BACKGROUND: Self-selection may compromise cost-effectiveness of screening programs. We hypothesized that nonparticipants have generally higher morbidity and mortality than participants. METHODS: A Swedish population-based random sample of 1,986 subjects ages 59 to 61 years was invited to sigmoidoscopy screening and followed up for 9 years by means of multiple record linkages to health and population registers. Gender-adjusted cancer incidence rate ratio (IRR) and overall and disease group-specific and mortality rate ratio (MRR) with 95% confidence intervals (95% CI) were estimated for nonparticipants relative to participants. Cancer and mortality rates were also estimated relative to the age-matched, gender-matched, and calendar period-matched Swedish population using standardized incidence ratios and standardized mortality ratios. RESULTS: Thirty-nine percent participated. The incidence of colorectal cancer (IRR, 2.2; 95% CI, 0.8-5.9), other gastrointestinal cancer (IRR, 2.7; 95% CI, 0.6-12.8), lung cancer (IRR, 2.2; 95% CI, 0.8-5.9), and smoking-related cancer overall (IRR, 1.4; 95% CI, 0.7-2.5) tended to be increased among nonparticipants relative to participants. Standardized incidence ratios for most of the studied cancers tended to be >1.0 among nonparticipants and
Widespread use of prophylactic colectomy has resulted in a reduction in the incidence of colorectal cancer in familial adenomatous polyposis (FAP) patients. A retrospective chart review of families registered at the Steve Atanas Stavro Familial Gastrointestinal Cancer Registry in Toronto was performed to determine whether the decrease in the number of patients developing colorectal cancer implies that causes of mortality in FAP patients are shifting to that of extracolonic manifestations of FAP. Information was available on 140 deaths within 158 families and among 461 individuals with FAP. When stratified by decade, from the 1930s to the 1990s, the ratio of deaths caused by extracolonic manifestations of FAP compared with deaths caused by colorectal cancer was noted to have risen. Even though most deaths in FAP patients are still from colorectal cancer, it appears that screening policies and prophylactic colectomy have resulted in a reduction in the number of FAP patients who develop colorectal cancer. Thus, in recent decades, a greater percentage of deaths in FAP patients appears to be attributable to extracolonic manifestations of the disease.
The cost-effectiveness of a series of mutually exclusive colorectal cancer screening programmes with varying screening interval and target group are analysed. Costs and effects for 60 possible screening programmes are simulated on the basis of data collected from a randomized trial initiated in 1985 in Funen County, Denmark. The screening test applied is the unhydrated Hemoccult-II. The analysis identifies six efficient programmes with cost-effectiveness estimates ranging from 17000 to 42500 Danish kroner (DKK) per life-year.
Prophylactic family screening and surgery has improved the outcome of patients with familial adenomatous polyposis (FAP) largely preventing deaths due to colorectal cancer. The present study compared the mortality rates and causes of death of FAP patients diagnosed by symptoms (probands) or by family screening (call-up).
The study comprised all 236 FAP patients registered in the Finnish Polyposis Registry until the end of June 1998. There were 116 probands and 120 call-up patients with a median age of 36.8 and 22.8 at diagnosis and median follow-up times of 6.3 and 9.9 years, respectively. Cumulative crude and relative survival estimates were calculated for each group and the causes of death were determined.
The life expectancy was significantly better in the call-up group than in the probands after colectomy (P
From the Department of Health Management and Health Economics, University of Oslo, Oslo (M.L., M.K., G.H., H.-O.A., M.B.), Department of Transplantation Medicine, Oslo University Hospital, Oslo (M.L., M.B.), Cancer Registry of Norway, Oslo (G.H.), Department of Research and Development, Telemark Hospital, Skien (M.K., G.H.), and Department of Medicine, Sørlandet Hospital Kristiansand, Kristiansand (Ø.H., M.B.) - all in Norway; the Department of Epidemiology, Harvard School of Public Health, Boston (M.L., M.K., Ø.H., H.-O.A., M.B.); and the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm (H.-O.A.).
Although colonoscopic surveillance of patients after removal of adenomas is widely promoted, little is known about colorectal-cancer mortality among these patients.
Using the linkage of the Cancer Registry and the Cause of Death Registry of Norway, we estimated colorectal-cancer mortality among patients who had undergone removal of colorectal adenomas during the period from 1993 through 2007. Patients were followed through 2011. We calculated standardized incidence-based mortality ratios (SMRs) using rates for the Norwegian population at large for comparison. Norwegian guidelines recommended colonoscopy after 10 years for patients with high-risk adenomas (adenomas with high-grade dysplasia, a villous component, or a size =10 mm) and after 5 years for patients with three or more adenomas; no surveillance was recommended for patients with low-risk adenomas. Polyp size and exact number were not available in the registry. We defined high-risk adenomas as multiple adenomas and adenomas with a villous component or high-grade dysplasia.
We identified 40,826 patients who had had colorectal adenomas removed. During a median follow-up of 7.7 years (maximum, 19.0), 1273 patients were given a diagnosis of colorectal cancer. A total of 398 deaths from colorectal cancer were expected and 383 were observed, for an SMR of 0.96 (95% confidence interval [CI], 0.87 to 1.06) among patients who had had adenomas removed. Colorectal-cancer mortality was increased among patients with high-risk adenomas (expected deaths, 209; observed deaths, 242; SMR, 1.16; 95% CI, 1.02 to 1.31), but it was reduced among patients with low-risk adenomas (expected deaths, 189; observed deaths, 141; SMR, 0.75; 95% CI, 0.63 to 0.88).
