For decades in the modern medical world, this common social and medical belief has been deeply ingrained that lung cancer mainly affects only those people who regularly smoke tobacco products like cigarettes, beedis or hookahs. The general public has been rest assured that if they are completely free from the habit of smoking, then their lungs are automatically protected from all kinds of life-threatening oncological dangers. However, a landmark and detailed global study published in the prestigious international scientific journal 'Science' has completely demolished this stereotypical belief. Extensive research conducted on a huge genetic and clinical database of more than 33 lakh individuals has proven that apart from lifestyle habits, subtle genetic mutations hidden within the human DNA can also be directly responsible for the transformation of healthy lung cells into malignant tumors.
According to shocking data compiled by researchers, about 20 percent of the total lung cancer patients globally are those who have never touched any tobacco product in their entire lifetime. When medical scientists closely examined the genome profiles of more than 33 lakh people to get to the root of this mysterious trend, they found that a rare hereditary mutation in a gene called 'Epidermal Growth Factor Receptor' (EGFR) is the main axis of this deadly disease. This particular genetic anomaly has the potential to directly increase the overall risk of lung cancer by up to 25 times in any healthy individual as compared to the general population, even if the individual is leading a balanced and disciplined life away from pollution and smoke.
In this detailed investigation, scientists have specifically identified a genetic mutation called 'EGFR T790M', which causes abnormal cellular growth in lung tissue at an unprecedented pace. The study's statistical models show that if this mutation is found in a person who smokes, their risk of developing lung cancer increases by up to 10 times compared to a typical smoker. But its most frightening and surprising aspect has come to light related to non-smokers. Research findings show that people who have never smoked cigarettes or tobacco in their lives, if they inherit the EGFR T790M mutation in their DNA, are more than 60 times more likely to develop lung cancer than normal people without the mutation, which is irrefutable evidence that the risk of cancer is not determined by smoking alone.
In this paper published in 'Science Journal', the molecular mechanism of uncontrolled proliferation of cancer cells within the lungs has also been revealed in detail. According to scientists, the role of 'Fusion Protein' in this entire disease cycle proves to be extremely destructive. During the biological process when the body's cells are dividing, two different genes are unexpectedly joined together due to abnormal genetic errors. This unusual fusion results in the formation of a completely new and distorted 'fusion protein'. This distorted protein hacks the signaling pathways found within normal lung cells and starts chemically ordering tumor cells to divide uncontrollably, causing the lungs to become clogged with severe tumors even without any exposure to outside smoke.
Dr. Jacqueline LoPiccolo, chief scientist and researcher at Boston-based Dana-Farber Cancer Institute, a top oncology research institute globally, has underlined the practical importance of this study. Dr. Lopiccolo said that in modern medical practice till date, initial screening and diagnosis of lung cancer has been done only on the basis of the patient's previous smoking history and age. If a person did not smoke cigarettes, doctors generally did not recommend lung cancer screening, due to which in non-smokers the disease was caught only in the third or fourth stage. According to Dr. Lopiccolo, after this new discovery, medical protocols are going to be completely changed in the future, where timely preventive screening of even high-risk non-smokers can be done on the basis of family history and hereditary genetic mapping.
Another of the most important and comforting findings of this much-discussed scientific investigation was that this specific genetic variant was not directly linked to any of the 17 other common cancers studied—such as breast cancer, colorectal cancer, prostate cancer, or liver cancer. What this means scientifically is that the biological effect of the EGFR T790M mutation is almost entirely limited to the respiratory system and epithelial cells of the lungs. Scientists believe that identifying this targeted behavior will make it easier for drug manufacturers to develop customized 'targeted therapy' molecules and drugs that can completely stop tumor growth by directly blocking this mutation without the side effects of chemotherapy.