Oesophageal cancer incidence in the United States by race, sex, and histologic type, 1977-2005.

BACKGROUND: In the United States, the rates and temporal trends of oesophageal cancer overall and for the two predominant histologic types - adenocarcinoma (ADC) and squamous cell carcinoma (SCC) - differ between Blacks and Whites, but little is known with regard to the patterns among Asians/Pacific Islanders or Hispanics. METHODS: Using the Surveillance, Epidemiology, and End Results programme data, we analysed oesophageal cancer incidence patterns by race, sex, and histologic type for the period 1977-2005. RESULTS: Total oesophageal cancer incidence has been increasing among Whites only; the rates among all other race groups have declined. Moreover, rates among White men surpassed those among Blacks in 2004. Oesophageal SCC rates have been decreasing among virtually all racial/ethnic groups; rates among Hispanic and Asian/Pacific Islander men have been intermediate to those of Blacks and Whites, with rates among women being lower than those among Blacks or Whites. The ADC rates among Hispanic men may be rising, akin to the historical trends among Whites and Blacks. The sex ratios for these cancers also varied markedly. CONCLUSIONS: These observations may provide clues for aetiological research.

Association of breast cancer and cervical cancer incidence with income and education among whites and blacks.

Data from the 1969-71 Third National Cancer Survey were used to study the association of cancer incidence with income and education as indicated by census tract of residence. Also considered was the effect of adjustment for differences in socioeconomic distribution on the observed excess risk of cervial cancer and lower risk of breast cancer among black women compared to white women. Strong positive associations with both income and education were found, with the rates based on 19,344 breast cancer cases among white women. These observations were noted in most geographic areas studied. The relative risk showed little apparent relationship to age. The rates based on 1,570 cases among black women indicated a strong positive association with education but not with income. Socioeconomic adjustment reduced by almost one-half the black-white difference in breast cancer rates, and education had a stronger effect than did income. White women continued to have a significantly higher rate after such adjustment. Conversely, the incidence of cancer of the cervix showed strong negative associations with each of the two variables among both the 3,802 cases in white women and 954 cases in black women. The negative gradient decreased with age and was apparent in almost all the areas. The excess risk among black women was reduced by two-thirds with socioeconomic adjustment, though the rates remained significantly different. Income had a stronger association than did education with cervical cancer incidence.

Declining breast cancer mortality among young American women.

Changes in age-specific breast cancer mortality rates among white females in the United States during 1950-80 were shown to be correlated with changes in patterns of childbearing in early adulthood. However, for the most recent 5-year period among women below age 40 years, small declines in breast cancer mortality were observed in the late 1970's, despite a predicted increase following delays in childbearing that began in the 1960's and despite evidence of a rising incidence of the cancer. Although correlation analyses have inherent limitations, the findings raise the possibility that recent changes in the detection and management of breast cancer have contributed to a lowered mortality from this cancer among young American women.

Declining lung cancer rates among young men and women in the United States: a cohort analysis.

Although overall age-adjusted rates of mortality from lung cancer in the United States continue to rise, rates at ages below 45 years have begun to decline. In this report we show that the decrease is greatest among white men, with a 29% drop between the mid-1970s and mid-1980s, but a decrease also occurred among black men and white and black women. Cohort analyses revealed that the rates of lung cancer peaked among men born around 1925-1930 and among women born around 1935-1940, and have declined thereafter. If these trends continue, overall lung cancer mortality rates will start to decline in the 1990s among men and after the year 2000 among women.

Cancer surveillance series: non-Hodgkin's lymphoma incidence by histologic subtype in the United States from 1978 through 1995.

