Trends in thyroid cancer incidence in Sweden, 1958-1981, by histopathologic type

Time trends in the incidence of malignant neoplasms of the thyroid were examined for Sweden for the period 1958-81, 5,838 cases being studied. Autopsy-diagnosed cases were excluded. Mean annual changes in the age-standardized rates over this period were 1.9% and 1.2% for women and men, respectively, for all thyroid carcinomas combined; 4.9% and 2.1% for papillary carcinoma; 0.9% and 2.1% for follicular carcinoma; and -1.0% and -2.1% for anaplastic carcinoma. Age, period and cohort models were fitted. There was a progressive increase in papillary cancer incidence for cohorts born since 1919. This increase cannot be satisfactorily explained as an artefact of trends in classification, and probably reflects a real increase in incidence. A less marked increase was seen for follicular cancer, and there was a decline for cohorts born since 1939. While the risk of papillary and anaplastic carcinoma was lower in iodine-deficient areas, follicular cancer risk was twice as high in these areas, for men only. There was a steady decline of anaplastic cancer in both sexes after 1965, largely attributable to a decline in cohorts born since 1924.     

Second primary neoplasms in 633,964 cancer patients in Sweden, 1958-1996.

The Swedish Family-Cancer Database was used to analyze concordant (same site) and discordant (different site) second primary neoplasms in 633,964 cancer patients diagnosed from 1958 to 1996. Cases of second malignant neoplasms were extracted from the Database if the diagnosis date of the first and second cancer differed by at least 1 month. The expected numbers of cancers were obtained by applying site-, sex-, age-, period-, residence- and socioeconomic level-specific rates in the corresponding population in the Database to the appropriate person-years at risk. The standardized incidence ratio (SIRs) of a second cancer was taken to be the ratio of observed to expected numbers of second cancers. Of all cancers, 8.5% were subsequent neoplasms (8.4% for males and 8.7% for females). SIRs for both concordant and discordant subsequent cancer were elevated in patients with cancer of the upper aerodigestive tract, colon, nose, breast, other female genitals, testis, kidney, urinary, bladder, skin, nervous system, endocrine, bone, connective tissue, melanoma, lymphoma and leukemia. The risks at some concordant sites, such as nose, squamous cell skin, bone and connective tissue in both sexes, breast in males and upper aerodigestive tract and leukemia in females, were very high (>10). At discordant sites, SIRs were less than 2 but significantly increased after all but gastric and prostatic cancer. Compared with the general population, cancer patients were at a modestly increased risk for new primary cancer after cancers at many sites, calling for attention in treatment, management and prevention.     

Changing patterns of lung cancer incidence by histological type.

Using data from five registries covering 7% of the U.S. population, we investigated lung carcinoma incidence trends from 1969-86 by histological type, sex, race, age, calendar time period, and cohort year of birth. Among white men, squamous cell carcinoma was the most frequent histological type, but by the mid-1980s the age-adjusted rates were decreasing while rates of adenocarcinoma and small (oat) cell carcinoma continued to rise. Among white women, adenocarcinoma was the most frequent type, followed by small cell carcinoma, with rates of all histological types rising over the entire study period. Similar time trends were seen among blacks. Rates for squamous cell carcinoma among both sexes and adenocarcinoma among men, however, were considerably higher for blacks than whites, whereas no racial disparity was seen for small cell carcinomas. Rates for each histological type were higher among men than women, although male-female sex ratios diminished over time. Age-specific rates varied considerably by cohort year of birth; incidence of squamous cell carcinoma among men increased steadily among those born from the late 1800s to the first quarter of this century before declining among those born thereafter. Cohort peaks were also reached, although about 10 to 20 years later, for small cell carcinoma and adenocarcinoma, suggesting an eventual reduction in incidence in these histological types as well. For each type, the peak incidence occurred earlier for men than women. These differing incidence patterns add to the evidence that the mechanisms of lung carcinogenesis may vary by histological type.     

