Late effects of cancer at a young age: Registry-based studies of the health of cancer patients and their off-spring

Modern cancer therapy has resulted in increased survival among patients diagnosed with cancer at a young age. These improvements have led to the investigation of late morbidity and mortality associated with cancer and its treatments. The aim of this study was to evaluate late effects of cancer treated at a young age on the health of patients and their offspring. Utilising the nationwide population-based registries in Finland, we evaluated the risk of hypothyroidism and the probability of parenthood in cancer survivors as well as preterm birth, neonatal outcomes, and the risk of cancer among offspring of patients. The survivor cohort, identified from the Finnish Cancer Registry, consisted of 25,784 cancer patients diag-nosed between ages 0 and 34 in 1953–2004. By linkage to the population register, siblings of these patients were identified for comparison. The prevalence of hypothyroidism was higher among former childhood cancer (aged 0–16) patients than in the general population. The probability of parenthood following early onset cancer was overall significantly reduced compared to siblings. Offspring of female cancer survivors were at an increased risk of preterm birth, this risk being highest among patients diagnosed in childhood and early adulthood (aged 20–34 years). The offspring were not, however, at a significantly increased risk of neonatal death or stillbirth, though they were more likely to need monitoring or intensive care in the neonatal period. The risk of sporadic cancer among offspring of male and female cancer survivors was not elevated in comparison to the general population. The study showed that former cancer patients are at risk of certain adverse endocrine and reproductive health outcomes and should be followed for timely intervention. The offspring of cancer survivors do not appear to be at risk for adverse health outcomes.

The Effects of the Breast Cancer Mammography Screening Programme in Women aged 40 to 84 years in Turku, Finland (1987-2009)

The objective of this thesis was to evaluate whether a more extensive mammography screening programme (TurkuMSP) conducted by the city of Turku, had an effect on breast cancer (BC) incidence, survival, or mortality in years 1987 to 2009. Despite the fact that some studies have suggested a 20 percent reduction in BC mortality due to mammography screening, there are findings of harm to subjects, which are claimed to negate the benefits of screening. Thus, the aims of this study are most pertinent. A total of 176 908 screening examinations were performed in 36 000 women aged 40−74 during the years 1987−1997. In all, 685 primary BCs were found in the screened women, either screen-detected (n=531) or during screening intervals (n=154). Survival and BC recurrence rate of women with screen-detected BC was compared to 184 women with clinical BCs detected among individuals who did not take part in the screening. The invitation interval, which may influence the outcome, was studied in the age group 40 to 49 by inviting those born in even calendar years annually for mammography screening and those born in odd years, triennially. In addition, BC incidence and mortality in the total female population of Turku aged 40 to 84 years was compared with the respective figures of Helsinki and the rest of Finland, both during the pre-screening era (1976-1986) and the screening era (1987-2009). The study was designed to compare women by age groups, because women aged 50 to 59 were generally screened in all of Finland, whereas only in Turku women aged 40 to 49 and 60 to 74 were screened in addition. Data regarding cancer recurrence were derived from the Finnish Cancer Registry and data on deaths were collected from Statistics Finland. In survival analyses, screened women with invasive BC had a significantly higher survival rate than the women with clinical BC. The survival benefit started to appear already during the first follow-up years and was evident in all age groups. A marginal survival extension was also seen in screened women when BC had spread to ipsilateral axillary nodes already at diagnosis. Recurrence-free survival rate after BC treatment was significantly more favorable among the screened women compared with women with BC found clinically. The screening invitation interval did not significantly influence BC mortality in the subset of women aged 40 to 49 years. There were no consistent differences in the changes of BC incidence between Turku and the comparison areas during the screening era. In Turku, the BC mortality incidence in women aged 55−69 years was significantly lower during the screening era (from 1987 to 1997) compared with the pre-screening era, whereas no such change was found in the city of Helsinki or Tampere. When comparing the changes in incidence-based BC mortality during years 1987 to 2009 in Turku to those of Helsinki and the rest of Finland, there was a suggestion of more than 20 percent lower mortality in Turku among oldest age group (75-84 years) compared with the reference residential areas, but the differences were not consistently significant. Interpretation of the study results should be made with caution because there were no random control groups, and on the other hand, the number of cases in subgroups was fairly low to yield definite conclusions. Also due to the many statistical analyses, some of the findings may be due to chance. The results are, however, suggestive for a decrease of BC mortality in the elderly age groups due to wide mammography screening. This finding needs confirmation in further studies before recommending an expansion of mammography screening to women up to the age of 74 years