Long-term survival and conditional survival of cancer patients in Japan using population-based cancer registry data.

Although we usually report 5-year cancer survival using population-based cancer registry data, nowadays many cancer patients survive longer and need to be followed-up for more than 5 years. Long-term cancer survival figures are scarce in Japan. Here we report 10-year cancer survival and conditional survival using an established statistical approach. We received data on 1,387,489 cancer cases from six prefectural population-based cancer registries in Japan, diagnosed between 1993 and 2009 and followed-up for at least 5 years. We estimated the 10-year relative survival of patients who were followed-up between 2002 and 2006 using period analysis. Using this 10-year survival, we also calculated the conditional 5-year survival for cancer survivors who lived for some years after diagnosis. We reported 10-year survival and conditional survival of 23 types of cancer for 15-99-year-old patients and four types of cancer for children (0-14 years old) and adolescent and young adults (15-29 years old) patients by sex. Variation in 10-year cancer survival by site was wide, from 5% for pancreatic cancer to 95% for female thyroid cancer. Approximately 70-80% of children and adolescent and young adult cancer patients survived for more than 10 years. Conditional 5-year survival for most cancer sites increased according to years, whereas those for liver cancer and multiple myeloma did not increase. We reported 10-year cancer survival and conditional survival using population-based cancer registries in Japan. It is important for patients and clinicians to report these relevant figures using population-based data.

Incidence of soft tissue sarcoma focusing on gastrointestinal stromal sarcoma in Osaka, Japan, during 1978-2007.

To clarify the incidence of soft tissue sarcoma and gastrointestinal stromal sarcoma in Osaka, Japan, we analyzed Osaka Cancer Registry's data. We identified a total of 6998 cases, except for those of bones and joints, during 1978-2007. The age-adjusted incidence rate of those sarcomas was 2.7 per 100 000 (male 2.8, female 2.6) person-years. The trend in the incidence for the last 10-year period (1998-2007) increased significantly overall and for females, while it was not significant for males. Except for cases not otherwise specified, the most prevalent histological subtype was leiomyosarcoma in digestive organs and gastrointestinal stromal sarcoma, followed by leiomyosarcoma excluding that in digestive organs and liposarcoma. Gastrointestinal stromal sarcomas were registered for the first time in 1988 and have increased since 1999, while leiomyosarcomas in digestive organs have decreased. Gastrointestinal stromal sarcoma might have been diagnosed as leiomyosarcoma in digestive organs before using immunohistochemistry.

Trends in the incidence of primary intracranial tumors in Osaka, Japan.

We analyzed the trends in the age-standardized incidence rates of 10,460 cases of primary intracranial tumors diagnosed during 1975 and 2004, Osaka, Japan using the Joinpoint regression analysis. During the period 1975-2004, the age-standardized incidence rates of total intracranial tumors increased until 1987 at 3.1% per year and then decreased significantly at -1.8% per year. The time trends were different according to the age groups. In the age group 0-19, the rate did not exhibit substantial increase or decrease. In the age group 20-74, the rates increased significantly until 1988 and then leveled off until 1999 and finally decreased. Whereas in the age group 75 and over, the rates increased drastically until 1984 and then leveled off. During the recent 10 year period 1995-2004, the age-standardized incidence rates of meningioma decreased significantly, but those of glioblastoma did not.

Population-based study of the relationship between hospital surgical volume and 10-year survival of breast cancer patients in Osaka, Japan.

Breast cancer is the most prevalent cancer among Japanese women; however, its outcome has never been analyzed in relation to hospital volume in Japan. We utilized data from the Osaka Cancer Registry for investigating correlations between hospital volume and 10-year survival of breast cancer patients. According to the total number of surgical procedures of breast cancer in each hospital during the period 1985-1991, we classified reporting hospitals in Osaka into four categories (high, medium, low, very low). The survival analysis was restricted to the 4333 female patients reported who were 30-64 years old, living in Osaka Prefecture (except for Osaka City), and for whom active follow up was available more than 10 years after diagnosis. In total, the relative 10-year survival was 79.7% in the high-volume, 80.3% in the medium-volume, 78.2% in the low-volume, and 68.2% in the very low-volume hospitals. After adjustment for age at diagnosis, clinical stage and clues for detection with the Cox regression model, the patients who received care in the very low-volume hospitals had a significantly higher risk of death than those in the high-volume hospitals. Meanwhile, no significant differences in risk were observed for the other two categories. These findings led us to conclude that the surgical volume of the hospitals did not affect the 10-year survival rate significantly, except for the very low-volume hospitals in Osaka, Japan. However, the study of these relationships should be continued and expanded in future to include quality of life.

Population-based study of relationship between hospital surgical volume and 5-year survival of stomach cancer patients in Osaka, Japan.

Despite the large number of surgical operations for stomach cancer in Japan, no study based on data from population-based cancer registries has been conducted regarding the relationship between hospital surgical volume for stomach cancer and patients' survival. Using data from the Osaka Cancer Registry (OCR), we performed survival analyses on 28,608 patients aged 35-79 years old who underwent surgery for stomach cancer, according to the extent of disease at diagnosis (localized: cancer is confined to the original organ; regional: cancer spreads to regional lymph nodes; adjacent: cancer infiltrates to adjacent tissue; distant: cancer metastasizes to distant organs). The study was divided into four periods; 1975-79, 1980-84, 1985-89 and 1990-94, according to year of diagnosis. Hospitals were stratified into four groups by total number of stomach cancer operations during each of the study periods, so that the numbers of operations in each group would be approximately equal. Cox's proportional hazards model was used to examine the relationships between hospital volume and 5-year survival according to the extent of disease, after adjustment for age at diagnosis and sex. Positive relationships between hospital volume and 5-year survival were seen in the localized and regional groups during the period 1975-79. These associations, however, decreased in later periods and disappeared in 1990-94 except for the very-low-volume hospitals. Stomach cancer patients treated in these hospitals remained at significantly higher risk of death than in the high-volume hospitals. In the case of the distant group, there was no clear relationship between hospital volume and 5-year survival during the study periods.