Impact of parity on the incidence of ovarian cancer subtypes: a population-based case-control study

Background Parity is known to have a protective effect as regards ovarian cancer, but its effect on the different histological subtypes of ovarian cancer is not well known. The impact of parity on the incidence of ovarian cancer subtypes was studied. Material and methods All Finnish women diagnosed 1994-2013 with ovarian cancer for the first time were included. Altogether, 5412 cases of ovarian cancer were identified in the Finnish Cancer Registry and stratified according to morphology into serous, mucinous, endometrioid, clear cell and others. Five age-matched controls were randomly selected for each case from the Finnish National Population Registry. Data on postmenopausal hormonal therapy were derived from the Registry of Prescribed drugs and used as cofactors. Multivariate conditional logistic regression for matched case-control data was used to examine the associations between parity parameters and ovarian cancer risk. Results Parous women had lower risk than nulliparous women in getting ovarian cancer of any type under age of 55 years. The odds ratio (OR) for serous cancer was 0.65 (95% confidence interval 0.56-0.77), for mucinous cancer 0.66 (0.52-0.83), for endometrioid cancer 0.52 (0.40-0.68), for clear-cell cancer 0.30 (0.19-0.46) and for other types 0.59 (0.43-0.80). In women aged 55 or older, the respective ORs were 0.86 (0.75-0.99), 0.78 (0.57-1.07), 0.61 (0.47-0.79), 0.44 (0.29-0.66) and 0.74 (0.57-0.95), adjusted for hormone therapy. Number of childbirths was associated with a trend toward reduction of risk, especially in serous and clear-cell cancers. Higher age at first birth was associated with higher risk of clear-cell cancer but otherwise age at first or last birth did not have an impact on the incidence of cancer subtypes. Conclusions Childbirths decrease the risk of all histologic subtypes of epithelial ovarian cancer in women in premenopausal and postmenopausal age.Peer reviewe

Epidemiology of Kaposi's sarcoma in the Nordic countries before the AIDS epidemic.

Based on data from the Nordic cancer registries, time-related trends in incidence of Kaposi's sarcoma (KS) were analysed in four ethnically similar populations before the AIDS epidemic. Data were available for different time periods in Denmark (1970-79), Sweden (1958-79), Finland (1953-79) and Norway (1953-79). KS was more common among men than among women aged 60 years or more, whereas no differences were observed for younger persons. The incidence of KS differed significantly between the four countries (P = 0.0001); Sweden having the highest and Denmark the lowest rates. Similarly, regional differences in incidence were observed within Sweden, rates being higher in the northern than in the southern areas (Ptrend = 0.002). Overall, in Nordic men the world standardised incidence rose from 0.5/1,000,000 person-years in the period 1953-57 to 1.8/1,000,000 person-years in 1978-79; in Nordic women, the corresponding rates were 0.2/1,000,000 person-years and 0.8/1,000,000 person-years respectively. The rate of increase was similar in Sweden, Finland and Norway (P = 0.14), whereas the short period of observation in Denmark precluded precise assessment of time-related incidence trends. These observations cannot be explained by registrational procedures or known risk factors for KS, and argue that environmental factors play an important role in the development of the disease

Temporal trends and spatial variation in stage distribution of non-small cell lung cancer in the Netherlands

Introduction To explore regional and temporal variation in clinical stage distribution of non-small cell lung cancer (NSCLC) and link the observations to the introduction of positron emission tomography (PET). Method All NSCLC patients diagnosed between 1989 and 2007 were selected from the Netherlands Cancer Registry (n=126,962). Maps of smoothed percentage distribution of clinical stage NSCLC were conducted by period of diagnosis. Join point regression analyses were performed to detect trends over time. Geographic variation in stage distribution was evaluated using spatial scan statistic. To evaluate the impact of PET in regions proportions of stage IV and Estimated Annual Percentage of Change (EAPC) were calculated for two regions in which PET was introduced between 1995 and 2000 and for two regions without a PET scanner during this period. Results The percentage of stage I and unknown decreased with 7.4% and 13.3% between 1989 and 2007, while the percentage of stage IV increased with 23.4%. The most rapid increase in stage I and IV were observed between 1997 and 2003. In two regions with a PET scan the proportion of stage IV increased annually with 10.3 and 8.5% compared to 5.4 and 6.4% in two regions without a PET scan. Conclusion The most rapid changes towards more stage IV NSCLC diagnoses correspond with the implementation of PET. However, trends were already visible before PET was introduced and regions without PET also showed considerable increases in stage IV diagnose, suggesting other factors or improvements in diagnostics also contributed substantially