A population-based study of lung cancer incidence trends by histologic type, 1974-81

All incident cases of microscopically confirmed lung cancer diagnosed between 1974 and 1981 in western Washington State were identified through the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, Bethesda, MD. The incidence of lung cancer by histologic type was studied in relation to time, with age, sex, and stage of disease at diagnosis being taken into account. Overall and within each sex, the incidence of adenocarcinoma has increased significantly since 1974. The rate of increase has been higher among females (86% increase) than among males (54% increase), with most of the increase in both sexes being among those over age 65 years with distant or unstaged disease at diagnosis. Similar patterns were not observed for squamous cell carcinoma. The potential effects of changes in diagnostic and pathology practice during the study period in producing these results were explored, and etiologic implications of the observed increase in adenocarcinoma were discussed.     

Trends in breast cancer incidence in Sweden 1958-1988 by time period and birth cohort.

Statistics from the Swedish National Cancer Registry based on all 110,658 cases of invasive breast cancer during the 31-year period 1958-1988 were analysed. Age-specific incidence rates increased over successive calendar periods. The average annual increase in the age-standardised incidence rate was 1.3%, with the greatest percentage changes among the youngest age groups. During the latter half of the study period, the rates of increase tended to diminish in the youngest age groups and even reversed significantly among women from 75 years of age. In analyses using age-period-cohort models, the best fit of the cancer incidence data was found for the full model which simultaneously considered the effects of age, period and cohort. Cohort effects were found to be more important than period effects, in terms of model fit. These effects emerged as a seemingly consistent, and in a logarithmic scale, fairly linear increase in the relative risk of breast cancer incidence with a 3-fold elevation in women born in the 1950''s relative to those born in the 1880''s. It is concluded that the rising breast cancer incidence in Sweden is explained chiefly by birth cohort effects, which indicate persistent secular changes in largely unknown risk factors associated with life style. We could not in the present data see any clear evidence for an adverse effect of contraceptive or replacement sex steroids on breast cancer incidence.     

Recent trends in breast cancer incidence in Sweden.

Breast cancer incidence in Sweden during the period 1984-93 shows no clear trend in women aged below 40 years but a transient increase at ages 50-69 years, probably as a result of mammography screening. Our data give no indication that use of oral contraceptives or replacement hormones have affected nationwide breast cancer incidence rates.     

Iodine supplementation in Sweden and regional trends in thyroid cancer incidence by histopathologic type

We studied regional patterns of thyroid cancer incidence in relation to iodine intake and iodinization in Sweden using 5,838 incident cases diagnosed in the period 1958–1981. Region was defined either by iodine status, urban-rural status or health-care region (internal controls). Age, period and cohort models were fitted to evaluate trends and regional variation in incidence by histopathologic type. In iodine-deficient areas, the relative risk (RR) of developing thyroid cancer was 0.92 for all histologic types combined, 0.80 for papillary cancer and 0.87 for anaplastic carcinoma. Residence in iodine-deficient regions was associated with a 2-fold increased risk of follicular cancer in men (RR 1.98) and a 17% increase in risk in women (RR 1.17). Regional differences in iodine intake fell after iodinization of the food supply, which was started in 1936 and enhanced in 1966. Nevertheless, incidence of both papillary and follicular carcinoma increased during the study period, with largely similar trends in iodine-deficient and iodine-sufficient areas. Overall, residence in urban or rural areas was not an important determinant of incidence, though trends in the incidence of papillary, follicular and anaplastic cancer did vary between urban and rural areas. The occurrence of thyroid cancer differed only marginally between the 6 health-care regions in Sweden, suggesting that the observations in regions defined by iodine intake were unlikely to be artifactual. Our data suggest that iodinization of the food supply is not associated with adverse trends in the occurrence of thyroid cancer. © 1996 Wiley-Liss, Inc.     

Changing trends in incidence of lung cancer by histologic type in Scotland

Lung cancer is a major public health concern worldwide. Our study aims to examine trends in incidence of lung cancer in Scotland during 1959-97 and by histologic type for 1975-97. In Scotland, lung cancer is the most commonly diagnosed cancer in men and is the second most commonly diagnosed cancer in women. Due to poor survival rates, trends in incidence and mortality display similar patterns. Within the United States and many parts of Europe, falls in the incidence of squamous cell carcinoma have occurred whilst the incidence of adenocarcinoma has increased. Data were extracted from the Scottish Cancer Registry. Trends in incidence were examined by standardising rates to the World Standard Population. Age-specific rates were examined by year of diagnosis and mid year of birth. In Scotland the incidence of lung cancer in men has fallen since the late 1970s, whereas incidence in women has continued to increase. Incidence rates of adenocarcinoma have increased over time but squamous cell carcinoma remains the predominant type of lung cancer in Scotland. The quality of lung cancer registration data has improved over time, although a large proportion of lung cancers (>20%) are not microscopically verified. Changes in histologic types are unlikely to be solely due to diagnostic advances. Rates of adenocarcinoma have increased steadily over time, and this may be due to changes in cigarette design during the 1950s.     

