Matthew M. Zack

Ulcerative colitis and colorectal cancer. A population-based study.

BACKGROUND The risk of colorectal cancer is increased among patients with ulcerative colitis. The magnitude of this increase in risk and the effects of the length of follow-up, the extent of disease at diagnosis, and age at diagnosis vary substantially in different studies. METHODS To provide accurate estimates of the risk of colorectal cancer among patients with ulcerative colitis, we studied a population-based cohort of 3117 patients given a diagnosis of ulcerative colitis from 1922 through 1983 who were followed up through 1984. RESULTS Ninety-two cases of colorectal cancer occurred in 91 patients. As compared with the expected incidence, the incidence of colorectal cancer in the cohort was increased (standardized incidence ratio [ratio of observed to expected cases] = 5.7; 95 percent confidence interval, 4.6 to 7.0). Less extensive disease at diagnosis was associated with a lower risk; for patients with ulcerative proctitis, the standardized incidence ratio was 1.7 (95 percent confidence interval, 0.8 to 3.2); for those with left-sided colitis, 2.8 (95 percent confidence interval, 1.6 to 4.4); and for those with pancolitis (extensive colitis, or inflammation of the entire colon), 14.8 (95 percent confidence interval, 11.4 to 18.9). Age at diagnosis and the extent of disease at diagnosis were strong and independent risk factors for colorectal cancer. For each increase in age group at diagnosis (less than 15 years, 15 to 29 years, 30 to 39 years, 40 to 49 years, 50 to 59 years, and greater than or equal to 60 years), the relative risk of colorectal cancer, adjusted for the extent of disease at diagnosis, decreased by about half (adjusted standardized incidence ratio = 0.51; 95 percent confidence interval, 0.46 to 0.56). The absolute risk of colorectal cancer 35 years after diagnosis was 30 percent for patients with pancolitis at diagnosis and 40 percent for those given this diagnosis at less than 15 years of age. CONCLUSIONS Close surveillance and perhaps even prophylactic proctocolectomy should be recommended for patients given a diagnosis of pancolitis, especially those who are less than 15 years of age at diagnosis.

Increased risk of large-bowel cancer in crohn's disease with colonic involvement

A cohort of 1655 patients with Crohns disease diagnosed during 1983 in the Uppsala health care region, Sweden, was followed up with respect to the occurrence of colorectal cancer to the end of 1984. 12 colorectal cancers were diagnosed, yielding an increased overall risk of 2.5. The relative risk was similar for males and females. Duration of follow-up did not affect risk. Relative risk for disease of the terminal ileum only was 1.0; for terminal ileum and parts of colon 3.2; and for colon alone 5.6. Patients in whom Crohns disease was diagnosed before age 30 with any colonic involvement at diagnosis had a higher relative risk (20.9) than those diagnosed at older ages (2.2).

The epidemiology of inflammatory bowel disease : a large, population-based study in Sweden

Previous population-based incidence studies of inflammatory bowel disease are limited by small numbers, short duration, or inadequate case-finding. To address these problems, we identified all persons with confirmed ulcerative colitis (n = 2509) or Crohns disease (n = 1469) in the Uppsala Health Care Region from 1965 to 1983. Age-specific incidence rates by sex were slightly greater for males with ulcerative colitis and females with Crohns disease. Incidence rates for ulcerative colitis and Crohns disease were higher in urban than rural areas. The annual incidence rate of ulcerative colitis increased from less than 7 per 100,000 to more than 12 per 100,000 during the study period, while the rate for Crohns disease remained between 5 and 7 per 100,000. The increase in the incidence of ulcerative colitis was the result of a marked increase in the number of patients with ulcerative proctitis. Analyses by 5-year birth cohorts suggest that those born from 1945 through 1954 were at higher risk for ulcerative colitis and Crohns disease, and that this effect was accounted for by those born in the first half of the year. The seasonality in the cohort effect, combined with the urban preponderance of disease, suggests that environmental causes may be involved in ulcerative colitis and Crohns disease.