BACKGROUND: Clinical investigations have shown prognostic heterogeneity within the non-Hodgkin's lymphomas (NHLs) according to histology, but few descriptive studies have considered NHLs by subgroup. Our purpose is to assess the demographic patterns and any notable increases in population-based rates of different histologic subgroups of NHL. METHODS: Using data collected by the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, we calculated incidence rates for the major clinicopathologic categories of NHL by age, race, sex, geographic area, and time period. RESULTS: Among the 60 057 NHL cases diagnosed during the period from 1978 through 1995, total incidence (per 100 000 person-years) was 17.1 and 11.5 among white males and females, respectively, and 12.6 and 7.4 among black males and females, respectively. However, rates for follicular NHLs were two to three times greater among whites than among blacks, with little sex variation. Blacks demonstrated much higher incidence than whites for peripheral T-cell NHL, with the incidence rates higher in males than in females. For other NHL subgroups, the incidence rates for persons less than 60 years of age were generally higher among males than among females, with little racial difference; at older ages, the rates were higher among whites than among blacks, with little sex difference. High-grade NHL was the most rapidly rising subtype, particularly among males. Follicular NHL increased more rapidly in black males than in the other three race/sex groups. Overall, the broad categories of small lymphocytic, follicular, diffuse, high-grade, and peripheral T-cell NHL emerged as distinct entities with specific age, sex, racial, temporal, and geographic variations in rates. CONCLUSIONS: Findings from our large, population-based study reveal differing demographic patterns and incidence trends according to histologic group. Future descriptive and analytic investigations should evaluate NHL risks according to subtype, as defined by histology and new classification criteria.

Recent trends in cutaneous melanoma incidence among whites in the United States.

BACKGROUND: It is not yet clear whether increasing melanoma incidence is real or whether recent incidence trends mainly reflect improved diagnosis. To address this question, we examined the most recent melanoma incidence patterns among the white population stratified by sex, age, tumor stage, and tumor thickness by use of data from the Surveillance, Epidemiology, and End Results Program. METHODS: We examined log-transformed age-specific rates for melanoma by 5-year age groups and time periods by year of diagnosis and birth cohort. Melanoma trends were further examined among broader age groups (<40 years, 40-59 years, and > or =60 years) by tumor stage and tumor thickness. Rates were age-adjusted to the 1970 U.S. standard population, and trends were tested by use of a two-sided Student's t test. RESULTS: Melanoma incidence increased in females born since the 1960s. From 1974-1975 through 1988-1989, upward trends for the incidence of localized tumors and downward trends for the incidence of distant-stage tumors occurred in the age group under 40 years. In the more recent time period, 1990-1991 through 1996-1997, age specific rates among females compared with males generally remained stable or declined more for distant-stage tumors and increased less for local-stage tumors. Thin tumors (<1 mm) increased statistically significantly in all age groups (P<.05 for all), except in men under age 40 years. In contrast, rates for thick tumors (> or =4 mm) increased statistically significantly (P =.0003) only in males aged 60 years and older. CONCLUSION: Melanoma incidence may well continue to rise in the United States, at least until the majority of the current population in the middle-age groups becomes the oldest population. The recent trends may reflect increased sunlight exposure.

Cancer surveillance series: changing patterns of cutaneous malignant melanoma mortality rates among whites in the United States.

BACKGROUND: Mortality from melanoma among whites is still increasing in the United States. In this study, we describe the changing patterns of melanoma mortality rates among whites by demographic factors and geography and further assess the relationship between the geographic patterns and the UV radiation (UV-B) level. METHODS: Age-adjusted incidence and mortality rates were computed by use of the 1970 U.S. population standard. Annual percent changes of mortality were estimated by fitting regression lines to the logarithm of rates. The relationships between melanoma mortality rates and UV-B level over time were assessed by weighted regressions. All statistical tests were two-sided. RESULTS: From 1950-1954 through 1990-1994, melanoma mortality rates increased by 191% and 84% among males and females, respectively. Mortality rates peaked in the 1930 through 1950 birth cohorts for females and in the 1935 through 1950 birth cohorts for males. In the 1950 through 1969 study period, melanoma mortality rates showed a strong North-South gradient, but the gradient weakened in recent periods. The absolute change in mortality for a 10% increase in UV-B among females decreased from 0.08 additional deaths per 100 000 person-years in 1950-1959 to 0.01 additional deaths in 1990-1995. In contrast, the absolute change in mortality among males showed little change over time; additional deaths increased from 0.11 to 0.12 per 100 000 person-years. CONCLUSIONS: Melanoma mortality in the United States reflects the complex interplay of UV radiation levels in each geographic region, the sun-protection behaviors of each generation of males and females in childhood and adulthood, the geographic mobility of the population, and the risk awareness and early detection.

