecessary and ineffective treatments. It will also prevent adverse events, improve quality of life and more effective targeted therapeutics will lead to reduced morbidity and mortality. Additionally, the information gained through these advances, along with machine learning, will help healthcare providers by offering sophisticated tools for decision-making.
It is now time for medical schools to start providing their students with an educational background and hands-on experience in genomic tests and the interpretation thereof. Personalised medicine will have a profound impact on human health, and although genomics is the driving force behind it, the combination of next-generation sequencing, artificial intelligence and gene-editing could cure cancer.
*Prof Anna-Mart Engelbrecht leads the Cancer Research Group in the Department of Physiological Sciences at Stellenbosch University (SU). She is also co-director of the SU Spin-Out Company, BIOCODE Technologies, which develops biomarker and biosignal screening solutions for inflammatory disease and cancer risk identification. The other team members are Prof Resia Pretorius (Physiologist), Prof Willie Perold (Electronic Engineer), Este Burger (Research and Design Engineer), Dr Andre du Toit (Biochemist) and Annemie Pretorius (Engineer).
