New data confirm link between smoking and pancreatic cancer

The role of smoking in the pathogenesis of pancreatic cancer has been clarified in a detailed analysis involving more than 18,000 patient records. Previous epidemiologic studies have suggested that smoking increases the risk for pancreatic cancer two to threefold, but this new analysis implicates smoking in both the initiation and progression of pancreatic cancer. To our knowledge, this is the first report that provides compelling evidence for the role of cigarette smoking early in neoplastic transformation of the pancreas. Previous studies have associated smoking with increased risk of pancreatic cancer, but our data show an earlier age (at) onset and hence further support the importance of cigarette smoking as a modifiable risk factor.

Data from the IMPAC Medical Registry Services Cancer Information Resource File were evaluated from 1993 to 2003. Of the 27,005 patients in whom pancreatic cancer histologically consistent with adenocarcinoma was diagnosed, 8,659 were excluded from the analysis because their smoking history was unavailable. The 18,346 remaining patients were classified as nonsmokers, previous smokers or current smokers. Of the study population, 8,886 were female and 9,460 were male. In general, stepwise reductions in age at diagnosis of pancreatic cancer were observed for nonsmokers, previous smokers and current smokers: Overall, the average age at diagnosis was 73 for non-smokers, 70 for previous smokers and 63 for current smokers, although some difference were found between the genders.

For males who had stopped smoking, their age at diagnosis (70 years) was similar to that of nonsmokers (70 years). However, for females, previous smokers had an older age at diagnosis (71 years) than current smokers (65 years), but it did not revert to that of nonsmokers (74 years). When patients were stratified by stage of disease at diagnosis, a similar relationship of age at diagnosis to smoking status was observed, showing a younger age at each stage for current smokers relative to previous smokers, and for previous smokers relative to nonsmokers. For example, the average of female patients with stage I or II disease was 75 in nonsmokers, 71 in previous smokers and 64 years in current smokers. The average age of male patients with stage I or II disease was 71 for nonsmokers or previous smokers and 63 years for current smokers. Among female patients with stage IV disease, the average age at diagnosis was 73 in nonsmokers, 71 in previous smokers and 64 in current smokers. Among male patients with stage IV disease, the average age at diagnosis was 69 in nonsmokers and 70 in previous smokers, but 62 in current smokers.

Another reason to quit smoking

Because of the relationship between smoking, age at diagnosis and stage of pancreatic cancer, hypothesized that smoking plays a role in initiating mutagenic events leading to malignant transformation. Although he noted that further studies are needed to precisely define the molecular events affected by smoking, doctor suggested that the findings have an immediate relevance to prevention programs. These results underscore the need to focus efforts on preventing smoking initiation along with smoking cessation programs in order to not only stem the tide of increasing pancreatic cancer deaths but also the additional years of lost life due to the earlier diagnosis. In the United States, almost 32,000 new cases of pancreatic cancer were diagnosed in 2004. The total number of deaths in 2004 due to pancreatic cancer was only slightly lower, making this malignancy the fourth leading cause of cancer death in the United States.

Because most patients have an advanced stage of cancer at diagnosis, the prognosis is generally dismal. Thus, it is extremely important to focus on strategies to prevent the development of pancreatic cancer. Although these data indicate that smoking is an etiologic factor in the development of pancreatic cancer. The relationship between smoking and pancreatic cancer has been understood for a decade or more. Doctor who has published numerous animal studies suggesting an association between nicotine exposure and pancreatic injury, observed that several new studies and reviews published during the past 12 months, in addition to the data presented have reinforced the notion that smoking increases the risk for pancreatic cancer.

In terms of calculating specific risk from smoking, there are many other factors, such as genetics, alcohol intake, diabetes and frequency of smoke exposure through the number of cigarettes smoked per day that may have an impact. However, he, like, indicated that patients who smoke can certainly be warned that pancreatic cancer is yet another significant health risk associated with this activity.