Alternate ranging methods for cancer mortality maps.

BACKGROUND: Mapping techniques can highlight the spatial or temporal variations in rates of cancer mortality. In mapping geographic patterns of cancer mortality, spatial units are grouped into categories defined by specified rate ranges, and then the units in each category are assigned a particular color in the map. We examined the consequences of using different ranging methods when comparing maps over several time intervals. METHODS: Maps of mortality rates for cancers of the breast, lung (including the lung, trachea, bronchus, and pleura), and cervix uteri in the United States by county or state economic area are created for different time intervals between 1950 and 1994. Two ranging methods are employed: 1) Ranges are defined for individual time interval by the deciles of rates in that interval (ranging within intervals), and 2) constant ranges for all time intervals are defined by the deciles of rates for the entire 45-year period from 1950 through 1994 (ranging across intervals). The time intervals from 1950 through 1969 and from 1970 through 1994 were chosen to accommodate the availability of detailed county-level population estimates specifically for blacks starting in 1970. RESULTS: The ranging method has little impact on maps for breast cancer mortality, which changed little over time. For lung cancer, which increased over time, and cervix uteri cancer, which decreased over time, ranging within time intervals shows the geographic variability but does not convey the temporal trends. Trends are evident when ranging across time intervals is employed; however, geographic variability is partially obscured by the predominance of spatial units in the highest rate categories in the recent time intervals for lung cancer and in the early time intervals for cervix uteri cancer. CONCLUSIONS: Ranging within time intervals displays geographic patterns and changes in geographic patterns, regardless of time trends in rates. Ranging across time intervals shows temporal changes in rates but with some loss of information about geographic variability.

Cancer surveillance series: changing geographic patterns of lung cancer mortality in the United States, 1950 through 1994.

BACKGROUND: Geographic surveys revealing variations in lung cancer mortality rates across the United States have prompted epidemiologic studies in high-risk communities. We have updated these maps to track the changing patterns and to provide further clues to the determinants of lung cancer. METHODS: Age-adjusted race- and sex-specific lung cancer mortality rates from 1950 through 1994 were calculated for nine Census Divisions and 508 State Economic Areas of the United States. RESULTS: Pronounced geographic variation in lung cancer rates was evident, with the patterns changing substantially over time. Among white males in the 1950s and 1960s, high rates were observed in urban areas of the northeast and north central states and in areas along the southeast and Gulf coasts. By the 1970s, the northern excess began to fade, with high rates starting to cover wider areas of the south. By the 1980s to the mid-1990s, clustering of elevated rates was prominent across the southeast and south central areas, with relatively low rates throughout much of the northeast. Among white females, little geographic variation was evident in the 1950s, but thereafter relatively high rates began to appear in clusters along the Atlantic and Pacific coasts. For both sexes, consistently low rates were seen in the mountain and the plains states. Rates among blacks were consistently elevated in northern areas and low across the south. CONCLUSIONS: The changing mortality patterns for lung cancer generally coincide with regional trends in cigarette smoking, indicating that public health measures aimed at smoking prevention and cessation should have a dramatic effect in reducing lung cancer rates.

Cancer surveillance series: recent trends in childhood cancer incidence and mortality in the United States.

