Incidence Rates Of Colon Cancer Research Articles

Trends in colorectal cancer incidence and mortality in New South Wales, 1973-1992.

To assess changes in incidence and mortality rates of colorectal cancer in different age groups in New South Wales (NSW) between 1973 and 1992. Descriptive analysis of data on incidence and mortality from the population-based NSW Central Cancer Registry and on colorectal cancer diagnostic tests from the Health Insurance Commission. Age-standardised incidence and mortality rates for colon and rectal cancer (defined by codes 153 and 154 in the International classification of diseases, 9th revision) by sex and age group (15-44, 45-59, 60-74 or > or = 75 years) and incidence by cancer spread at diagnosis; age-standardised rates for faecal occult blood tests, sigmoidoscopy and colonoscopy. From 1973 to 1992, colorectal cancer incidence increased significantly in NSW by an average of 2.0% per year in males (95% confidence interval [CI], 1.8 to 2.3) and 0.9% in females (95% CI, 0.7 to 1.1). Mortality rates remained nearly constant in males, but fell significantly in females by an average of -1.0% per year (95% CI, -1.3 to -0.7). In the youngest age group (15-44 years) both incidence and mortality rates fell significantly, while rates were stable or rose in older age groups, except for a significant fall in mortality in women aged > or = 75 years. Use of colonoscopy (an early detection method) increased, but a corresponding shift to detection of earlier-stage cancers was not seen. A reduction in risk factors and better treatment leading to longer survival may have contributed to the falls in incidence in younger people and in mortality in females.

Adjustment of a sparse and irregular reference rate matrix.

Regional sex-specific rates of a rare disease often show conspicuous fluctuations over conventional strata of age and calendar time. In a cohort study, when such rates are used as references in the calculation of the expected number of cases, the accumulated person-time of the study cohort may somewhat haphazardly contribute to the result. For example, only the person-time observed in the strata with at least one reference case registered contributes to the expected number of cases. It may therefore be important to evaluate whether the regional rates seem to differ systematically from the more stable national rates. When such differences may be indicated, a fairly simple method is proposed for smoothing rates. This method aims to produce rates that better reflect the underlying, supposedly smooth, rate pattern over age and calendar time in a population of interest. The present paper illustrates the technique by considering right-sided colon cancer incidence rates from a regional male population, which the authors use to calculate the expected number of such cases in an occupational cohort.

Dietary factors and risk of colon cancer.

The incidence rates of colon cancer are high in North America and northern Europe, lower in southern Europe, and much lower in Asia and Africa. It is widely believed that environmental factors, particularly dietary patterns, account for most of this marked variation in rates. Over the past decade, a large number of case-control and cohort studies have added a substantial body of evidence regarding our understanding of the causes of colon cancer. Although the data are not entirely consistent, several important risk factors have emerged. The epidemiological evidence that physical inactivity or excess energy intake relative to requirements increases risk of this malignancy is quite strong. Intake of red meat appears to increase risk, but protein-rich sources other than red meat probably do not elevate risk and may even reduce the occurrence of colon cancer. Dietary fat, at least that from sources other than red meat, does not appear to increase risk appreciably. High consumption of vegetables and fruits and the avoidance of highly refined sugar containing foods are likely to reduce risk of colon cancer, although the responsible constituents remain unclear. Alcohol intake may enhance risk of cancers of the distal colorectum, although the evidence is not entirely consistent. The influence of alcohol may be particularly strong when combined with a diet low in methionine and folate, suggesting that the effect of alcohol may be through antagonism of methyl-group metabolism. The combined effect of these dietary factors, as well as modifiable non-dietary factors such as cigarette smoking, suggest that the majority of cases of colon cancer are preventable.

Colon cancer prevention update.

