Cigarette smoking is a rapidly growing healthcare issue and the leading cause of more than 30% of all cancer-related deaths. Cigarette smoking has been identified as a potential risk factor for a person to develop primary cancers such as those of the lung, kidney, head, bladder and neck. Now, a new study published (online on November 10, 2014) in the Journal of Clinical Oncology says that cigarette smoking prior to the first cancer diagnosis poses an increased risk of a second smoking-associated cancer.
Based on an analysis of five large and prospective cohort studies conducted in the U.S., the researchers found that the risk for a smoking-related second cancer was 3.3 to 5.3 times higher in current smokers who smoke 20 cigarettes or more per day before their first cancer diagnosis. They analyzed data on more than 15,000 patients – 2552 patients with stage 1 lung cancer, 2967 patients with head and neck cancer, 3179 patients with kidney cancer and 6386 patients suffering from bladder cancer. The association between smoking status of patients before the disease diagnosis and second smoking-associated cancer risk was studied. The key findings of the study are as follows
- Among survivors, about 866 patients (6%) were diagnosed with second smoking-associated cancers, which were primary cancers
- For the four types of cancers, patients who smoked 20 or more cigarettes per day before the initial diagnosis had higher chances of developing a second-smoking associated cancer that those who never smoked
- For patients with stage 1 lung cancer, the risk of developing a second smoking-related cancer was 2.6 times higher in survivors who smoked less than 20 cigarettes per day and was 3.3 times higher in those persons who smoked 20 cigarettes or more per day.
Similar diagnosis was done for other type of cancer survivors as well and it was found that
- Kidney cancer: 5.3 times more likely to develop a second cancer
- Head and neck cancers: 4.5 times more likely to develop a second cancer
- Bladder cancer: 3.7 times more likely to develop a second cancer
In addition, the risk for death was also found to followed similar dose-related trends.
The results of the study highlight the importance of smoking cessation programs. Cancer survivors who smoke should be encouraged to enroll in these programs as not quitting would increase the risk of a second cancer. It is the responsibility of physicians to support the tobacco cessation programs and encourage and implement interventions to help smokers quit.