BACKGROUND: Public concern about possible increases in childhood cancer incidence in the United States led us to examine recent incidence and mortality patterns. METHODS: Cancers diagnosed in 14540 children under age 15 years from 1975 through 1995 and reported to nine population-based registries in the National Cancer Institute's Surveillance, Epidemiology, and End Results Program were investigated. Age-adjusted incidence was analyzed according to anatomic site and histologic categories of the International Classification of Childhood Cancer. Age-adjusted U.S. mortality rates were calculated. Trends in rates were evaluated by use of standard regression methods. RESULTS: A modest rise in the incidence of leukemia, the most common childhood cancer, was largely due to an abrupt increase from 1983 to 1984; rates have decreased slightly since 1989. For brain and other central nervous system (CNS) cancers, incidence rose modestly, although statistically significantly (two-sided P = .020), largely from 1983 through 1986. A few rare childhood cancers demonstrated upward trends (e.g., the 40% of skin cancers designated as dermatofibrosarcomas, adrenal neuroblastomas, and retinoblastomas, the latter two in infants only). In contrast, incidence decreased modestly but statistically significantly for Hodgkin's disease (two-sided P = .037). Mortality rates declined steadily for all major childhood cancer categories, although less rapidly for brain/CNS cancers. CONCLUSIONS: There was no substantial change in incidence for the major pediatric cancers, and rates have remained relatively stable since the mid-1980s. The modest increases that were observed for brain/CNS cancers, leukemia, and infant neuroblastoma were confined to the mid-1980s. The patterns suggest that the increases likely reflected diagnostic improvements or reporting changes. Dramatic declines in childhood cancer mortality represent treatment-related improvements in survival.

Recent cancer trends in the United States.

BACKGROUND: Cancer incidence rates have been reported to be increasing in the United States, although trends vary according to form of cancer. PURPOSE: We identify the cancers accounting for the rising incidence, quantify the changes that have occurred from the mid-1970s to the early 1990s, and contrast incidence and mortality trends to provide clues to the determinants of the temporal patterns. METHODS: Sex-, race-, and age-specific and age-adjusted incidence rates for the 5-year periods 1987-1991 versus 1975-1979 were calculated for 28 cancers among men and 30 cancers among women using data from the Surveillance, Epidemiology, and End Results (SEER) Program of cancer registration covering about 10% of the U.S. population. Similar rates were computed using national mortality data. Cancers were ranked according to the change in incidence rates over the two periods. RESULTS: Age-adjusted incidence rates for all cancers combined increased by 18.6% among males and 12.4% among females from 1975-1979 to 1987-1991, due largely to rising rates for prostate cancer among men and for breast and lung cancers among women. National mortality rates for all cancers combined rose less steeply, 3% and 6% among men and women, respectively, driven mostly by continuing increases in lung cancer mortality, while death rates for the majority of the cancers were steady or declining. Total cancer incidence rose at all ages, but with different tumors responsible for the increases at different ages: leukemia and brain/nervous system cancer among children; testicular cancer, nonmelanoma skin cancer (largely Kaposi's sarcoma), non-Hodgkin's lymphoma, and melanoma among young and middle-aged adults; and prostate, breast, and lung cancers among older individuals. In contrast, mortality rates for all cancers combined declined among both males and females under age 55 years, increasing only among older persons. CONCLUSIONS: Trends in cancer incidence and mortality differ. For most cancers, incidence rates are rising, while mortality rates are generally stable or declining. IMPLICATIONS: Much of the recent increase in cancer incidence can be explained by known factors. Improved detection appears to account for most of the increases in breast cancer among women and prostate cancer among men. On the other hand, cigarette smoking is the major determinant of the rise in lung cancer among women, acquired immunodeficiency syndrome has led to increases in non-Hodgkin's lymphoma and Kaposi's sarcoma among young and middle-aged men, and sunlight exposure patterns have affected the trends in melanoma. Some trends remain unexplained, however, and may reflect changing exposures to carcinogens yet to be identified and clarified.