Increasing incidence of non-Hodgkin's lymphomas in Sweden 1958-1992

In recent years, there have been many reports from Europe and North-America describing non-Hodgkin's-lymphoma (NHL) as one of the most rapidly increasing malignancies. The reasons for this are poorly understood. This study describes the incidence pattern of NHL in Sweden during 1958-1992. A total of 26,925 cases (14,854 males and 12 071 females aged 15 years or older reported to the Swedish Cancer Registry between 1958 and 1992 were analysed. The increase in the age-adjusted incidence during this period was 433% among men and 386% among women, a mean yearly increase of 3.6% in men and 2.9% in women. The highest rates were seen during the most recent years and in the oldest age group, although there was a clear trend with increased age-adjusted incidence over time in both the male and the female groups in ages over 35. The incidence was low in the ages below 35 years. Known etiologic factors including viruses, environmental exposures and immunosuppression of different types are discussed. It is concluded that there has been a true increase in the age-adjusted incidence of non-Hodgkin's lymphomas in Sweden during the years 1958-1992.     

Increasing thyroid cancer incidence in Canada, 1970-1996: time trends and age-period-cohort effects.

We examined time trends in thyroid cancer incidence in Canada by age, time period and birth cohort between 1970 and 1996. Age-specific incidence rates by time period and birth cohort were calculated and age-period-cohort modelling used to estimate effects underlying the observed trends. Overall age-adjusted incidence rates of thyroid cancer doubled, from 3.3 and 1.1 per 100 000 in 1970-72 to 6.8 and 2.2 per 100 000 in 1994-96, among females and males respectively. Almost all the increase between 1970-72 and 1994-96 was due to papillary carcinoma of the thyroid. Age, birth cohort and period effects significantly improved the fit of the model for females, while age and birth cohort effects were significant determinants of the incidence among males. There were significant differences in the patterns/curvature for age, period and birth cohort effects between women and men. Our results suggest that the increases in thyroid cancer incidence in Canada may be associated with more intensive diagnostic activities and change in radiation exposure in childhood and adolescence. Temporal changes in reproductive factors among young women may explain some of the gender differences observed.     

Colorectal cancer survival trends in Norway 1958-1997

The purpose of this study was to examine the pattern of survival for colorectal adenocarcinoma (CRC), and to investigate the prognostic factors for the disease. In the analysis, 50993 cases of CRC aged 40-84 years, diagnosed between 1958 and 1997 in Norway, were included. Esteve's relative survival method was used, together with a time trend analysis, conducted by least-squares linear regression. Cox proportional hazards regression analysis was used to examine cause-specific mortality. Five-year relative CRC survival has increased by an estimated 3% per 5-year diagnostic period. In 1958-1962, relative survival was about 40% for both males and females, and increased to 56 and 60%, respectively, in 1993-1997. Rectal cancer had a higher cause-specific mortality (RR 1.26, 95% CI 1.22-1.30) than proximal colon (reference) and distal colon (RR 0.97, 95% CI 0.93-1.00 cancers), while females had a lower cause-specific mortality than males (RR 0.88, 95% CI 0.86-0.90). The increase in the relative survival rate in Norway is probably due to improved treatments and advanced diagnostics. Norway has a higher CRC survival rate than the EUROCARE average.     

International trends in lung cancer incidence by histological subtype: Adenocarcinoma stabilizing in men but still increasing in women

Objectives

Trends in overall lung cancer incidence in different countries reflect the maturity of the smoking epidemic. Further understanding of the underlying causes for trends over time can be gained by assessing the trends by sex and histological subtype. We provide a temporal analysis of lung cancer incidence in 12 populations (11 countries), with a focus on cohort-specific trends for the main histological subtypes (squamous cell carcinomas (SCC), adenocarcinomas (AdC), and small cell carcinoma).