C OLORECTAL cancer is second only to lung cancer in mortality in the United States. 1 A review of the epidemiology of colorectal cancer shows interesting findings in general trends, in geographic distribution, in migrant populations, in ethnic variation, and in location of cancer within the colon itself. 2-4 In the United States, colon cancer mortality has remained flat over the last 40 years. Incidence peaked during 1985, with increased screenings after President Reagan's diagnosis of colon cancer that same year ) Since 1985, incidence rates for colorectal cancer have been lower, but they show marked geographic and racial disparity. The highest rates of colorectal cancer occur in the United States, other Anglo-Saxon countries, and western and northern Europe. 4 Africa, China, Japan, and India have low incidence rates, especially in the nonurban areas. 4 Migrants from areas with low colorectal incidence to areas with higher incidence rates show an increase in colorectal cancer. 5'6 Similarly, migrants from areas with higher incidence rates to areas with lower incidence rates evidence a decrease in risk. 7 From 1973 to 1988, the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program reported an increase in age-adjusted colon cancer incidence rates of 30.6% for blacks and only 5.4% for whites. 2 Colorectal cancer occurs in the proximal colon, the distal colon, and the rectum. These divisions of the colon are significant for cancer development and, potentially, for cancer prevention. In areas of the world where the incidence of colorectal cancer is low, for example, colorectal cancer occurs predominantly in the proximal or transverse colon. 4 In geographic areas that have a high incidence of colorectal cancer, the cancer occurs more frequently in the distal colon. 8 Areas with a high incidence of colon cancer appear to have a high risk of rectal cancer. Aneuploidy, K-ras mutations, and allelic losses of chromosomes 5, 17, and 18 vary with location in the colon. 9 Rectal cancer occurs with higher frequency in men than in women, is positively associated with alcohol consumption, and is less common among persons of Jewish ancestry than is colon cancer, j~ There are also differences in age-specific sex ratios for various parts of the large bowel, as exemplified by older women who show an increase in right-sided colorectal cancer. 8 The reasons for these differences are not clear and may be attributed to variations in fecal contents, differences in the colonic and rectal mucosa, or differences in length of fecal contact. 10

Colorectal cancer in Denmark 1943?1988

Nation-wide incidence rates are presented of colorectal cancer in Denmark from 1943 to 1988. In Denmark notification of malignant and related diseases is mandatory. The percentage of histologically confirmed tumours is now 95. The annual incidence rate of colon cancer in Denmark has been increasing among men and women combined from 684 cases in 1943-47 to 2020 cases in 1988. In the same period the incidence of rectal cancer has been increasing from 762 cases in 1943-47 to 1108 cases in 1988. We analyzed the effects of age, calendar time, and birth cohort with multiplicative Poisson models. We did not find consistent period effects in the models. We suggest the trends in colorectal cancer incidence rates may be due to changes in environmental factors such as dietary habits and in physical activity. Furthermore, we suggest an etiologic distinction between carcinoma of the rectum, the left colon and the right colon.

Multistage carcinogenesis: population-based model for colon cancer.

Recent laboratory work and previous models suggest that multiple mutations are associated with the development of colon cancer. To estimate the number of mutations required for colon carcinogenesis, we used likelihood analysis to obtain the best fit between mathematical models postulating different numbers of rate-limiting events and data on incidence rates of colon cancer in two human populations--the general population of Birmingham, England, from 1968 to 1972 and patients with familial adenomatous polyposis (FAP) diagnosed at Saint Mark's Hospital, London, England, between 1925 and 1965. The Armitage-Doll model and two- and three-mutation models that explicitly incorporated cell proliferation kinetics were used. When cell kinetics were considered, models postulating either two or three rate-limiting events described the incidence rates of colon cancer equally well in both human populations. A comparison of the incidence rate of colon cancer in the general population with that in patients with polyposis suggests that a mutation at the FAP gene locus is not one of the rate-limiting events in colon carcinogenesis. Compared with the two-mutation model, the three-mutation model was more consistent with the number of mutations reported to date in colon cancer and with mutation rates measured in the laboratory. A mutation at the FAP locus may not be a rate-limiting step but may act indirectly by stimulating the proliferation of stem cells. Thus, the development of colon cancer in patients with FAP does not appear to fit the retinoblastoma paradigm.

Colorectal cancer and solar radiation.

It has been suggested that sunlight might have a role in the prevention of colorectal cancer via a mechanism involving vitamin D. We used data from nine population-based cancer registries in the United States to analyze incidence rates for colon and rectal cancer during 1973-84 as a function of regional variation in the levels of available solar radiation. Data were restricted to include only those persons born and diagnosed in the same state. Incidence rates of colon and rectal cancer among men tended to increase with decreasing levels of solar radiation. Compared to rates in New Mexico and Utah, for example, rates in the Detroit area (MI), Connecticut, and western Washington were 50 percent to 80 percent higher. Among women, colon cancer rates showed a similar trend, though of smaller magnitudes; rates of rectal cancer among women did not vary in relation to levels of available solar radiation.

