Cancer incidence in Japan in 1990: estimates based on data from Population-based Cancer Registries. The Research Group for Population-based Cancer Registration in Japan

Assessment of transposed ovarian movement: how much of a safety margin should be added during pelvic radiotherapy?

The purpose of this study was to analyze transposed ovarian movement. Data from 27 patients who underwent ovarian transposition after surgical treatment for uterine cancer were retrospectively analyzed. Computed tomography (CT) images including transposed ovaries were superimposed on other CT images acquired at different times, and were matched on bony structures. Differences in ovarian position between the CT images were measured. The planning organ at risk volume (PRV) margins were calculated from the formula of the 90% reference intervals (RIs) and the 95% RI, which were defined as mean ± 1.65 standard deviation (SD) and mean ± 1.96 SD, respectively. The 90% RI in the cranial, caudal, anterior, posterior, left and right directions were 1.5, 1.5, 1.4, 1.0, 1.7 and 0.9 cm, respectively. The 95% RI in the corresponding directions were 1.5, 2.0, 1.7, 1.2, 1.9 and 1.2 cm, respectively. These data suggest that bilateral ovaries need a PRV margin of ∼2 cm in all directions. The present study suggests that a transposed ovary needs the same PRV margin as a normal ovary (∼2 cm). Even after transposition, ovaries should be kept away from the radiation field to take into consideration the degree of ovarian movement.

Secular trends in the incidence, mortality, and survival rate of gastric cancer in a general Japanese population: the Hisayama study

To examine secular trends in the incidence and mortality of gastric cancer in a Japanese community, Hisayama, we established three study-cohorts of Hisayama residents aged > or =40 years in 1961 (1637 subjects), 1974 (2054), and 1988 (2602). Each cohort was followed up for ten years. The age-standardized mortality from gastric cancer significantly decreased from 2.4 per 1000 person-years in the first cohort to 0.8 in the third cohort for men, and from 1.0 to 0.2, respectively, for women (p < 0.01 for trend in both sexes). The five-year survival rate after gastric cancer significantly improved from the first (32.6%) to the third cohort (73.0%, p < 0.01) for men and from 43.2% to 72.3% (p < 0.05), respectively, for women. The age-standardized incidence of cancer in men was not different among the cohorts (4.3 per 1000 person-years in the first, 5.0 in the second, and 4.9 in the third cohort), while it decreased significantly in women (2.0, 1.8, and 1.2, respectively, p < 0.01 for trend). In conclusion, our findings suggest that in a Japanese population, the mortality from gastric cancer declined during the past 40 years, due mainly to the improvement of survival in both sexes and a decrease in the incidence for women.

Randomized trial of dietary fiber and Lactobacillus casei administration for prevention of colorectal tumors

The epidemiologic evidence that dietary fiber protects against colorectal cancer is equivocal. No large-scale clinical study of the administration of Lactobacillus casei has been reported. We examined whether dietary fiber and L. casei prevented the occurrence of colorectal tumors. Subjects were 398 men and women presently free from tumor who had had at least 2 colorectal tumors removed. Subjects were randomly assigned to 4 groups administered wheat bran, L. casei, both or neither. The primary end point was the presence or absence of new colorectal tumor(s) diagnosed by colonoscopy after 2 and 4 years. Among 380 subjects who completed the study, 95, 96, 96 and 93 were assigned to the wheat bran, L. casei, both and no treatment groups, respectively. Multivariate adjusted ORs for occurrence of tumors were 1.31 (95% CI 0.87-1.98) in the wheat bran group and 0.76 (0.50-1.15) in the L. casei group compared to the control group. There was a significantly higher number of large tumors after 4 years in the wheat bran group. The occurrence rate of tumors with a grade of moderate atypia or higher was significantly lower in the group administered L. casei. No significant difference in the development of new colorectal tumors was observed with administration of either wheat bran or L. casei. However, our results suggest that L. casei prevented atypia of colorectal tumors.