Trends in the mortality (1950-1997) and incidence (1975-1993) of malignant ovarian neoplasm among Japanese women: analyses by age, time, and birth cohort

Global patterns and trends in ovarian cancer incidence: age, period and birth cohort analysis

BACKGROUND

Ovarian cancer (OC) is the seventh most common malignancy worldwide and the most lethal gynaecological malignancy. We aimed to explore global geographical patterns and temporal trends from 1973 to 2015 for 41 countries in OC incidence and especially to analyse the birth cohort effect to gain further insight into the underlying causal factors of OC and identify countries with increasing risk of OC.

METHODS

OC data were drawn from the Cancer Incidence in Five Continents databases and online databases published by governments. The joinpoint regression model was applied to detect changes in OC trends. The age-period-cohort model was applied to explore age and birth cohort effects.

RESULTS

The age-standardized rate of OC incidence ranged from 3.0 to 11.4 per 100,000 women worldwide in 2012. The highest age-standardized rate was observed in Central and Eastern Europe, with 11.4 per 100,000 women in 2012. For the most recent 10-year period, the increasing trends were mainly observed in Central and South America, Asia and Central and Eastern Europe. The largest significant increase was observed in Brazil, with an average annual percentage change of 4.4%. For recent birth cohorts, cohort-specific increases in risk were pronounced in Estonia, Finland, Iceland, Lithuania, the United Kingdom, Germany, the Netherlands, Italy, Malta, Slovenia, Bulgaria, Russia, Australia, New Zealand, Brazil, Costa Rica, Ecuador, India, Japan, the Philippines and Thailand.

CONCLUSIONS

Disparities in the incidence and risk of OC persist worldwide. The increased risk of birth cohort in OC incidence was observed for most countries in Asia, Central and Eastern Europe, and Central and South America. The reason for the increasing OC risk for recent birth cohorts in these countries should be investigated with further epidemiology studies.

[Effects of age-period and cohort on mortality due to ovarian cancer in Brazil and its regions]

This article sought to evaluate the effects of age, period and birth cohort (APC) on the temporal evolution of mortality due to ovarian cancer in Brazil and its regions from 1980 to 2014. This is an ecological, time-trend study using APC models with a Baysean approach and INLA (Integrated Nested Laplace Approximations) deterministic method for parameter inference. Mortality data and population data were obtained from the Brazilian Health Informatics Department. Rates of mortality due to ovarian cancer, according to geographical region, were standardized using the direct method, after correcting deaths for undefined causes and incomplete cancer diagnosis. In the period we studied, Brazil had 4.91 deaths due to ovarian cancer per 100,000 women, the Southern (5.66) and Southeastern regions (5.70) had higher rates per 100,000 women and the Northern region had the lowest rate (3.13/100,000 women). In all regions, there was a progressive increase in mortality as ages advanced. The multivariate best fit APC model showed positive risk of death in the Central and Northeast between 2010-2014 and, beginning in 1995-1999, in the South. We also observed a positive and significant risk of death for older cohorts in the South and Southeast and a reduced risk for younger cohorts. The inverse was opposed in the Northern and Northeastern regions. The data shows a heterogeneous pattern in the temporal evolution of mortality due to ovarian cancer in the Brazilian geographical regions, which may be related to the distinct demographic and epidemiological transition processes experienced in these regions.

Descriptive epidemiological study of food intake among Japanese adults: analyses by age, time and birth cohort model

BACKGROUND

Although food and nutrient consumption among the Japanese population, known to have one of the longest life expectancies in the world, has changed markedly after World War II, little is known about the influences age, time and birth cohort have had. The present study examined the effects age, time and birth cohort have had on intake of 14 food groups from 1989 to 2009, using published data from the National Health and Nutrition Survey in Japan.

