Heart disease and Cancer, the topmost and the second most common killer in the US, inhabited parallel universes of medical science till recently. Cardio-oncology or Onco-cardiology is a pretty new stream which is basically the intersection of heart conditions in patients who have been treated for cancer.
Two cardiologists, Peter Libby and Paul Ridker, saw plaque formation as something more than an outcome of just cholesterol and lipid accumulation.The other variable they introduced (which is seldomly discussed) was inflammation. Inflammation occurs when the immune cells get activated and infiltrate blood vessels early in the course of coronary disease, that, in turn, enables plaque growth. Of course, they proposed, bad cholesterol is a major player in inciting the immune cells and catalyses the process of inflammation.
That’s when the question arose,
If inflammation triggers heart disease, can targeting it directly, without dealing with cholesterol levels, decrease the risk of heart attacks?
Recently, researchers have shown that an anti-inflammatory drug brings down the risk of attacks and strokes in heart patients, even when they are not getting any other treatment.
But what came as an unexpected bonus side-effect of this treatment was - decreased rates of incidence of cancer, especially lung cancer.
Clearly, some element of inflammation that drives plaque formation in coronary disease is also driving cancer progression.
The drug, manufactured by Novartis, was initially named ‘Canakinumab’ and the company plans to take the FDA approval to market it as a preventative medication for heart attacks that also significantly reduces the effect of lung cancer.
While the connection between heart disease and cancer may not seem obvious, doctors say that many heart patients are smokers or have been smokers in the past. Smoking increases lung inflammation. This is the fact that, at first place, prompted the researchers to look at cancer deaths as well as heart events in the study population.
Cancer and Heart Disease: The Connecting Link
An avalanche of studies has implicated inflammation as a central player in many diseases, but not every inflammation is the same. In case of lupus, the risk of most cancers is only marginally higher. Rheumatoid arthritis increases the risk of lymphomas, but strangely lowers the risk of breast cancer. Tuberculosis induces inflammation too that appears to promote the risk of lung-cancer, while eczema oddly reduces the risk of skin cancer. Meanwhile, an alternative-medicine industry daily peddles “anti-inflammatory” diets — but which of these reduce inflammation, or what types of inflammation are affected, remains far from known.
There isn’t one inflammation: Lupus, tuberculosis and influenza all cause “inflammation,” but each might provoke different or overlapping wings of immune responses. It is a response to injury, mediated by immunological cells. But there are dozens of cell types communicating through even further dozens of signals.
A New Era of Therapeutics
Many people with normal cholesterol suffer from heart attacks. The reason behind this is chronic inflammation that leads to clogged arteries. Almost a quarter of people who suffer from a heart attack are hit by another one in a span of 5 years, and inflammation is a culprit in half of such cases. Chronic inflammation is usually unseen and occurs as an outcome of chemical responses over time throughout the body with unhealthy habits. A widely accepted test that indicates inflammation is checking for the presence of C-reactive protein (CRP) in blood.
A paper published in the New England Journal of Medicine and presented at the European Society of Cardiology meeting, scientists say they now have proof that lowering inflammation alone, without affecting cholesterol, also reduces the risk of a heart attack. For the first time, we’ve been able to definitively show that lowering inflammation independent of cholesterol reduces cardiovascular risk.
“This has far-reaching implications. It tells us that by targeting inflammation, we may be able to significantly improve outcomes for certain very high-risk populations.”
Ridker said the study showed that the use of anti-inflammatories was the next big breakthrough following the linkage of lifestyle issues and then statins.
The Research Study
Canakinumab works by lowering CRP and is currently approved to treat rare immune-related conditions through reducing inflammation without affecting cholesterol levels. The study tested the drug in 10,000 heart attack survivors who were on statins and had low cholesterol but high CRP. They were given three different doses (high, medium, low) of canakinumab or a placebo as a shot every 3 months.
Those on the medium dose had a 15% reduced chance of another heart attack over the next 4 years compared to people given dummy shots. The highest dose also lowered risk but not enough to say the drug was the reason. The lowest dose had no effect.
Anti-cancer effect
Inflammation also affects how cancers grow and spread. Although doctors don’t think the drug prevents new cancers from developing, it might slow the growth of tumors that had already started.
Among those getting canakinumab, the cancer death rate was only half as large, and death rates for lung cancer were lower in people getting the two top doses. These results were unexpected and intriguing, but not consistent across all types of tumors. The lower risk for lung cancer is a ‘promising lead’ for future research, but it comes with concern about the drug’s side effect.
