We examined the effect of different invitational policies on the reduction of breast cancer mortality at 60-79 years of age within the Finnish mammography programme in 1992-2003, which varied in its coverage at 60-69 years of age. The data from 260 municipalities were grouped into three categories: regular invitations at 50-59 years of age only, regular invitations at 50-69 years of age, and regular invitations at 50-59 years of age with irregular invitations at 60-69 years of age. Observed deaths from breast cancer were compared to those expected without screening among all women and among the screened and non-screened women. Observed deaths were obtained from population data and from a cohort follow-up in 1992-2003. Expected deaths were derived by modelling breast cancer mortality at population level in 1974-1985 and 1992-2003. The reduction in breast cancer mortality was strongest, 28% (0.72, 0.51-0.97), in municipalities with regular invitations at 50-69 years of age. No overall effect at 60-79 years of age was observed with regular invitations at 50-59 years of age. The study confirms a reduction by screening of breast cancer mortality in Finland. Uniform extension of invitations to 60-69 years of age would increase the number of prevented breast cancer deaths among the elderly.
In the analysis of cause-specific survival, the causes of death must be known. For single-cancer patients with a known cause of death, the estimation of the cause-specific survival rate is straightforward. For multiple-cancer patients with two primary cancers, however, the analysis of cause-specific survival rates is more complex, particularly if the cancers are of the same primary site. In these situations, a concept of cancer-specific survival may also be distinguished from cause-specific survival. Cancer-specific survival rates are studied here by introducing two models, the primary one where the death from cancer is attributed to one of the cancers, and an alternative where such an attribution is not necessary. The models are illustrated using data on patients with multiple breast cancers. The model-based survival rates are compared with each other and with the corresponding relative survival rates based on analogous modelling of relative survival. The results show that for the subsequent breast cancer, the cancer-specific survival rates based on the alternative, where the distinction between the cancers as a cause of death was not necessary, tended to be higher than those based on that distinction. It is thus possible that the subsequent cancer was too often coded as a cause of death, particularly when being localized at diagnosis.
For an effective colorectal cancer (CRC) screening program, high participation rate is essential. However, non-participation in CRC screening program has increased in Finland.
The study was based on a population-based nationwide cohort of persons invited for CRC screening in 2004-2011. Information on the first round of the CRC screening participation and related background factors was obtained from the Finnish Cancer Registry, and information about health behavior factors from the Health Behavior Survey (HBS) in 1978-1999. Non-participation in CRC screening was analyzed with Poisson regression as incidence rate ratios (IRR) with 95% confidence intervals (95% CI).
Of all persons invited for CRC screening (79 871 men and 80 891 women) 35% of men and 21% of women refused. Of those invited for screening, 2456 men (3.1%) and 2507 women (3.1%) were also invited to the HBS. Persons, who declined HBS, were also more likely to refuse CRC screening (men IRR 1.40, 95% CI 1.26-1.56, women 1.75, 1.52-2.02) compared to HBS participants. Never married persons had about a 75% higher risk for refusing than married ones. The youngest age group (60 years) was more likely to refuse screening than the older age groups (62 or?>64 years). Smoking was associated with non-participation in screening (current smokers, men: IRR 1.32, 95% CI 1.05-1.67, women: 2.10, 1.61-2.73).
Participation in CRC screening was affected by gender, age, and marital status. Persons, who refused the HBS, were also more likely to refuse CRC screening. Smoking was a risk factor for non-participation in CRC screening.
The aim of this study was to evaluate the effectiveness of a large-scale screening programme for breast cancer (BC) in Turku, Finland. Incidence and incidence-based mortality (IBM) figures were compared with the areas applying different screening policies.
Deaths and person-time of women aged 40-84 were assessed for the period 1976-1986 (prescreening era) and the periods 1987-1997 and 1998-2009 (screening periods) using incidence and IBM by age at diagnosis and at death. There was a total of 40.7 million women-years, 83?497 invasive BCs obtained from the Finnish Cancer Registry; 17?508 BC deaths were linked with the data from Statistics Finland.
In Turku, a significant (> 20%) reduction in IBM occurred during 1987-2009 among women aged 60-74 years at diagnosis compared with Helsinki (IBMRR: 0.75, 95% CI: 0.57-1.00), and in women aged 75-84 years at death compared with the rest of Finland (IBMRR: 0.72, 95% CI: 0.53-0.96).