International incidence rates of invasive cervical cancer after introduction of cytological screening

Because Pap-smear screening can detect pre-invasive cervical cancer,such screening can markedly reduce the occurrence of invasive cancer.However, its impact in different populations is uncertain. This studycompares the changes in cervical cancer incidence at different ages after theintroduction of screening in different populations, and addresses the impactof organized and opportunistic smear taking. We identified 17 cancerregistries large enough and existing long enough to analyze screeningeffects. For each registry, we calculated the relative reduction inage-specific incidence rates and in incidence rates age-standardized to theworld population after the introduction of cytologic screening. In 11 of the17 populations, age-standardized incidence rates declined markedly from 27percent in Norway and to 77 percent in Finland. Age-specific declines wereconfined to women aged 30 to 70 years old with a nadir around ages 40 to 55.In six other populations, age-standardize d incidence rates declined lessthan 25 percent, an amount too small to provide unambiguous evidence of ascreening effect. In several populations, cytologic screening had a morepronounced effect than is generally recognized. Because age-specific declinesin cervical cancer incidence rates were strikingly similar in populationswith widely different screening practices, organized screening may not bemarkedly superior to opportunistic screening. The reduction in reportedcancer incidence because of screening is smaller in younger and older women.

Survival and causes of death in patients with inflammatory bowel disease: A population-based study

Relative survival up to December 31, 1986 was analyzed for all patients diagnosed with ulcerative colitis (UC) (n = 2,509) and Crohns disease (CD) (n = 1,469) within the Uppsala Region, Sweden 1965-1983. After 10 years survival was 96% of that expected for UC and CD. Patients with ulcerative proctitis, left-sided colitis, and pancolitis at diagnosis had relative survival rates of 98%, 96%, and 93% respectively. Survival did not differ by extent at diagnosis for patients with CD. After including prevalent cases, 684 deaths occurred compared with 481.1 expected deaths [standardized mortality ratio (SMR) = 1.4; 95% confidence interval (CI) = 1.3-1.5]. Inflammatory bowel disease was the main reason for this excess mortality. Colorectal cancer increased mortality (50 deaths observed vs. 15.2 expected). Death from other cancers were not greater than expected. Obstructive respiratory diseases, especially bronchitis, emphysema, and asthma increased mortality SMR = 1.5 (95% CI = 1.1-2.2) in UC. Cerebrovascular disease mortality occurred less often than expected (SMR = 0.7; 95% CI = 0.5-1.0). Mortality for other diseases and groups of diseases was close to that expected.

Clinical epidemiology of toxic-oil syndrome. Manifestations of a New Illness.

An epidemic of a new illness involving multiple organ systems began in Spain in May 1981, with 19,828 cases and 315 deaths reported by June 1, 1982. An epidemiologic investigation has linked the occurrence of illness with ingestion of an unlabeled, illegally marketed cooking oil. To elucidate the natural history of this illness, we reviewed the medical records of 121 patients in one severely affected town 100 km northwest of Madrid. The findings during the first week after onset were those of a febrile, pneumonia-like illness. Gastrointestinal findings and striking eosinophilia became prominent later in the first month. Although the disease followed a self-limited course in many patients, severe neuromuscular manifestations (myalgia severe enough to restrict movement, motor deficits, atrophy of major muscle groups, and contractures of the jaw and extremities) occurred late in the course of the illness (an average of 96 days after onset) in 23 per cent of the patients. The onset of disease early in the epidemic and particularly severe initial systemic findings were associated with progression to neuromuscular illness.

Stomach Cancer after Partial Gastrectomy for Benign Ulcer Disease

We followed for 25 to 33 years 6459 patients who had undergone partial gastrectomy for benign ulcer disease to determine the incidence of stomach cancer. The overall risk was no different from that among sex- and age-matched controls from the Swedish Cancer Registry (standardized incidence ratio = 0.96; 95 percent confidence limits, 0.78 and 1.16). However, when the patients were classified according to the duration of follow-up after operation, sex, surgical procedure, diagnosis at the time of operation, and age at operation, differences in risk were observed between the subgroups. After adjustment for potential confounding variables, the average adjusted risk increased 28 percent (adjusted standardized incidence ratio = 1.28; 95 percent confidence limits, 1.11 and 1.49) for each successive five-year interval after operation. The adjusted risk was greater among women than men (adjusted standardized incidence ratio = 1.96; 95 percent confidence limits, 1.18 and 3.24). Patients who had undergone a Billroth I anastomosis had a lower crude risk, both overall (standardized incidence ratio = 0.40; 95 percent confidence limits, 0.20 and 0.71) and after we controlled for other confounding variables (adjusted standardized incidence ratio = 0.27; 95 percent confidence limits, 0.12 and 0.62), than did those who had undergone a Billroth II procedure. The adjusted risk of stomach cancer was greater among patients operated on for gastric ulcer than among those operated on for duodenal ulcer (adjusted standardized incidence ratio = 2.21; 95 percent confidence limits, 1.45 and 3.35). Risk decreased with increased age at operation. Between successive strata of age at operation (less than 39, 40 to 49, 50 to 59, and greater than or equal to 60 years of age), the adjusted risk decreased on the average by about half (adjusted standardized incidence ratio = 0.52; 95 percent confidence limits, 0.41 and 0.66).