Material and methods

We restrict the analysis to population-based registry data of sufficient quality to provide meaningful interpretation, using data in Europe, North America and Oceania, extracted from successive Cancer Incidence in Five Continents Volumes. Poorly specified morphologies were reallocated to a specified grouping on a population, 5-year period and age group basis.

Results

In men, lung cancer rates have been declining overall and by subtype, since the beginning of the study period, except for AdC. AdC incidence rates have risen and surpassed those of SCC (historically the most frequent subtype) in the majority of these populations, but started to stabilize during the mid-1980s in North America, Australia and Iceland. In women, AdC has been historically the most frequent subtype and rates continue to increase in most populations studied. Early signs of a decline in AdC can however be observed in Canada, Denmark and Australia among very recent female cohorts, born after 1950.

Conclusions

The continuing rise in lung cancer among women in many countries reinforces the need for targeted smoking cessation efforts alongside preventive actions.     

Temporal trends in non-small cell lung cancer survival in Sweden

We modeled temporal trends in the 1- and 5-year survival of 32 499 patients with adenocarcinoma and squamous cell carcinoma of the lung in the Swedish Cancer Register between 1961 and 2000. The 1-year relative survival for adenocarcinoma improved from 37% for patients diagnosed 1961-1965 to 45% for those diagnosed 1996-2000 and from 39 to 45% for squamous cell carcinoma. The adjusted excess mortality ratios for the period 1996-2000 compared with 1961-1965 were 0.80 for adenocarcinoma and 0.81 for squamous cell carcinoma. Thus, a previous report in a Dutch study of a relatively worsening prognosis for adenocarcinoma over time could not be confirmed.     

Comparison of lung cancer incidence rates by histological type in high and low incidence countries, with reference to the limited role of smoking

To find a clue to lung cancer etiology in Japan, differences in the pattern of lung cancer histology and related time trends between Osaka, Japan, and the North West Region of England were investigated. Material comprised all incident lung cancer cases registered in both regional registries (14,521 in the Osaka Cancer Registry and 29,859 in the North West Regional Cancer Registry). (1) The age-standardized incidence rate of lung cancer was higher in the North West Region than in Osaka (80.4 among males and 20.9 among females per 100,000 population in 1979-82 versus 32.1 and 9.2 respectively). (2) A higher proportion of adenocarcinoma was observed in Osaka (36.3% in males and 62.0% in females) than in the North West Region (12.3% and 18.9% respectively). (3) Using the relative frequencies of each histological type according to sex and age-group, age-standardized incidence rates were calculated for the main lung cancer histological types. It was shown that the incidence rates of adenocarcinoma were similar in the two areas (10.6 in males and 5.3 in females in Osaka versus 10.0 and 3.5 in the North West Region, respectively) while those of squamous cell and small cell carcinomas were much higher in the North West Region than in Osaka. (4) Time trends of incidence rates showed an increase only for adeno- and small cell carcinomas in Osaka. Slight increases were observed for adenocarcinoma in both sexes and for squamous cell carcinoma in females in the North West Region. (5) Considering cigarette consumption and the relative risks of smoking in the two areas, the possible existence of other risk factors for adenocarcinoma in both sexes in Japan, besides active smoking, was suggested.     

Digitalis use and lung cancer risk by histological type in men

Lung cancer risk and tumor characteristics differ between sexes. Estrogen has been suggested to counteract lung cancer development. We aimed to test the hypothesis that digitalis use decreases lung cancer risk due to its estrogenic and other anticancer properties in men. This was a nationwide Swedish population‐based cohort study between July 1, 2005 and December 31, 2013. Data on the use of digitalis and organic nitrates in all male individuals were derived from the Swedish Prescribed Drug Registry. New lung cancer diagnoses among cohort participants were identified from the Swedish Cancer Registry. Cox proportional hazards regression was employed to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) of lung cancer in digitalis users (exposed participants) compared to users of organic nitrates without digitalis medication (unexposed participants). The study cohort contained 74,437 digitalis users and 297,301 organic nitrates users. Long‐term use (≥2 years) of digitalis was associated with decreased HRs of total lung cancer (HR 0.55, 95% CI 0.39–0.79) and squamous cell carcinoma (HR 0.40, 95% CI 0.19–0.87). This large and population‐based study suggests decreased risks of lung cancer overall and squamous cell carcinoma associated with long‐term use of digitalis in men.