METHODS

The survey included 575 adults (271 men and 304 women) in 1989, 8431 (3952 men and 4479 women) in 1999 and 5632 (2629 men and 3003 women) in 2009. The effects of age on energy-adjusted food intakes defined by gender and birth cohort (birth in 1930-1939, 1940-1949, 1950-1959, 1960-1969, 1970-1979) were estimated using the mean polish process.

RESULTS

Intakes of meat and confectionary increased whereas those of milk and dairy products, sugar, and fats and oils decreased from 1989 to 2009. Both men and women in the 1940's birth cohort consumed more fruit, although differences in food intake by birth cohort were less discernible. Furthermore, meat, fats and oils, and wheat intake decreased while fruits, fish, beans and vegetables consumption increased with aging in both men and women.

CONCLUSIONS

The present analysis suggests intakes of meat and confectionary have increased in Japan over the past 20 years regardless of age and generation. Also, younger individuals are less likely to consume fruits, fish, beans and vegetables regardless of the birth cohort and time period. Differences in food group consumption by birth cohorts born between 1930 and 1979 were not obvious. The first indication of these findings would be that in order to avoid ongoing increases in meat and confectionery intake, the public health strategy should target the whole Japanese population. Secondly, intervening with the diet of younger individuals, especially today, would be reasonable as it is unknown whether today's younger individuals will adopt a healthier diet when they age as the other generations did.

Histology-specific long-term trends in the incidence of ovarian cancer and borderline tumor in Japanese females: a population-based study from 1983 to 2007 in Niigata

AIM

The histology-specific long-term trends in the incidence of ovarian cancer and borderline tumors in Japanese women were examined, based on data from the population-based cancer registry in Niigata, Japan.

MATERIAL AND METHODS

Data were obtained from the Niigata Gynecological Cancer Registry, which covered the entire female population in Niigata prefecture, Japan, during the period from 1983 to 2007.

RESULTS

A total of 3134 females with epithelial ovarian cancer, including borderline tumor cases, were diagnosed between 1983 and 2007. The age-standardized rates (ASRs) of both ovarian cancer and borderline tumors have steadily increased, with significant changes in ovarian cancer in all age groups, and borderline ovarian tumors in subjects aged <50. The ASRs of endometrioid adenocarcinoma showed a steady increasing trend, and those of clear cell and mucinous adenocarcinomas showed significant increasing trends in the total population. The ASRs of clear cell, mucinous, and endometrioid adenocarcinomas in the 50+ age group were significantly increased, especially the incidence of clear cell adenocarcinoma, which strikingly increased by approximately threefold from 1.2 (1983-1989) to 3.5 (2000-2007) per 100,000 females.

CONCLUSION

This prefecture-wide study showed the practical trends in ovarian cancer and borderline tumors in Japanese females. The incidence of ovarian cancer has steadily increased, with significant increases in the incidence of clear cell and mucinous adenocarcinomas in the total population during the past two decades. Because of the poor response rate of these histological subtypes to platinum-based regimens, novel treatment approaches should be adopted to improve the prognostic outcome in patients with ovarian cancer in Japan.

Comparison between serous and non-serous ovarian cancer as a prognostic factor in advanced epithelial ovarian carcinoma after primary debulking surgery

BACKGROUND

Residual tumor size after primary surgery is the most important prognostic factor in advanced ovarian cancer. We conducted a retrospective study in Japanese women to evaluate the association of various residual disease diameters and histological subtypes with overall survival (OS) in patients with residual disease ≥1 cm.

METHODS

Demographic and clinicopathological data were obtained from the Tokai Ovarian Tumor Study Group; 294 patients with International Federation of Gynecology and Obstetrics stage III and IV epithelial ovarian carcinoma who had undergone primary debulking surgery between 1986 and 2007 and had ≥1 cm residual tumor were identified. A Cox proportional hazards model was used to assess the association of prognostic factors with OS.

