A study by researchers at the University of Hawaii at Manoa's Cancer Research Center of Hawaii has opined that size and weight gain in younger and older adulthood may help weigh a man's proneness to prostate cancer.
Led by Dr. Brenda Hernandez, the researchers said that the risk varies among different ethnic groups
For the study, the researchers studied the relationship in a multiethnic population consisting of blacks, Japanese, Hispanics, Native Hawaiians and whites, and compared differences among age groups using the Multiethnic Cohort, a longitudinal study of men 45-75 years of age established in Hawaii and California from 1993-1996.
Of the 83,879 men who participated in the study, 5,554 developed prostate cancer.
Overall, men who were overweight or obese by age 21 had a decreased risk of localized and low-grade prostate cancer, according to Hernandez.
Their results suggested that being overweight in older adulthood was associated with increased prostate cancer risk among white and Native Hawaiian men, but a decreased risk among Japanese men.
While excessive weight gain between younger and older adulthood was observed to increase the risk of advanced and high-grade prostate cancers in white men and increase the risk of localized and low-grade disease in black men, it appeared to decrease the risk of localized prostate cancer in Japanese men.
"The relationship of certain characteristics, such as body size, with cancer risk may vary across ethnic groups due to the combined influence of both genes and lifestyle," said Hernandez.
However, the relationship between body size and prostate cancer risk is not entirely understood.
Excess fat is associated with a number of conditions that contribute to cancer development including low-grade chronic inflammation, insulin resistance, metabolic abnormalities, and hormone imbalances.
These conditions may in turn contribute to more aggressive prostate malignancies.
Ethnic differences in cancer risk may be explained by differences in the distribution of stored body fat that could have a differential effect on the development of prostate cancer.
And the distribution of body fat may influence the specific way that excess fat influences cancer risk.
The study has been published in Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.