Accuracy of Medicare Claims Data for Estimation of Cancer Incidence and Resection Rates Among Elderly Americans

To explore the reliability of Medicare Part A claims data for clinical and health services research related to the care of patients with cancer, the authors compared estimates of the incidence of and resection rates for cancer of the breast, colon, and lung derived from analysis of Medicare Part A data versus data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. Incidence rates of breast, colon, and lung cancer estimated from Medicare Part A data were within 6% of estimates derived from SEER data. Resection rates estimated from Medicare Part A data, in contrast, were 12% to 27% lower than resection rates based on SEER data. This discrepancy is not explained by variations in practice between regions participating in versus those not participating in the SEER registries but may be due to undercoding of surgical procedures in Medicare Part A data. This analysis suggests that Medicare data can provide useful insights into the care of patients with cancer, but research regarding inpatient procedures employed in management of cancer should be based on analysis of Medicare Parts A and B data combined.

Colon cancer incidence: recent trends in the United States.

Between 1976-78 and 1985-87, the age-adjusted incidence rates of invasive colon cancer in the United States rose by 15 percent, 3 percent, 21 percent, and 16 percent among White males, White females, Black males, and Black females, respectively. The increases in incidence occurred in all age groups over age 54 and affected each of the major subsites of the colon nearly equally. The larger rates of increase have resulted in higher incidence among Blacks than Whites by the mid-1980s and an increasingly greater excess of this cancer in males. Trends toward earlier diagnosis of invasive colon cancer were found, with increasing rates for localized and regional diseases coupled with stable or decreasing distant-stage disease-rates. The incidence of in situ colon cancer also rose substantially. The findings suggest that changes in diagnostic trends and risk-factor prevalence may be contributing to these patterns, and that the era when colon cancer predominated among White females is clearly over.

Can colon cancer incidence and death rates be reduced with calcium and vitamin D?

It was proposed in 1980 that vitamin D and calcium could reduce the risk of colon cancer. This assertion was based on the decreasing gradient of mortality rates from north to south, suggesting a mechanism related to a favorable influence of ultraviolet-induced vitamin D metabolites on metabolism of calcium. A 19-y prospective study of 1954 Chicago men found that a dietary intake of greater than 3.75 micrograms vitamin D/d was associated with a 50% reduction in the incidence of colorectal cancer, whereas an intake of greater than or equal to 1200 mg Ca/d was associated with a 75% reduction. Clinical and laboratory studies further support these findings. A nested case-control study based on serum drawn from a cohort of 25,620 individuals reported that moderately elevated concentrations of 25-hydroxyvitamin D, in the range 65-100 nmol/L, were associated with large reductions (P less than 0.05) in the incidence of colorectal cancer.

Reproductive factors and colon cancers

In Los Angeles County, the age-adjusted incidence rate of colon cancer in men is almost 30% higher than that in women; however, in the descending and sigmoid colon, age-specific incidence rates for women are higher than those for men before age 55. Since menstrual and/or reproductive factors may be involved in producing this crossover in age-specific rates, they were examined in a population-based case-control study involving 327 white women with adenocarcinoma of the colon and age-, race- and neighbourhood-matched controls. After adjustment for other factors associated with colon cancer in this study (family history of large bowel cancer, total fat intake, calcium, weight and activity level), ever having been pregnant was protective (RR = 0.56, 95% CI = 0.33-0.97). For one to two pregnancies, the RR was 0.76 (CI = 0.42-1.37); for three or more pregnancies, the RR was 0.45 (CI = 0.25-0.81). However, the relationship between the number of pregnancies and colon cancer risk was actually U-shaped, with risk decreasing with successive pregnancies up to four and then increasing with additional pregnancies. The U-shaped relationship was present for incomplete as well as for full-term pregnancies and was more striking for cancers occurring in the distal (descending and sigmoid) than proximal (caecum to splenic flexure) colon. Risk was not related to age at menarche or use of exogenous oestrogens, but delayed natural menopause was weakly protective in the proximal but not distal colon. The crossover in incidence rates in the distal colon can be completely accounted for by the pregnancy effect. The U-shape of the pregnancy curve suggests the possibility of competing factors, some protective, especially after one or several pregnancies, and others conferring increasing risk with successive pregnancies, regardless of the pregnancy outcome.

