In addition to being a risk factor for bladder cancer, smoking may affect its course, with people who smoke more having a greater likelihood of developing more aggressive and deadly disease, according to a study.
The study authors also reported that a series of bladder cancer markers can predict which particular cases face the highest risk of a fatal outcome.
Researchers have known that smoking is one of the most common causes of bladder cancer, but not specifically whether it also affects how the disease progresses. To investigate, Richard J. Cote, MD, of the University of Miami Miller School of Medicine, and Anirban Mitra, MD, PhD, of the Keck School of Medicine of the University of Southern California, led a team that analyzed bladder tumors and smoking history in 212 multi-ethnic patients recruited through the Los Angeles County Cancer Surveillance Program between 1987 and 1996.
The researchers found that the bladder cancers that developed in individuals who smoked intensely were more likely to be deadly than bladder cancers in those who never smoked, or who smoked less. The study also revealed that changes in particular proteins often are present in bladder cancers that have become deadly.
“We have identified a panel of nine molecular markers that can robustly and reproducibly predict bladder cancer prognosis independent of standard clinical criteria and smoking history,” Mitra said in a news release. Patients with alterations in six to nine markers had poor outcomes, raising the hypothesis that these individuals could have benefited from more aggressive treatment.
Because the number of changes in these proteins was directly proportional to patients health outcomes in a progressive fashion, the findings confirm the theory that an accumulation of changes is more important than individual changes in determining the characteristics of a given cancer, the researchers said. The link between smoking intensity and prognosis found in this study points to the incrementally harmful effects of smoking.
“The studys findings are extremely clinically relevant as bladder cancer is one of the most expensive malignancies to treat,” said Cote, the director of the Genitourinary Malignancies Program at the University of Miamis Sylvester Comprehensive Cancer Center. “Personalized patient management is urgently needed for this disease as current clinical stratification cannot predict outcomes of individual patients.”
The study is scheduled for publication in Cancer, a peer-reviewed journal of the American Cancer Society. The study abstract is available at http://onlinelibrary.wiley.com/doi/10.1002/cncr.27763/abstract.