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Quitting smoking greatly reduces the risk of deadly cancers

In a study that underscores the vast health benefits of quitting smoking, researchers have found compelling evidence that kicking the habit can significantly decrease the risk of developing cancer

The study revealed that the benefits of quitting smoking accumulate over time and are particularly pronounced after the first decade of cessation. 

Quitting smoking 

The research, involving nearly 3 million Koreans, has illuminated the path to a healthier future for individuals who choose to quit smoking, emphasizing that it’s never too late to make a change.

“Regardless of age, quitting smoking has been shown to reduce the risk of developing cancer, especially lung cancer, with early cessation before middle age leading to significant reductions,” said Dr Jin-Kyoung Oh, who led the study at the National Cancer Center near Seoul.

Focus of the research 

The experts meticulously analyzed medical records from individuals who underwent health examinations in 2002. The individuals were tracked and monitored for cancer incidences – including lung, liver, stomach, and colorectal cancers – until 2019. 

This longitudinal approach allowed the team to witness nearly 200,000 cancer diagnoses among the participants, providing a strong dataset for understanding the relationship between smoking cessation and cancer risk.

Protective effects

One of the most striking findings from the research was that quitting smoking can halve the chances of developing cancer after at least 15 years, compared to those who continue smoking. 

The study specifically highlighted the substantial reduction in lung cancer risk, which plummeted by 42% among those who quit compared to persistent smokers. 

The risks for liver, colorectal, and stomach cancers were also notably reduced. The findings reinforce the notion that quitting smoking has a broad protective effect against various forms of cancer.

Broader implications 

The study is particularly relevant given the grim statistics surrounding cancer and smoking in the UK, where cancer accounts for more than a quarter of all deaths annually – with lung cancer being the predominant killer. 

Smoking is implicated in at least 15 different cancers, marking it as the largest preventable cause of cancer and death. 

Reducing cancer risk

The results of the study clearly demonstrate that quitting smoking can profoundly impact one’s health, reducing the risk of developing deadly cancers.

Interestingly, the study also revealed age-related benefits of quitting smoking. Individuals who quit before the age of 50 saw a 57% reduction in lung cancer risk over the study’s follow-up period, compared to those who continued smoking. 

Even those who quit at 50 or older experienced significant benefits, with a 40% reduction in lung cancer risk.

Benefits at every age

Professor Robert West of University College London noted the importance of quitting smoking as early as possible to minimize the cumulative risk of cancer. 

“This study confirms two crucial facts,” said Professor West. “One is that it can take many years for the risk of cancer to decrease relative to continuing smoking. The other is that the decrease is greater for those who quit at a younger age.”

“For smokers, this shows how crucial it is to stop smoking as young as possible. There is a benefit at every age but, the younger smokers can stop, the more of their lives they get back.”

“The way out of smoking is clear: try to stop at least once a year and make use of evidence-based specialist stop-smoking support at every quit attempt rather than trying to go cold turkey.”

The study is published in the journal Jama Network Open.

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