Smoking history is associated with an increased risk of metastatic prostate cancer when patients are treated with external beam radiation therapy (EBRT) according to a retrospective review of about 450 men.
The men, all with PSA levels <100 ng/mL and no evidence of metastasis were categorized as non-smokers, current smokers or previous smokers (>6 months). Information was collected including time from treatment to recurrence, and whether the recurrence was local or distant. Overall and specific survival rates were calculated based on these findings.
Seventy one percent of the men had been smokers at one point in their lives, and 17 percent were current smokers. Non-smokers were 29 percent of the group.
Median age of the men was about 66 years for the smokers, and about 70 years old for previous smokers and those who never smoked. Initial PSA, T stage and Gleason scores were not significantly varied among the groups.
Just under 45 percent had recurrence as detected by biochemical failure, 23 percent had local disease recurrence, and 15.5 percent developed metastasis overall. Local failure reates where similar between groups, but metastatic rates were significantly higher for smokers.
The death rate for the group was 34 percent and 39 percent of these deaths were due to prostate cancer.
It has been theorized that smoking induced hypoxia caused by high serum carboxyhemoglobin levels may contribute to cancer development.