Cancer incidence and mortality trends among whites in the United States, 1947-84.

Cancer incidence trends from the late 1940s to 1983-84 were assessed among white residents of five geographic areas (Atlanta, Connecticut, Detroit, Iowa, San Francisco-Oakland) by means of data derived from several National Cancer Institute surveys, the Connecticut Tumor Registry, and the Surveillance, Epidemiology, and End Results Program. Incidence trends were compared with mortality trends for the entire United States and for the same five study areas. This study documented rising incidence and mortality rates for four cancers: lung cancer, melanoma of the skin, multiple myeloma, and non-Hodgkin's lymphomas. Increases in lung cancer continued through the early 1980s, but the rate of increase has been moderating during recent years, particularly among males and at younger ages for whom recent declines are evident. Overall, lung cancer incidence rates increased more than 220 and 400% among males and females, respectively. Although much rarer than lung cancer, melanoma of the skin and multiple myeloma increased greatly until the early 1980s among both males and females. The overall rate of increase in melanoma incidence among males was greater than that for lung cancer, and the rate of increase in multiple myeloma mortality among females was exceeded only by that for lung cancer. Increases of 70-120% were observed for non-Hodgkin's lymphomas. Increases in incidence and mortality rates for pancreatic cancer were apparent during the early years but less conspicuous in recent years. Laryngeal and kidney cancer rates generally increased substantially, although the changes were not remarkable for laryngeal cancer mortality among males and kidney cancer mortality among females. The rates for cancers of the mouth and pharynx increased among females but not males. Prostate, colon, and bladder cancer incidence rates increased more than 65% among males, whereas mortality rates changed only moderately. The incidence of thyroid cancer increased more than 75% among both sexes until the late 1970s, but mortality rates have declined during the period of study. Breast cancer incidence increased 30%, whereas mortality rates remained remarkably constant. The incidence of corpus uteri cancer increased dramatically during the mid-1970s and decreased substantially thereafter; these changes were not reflected in the mortality rates, which continually declined during the entire time period. The incidence of testicular cancer increased more than 90% and that of Hodgkin's disease did not change greatly; however, mortality rates for both cancers declined more than 50% since the late 1960s and early 1970s.(ABSTRACT TRUNCATED AT 400 WORDS)

Non-Hodgkin's lymphoma time trends: United States and international data.

Incidence data from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, earlier incidence surveys, and the International Agency for Research on Cancer, mortality data from the National Center for Health Statistics, and population data from the Census Bureau were used to assess rates of non-Hodgkin's lymphoma. Mortality and incidence rates have been increasing for many years. Larger increases among older persons suggest a role for improving diagnosis, particularly during the 1950s and 1960s. Urban/rural and socioeconomic differences have diminished over time. Since the early 1970s, incidence rates increased at 3-4%/year, more rapidly than for all other cancers except melanoma of the skin and lung cancer among women. Incidence rates increased over all ages except the very young, among whites and blacks, in geographic areas both in the United States and internationally, and both sexes. During the 1980s, the impact of AIDS is apparent among young and middle-aged men. Differences in non-Hodgkin's lymphoma rates persist between races and sexes. Increases have been more marked for extranodal disease, particularly those arising in the brain, and for high-grade tumors. Explanations accounting for all the increases in rates are not readily available.

Quantification of the impact of known risk factors on time trends in non-Hodgkin's lymphoma incidence.