RESULTS

Non-serous advanced ovarian cancer was associated with a significant increase in the risk of death. For serous ovarian cancer, residual tumor size was not an independent prognostic factor [multivariate hazard ratio (HR) = 1.63, 95% confidence interval (CI) = 0.96-2.79 (2-5 cm); HR = 1.25, 95% CI = 0.72-2.17 (>5 cm); trend P = 0.480], whereas taxane-based chemotherapy was associated with a better prognosis (HR = 0.66, 95% CI = 0.44-0.99, P = 0.046). For non-serous ovarian cancer, in contrast, residual tumor size was associated with an increased risk of death [multivariate HR = 0.87, 95% CI = 0.36-2.14 (2-5 cm); HR = 2.21, 95% CI = 0.96-5.08 (>5 cm); trend P = 0.067], whereas taxane-based chemotherapy was not a prognostic factor [HR = 0.70, 95% CI = 0.29-1.65, P = 0.409 (taxane-based)].

CONCLUSIONS

Although primary maximal cytoreduction is essential to improving OS in advanced ovarian cancer, our findings suggest the management of patients with suboptimal residual tumor should take into account differences between histological subtypes.

Cervical, uterine corpus, and ovarian cancer mortality in Greece during 1980 to 2005: a trend analysis

INTRODUCTION

The aim of the present study was to analyze cervical, uterine corpus, and ovarian cancer mortality, between 1980 and 2005, in Greece.

METHODS

Mortality data and population age distribution were provided by the National Statistical Service of Greece. Time trends of mortality were calculated for each tumor type per 100,000 women in the whole female population of Greece, and 2 different age groups, that is, women aged 49 years and younger and those 50 years and older. Joinpoint regression was used for further analysis of mortality trends.

RESULTS

Overall, cervical and uterine corpus cancer mortality in the whole female population of Greece had a slightly decreasing trend between 1980 and 2005, whereas ovarian cancer mortality rates increased steadily throughout the period studied. Subgroup analyses according to age showed that cervical cancer mortality decreased very slightly only in women older than 50 years, whereas it remained steady in younger women. Uterine corpus cancer mortality decreased slightly in both age groups, but increased during the last years of the study period in the older age group. Ovarian cancer mortality increased in women older than 50 years, whereas it remained steady in the younger age group. Joinpoint regression analysis showed that only the increase after 1997 in the mortality trend for uterine corpus cancer in women 50 years and older was statistically significant (P = 0.0044).

CONCLUSIONS

Although our findings regarding cervical cancer mortality in Greece are encouraging, still more efforts are needed, particularly in preventing cervical cancer in younger women. The increasing trend of uterine corpus and ovarian cancer mortality in older women suggests that development of well-organized tertiary centers for the implementation of modern therapeutic modalities is urgently needed.

