Eero Pukkala

Socioeconomic position and risk of cervical cancer in the Nordic countries: Results from the Nordic Occupational Cancer Study

AbstractThe Nordic countries benefited from declines in cervical cancer incidence rates due to the implementation of screening programmes. However, it is unclear whether all social groups have equally benefited from these preventive services. We provide an assessment of the temporal trends in cervical cancer incidence by socioeconomic position (SEP) in Denmark, Norway, Finland and Sweden, using data from the Nordic Occupational Cancer Study. Truncated age‐standardized incidence rates and 95% confidence intervals (CI) of cervical cancer per 100,000 person‐years were computed for women aged 50–69 by SEP and country within the period 1961–2005. We used Poisson regression models to compute relative risks (RRs) and 95% CIs of cervical cancer across SEP, pooling data for the three most recent 5‐year periods (except for Denmark 1991–1995 and Norway 1991–2003). Throughout the study period, declines in the rates of cervical cancer were observed among all SEP groups. Lower SEP rates, which started from higher values, declined faster than those for higher SEP. At the conclusion of the study period, we still observed a social gradient, with higher rates seen in lower SEP women. Farmers had the lowest risk in all four countries. The RRs for lowest versus highest SEP ranged from 1.33 (95% CI 1.05–1.69) in Sweden to 1.76 (95% CI 1.13–2.85) in Denmark, with a pooled RR of 1.41 (95% CI 1.22–1.64). Lower SEP women still face the highest risks, indicating a need for continued efforts to provide equitable access to preventive services.

Long‐term risk of cancer among the first‐degree relatives of epithelial ovarian cancer patients: A cohort study with 48 years of follow up

AbstractIntroductionThe long‐term risk of cancer among first‐degree relatives of ovarian cancer patients, especially their offspring, is of apparent clinical importance. Risks caused by known inherited factors such as BRCA1 or BRCA2 pathogenic variants are well established, but these account for only about 15% of ovarian cancer cases. Less is known about the possible familial risks of sporadic ovarian cancers.Material and methodsUsing registry data, we conducted a retrospective cohort study with a total of 6501 first‐degree relatives of 559 epithelial ovarian cancer patients. We studied the occurrence of overall cancer and cancer in specific sites known or suspected to be associated with ovarian cancer (breast, cervix, colon, endometrium, lung and trachea, skin melanoma, ovary, pancreas, prostate, rectum, and stomach).ResultsThe overall number of cancers was not increased among the first‐degree relatives of epithelial ovarian cancer patients during the up to 48 years of follow up. Among female relatives, the standardized incidence ratio for ovarian cancer was 1.92 (95% CI 1.27–2.79), mostly explained by a 2.30‐fold (95% CI 1.46–3.45) risk among the patients' sisters. There was a decreasing trend in the standardized incidence ratio for ovarian cancer among patients' sisters by increasing age of the index patient.ConclusionsIn our study cohort, we did not observe an increase in the overall cancer risk among the first‐degree relatives of epithelial ovarian cancer patients in comparison with the general population. The risk for ovarian cancer, however, was increased. Current recommendations suggest prophylactic removal of the fallopian tubes and ovaries only with identified inherited risk factors. Our results emphasize the role of genetic counseling and testing, particularly in young ovarian cancer patients and their close female relatives.

Effectiveness of various human papillomavirus vaccination strategies: A community randomized trial in Finland

AbstractIntroductionWe conducted a community‐randomized trial (NCTBLINDED) in Finland to assess gender‐neutral and girls‐only vaccination strategies with the AS04‐adjuvanted human papillomavirus (HPV)‐16/18 (AS04‐HPV‐16/18)vaccine.MethodsGirls and boys (12−15 years) were invited. We randomized 33 communities (1:1:1 ratio): Arm A: 90% of randomly selected girls and boys received AS04‐HPV‐16/18 vaccine and 10% received hepatitis B vaccine (HBV); Arm B: 90% of randomly selected girls received AS04‐HPV‐16/18 vaccine, 10% of girls received HBV, and all boys received HBV; Arm C: all participants received HBV. Effectiveness measurements against prevalence of HPV‐16/18 cervical infection were estimated in girls at 18.5 years. The main measures were: (1) overall effectiveness comparing Arms A or B, regardless of vaccination status, vs Arm C; (2) total effectiveness comparing AS04‐HPV‐16/18 vaccinated girls in pooled Arms A/B vs Arm C; (3) indirect effectiveness (herd effect) comparing girls receiving HBV or unvaccinated in Arm A vs Arm C. Co‐primary objectives were overall effectiveness following gender‐neutral or girls‐only vaccination.ResultsOf 80,272 adolescents invited, 34,412 were enrolled. Overall effectiveness was 23.8% (95% confidence interval: −19.0, 51.1; P = 0.232) with gender‐neutral vaccination. Following girls‐only vaccination, overall effectiveness was 49.6% (20.1, 68.2; P = 0.004). Total effectiveness was over 90% regardless of vaccination strategy. No herd effect was found. Immunogenicity of the AS04‐HPV‐16/18 vaccine was high in both sexes.ConclusionsThis study illustrates the difficulty in conducting community randomized trials. It is not plausible that vaccinating boys would reduce overall effectiveness, and the apparent lack of herd effect was unexpected given findings from other studies. This analysis was likely confounded by several factors but confirms the vaccine's high total effectiveness as in clinical trials.