Smoking raises risk of second smoking-related cancer

Survivors of bladder, kidney, and two other forms of cancer who smoked 20 or more cigarettes a day prior to their cancer diagnoses have an up to fivefold higher risk of developing a second smoking-associated cancer compared to survivors of the same cancers who never smoked.

That is the finding of an analysis of five large, prospective cohort studies of bladder, kidney, lung (stage I), and head and neck cancer survivors.

RELATED: Use of robotic RN rising, despite unclear advantages

The association between smoking and developing a second primary smoking-associated cancer was similar to the association between smoking and developing a first primary smoking-associated cancer (patients who smoked more than 20 cigarettes per day had a 5.41-fold higher risk of developing cancer than individuals who have never smoked). Notably, current smoking at any level increased the risk of overall mortality across all cancer disease sites.

The study, published online in the Journal of Clinical Oncology (Nov. 10, 2014),  affirms the 2014 Surgeon General report’s conclusion that patients and survivors who smoke are at a higher risk of developing a second cancer, according to a news release from the American Society of Clinical Oncology, which publishes the Journal of Clinical Oncology.

“As survival improves for a number of smoking-related cancers, patients are living longer; however, smoking may increase the risk of developing a second smoking-related cancer among these survivors,” said lead study author Meredith S. Shiels, PhD, MHs, of the National Cancer Institute’s Division of Cancer Epidemiology and Genetics. “Our study demonstrates that health care providers should emphasize the importance of smoking cessation to all their patients, including cancer survivors.”

According to the authors, this is the largest study of its kind to explore the association between smoking and second cancer risk.

Researchers examined data from five prospective epidemiologic cohorts, which included 2,552 patients with stage I lung, 6,386 with bladder, 3,179 with kidney and 2,967 with head and neck cancer.

Next: Risk increases for bladder, kidney cancers

More on Kidney and Bladder Cancers

Studies reveal genes key to RCC development, growth

‘Obesity paradox’ appears to fit for men with renal cell carcinoma

Gene set breaks high-grade bladder cancer into two subtypes

Bladder cancer study identifies therapeutic targets

Across all four cancer types, survivors who smoked 20 or more cigarettes per day prior to their first primary diagnoses were more likely to develop a second smoking-associated cancer when compared to those who never smoked. For the two urinary tract cancers, the risk increases were as follows:

• bladder cancer: 3.7 times more likely to develop a second cancer

• kidney cancer: 5.3 times more likely to develop a second cancer.

Current smokers who smoked fewer than 20 cigarettes per day and former smokers who had quit before their first cancer diagnosis also had an elevated risk of developing a second primary smoking-associated cancer compared to survivors who never smoked (although risks decreased with the number of years since smoking cessation).

To get weekly news from the leading news source for urologists, subscribe to the Urology Times eNews.