The wide mammography screening programme in Turku was effective in decreasing BC mortality in the elderly age groups. These results support the implementation of BC screening from age 50 up to 74 years.
Overdiagnosis is the most important adverse event of breast cancer screening with the estimates ranging from 0% to 40-50% depending on invitational age and methods. We updated the estimates of overdiagnosis in Helsinki service screening study in Finland by comparing the observed and expected cumulative incidence of all breast carcinomas and invasive breast carcinomas.
Women aged 50-59 years have been invited to Helsinki service screening since 1986. The incidence of breast carcinoma in the first invited birth cohorts born in 1935-1939 was compared with older, non-invited cohorts. The minimum follow-up time of the invitees after the last screening round was 14 years. Expected cumulative incidence rates were estimated with two alternative approaches.
For both any breast carcinoma and invasive breast carcinoma, the estimates of overdiagnosis varied from 5% (95% CI=-1, 11%) to 7% (95% CI=1, 13%) depending on the approach.
Our estimates of overdiagnosis are of the same magnitude than other plausible estimates in Europe. Both alternative approaches produced similar estimates for the expected cumulative incidence, which increased the confidence in the estimates of overdiagnosis.
This study aimed to provide a parametric mixture model for analysing relative survival and cure rates of patients with multiple cancers.
A new model was introduced by extending a parametric mixture model on relative survival of patients with a single cancer. The model was applied to empirical data on lung cancer as a first and second tumour after a first localised colorectal cancer.
Survival and cure from subsequent cancer are estimatable with the parametric mixture model on relative survival of patients with multiple cancers. Survival from lung cancer does not differ between the first and second tumour, but there is suggestive evidence that survival from second lung cancer is higher than that from the first lung cancer.
Relative survival analysis of patients with multiple cancers can be extended to incorporate cure rates and excess hazards related to the individual cancers. Prognostic factors can be included in the model.
In recent decades, management of prostate and breast cancer patients has changed considerably. The purpose of our study is to interpret patterns of prostate and breast cancer incidence and mortality in four Nordic countries across age groups and time periods. Prostate and breast cancer incidence and mortality data (1975-2013) were obtained from the NORDCAN database. Joinpoint regression models were used to identify changes in the trends. A more prominent increase in prostate than breast cancer incidence was observed. From the mid-1990s, mortality rates in patients below 75 years of age have decreased for both cancers in all four countries. The relative decline in breast cancer mortality from 1985-1989 to 2009-2013 were largest in women under 50 years of age, with reductions in mortality rates ranging from 38% in Finland to 55% in Denmark. In the age group 55-74 years, mortality rates for prostate cancer declined more than for breast cancer in all countries except Denmark, ranging from 14% in Denmark to 39% in Norway. The substantial decrease in breast cancer mortality in women below regular screening age and the reductions in mortality from both cancers in Denmark from the mid-1990s are consistent with beneficial contributions from improved treatment besides mammography screening and increased PSA testing. Alongside similar mortality decreases, the larger increases in prostate cancer incidence as compared to breast cancer indicate that a higher proportion of prostate cancer cases are overdiagnosed.
With the increasing numbers of patients with multiple primary cancers, survival from subsequent cancers is of growing interest. The majority of the analyses on the subject so far have, however, suffered from methodological difficulties.
A new model is now proposed for estimating relative survival of patients with subsequent primary cancer. The model is an extension to that proposed earlier by Estève et al. for estimating relative survival using individual patient data. The model is illustrated with real data on patients with one or two primary breast cancers and used in comparing the excess hazards between first and subsequent breast cancer.
For patients with multiple cancers, the traditional analysis of relative survival can be made cancer-specific. The excess hazards are different between the first and subsequent breast cancer: The excess hazard of the subsequent breast cancer tends to decrease with increasing age when compared to the corresponding hazard of the first breast cancer.
Relative survival of patients with subsequent cancer can be modelled facilitating studies on different hypothesis on the excess hazards of a first and subsequent cancer.
A survey of public knowledge about naevi, melanoma/ skin cancer and sunscreens was undertaken in Denmark at a time when no public awareness campaign had taken place. A total of 339 study subjects, aged 18-79 years, was recruited at our dermatology outpatient clinic, and data were collected by a self-administered questionnaire. The study group differed from the population in that females and the younger age groups were over-represented. A knowledge score was calculated. Males, the oldest age group and those with shortest school education were less knowledgeable. The study revealed several points of public uncertainty and ignorance with regard to early signs of melanoma and risk factors, which need to be emphasized in future public education.