Tobacco, Alcohol, Coffee, and Caffeine as Risk Factors for Colon Cancer in a Low-Risk Population

We used data from a population-based case-control study to examine how use of tobacco products and consumption of alcohol, coffee, and caffeine relate to colon cancer in Utah. We hypothesized that low use of these substances is one factor contributing to the low colon cancer incidence in Utah and could help explain the low risk associated for colon cancer with being a member of the Church of Jesus Christ of Latter-day Saints. In females, we observed little or no increase in risk of colon cancer from smoking cigarettes or from consumption of alcohol, caffeine, or coffee. Males who used pipes, however, experienced an increased risk for colon cancer (OR = 4.1, 95% CI = 1.3-12.3). Risk for colon cancer associated with alcohol use was greatly attenuated after adjusting for caffeine and pipe use in males; males who consumed higher levels of caffeine during the two to three years prior to the interview were at higher risk than males who consumed low levels of caffeine (OR = 2.0, 95% CI = 1.0-4.2); similar associations were observed for coffee consumption. Nonuse of these substances could explain the low colon cancer incidence rates observed in members of the Church of Jesus Christ of Latter-day Saints and Utah males.

Risk for colorectal adenocarcinoma in pernicious anemia. A population-based cohort study.

To determine the long-term risk for colorectal cancer among patients with pernicious anemia. Historical cohort study. Population-based inception cohort of Rochester, Minnesota, residents. We identified 150 Rochester residents who had the onset of pernicious anemia during the 30-year period from 1950 through 1979, and we followed this cohort for 1664 person-years of observation. The observed risk for subsequent colorectal cancer in the cohort was compared with that expected based on incidence rates of colon and rectal cancer for the local population. There were 14 cases of colorectal cancer among the 150 patients with pernicious anemia (where 10.5 cases were expected), and 9 of these cases were found after the diagnosis of pernicious anemia was established (where 5.1 cases were expected). The relative risk for colon cancer at any time after the diagnosis of pernicious anemia was 1.8 (CI, 0.8 to 3.3). The relative risk was greatest (4.1; CI, 1.7 to 8.7) in the 5-year period immediately after the diagnosis of pernicious anemia; during this period, 7 cases of colon cancers were observed but only 1.7 were expected (P less than 0.0001). Although the overall risk does not achieve statistical significance, patients with pernicious anemia may have an increased risk for colorectal adenocarcinoma in the 5 years after diagnosis.

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)

Fecal bacterial flora of four Nordic population groups with diverse incidence of large bowel cancer

Fecal samples were collected and biologically examined from 4 population groups, exhibiting a 3-fold range in colon cancer incidence, in Denmark and Finland. Carrier rates and counts per gram feces of several aerobic as well as anaerobic genera, including nuclear dehydrogenase-producing clostridia, were calculated. The results obtained with the described method did not confirm a relationship between colon cancer incidence and carrier rates of intestinal bacteria.

Mathematical modeling of cancer incidence rates: Linear models of colon cancer in connecticut

Mathematical models of cancer incidence were developed to evaluate substantively trends in age and period of diagnosis and to identify differences in these trends with regard to qualitative variables such as sex and anatomical localization of tumor. Parameter estimates were obtained through a weighted least-squares procedure, and hypothesis testing was carried out using minimum modified χ 2 statistics. These procedures were applied to colon cancer incidence rates for Connecticut males and females during the period 1940–1974. The initial model of changes in incidence over calendar time for males and females showed a different pattern and excess risk among males and a possible birth cohort effect among females. The changing pattern of risk in males was modeled as an exponential function of age and a two-stage, age-related process was identified. While proportional comparisons of time trends between the ascending and sigmoid colon showed significant differences for certain groups, patterns in absolute changes were not found to be statistically different. Using mathematical models of cancer incidence rates for substantive analysis can be useful for hypothesis generation in cancer epidemiology. Such modeling proves worthwhile because it allows the investigator to summarize the trends and patterns of cancer incidence through model parameters which then may be tested statistically for the purpose of identifying significant effects of independent variables.

Cancer of the Colon: 32 years of experience in Bombay, India.

Incidence rate of colon cancer is low in India compared to the Western countries. The dietary habits may be the protective factor in our population. During a 32 year period (1941-1972), 555 cases of colonic cancer were recorded at the Tata Memorial Hospital, Bombay. Among the social groups utilizing this hospital, the Parsis (Zoroastrians) have the highest incidence of colonic cancer. The frequency of cancer of the caecum and sigmoid are almost equal. Cancer of splenic and hepatic flexures are predominantly seen in men. Of the resected cases 50% survived for 5 years and 40% for 10 years. When cancer was localised, the 5 year survival rate was 64%. The 5 year survival rat among transverse colon cancer patients was 70%. The skin was the commonest site of a second cancer among colon cancer patients; the possible etiological association of these two cancers appears very intriguing.

Large-bowel carcinogenesis: fecal constituents of populations with diverse incidence rates of colon cancer.

Large-bowel carcinogenesis: fecal constituents of populations with diverse incidence rates of colon cancer.