Perinatal measles infection and subsequent Crohn's disease

Although the aetiology of Crohns disease is unknown, morphological and epidemiological studies have implicated measles virus as a potential component cause, particularly when exposure occurs in utero or early in life. An increased incidence of Crohns disease among people born during measles epidemics would support this hypothesis. We identified all individuals born in four counties in central Sweden in 1945-54 who had had Crohns disease diagnosed before the age of 30 years. Yearly reports compiled in these counties revealed that five measles epidemics had affected all four counties during the trial period. After adjusting for monthly differences in the number of livebirths in the four counties, we calculated the expected number of patients with Crohns disease and ulcerative colitis born during the 3-month period after the peaks of the epidemics. The number of people with Crohns disease significantly exceeded that expected: 57 versus 39.0 (standardised incidence ratio 1.46, 95% CI 1.11-1.89). For patients with ulcerative colitis, the observed number (42) was close to that expected (46.8). Our results strengthen the hypothesis that measles is related to Crohns disease and that the perinatal period is a time of vulnerability.

EPIDEMIC MALATHION POISONING IN PAKISTAN MALARIA WORKERS

In 1976, epidemic organophosphate insecticide poisoning due to malathion occurred among 7500 field workers in the Pakistan malaria control programme. In July, the peak month of the epidemic, it is estimated that there were about 2800 cases. In field studies low red-cell cholinesterase activities were associated with the signs and symptoms of organophosphate insecticide intoxication. Toxicity was seen with 3 different formulations of the insecticide and was greatest with the products containing increased amounts of isomalathion, a toxic malathion degradation product. Poor work practices, which had developed when D.D.T. was the primary insecticide for malaria control, resulted in excessive skin contact with and percutaneous absorption of the pesticide. Airborne malathion concentrations were very low. Implementation of good work practices and proscription of use of the 2 pesticide formulations most contaminated with isomalathion halted the epidemic in September. An extensive training programme and surveillance system for pesticide toxicity preceded 1977 spraying operations.

Comparison of Sudden and Nonsudden Coronary Deaths in the United States

BACKGROUND The present study was designed to compare risk factor prevalences in coronary heart disease deaths in persons dying within 1 hour of onset of cardiovascular symptoms (sudden coronary death), those dying without such sudden symptoms (nonsudden coronary death), and those with unknown duration of symptoms before death (other coronary death). METHODS AND RESULTS Data from the 1986 National Mortality Followback Survey and the US Bureau of the Census were examined to assess death rates for sudden, nonsudden, and other coronary deaths. Multivariate logistic regression methods were used to calculate the odds ratio (OR), compared with nonsudden and other coronary deaths, for sudden coronary death associated with socioeconomic status variables, the persons location at death, and coronary heart disease risk factors. Mortality rates for all coronary deaths increased with age, were higher for men than women, and increased with decreasing years of schooling. The rate of sudden coronary death was highest for Hispanics. In 1986, an estimated 251,000 sudden coronary deaths (95% CI = 238,000 to 263,000) occurred in the United States. Sudden coronary deaths were less likely than nonsudden coronary deaths to occur at home (OR = 0.5, 95% CI = 0.4 to 0.6), but individuals who died of sudden coronary death were more likely to have been current cigarette smokers (OR = 1.3, 95% CI = 1.0 to 1.8). No other modifiable risk factors for coronary heart disease distinguished sudden coronary deaths from nonsudden coronary deaths. CONCLUSIONS Contrary to the commonly held view, coronary deaths in the home are more likely to be nonsudden than sudden. Cigarette smoking more likely results in sudden than nonsudden coronary death, perhaps because of nicotine-induced ventricular arrhythmias.