Solid cancer incidence in atomic bomb survivors: 1958-1998

This is the second general report on radiation effects on the incidence of solid cancers (cancers other than malignancies of the blood or blood-forming organs) among members of the Life Span Study (LSS) cohort of Hiroshima and Nagasaki atomic bomb survivors. The analyses were based on 17,448 first primary cancers (including non-melanoma skin cancer) diagnosed from 1958 through 1998 among 105,427 cohort members with individual dose estimates who were alive and not known to have had cancer prior to 1958. Radiation-associated relative risks and excess rates were considered for all solid cancers as a group, for 19 specific cancer sites or groups of sites, and for five histology groups. Poisson regression methods were used to investigate the magnitude of the radiation-associated risks, the shape of the dose response, how these risks vary with gender, age at exposure, and attained age, and the evidence for inter-site variation in the levels and patterns of the excess risk. For all solid cancers as a group, it was estimated that about 850 (about 11%) of the cases among cohort members with colon doses in excess of 0.005 Gy were associated with atomic bomb radiation exposure. The data were consistent with a linear dose response over the 0- to 2-Gy range, while there was some flattening of the dose response at higher doses. Furthermore, there is a statistically significant dose response when analyses were limited to cohort members with doses of 0.15 Gy or less. The excess risks for all solid cancers as a group and many individual sites exhibit significant variation with gender, attained age, and age at exposure. It was estimated that, at age 70 after exposure at age 30, solid cancer rates increase by about 35% per Gy (90% CI 28%; 43%) for men and 58% per Gy (43%; 69%) for women. For all solid cancers as a group, the excess relative risk (ERR per Gy) decreases by about 17% per decade increase in age at exposure (90% CI 7%; 25%) after allowing for attained-age effects, while the ERR decreased in proportion to attained age to the power 1.65 (90% CI 2.1; 1.2) after allowing for age at exposure. Despite the decline in the ERR with attained age, excess absolute rates appeared to increase throughout the study period, providing further evidence that radiation-associated increases in cancer rates persist throughout life regardless of age at exposure. For all solid cancers as a group, women had somewhat higher excess absolute rates than men (F:M ratio 1.4; 90% CI 1.1; 1.8), but this difference disappears when the analysis was restricted to non-gender-specific cancers. Significant radiation-associated increases in risk were seen for most sites, including oral cavity, esophagus, stomach, colon, liver, lung, non-melanoma skin, breast, ovary, bladder, nervous system and thyroid. Although there was no indication of a statistically significant dose response for cancers of the pancreas, prostate and kidney, the excess relative risks for these sites were also consistent with that for all solid cancers as a group. Dose-response estimates for cancers of the rectum, gallbladder and uterus were not statistically significant, and there were suggestions that the risks for these sites may be lower than those for all solid cancers combined. However, there was emerging evidence from the present data that exposure as a child may increase risks of cancer of the body of the uterus. Elevated risks were seen for all of the five broadly classified histological groups considered, including squamous cell carcinoma, adenocarcinoma, other epithelial cancers, sarcomas and other non-epithelial cancers. Although the data were limited, there was a significant radiation-associated increase in the risk of cancer occurring in adolescence and young adulthood. In view of the persisting increase in solid cancer risks, the LSS should continue to provide important new information on radiation exposure and solid cancer risks for at least another 15 to 20 years.

Proteomic search for potential diagnostic markers and therapeutic targets for ovarian clear cell adenocarcinoma

Clear cell adenocarcinoma (CCA) has a highly malignant potential in human epithelial ovarian cancer. The serum CA-125 is widely used as a marker for ovarian cancer, but the level is relatively low in CCA. Therefore, new sensitive biomarkers are required. In this report, we describe a promising proteomic analysis that is differentially expressed in CCA when compared to mucinous adenocarcinoma, using the ovarian cultured cell lines OVISE, OVTOKO, and MCAS. The disease-associated proteins were identified by 2-D differential gel electrophoresis (2-D DIGE) and MS. In this analysis, 18 up-regulated and 31 down-regulated spots were observed that had at least two-fold differences in the two CCA cell lines than in MCAS as control cells. Some of the proteins differentially expressed in CCA were previously observed as alternative expression levels in ovarian and/or other cancers in clinical samples. In a subsequent preliminary differential study using surgical specimens from patients with CCA, it was demonstrated that the identified proteins were expressed differentially in actual tissues, as well as in the CCA culture cells. The results from this investigation show the potentiality of a proteomic approach for identifying disease-associated proteins, which may eventually serve as diagnostic markers or therapeutic targets in CCA.

A pathology study of malignant and benign ovarian tumors among atomic-bomb survivors--case series report

The present article describes the series of incident primary ovarian tumors in the Life Span Study (LSS) cohort of the Radiation Effects Research Foundation, with particular emphasis on case ascertainment and characterization of histological features of the tumors. We identified 723 ovarian tumors (260 malignant, 463 benign) in 648 individuals of about 70,000 female LSS subjects; 71 cases had more than one ovarian tumor. We histologically confirmed 601 tumors (182 malignant, 419 benign tumors). The most frequent histological type was common epithelial tumor (90.7% for malignant and 59.7% for benign tumors). The distributions of ovarian tumors by histological type were similar to those from other studies. Among malignancies, the frequency of common epithelial types relative to other tumor types increased with radiation dose (p = 0.02). Among benign tumors, the relative frequency of sex-cord stromal tumors increased with radiation dose (p = 0.04). The women with mucinous cancer had better survival than those with serous cancers (p = 0.03). Within tumor types, there was no consistent pattern of survival by radiation dose. Variations in histological types of ovarian tumors in response to radiation dose, suggested by the case series data need to be followed up by population-based incidence analysis.

