1994 Volume 85 Issue 12 Pages 1734-1742
The incidence and mortality rate of urogenital cancers in Japan are both low compared to those in western countries. However, the incidence and mortality patterns of cancer in Japan are currently becoming closer to those of western countries, and the importance of urogenital cancers is increasing. We conducted an analysis of urogenital cancers in Gunma Prefecture.
The subjects were newly detected urogenital cancer patietns living in Gunma Prefecture diagnosed between 1985 and 1992. Details were as follows: prostate cancer 1411, bladder cancer 1253 (male 937, female 316), renal cell carcinoma 411 (male 287, female 124), renal pelvic and ureter cancer 187 (male 127, female 60) and testicular cancer 162. Incidence rate was calculated by year, district and age, and was expressed per 100, 000/year and was adjusted to world population. Regarding the incidence rate per year for males, that of prostate cancer and renal cell carcinoma increased dramatically from 8.3 to 13.6 and from 1.1 to 3.2, respectively. Incidence rate of other cancers in males showed a slight increase or remained almost stable. Incidence rate by year for females showed a slight increase or remained almost stable as a whole.
Gunma Prefecture was divided into 10 districts by the range of daily life of people and the incidence rates of prostate cancer, bladder cancer and renal cell carcinoma for each district were calculated. Incidence rate of prostate cancer tended to be higher in the northern parts of the prefecture, while that of bladder cancer showed no detectable trend. Incidence rate of renal cell carcinoma tended to be higher in the central parts of the prefecture and to be lower in eastern and western parts of the prefecture.
Each cancer was categorized by the slope of the line when the age-specific incidence rate of each cancer was plotted on double logarithmic scales. The 3 categories were linear (prostate and bladder cancer), linear until a certain age and then leveled off or decreased thereafter (renal cell carcinoma and renal pelvic and ureter cancer) and irregular (testicular cancer). Age-specific incidence rates of prostate and bladder cancer increased in proportion to the 11th and 5th power of age, respectively.
