Obese men have an
increased risk of cancer recurrence after undergoing
treatment with radiotherapy for localized prostate cancer,
new research shows. The findings "suggest a link to
the biologic basis of tumor progression that can be
therapeutically exploited," lead author Sara S. Strom,
from the M.D. Anderson Cancer Center in Houston, and
have linked obesity with an increased risk of
biochemical failure--treatment failure determined by
laboratory tests--after prostate surgery.
However, it was unclear if the same held true for men
treated with radiotherapy.
reported in the current online issue of the journal
Cancer, involved 873 men who underwent radiation
treatment as their only treatment for localized prostate
cancer between 1988 and 2001.
determined by an elevated body mass index, a ratio of height
to weight commonly used to determine if a person is
overweight or underweight. The researchers found that
18% of the men were mildly obese and 5% were
moderately to severely obese.
were more likely to be a younger age at diagnosis, to have
a more recent diagnosis, and to be African-American.
After an average
follow-up period of 96 months, 295 men experienced
biochemical failure, and 127 had full disease recurrence
analysis revealed that obesity was a statistically
significant independent predictor of both biochemical
failure and disease recurrence. Moreover, as the
severity of obesity worsened, the risk of these negative
mildly obese men had a 55% higher risk of biochemical
failure, and moderately-to-severely obese men had a 99%
higher risk compared with normal-weight men.
Similarly, the corresponding increases for prostate
cancer recurrence were 65% and 66%.
say the findings underscore the importance of obesity in
prostate cancer progression. Understanding the mechanism
involved, they hope, "will lead to rationally designed
preventive strategies." (Reuters)