Cigarette smoking and the risk of ovarian cancer in the Japanese population: Findings from the Japanese Collaborate Cohort study

AIM

The many studies into the relation between cigarette smoking and the risk of ovarian cancer have produced inconsistent results. Here we investigated this relation using data from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk, initiated in 1988.

METHODS

A self-administered questionnaire on smoking habits and other risk factors for cancer was completed by 34 639 Japanese women. After 7.6 years of follow up, 39 cases of ovarian cancer were available for analyses. Cox proportional-hazards models were used to compute relative risks (RR) and to adjust for confounders.

RESULTS

Relative to those who had never smoked, the RR of ovarian cancer were 1.63 (95% confidence interval [CI] = 0.21-12.50) for former smokers and 2.27 (95% CI = 0.85-6.08) for current smokers. Among current smokers, the RR were 1.48 (95% CI = 0.20-10.92), 5.56 (95% CI = 1.68-19.06), and 1.86 (95% CI = 0.25-14.30) among women who smoked <10, 10-19, and at least 20 pack-years ([number of cigarettes smoked per day/20] x number of years subject has smoked), respectively, relative to those who had never smoked. A test for trend was statistically significant (P = 0.044).

CONCLUSIONS

These data indicate that cigarette smoking increases the risk of developing ovarian cancer in the Japanese population.

Firm measures are required to effect any significant decrease in the Japanese age-adjusted mortality rate from malignant neoplasms for the 21st century

The Japanese have the longest lifespan worldwide, but this has been mostly due to reductions in the mortality rates from diseases other than malignant neoplasms. Changes in the age-adjusted mortality rates (AMRs) for malignant neoplasms in Japan from 1950 to 2000 are analyzed to elucidate the overall trend. The overall AMRs for all malignant neoplasms in men increased from 1950 to 2000, and decreased slowly in women during the same period. Changes since 1990 have been small in both genders, but show a hopeful trend towards a decrease in the total AMR since 1995. These trends reflect a balance between the decreased AMR from gastric (both male and female) and uterine cancers and increases in many other malignant neoplasms. However, in the period 1990-2000, the decrease in the AMR from gastric and uterine cancers has shown a trend towards leveling off. Therefore, improving the trend towards reductions in cancer incidence and mortality in the 21st century and beyond will depend on achieving changes in other cancer sites, which can only be realized through the twofold approach of preventative medicine and research as well as improvements in the levels of diagnosis and therapy. Much more emphasis must therefore be placed on primary prevention, in particular on anti-smoking campaigns, as well as stepping-up research into the etiology of, and novel treatments for other malignant neoplasms, especially colorectal and breast cancers.

Influence of hospital procedure volume on ovarian cancer survival in Japan, a country with low incidence of ovarian cancer

