Risk of Second Cancers Among Current Smokers

November 26, 2014

This slide show reports on a pooled analysis that found up to a fivefold risk of second cancers among smokers, compared with cancer survivors who never smoked.

Risk of Second Cancers Among Current Smokers:

Results of a pooled analysis funded partly by the National Cancer Institute (NCI) show up to a fivefold risk of second cancers among smokers, compared with cancer survivors who never smoked. The study is the largest of its kind to date exploring risks of second cancers among smokers.

2014 US Surgeon General Report:

The findings, reported earlier this month in the

Journal of Clinical Oncology

, support the conclusion of the 2014 US Surgeon General report that patients and survivors who smoke are at risk for second cancers, and emphasize the importance of discussing smoking cessation with all patients, including cancer survivors.

Investigators Analyzed Five Large Prospective Cohort Studies:

National Institutes of Health-AARP Diet and Health Study; Agricultural Health Study; Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study; Iowa Women’s Health Study; and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO).

Four Primary Cancer Types in 15,084 Survivors Were Assessed:

Stage I lung cancer (n = 2,552), bladder cancer (n = 6,386), kidney cancer (n = 3,179), and head and neck cancer (n = 2,967).

Among Survivors, 866 Second Primary Smoking-Associated Cancers Were Diagnosed:

Survivors who smoked 20 or more cigarettes per day before their primary cancer diagnoses were more likely to develop a second smoking-associated cancer, compared with survivors who were never-smokers.

Risk Increases for Developing a Second, Smoking-Associated Cancer:

Compared with survivors of the same cancers who never smoked-3.3-fold for patients with stage I lung cancer, 3.7-fold for patients with bladder cancer, 4.5-fold for patients with head and neck cancer, and 5.3-fold for patients with kidney cancer.

Planning Future Research:

Lead study author Meredith S. Shiels, PhD, MHS, a research fellow with the NCI’s division of Cancer Epidemiology and Genetics, said future research should directly assess the association between smoking following a primary cancer diagnosis and the risk of a second cancer.