Genetic testing: a brighter future for cancer diagnosis and treatment

Genetic testing is often the victim of overactive imaginations conjuring up images of crazed scientists plotting to create unholy creations. Contrary to Hollywood dramatisation and the hysteria of well-meaning religious institutions, however, this practice is a literal lifesaver for millions of families around the world.

Last month was Breast Cancer Awareness Month. Given the recent focus on breast cancer, here, at The Sunday Morning, we decided to take a look at the role human genetics plays in this condition and its cure. Speaking to renowned medical geneticist, Professor Vajira Dissanayake, we got a first-hand look as to why this area of science remains so crucial to oncologists and the rest of the medical world.

Genetics and cancer

What many may not know is that to geneticists, cases of cancer often fall into three categories – sporadic, familial, or genetic cancers.

The first type is where no family history is recorded for the condition in question. The second is where there may be a familial influence, but which could also result shared environmental factors. The third, which represents an area of interest to experts in this field, is where genetic mutations are to blame for the onset of cancer.

In this regard, there are 94 genes which can predispose an individual to develop cancer, should a mutation be detected. At the Human Genetics Unit of the University of Colombo – where Prof. Dissanayake serves as Director – all of these are tested at once, allowing experts to determine the underlying cause triggering the onset of this disease.

Beyond holistic research, therefore, the unit also conducts tests for individuals who wish to know the genetic effect of certain conditions, including cancer.

If the condition is genetic in nature, entire families can be tested to determine if they carry the mutations that make them more susceptible to the type of cancer detected. In most cases, the patient is usually tested first, followed by any family member who wishes to determine if they’re at risk.

In the case of breast cancer, Prof. Dissanayake stated those who display a mutation can seek preventative relief either through a mastectomy and reconstructive surgery or through regular Magnetic Resonance Imaging (MRI) scans. In this manner, genetic tests allow families to guard themselves against any uncertainties and take proactive measures regarding their health.

Speaking of the infinite value of this kind of knowledge when it comes to prevention and treatment, Prof. Dissanayake stated that with these tests, it is possible to both identify personalised treatment that works for specific cancer patients, and save money in the long-run.

Citing the example of an individual with colorectal cancer, he stated that if the mutation is being caused in a tumour tissue known as KRAS, traditional treatment may be largely ineffective. In these scenarios, families often shell out an arm and a leg to fund medical drugs that yield little to no result.

Before embarking on treatment, therefore, seeking genetic tests may be a way of improving one’s prognosis when combined with the right therapeutic options.

On risk factors and prevention

Discussing, thereafter, the differences in patterns of cancer seen in Sri Lanka and those present abroad, the academic noted that the factors which trigger the disease in one location may not be the same in another.

While this broadly spans genetic and environmental factors, specific considerations such as everyday meals, also play an influential role.

Speaking of the nutritional goodness inherent to the Sri Lankan diet, Prof. Dissanayake stated that: It’s important for us to preserve our traditional food habits. Commending the rich variety of spices and vegetables we consume, he believes that this fact prevents a great number of cancer diagnoses in the country.

When asked what could be done to prevent the occurrence of breast cancer (and other types as well), the professor spoke of the importance of an active lifestyle and a diet relatively free of fatty foods. Cumin and pomegranate were singled out as being extremely beneficial in preventative care.

Beyond cancer, Prof. Dissanayake also spoke of how genetic tests assist couples who have difficulty getting pregnant. By allowing families to identify any genetic factors which may be preventing them from conceiving, this even allows older couples to engage in the right kind of fertility treatments.

Hope for the future

Wrapping up the discussion, Prof. Dissanayake also commented on the muddied reputation genetic testing has suffered in the past. He stated that while people place so much stock on unscientific opinions in the modern day and age, his area of study remains cold, hard fact.

Given the availability of these tests, therefore, it is perhaps time to recast how we approach treating certain conditions, including breast cancer. With the ability to predict who may be susceptible – and what kinds of treatments are most fitting – it is perhaps possible to reduce the mortality rate of a condition that claims the lives of so many every year.


Prof. Vajira H. W. Dissanayake MBBS, PhD, FNASSL, is a Medical Geneticist. His special interests are Genetics & Genomic Medicine; Biomedical informatics; and Bioethics. He is currently the President of the Commonwealth Medical Association (2016-2019); a steering Committee Member of the Global Genomic Medicine Collaborative (G2MC), a Steering Committee Member of the International Genetics Education Network; and a Board Member of the Forum for Ethical Review Committees in Asia and the Western Pacific (FERCAP).


By Archana Heenpella

Photos: Saman Abesiriwardana