The incidence of non-Hodgkin's lymphoma among white men in the United States was measured as 6.9/100,000 person-years in 1947-1950 and as 17.4 in 1984-1988. We have estimated how much the known and suspected diagnostic and risk factors might have contributed to this apparent increase of 152%. Firm conclusions cannot be drawn without more data on risk and changes in prevalence, but a reasonable range of impacts can be constructed. After accounting for the likely effects of misdiagnosis of Hodgkin's disease as non-Hodgkin's lymphoma, of the acceptance of new entities of non-Hodgkin's lymphoma, of familial factors, of human immunodeficiency virus and other immunosuppressive conditions or drugs, and of occupation, we estimate that the percentage increase in incidence was still 80% among all males and 42% among those aged 0-64. An agent carrying a relative risk of 2.0 rising in prevalence from 0 to 42% would account for the latter rise. Diet, hair dyes, and general environmental exposures to pesticides may be contributing, but currently estimated risks and changes in exposure levels do not appear large enough to account for the residual rise. Among men aged 75-84, some of the residual rise of 109% probably is diagnostic, but only further research will clarify the issue.

Incidence of cancer in United States blacks.

Incidence rates for the black population of six Standard Metropolitan Statistical Areas in the United States are examined using data collected in the Third National Cancer Survey, 1969 to 1971. For all sites combined, black males had the highest rates among the four major race-sex groups; black females had the lowest rates. For fourteen common sites accounting for 80% of the cancers among blacks, black/white ratios, survival data, trends between 1935 and 1969, and geographic variation are presented. United States black data adjusted to an African Standard are compared with similar data from Nigeria, Rhodesia, and South Africa.

Recent trends in the incidence of testicular germ cell tumors in the United States.

Testicular germ cell tumors (TGCT), which comprise 98% of all testicular malignancies, are the most commonly occurring cancers among men between the ages of 15 and 44 years in the United States (US). A prior report from our group found that while TGCT incidence among all US men increased between 1973 and 2003, the rate of increase among black men was more pronounced starting in 1989-1993 than was the rate of increase among other men. In addition, TGCT incidence increased among Hispanic white men between 1992 and 2003. To determine whether these patterns have continued, in the current study, we examined temporal trends in incidence through 2011. Between 1992 and 2011, 21 271 TGCTs (12 419 seminomas; 8715 non-seminomas; 137 spermatocytic seminomas) were diagnosed among residents of the Surveillance, Epidemiology, and End Results 13 registry areas. The incidence of TGCT was highest among non-Hispanic white men (6.97 per 100 000 man-years) followed by American Indian/Alaska Native (AI/AN; 4.66), Hispanic white (4.11), Asian/Pacific Islander (A/PI; 1.95), and black (1.20) men. Non-Hispanic white men were more likely to present with smaller tumors (3.5 cm) and localized disease (72.6%) than were men of other races/ethnicities. Between 1992 and 2011, TGCT incidence increased significantly among Hispanic white [annual percent change (APC) = 2.94, p < 0.0001], black (APC = 1.67, p = 0.03), non-Hispanic white (APC = 1.23, p < 0.0001), and A/PI (APC = 1.04, p = 0.05) men. Incidence rates also increased, although not significantly, among AI/AN men (APC = 2.96, p = 0.06). The increases were greater for non-seminoma than seminoma. In summary, while non-Hispanic white men in the US continue to have the highest incidence of TGCT, they present at more favorable stages of disease and with smaller tumors than do other men. The increasing rates among non-white men, in conjunction with the larger proportion of non-localized stage disease, suggest an area where future research is warranted.

International patterns and trends in testicular cancer incidence, overall and by histologic subtype, 1973-2007.

Incidence rates of testicular cancer in Northern European and North American countries have been widely reported, whereas rates in other populations, such as Eastern Europe, Central/South America, Asia, and Africa, have been less frequently evaluated. We examined testicular cancer incidence rates overall and by histologic type by calendar time and birth cohort for selected global populations 1973-2007. Age-standardized incidence rates over succeeding 5-year periods were calculated from volumes 4-9 of Cancer Incidence in Five Continents electronic database (CI5plus) and the newly released CI5X (volume 10) database. Annual percent change over the 35-year period was calculated using weighted least squares regression. Age-period-cohort analyses were performed and observed rates and fitted rate ratios presented by birth cohort. Incidence rates of testicular cancer increased between 1973-1977 and 2003-2007 in most populations evaluated worldwide. Of note, incidence rates in Eastern European countries rose rapidly and approached rates in Northern European countries. Rates in Central and South America also increased and are now intermediate to the high rates among men of European ancestry and low rates among men of Asian or African descent. Some heterogeneity in the trends in seminoma and nonseminoma were observed in Denmark, the United Kingdom, and among US whites, particularly in recent generations, with rapid and uniform increases in the incidence of both histologic types in Slovakia. Reasons for the rising incidence rates among European and American populations remain unexplained; however, changing distributions in the prevalence of risk factors for testicular cancer cannot be ruled out.

