Dispatches from the war on cancer

Can our bodies fight cancer as if it were the common cold? Dr. Kulsoom Ghias explains

Dispatches from the war on cancer
One in three people, on average, are diagnosed with cancer. Continued research and development efforts are ensuring that not all of them die of the disease. A new drug recently touted as a “game-changer”, for example, has offered hope to many patients. The drug is a checkpoint inhibitor that has shown promising results in clinical trials conducted in the US. As compared to chemotherapy, particularly in patients suffering from head and neck cancer, the new drug has been shown to shrink kidney tumours. Cancers of the head and neck are among the most common in both males and females in Pakistan and we have poor survival rates. Unfortunately, checkpoint inhibitors are not commonly available in Pakistan - the costs are prohibitively expensive for the average patients. But, how do they work?

The hypothesis that the body’s immune system can be involved in surveillance to prevent cells from growing into tumours, through the same defense mechanisms mounted against a virus or bacteria, was proposed over a hundred years ago. The idea went through decades of inattention and skepticism before garnering experimental support at the start of the new millennium. Can the body fight off the formation of a tumour or clear a tumour once formed in the same way that it clears the common cold?

The body’s immune system is capable of mounting a multi-pronged attack against infectious agents. The cells of the immune system recognise foreign invaders either directly or through intermediates and clear infections. It is not inconceivable that the same immune system could rid the body of unwanted cancer cells. If only it were that simple. An infection like the flu is caused by a virus, which is distinctly different from the body’s own cells, allowing for recognition by cells of the immune system. Cancer is uncontrolled growth of the body’s own cells. In the ultimate betrayal, cancer cells not only ignore signals that would normally keep their growth in check, but they hijack normal processes to suit their own end-game. These rogue cells are often indistinguishable from normal cells and are therefore, tolerated by the immune system. To make matters worse, cancer cells have special tactics to not evade immune surveillance, but to co-opt the immune system to their own advantage.
So is your grandmother's totka the next "game-changer"?

Despite this seemingly gloomy scenario, several streams of evidence have shown that the immune system does mount a defense against cancer cells. This has prompted researchers to devise strategies to potentiate this attack from within. The new wonder-drug does exactly that - as a checkpoint inhibitor, it blocks a signal that would otherwise prevent immune cells from targeting the cancer cells. With the pro-tumour communication disrupted, the immune system can enter the arena and clear the cancer. Decades of research efforts underlie this therapeutic advancement; from unraveling the mysteries of basic immunology to identifying the specific components of anti-tumour immunity, from using laboratory animals such as mice that are “humanised” to study the disease to clinical trials with real patients.


To some extent, work has also been done on natural remedies. Garlic, ginger, kalonji and karela, among others, are known to be natural immune boosters. So is your grandmother’s totka the next “game-changer”? Some population-based studies have shown an association with garlic intake, for example, and reduced risk of certain types of cancers. These studies have several limitations, however, and the handful of recorded clinical trials involving garlic has not provided any conclusive evidence to indicate a recommended daily dose of garlic. While diet is known to affect cancer incidence in various populations, well-designed studies are required to determine any role that specific dietary factors may have in preventing cancer. Similarly, any possibility that natural extracts may modulate the immune system to respond to cancers needs to be rigorously tested, a process that can take decades for conclusive data-gathering and analysis.

Not surprisingly, research and development is almost entirely the domain of developed countries that have the infrastructure and ample financial and human resources. Several studies have shown, however, that it important to study a disease like cancer and its possible treatments in different populations because of varied genetic, biological and social backgrounds. In a country like Pakistan where basic healthcare needs are not met, research comes a distant second. Till the government and philanthropic efforts change that and till we have the resources to study the diseases that affect us the most, our population will continue to be deprived of these “game-changers”.

Dr. Kulsoom Ghias is a cancer researcher at the Aga Khan University and can be reached at kulsoom.ghias@aku.edu