The survival of ovarian cancer patients has been reported to be superior at hospitals with a high volume of operations. A population-based study was carried out to assess whether this is true in Japan, where the incidence rate is relatively low as compared with other developed countries. The Osaka Cancer Registry's data were used to investigate associations between hospital procedure volume and survival of ovarian cancer patients. Hospitals were ranked according to the number of operations for ovarian cancer performed per year (high/medium/low/very low). Survival analysis was restricted to the reported 2450 cases who lived in Osaka Prefecture (except for Osaka City) diagnosed in 1975-1995, or those who resided in Osaka City in 1993-1995, since active follow-up data on vital status 5 years after the diagnosis were available. The relative 5-year survival for all ovarian cancer cases was 38.8%, and the survival was higher with greater hospital volume (22.3% / 34.2% / 46.2% / 55.0%). After adjustment for age, histologic type and cancer stage by the Cox regression model, patients receiving care in very-low-volume hospitals were seen to have a 60% higher risk of death than patients receiving care in high-volume hospitals (P < 0.01). Although some limitations existed in this study, the results indicated that further centralization of operative treatment in high-volume hospitals might improve survival of ovarian cancer patients in Japan.

Risk factors for ovarian cancer in Taiwan: a case-control study in a low-incidence population

OBJECTIVE

We conducted a case-control study to identify risk factors for ovarian cancer in Taiwan, a low-incidence population where the incidence has been on the rise.

METHODS

Cases were 86 women (age range 20-75, median 47) drawn from patients with primary, invasive epithelial ovarian cancer diagnosed between 1993 and 1998 in the Taipei metropolitan area, with the following histologic subtypes: 35% serous, 27% mucinous, 21% endometrioid, 15% clear cell, and 2% unspecified adenocarcinoma. Controls were 369 women (age range 20-75, median 44) selected from patients who were hospitalized at the same time for treatment of unrelated diseases. Subjects were interviewed in person regarding sociodemographic and reproductive characteristics, family and medical history, and diet.

RESULTS

A strong inverse relationship of ovarian cancer to each live birth was observed (odds ratio (OR) = 0.43, 95% confidence interval (CI) = 0.20-0.89; OR = 0.30, 95% CI = 0.13-0.69; and OR = 0.18, 95% CI = 0.05-0.62 for parity of 1 or 2, 3-5, and >5, respectively). Menopause was associated with increased risk of disease (OR = 2.15, 95% CI = 1.21-3.83). A trend toward protection was seen with breastfeeding for more than 1 year (OR = 0.55, 95% CI = 0.29-1.01). No dietary factor was associated with an increased disease risk. Milk intake was associated with a decreased disease risk (OR = 0.45, 95% CI = 0.28-0.74).

CONCLUSION

The strong protective effect of parity was supported by this study, and the decline in parity is likely an important reason for the rising incidence of ovarian cancer in Taiwan. A decreased disease risk was also seen with milk intake. In addition, the difference in the distribution of histologic subtypes in this population compared with high-incidence populations may point to further differences in risk factors.

Ovarian cancer incidence and survival by histologic type in Osaka, Japan

The incidence of ovarian cancer among Japanese has increased since the 1970s. Histologic diversity is a characteristic of this cancer. However, there has been no population-based study made on the incidence and survival by histologic type. Osaka Cancer Registry's data was used for incidence and survival analyses of ovarian cancer by histologic type in this study. Seven thousand one hundred sixty-seven incident cases were registered during the period 1975 to 1998. According to the IARC's histologic classification, types of ovarian cancer were classified into five categories. Survival analysis was restricted to the reported 2431 cases who lived in Osaka Prefecture (except for Osaka City) and were diagnosed in 1975-1994, since active follow-up data on vital status 5 years after the diagnosis were available. The age-standardized incidence rate of ovarian cancer increased from 4.0 to 5.4 per 100,000 women (standard: world population) in Osaka during the period 1975-1998. Carcinoma, the major histologic category, also increased (from 3.4 to 4.8 per 100,000 women), while sex cord-stromal tumors decreased after 1980 and germ cell tumors remained stable. The 5-year relative survival was 36.4% for ovarian cancer patients diagnosed in 1975-1994. The survival for carcinoma was 38.3%, which was lower than that in sex cord-stromal tumors or germ cell tumors (55.3% and 58.6%, respectively). The increase in the incidence of ovarian cancer was caused by the increase in carcinoma. The relative 5-year survival of ovarian cancer improved over the period, but was different by histologic type.