For the first time, researchers find that a majority of cancerous mutations are linked to DNA, while a small number are caused by environmental factors and lifestyle choices, according to a numerical model based on DNA sequencing and epidemiological data.
But this does not mean your lifestyle no longer affects your chances of getting sick, experts asserted.
Could It Be Just Bad Luck?
In general, 66 percent of mutations resulted from random errors as cells replaced themselves, the research from a Johns Hopkins University team noted. Environmental factors, on the other hand, form 29 percent, and the remaining 5 percent are attributed to genetics.
Researchers Dr. Bert Vogelstein and Cristian Tomasetti previously proposed that the risk of cancer development is primarily anchored on random DNA mistakes occurring when self-reviving cells are in the process of division. Their new paper details the prevalent role of “chance” in the disease.
In a press briefing, Vogelstein explained that a completely normal cell could make several errors or mutations as it divides.
“Now most of the time, these mutations don't do any harm … That's the usual situation and that's good luck,” he said in a CNN report.
“Bad luck” occurs when one of such random mistakes take place in a cancer-driving gene, he added, noting that this finding might be comforting for people with cancer in their family history.
Lifestyle Still Matters
Even mutations from environmental or lifestyle factors can be quite reckless as well, Tomasetti added.
Smoking, for instance, causes more DNA mutations than normal, but the location of the DNA defect on a smoker’s genome is also accidental.
But there remains a strong case for making smart lifestyle choices to prevent the disease.
According to Tomasetti, a single mutation is not enough to lead to cancer. Typically there should be three or more, and factors such as poor diet, obesity, lack of exercise, and smoking can supply the needed gene defect that brings the body to a diseased state.
American Cancer Society chief medical officer Dr. Otis Brawley favored this new paper over the 2015 one, which caused a stir and elicited hundreds of responses in the community.
"And it really upset the anti-smoking people, it upset the folks who are in the nutrition and physical activity for cancer prevention - he really upset the prevention crowd," Brawley said, believing the current paper explains the theory better.
The Mayo Clinic outlines seven tips to prevent cancer:
Don't use tobacco. Using any type of this substance can set one off on a collision course with cancer, including that of the lung, mouth, throat, and pancreas.
Consume a healthy diet, which includes eating plenty of fruits and vegetables, maintaining a healthy weight, drinking alcohol in moderation, and limiting intake of processed meats.
Stay physically active, which directly assists in weight management and might lower the risk of cancer of the breast, prostate, colon, lung, and kidney.
Get sun protection, including avoiding midday sun, staying in the shade, and avoiding tanning beds and sunlamps.
Get immunized against certain viral infections, from hepatitis B to the human papillomavirus (HPV).
Avoid risky behaviors. Practice safe sex and do not share needles, which can lead to HIV, hepatitis B, and hepatitis C. These conditions can up the risk of liver cancer.
Get regular medical care. Undergo regular self-exams and screenings, from skin and breast to colon and cervix health.
The study is discussed in the journal Science and has an accompanying editorial penned by Harvard professor Martin A. Nowak and University of Edinburgh research fellow Bartlomiej Waclaw.
Recently, researchers developed a blood test that can detect cancer and identify its location in the body. The test involves a computer program and works by analyzing the amount of tumor DNA making rounds in a person’s blood.