Prostate cancer mortality in the United States by cohort year of birth, 1865-1940.

Prostate cancer is the second leading cause of cancer death among United States men, with rates among blacks twice those among whites. Over time, mortality has increased among nonwhites but has changed little among whites. Earlier reports have predicted that the rise among nonwhites would diminish because it appeared that those born in the late 1800s were at highest risk. Based on 1950-1989 United States mortality data and populations at risk estimated using census data, we assessed prostate cancer mortality trends over time in white, nonwhite, and black men. From 1950-1954 to 1985-1989, age-adjusted prostate cancer mortality rates increased slightly for whites (9%) but substantially for nonwhites (67%). Among whites, rates increased over time in men over age 80 years but remained constant for younger men. Among nonwhites, rates increased steeply in those above age 74 years and slightly in the age group 65-74 years but declined in those under age 65 years, with the rate of decrease much more rapid in those under 55. The predicted reduction in risk among nonwhite men born since 1900, reported in an earlier study based on the mortality pattern through 1970, has not occurred because rates continued to increase among older nonwhites. In summary, prostate cancer mortality rates are rising among older men and decreasing in nonwhite young men. While improved detection of the cancer may partly account for the trend, analytical studies are needed to investigate the reasons for the increase in prostate cancer mortality in older men, the decrease in nonwhite young men, and the increasing excess risk among blacks.

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.

Colorectal cancer incidence trends by subsite in urban Shanghai, 1972-1994.

Epidemiological characteristics of colorectal cancer may differ by particular anatomical subsite, suggesting that the subsite-specific colorectal cancers may represent different disease entities. This study explored the time trends over a 23-year period in colorectal cancer incidence at various subsites by sex and age group. Data on the incidence of colorectal cancer were obtained from a population-based cancer registry in Shanghai, People's Republic of China. Between 1972 and 1994, 30,693 patients with colorectal cancer were registered at the Shanghai Cancer Registry. The overall age-adjusted colorectal cancer incidence rates increased > 50%, or 2% per year from 1972-1977 to 1990-1994, from 14 to 22 per 100,000 among men and from 12 to 19 per 100,000 among women. The increases in rates were considerably more rapid for colon cancer, with rates approximately doubling, than they were for rectal cancer. Proximal colon cancer was more common than distal colon cancer over the whole study period, whereas rates for both cancers rose with similar annual percentage changes (> 5% per year) and across virtually all age groups. The estimated annual increases rose from 2% at ages 35-44 years to 7% at ages 75-84 years for proximal colon cancer, but they were more uniform for distal colon cancer (5-6% per year). Age-adjusted and age-specific rectal cancer rates changed little. The male:female age-adjusted rate ratio for colorectal cancer was 1.19 in 1990-1994. The ratios increased over time and varied by subsites, with ratios increasing from the proximal colon to the distal colon and to the rectum. Furthermore, men had higher rates than women for distal colon and rectal cancers at ages 55 and older, whereas women had higher rates than men at younger ages for these two cancers. Male:female rate ratios for proximal colon cancer did not vary substantially with age. The findings from this study indicate that subsite-specific incidence rates of colorectal cancer differ by sex and age and in their time trends. Cancers arising in the proximal colon, distal colon, and rectum may have somewhat different disease etiologies.