The big cure for the big C still remains largely elusive, but 2018 witnessed significant progress in the diagnosis of various types of cancer, as well as important breakthroughs in treatment.
In fact, the Nobel Prize in Medicine was awarded to James P Allison and Tasuku Honjo for their work in immunotherapy, which the Nobel Prize committee said is “revolutionising cancer treatment” and “fundamentally” changing the way cancer is perceived and managed.
Effective cure or false hope?
And yet, world over, both cancer patients and doctors have hardly heard of these advances, and many of those who have, view them with perhaps justified suspicion. Furthermore, the research is so complex and drowned in scientific jargon that communicators are struggling to sift the hype from the fact.
These breakthroughs and drug trials have upped the hope of a cancer cure, however, what exactly are these new treatments? How effective are they? Are they making a real difference on the ground?
Until recently, cancer treatment meant basically three options: surgery, radiation and chemotherapy. These are what doctors call the ‘cut, burn and poison’ techniques, which are not completely effective — according to the US-based National Cancer Institute, cancer today is one of the leading causes of death worldwide and the number of new cancer cases per year is expected to rise to 23.6 million by 2030. This is where immunotherapy comes in.
Cancer genetics researcher from Harvard Medical School, Dr Ajit Johnson, says that although there is no ‘magic bullet’ that will cure all cancers, immunotherapy has shown impressive success in the recent past.
Now, what exactly is immunotherapy? We all know that our immune system mounts a defence against any disease... Except in the case of cancer. This strange phenomenon was a mystery until Allison and colleagues discovered something important. It is not as if our immune system is not aware of cancer, but clever cancer cells ‘trick’ it to shut down by employing our body’s natural mechanisms to control any activation of immune cells. But, what if there is a way to ‘block’ these tricks? This is what scientists are trying to do through immunotherapy.
“Scientists have identified clever ways to re-awaken the patient’s immune system to kill the cancer cells. They do it either by genetically engineering the immune cells outside the patient’s body (and re-infusing it back into the patient) or by removing the brakes that keep the immune cells from becoming activated,” Dr Johnson explains. These brakes are removed with the help of drugs, which block the signals that suppress the activation of immune cells. “Designing a cocktail of drugs,” as Dr Johnson puts it, is another exciting treatment scientists are pursuing these days to cut off nutrient and blood supply to the cancer cells and thus ‘starve’ them to death. There is also a flurry of research and trials regarding liquid biopsy, which in layman terms is the eventual possibility of diagnosing cancer with a simple blood test.
- How does cancer screening work and what exactly does it reveal?
- Cancer screening tests are used to detect either precancerous cells or early cancer in people with no symptoms. This allows healthcare professionals to a) prevent cancer by removing precancerous lesions and b) cure early-stage cancer.
- Can screening be done for all cancers?
- Screening is usually performed for breast, cervical, colorectal, prostate and lung cancer. In high-risk individuals, screening is also undertaken for skin, ovarian, endometrial and oral cancer.
- When should one get screened?
- Screening intervals depend on the type of cancer, age of the individual as well as his family and genetic history. Speak to your family doctor first, especially if a blood relative has had it.
- (Inputs from Dr Santosh Gowda, Director (Medical Oncology), Fortis Hospital, Bengaluru)
Prevention first, cure later
Unfortunately, as promising as all these new treatments appear to be, the challenges scientists and public health professionals are facing with regard to their efficacies are intimidating, to put it mildly.
“Unless you are rich, part of a clinical trial or covered by a fantastic insurance, you cannot afford immunotherapy,” Dr Ravi Mehrotra, who heads the National Institute of Cancer Prevention and Research (NICPR) and the WHO Global Knowledge Hub on Smokeless Tobacco, says. “Moreover, only certain types of cancers are amenable to these new treatments and patients should not be under any illusion that immunotherapy can be a cure for all cancers.” Another problem with immunotherapy is its terrible side-effects.
For years, cancer research has focussed on cure and survival. But with millions of survivors worldwide today, researchers are waking up to looking at ways of reducing the often disabling and mind-shattering side-effects of treatment.
As Dr Mehrotra says, in a country like India, where it is economically not feasible for most to even afford basic radiation therapies, immunotherapy and precision drugs remain in the realm of science fiction. “Rather than investing 99% in curing and 1% in prevention, making people aware of screening (see box) and early diagnosis has far more benefits.”
Dr Johnson though cautions that the high costs of new cancer treatments should not deter countries from ‘re-thinking’ healthcare systems and investing in indigenous research and drug development.
The Harvard researcher says that although it may sound implausible today, with enough data and research, we may be able to build AI that can not only predict the emergence of cancer, but also suggest the treatment the patient will best respond to, based on his unique genetic and molecular profile. “Cancer then will no longer be a terminal illness but a disease we can simply live with.”
Published - February 04, 2019 11:15 am IST
