Effectiveness of screening for colorectal cancer with a faecal occult-blood test, in Finland.

BACKGROUND: Screening for colorectal cancer (CRC) with guaiac-based faecal occult-blood test (FOBT) has been reported to reduce CRC mortality in randomised trials in the 1990s, but not in routine screening, so far. In Finland, a large randomised study on biennial FOB screening for CRC was gradually nested as part of the routine health services from 2004. We evaluate the effectiveness of screening as a public health policy in the largest population so far reported. METHODS: We randomly allocated (1:1) men and women aged 60-69 years to those invited for screening and those not invited (controls), between 2004 and 2012. This resulted in 180 210 subjects in the screening arm and 180 282 in the control arm. In 2012, the programme covered 43% of the target age population in Finland. RESULTS: The median follow-up time was 4.5 years (maximum 8.3 years), with a total of 1.6 million person-years. The CRC incidence rate ratio between the screening and control arm was 1.11 (95% CI 1.01 to 1.23). The mortality rate ratio from CRC between the screening and control arm was 1.04 (0.84 to 1.28), respectively. The CRC mortality risk ratio was 0.88 (0.66 to 1.16) and 1.33 (0.94 to 1.87) in males and females, respectively. CONCLUSIONS: We did not find any effect in a randomised health services study of FOBT screening on CRC mortality. The substantial effect difference between males and females is inconsistent with the evidence from randomised clinical trials and with the recommendations of several international organisations. Even if our findings are still inconclusive, they highlight the importance of randomised evaluation when new health policies are implemented. TRIAL REGISTRATION: 002_2010_august.

Impact of cancer screening on women's health.

Worldwide, 31% of cancers in women are in the breast or uterine cervix. Prevention of cervical cancer is effective with the use of the cervical Pap smear test if applied in an organized and continuous fashion, including treatment of precancerous lesions. At best such programs have led to a 60% decrease in cervical cancer incidence and mortality in the Nordic countries. Early detection of breast cancer in a population based screening may lead to a 30% reduction of mortality from this disease in the screened population. Measures to guarantee high coverage and attendance, adequate field facilities, organized program for quality control and adequate facilities for diagnosis and treatment are prerequisites of successful programs. In absolute terms the contribution of screening to the total mortality reduction among middle-aged populations is small, much smaller than the potential gains from cancer prevention.

Breast self-examination and survival from breast cancer: a prospective follow-up study.

A prospective study was conducted to investigate the possible effect of breast self-examination (BSE) on cause-of-death-specific survival rate of breast cancer patients. Six hundred and four breast cancer patients diagnosed in 1984-1986 in Finland, and applying for breast prostheses, were interviewed about both their BSE practices prior to cancer diagnosis and the actual method of tumor detection. No clear differences were observed in the stage distribution or cause of death-specific five-year survival rates between individuals with different BSE practices. After adjustment for potential confounders in the Cox proportional hazards analysis, no differences in risk of breast cancer death were observed for those who performed BSE monthly as compared to those who practised BSE less frequently or not at all. When the method of detection was taken into account, it turned out that only 34 (7.6 %) of the 448 regular BSE practisers had actually detected their cancers by means of BSE. Furthermore, no survival advantage was associated with detection of breast cancer by means of BSE. Those BSE practisers whose cancer was detected by BSE had a similar or slightly worse prognosis compared to BSE practisers whose cancer had been detected by other means. Our results suggest that BSE practice is not beneficial in terms of breast cancer survival, nor is detection of breast cancer by means of BSE. Conclusive evidence should, however, be obtained from prospective randomized studies of breast cancer mortality.

Breast cancer screening as public health policy in Finland.

A nationwide mammographic screening for breast cancer was started in Finland in 1987. During the first 2 years of the organised screening programme, 126,000 women were invited. Most of them (103,000) belonged to the birth year cohort in the 50-59 years' age groups. Among the 112,000 screenees, 418 cancers (0.4%) were found. Specificity of the test was about 96%. The screening prevalence was 2.4 times the annual incidence and a minimum estimate for the detection rate among those invited was 1.6 times that among those not invited. These estimates indicate a relatively low test and programme sensitivity. The final effectiveness of a public health policy cannot be predicted on the basis of limited preventive trials, and there is need to evaluate also a public health policy by experimental means.