Itsuro Yoshimi

Projection of lung cancer mortality in Japan

According to the National Vital Statistics data, age‐standardized mortality rates (ASRs) of lung cancer have shown slightly declining trends in Japan for both men and women. In order to evaluate whether this tendency will continue, a Bayesian age‐period‐cohort (APC) model was applied using the National Vital Statistics data from 1952 to 2001. In the projection, a Gaussian autoregressive prior model was applied to smooth age, period, and cohort effects from its 2 immediate predecessors by extrapolation. Posterior distributions from which we drew inferences on mortality rates were derived from 15,000 iterations using 5000 burn‐in iterations. We defined the median of the iterated values as the overall summary mortality rate of the iterated results. Our results suggest that the number of deaths due to lung cancer will double for men and women during the next 3 decades due to the aging of the baby‐boomer generation (individuals who were born between 1947 and 1951). Currently declining trends in some age groups will reverse and start to increase again in the next decades. However, for recent birth cohorts, the results of the projection varied according to whether the data set included early age group mortality or not. Lung cancer mortality in the future depends on the risk factors engaged in by todays young people, especially smoking. Strong promotion of anti‐smoking measures and careful surveillance for lung cancer are needed.

Human T-lymphotropic virus type-I infection, survival and cancer risk in southwestern Japan: a prospective cohort study

Objectives: This study prospectively evaluated the associations of human T-lymphotropic virus type-I (HTLV-I) infection with survival and cancer incidence. Methods: The study base comprised 4297 adults (aged 40–69 years in 1993) who had either visited the outpatient clinic or who had received annual health check-ups at the A Hospital, Nagasaki, Japan, between 1985 and 1992 (HTLV-I seropositivity = 24.7%). During the follow-up period (1993–1999 or 2000), 290 deaths and 261 cases of malignant neoplasms occurred, including ten deaths and six incident cases of adult T-cell leukemia/lymphoma (ATL). Results: After adjustment for gender, age and other covariates, HTLV-I seropositivity was associated with an increased mortality from all-causes excluding ATL (rate ratio, RR = 1.3, 95% confidence interval, CI = 1.0–1.7), all non-neoplastic diseases (RR = 1.5, 95% CI = 1.0–2.3) and heart diseases. HTLV-I infection was not found to be associated with an increased risk of developing total cancers other than ATL (RR = 0.98, 95% CI = 0.74–1.3), colorectal cancers, liver cancer or lung cancer, but was associated with a reduced risk of gastric cancer (RR = 0.42, 95% CI = 0.17–0.99). Conclusions: HTLV-I infection is associated with increased mortality from all-causes excluding ATL and all non-neoplastic diseases. HTLV-I carriers may not be at increased general cancer risk, but at reduced risk of gastric cancer.

Appendicular bone mass and knee and hand osteoarthritis in Japanese women: a cross-sectional study

BackgroundIt has been reported that there is an inverse association between osteoarthritis (OA) and osteoporosis. However, the relationship of bone mass to OA in a Japanese population whose rates of OA are different from Caucasians remains uncertain.MethodsWe studied the association of appendicular bone mineral density (second metacarpal; mBMD) and quantitative bone ultrasound (calcaneus; stiffness index) with knee and hand OA among 567 Japanese community-dwelling women. Knee and hand radiographs were scored for OA using Kellgren-Lawrence (K/L) scales. In addition, we evaluated the presence of osteophytes and of joint space narrowing. The hand joints were examined at the distal and proximal interphalangeal (DIP, PIP) and first metacarpophalangeal/carpometacarpal (MCP/CMC) joints.ResultsAfter adjusting for age and body mass index (BMI), stiffness index was significantly higher in women with K/L scale, grade 3 at CMC/MCP joint compared with those with no OA. Adjusted means of stiffness index and mBMD were significantly higher in women with definite osteophytes at the CMC/MCP joint compared to those without osteophytes, whereas there were no significant differences for knee, DIP and PIP joints. Stiffness index, but not mBMD, was higher in women with definite joint space narrowing at the CMC/MCP joint compared with those with no joint space narrowing.ConclusionsAppendicular bone mass was increased with OA at the CMC/MCP joint, especially among women with osteophytes. Our findings suggest that the association of peripheral bone mass with OA for knee, DIP or PIP may be less clearcut in Japanese women than in other populations.