After a median of 7.7 years of follow-up, colorectal-cancer mortality was lower among patients who had had low-risk adenomas removed and moderately higher among those who had had high-risk adenomas removed, as compared with the general population. (Funded by the Norwegian Cancer Society and others.).
Comment In: N Engl J Med. 2014 Aug 28;371(9):860-125162893
Considering the present state of knowledge, only the strategy of screening for intestinal tumours at the asymptomatic stage could reduce such a problem as colorectal cancer. Data from case-control studies provide evidence of the efficacy of screening by rigid proctosigmoidoscopy. But compliance with such a strategy is not known. The effectiveness of screening by sigmoidoscopy has yet to be demonstrated. A European controlled study of flexible sigmoidoscopy in association with the Hemoccult test versus the Hemoccult test alone has been set up. Evaluation by a randomized screening trial with a single flexible sigmoidoscopic examination at age 55 to 60 years has also been suggested. Case-control studies and a randomized study conducted among volunteers demonstrate that it is possible to reduce mortality from colorectal cancer in people who accept screening with faecal occult blood testing, using the Hemocult test. Four population-based studies have been set up in Europe (in England, Denmark, France and Sweden). They are based on a biannual Hemoccult test. Compliance in the test group ranges between 55% and 65% in the first screening campaign and remains high in the following screening campaigns. In France, to achieve this goal, the test must be proposed by GPs and then mailed to those who do not consult GPs. Reliable mortality data will be available within 1 to 3 years. The results of the European trials must be awaited to know if screening biennually is effective in reducing colorectal cancer mortality.
BACKGROUND: Three randomised trials have demonstrated reduction in mortality from colorectal cancer (CRC) by repeated screening with faecal occult blood tests, including the trial presented here, which is the only one still in progress. AIMS: To evaluate reduction in mortality after seven screening rounds and the possible influence of compliance on mortality from CRC. METHODS: At Funen in Denmark, random allocation to biennial screening with Hemoccult-II in 30 967 subjects aged 45-75 years and 30,966 controls was performed in 1985 from a population of 137,485 of the same age. Only participants who completed the first screening round were invited for further screening. Colonoscopy was offered if the test was positive. The primary end point was death from CRC, and the 10 year results were published in 1996. RESULTS: From the beginning of the first screening to the seventh round, mean age increased from 59.8 to 70.0 years in the screening and control groups, and the male/female ratio decreased from 0.92 to 0.81. Those who accepted screening were younger than non-responders. Positivity rates varied from 0.8% to 3.8%, the cumulative ratio of a positive test was 5.1% after seven rounds, and 4.8% of patients had at least one colonoscopy. Mortality from CRC was significantly less in the screening group (relative risk (RR) 0.82 (0.69-0.97)), and the reduction in mortality was most pronounced above the sigmoid colon. After seven rounds, RR was reduced to less than 0.70 compared with controls. Mortality rates from causes other than CRC did not differ. Non-responders had a significantly increased risk of death from CRC compared with those who accepted the full programme. Subjects who accepted the first screening, but not subsequent ones, demonstrated a tendency towards increased risk. CONCLUSIONS: The persistent reduction in mortality from CRC in a biennial screening program with Hemoccult-II, and a reduction in RR to less than 0.70 in those adhering to the programme, support attempts to introduce larger scale population screening programmes. The smaller effect on mortality from CRC in the rectum and sigmoid colon suggests evaluation by additional flexible sigmoidoscopy with longer intervals.
OBJECTIVE: To determine the risk of colorectal cancer after screening with flexible sigmoidoscopy. DESIGN: Randomised controlled trial. SETTING: Population based screening in two areas in Norway-city of Oslo and Telemark county (urban and mixed urban and rural populations). PARTICIPANTS: 55 736 men and women aged 55-64 years. INTERVENTION: Once only flexible sigmoidoscopy screening with or without a single round of faecal occult blood testing (n=13 823) compared with no screening (n=41 913). MAIN OUTCOME MEASURES: Planned end points were cumulative incidence and mortality of colorectal cancer after 5, 10, and 15 years. This first report from the study presents cumulative incidence after 7 years of follow-up and hazard ratio for mortality after 6 years. RESULTS: No difference was found in the 7 year cumulative incidence of colorectal cancer between the screening and control groups (134.5 v 131.9 cases per 100 000 person years). In intention to screen analysis, a trend towards reduced colorectal cancer mortality was found (hazard ratio 0.73, 95% confidence interval 0.47 to 1.13, P=0.16). For attenders compared with controls, a statistically significant reduction in mortality was apparent for both total colorectal cancer (hazard ratio 0.41, 0.21 to 0.82, P=0.011) and rectosigmoidal cancer (0.24, 0.08 to 0.76, P=0.016). CONCLUSIONS: A reduction in incidence of colorectal cancer with flexible sigmoidoscopy screening could not be shown after 7 years' follow-up. Mortality from colorectal cancer was not significantly reduced in the screening group but seemed to be lower for attenders, with a reduction of 59% for any location of colorectal cancer and 76% for rectosigmoidal cancer in per protocol analysis, an analysis prone to selection bias. TRIAL REGISTRATION: Clinical trials NCT00119912.