Sociodemographic factors, health indicators and lifestyle factors among participants in BreastScreen Norway 2006-2016 – a cohort profile

Purpose: To collect information on sociodemographic factors, health indicators, and lifestyle factors in women who attended the nationwide breast cancer-screening program, BreastScreen Norway, with the aim of investigating how these factors influence the risk of breast cancer, other cancer types, and cancer-related outcomes. Participants: The cohort data includes self-reported responses to questionnaires from 554,149 women aged 50- 69 years, who attended BreastScreen Norway during the data collection period, 2006-2016. Findings to date: Information about sociodemographic factors, health indicators, and lifestyle factors was collected for the current time and retrospectively back to birth. For the cohort, we have complete mammographic screening data, including information about 24,000 breast cancer cases and other cancer types from the Cancer Registry of Norway. These outcomes are aggregating continuously. Data from the cohort have been utilized in studies related to breast cancer and menopausal status. Future projects: Data will be utilized in studies related to tumour growth and risk of breast cancer as well as other cancer types, in addition to overall and cancer-specific death. Registration: The cohort profile is not registered in Clinical Trials

Subsite-Specific Dietary Risk Factors for Colorectal Cancer: A Review of Cohort Studies

Objective. A shift in the total incidence from left- to right-sided colon cancer has been reported and raises the question as to whether lifestyle risk factors are responsible for the changing subsite distribution of colon cancer. The present study provides a review of the subsite-specific risk estimates for the dietary components presently regarded as convincing or probable risk factors for colorectal cancer: red meat, processed meat, fiber, garlic, milk, calcium, and alcohol. Methods. Studies were identified by searching PubMed through October 8, 2012 and by reviewing reference lists. Thirty-two prospective cohort studies are included, and the estimates are compared by sex for each risk factor. Results. For alcohol, there seems to be a stronger association with rectal cancer than with colon cancer, and for meat a somewhat stronger association with distal colon and rectal cancer, relative to proximal colon cancer. For fiber, milk, and calcium, there were only minor differences in relative risk across subsites. No statement could be given regarding garlic. Overall, many of the subsite-specific risk estimates were nonsignificant, irrespective of exposure. Conclusion. For some dietary components the associations with risk of cancer of the rectum and distal colon appear stronger than for proximal colon, but not for all

Sunscreens With High Versus Low Sun Protection Factor and Cutaneous Squamous Cell Carcinoma Risk: A Population-Based Cohort Study

Evidence on sunscreen use and cutaneous squamous cell carcinoma (cSCC) risk is limited. Most studies have not taken sun protection factor (SPF) into consideration and used nonusers of sunscreen as the reference group. Nonusers are likely a priori at lower cSCC risk than users. No study has investigated the effect of high- versus low-SPF sunscreens on cSCC, appropriately adjusting for time-varying confounding. Using data from the Norwegian Women and Cancer Study (1991–2016), we investigated whether use of SPF ≥15 versus SPF <15 sunscreens reduces cSCC risk. We used a marginal structural Cox proportional hazards model with inverse probability of treatment and censoring weights to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During follow-up of 148,781 women (mean follow-up, 14.3 years), 653 women were diagnosed with cSCC. The effect on cSCC risk of sunscreens with SPF ≥15 versus SPF <15 was close to the null when used at any latitudes (HR = 1.02, 95% CI: 0.82, 1.27) and when used in lower-latitude settings (HR = 1.05, 95% CI: 0.84, 1.32). In conclusion, we found no indication that sunscreens with SPF ≥15 reduced Norwegian women’s cSCC risk more than sunscreens with SPF <15, suggesting that either there is no difference in their effects long-term or the difference is diluted by incorrect application

No association between physical activity and primary melanoma thickness in a cohort of Norwegian women

Knowledge about factors associated with melanoma thickness, the most important prognostic factor for localized primary melanoma survival,1 may help reduce the risk of melanoma deaths. Previously reported associations of melanoma thickness with pigmentary characteristics, number of naevi, diet quality and body mass index (BMI)2–4 may be explained by behavioural and biological mechanisms. Physical activity (PA) has been associated with improved outcomes for several cancers,5 but its relation with melanoma thickness and prognosis is unknown

Physical activity and cutaneous melanoma risk: A Norwegian population-based cohort study

Physical activity (PA) is an important factor in cancer prevention, but positive association between PA and risk of cutaneous melanoma found in recent studies may complicate this strategy. Ultraviolet radiation (UVR) exposure during outdoor PA is a plausible explanation for a positive association. We investigated the associations between PA, UVR and melanoma risk in the Norwegian Women and Cancer cohort. Overall PA was reported by 151,710 women, aged 30–75 at inclusion, using a validated 10-point-scale at enrolment and during follow-up, together with recent numbers of sunburns, indoor tanning sessions and weeks on sunbathing vacations. Seasonal outdoor walking and seasonal PAs were recorded in subsamples (n = 102,671 and n = 29,077, respectively). Logistic and Cox regression were used. Mean follow-up was 18.5 years, and 1565 invasive incident melanoma cases were diagnosed. Overall PA was inversely associated with sunburns, while positively associated with sunbathing vacations and indoor tanning. Overall PA was not associated with melanoma risk in all body sites combined (ptrend = 0.61), but reduced risk was found in upper limb melanomas (hazard ratio (HR) = 0.70, 95% confidence interval (CI) 0.51–0.96; high versus low PA). Non-significant reduced risks were found for seasonal outdoor walking >2 h/day versus 30–60 min/day (summer HR = 0.81, 95% CI 0.66–1.00; autumn HR = 0.74, 95%CI 0.55–1.01). Seasonal PAs were not associated with melanoma risk. In conclusion, we found positive associations between overall PA and sunbathing vacations and indoor tanning, and, unlike literature, inverse association between overall PA and sunburns. Our results do not support a positive association between PA and melanoma risk in Norwegian women

Clinical Suspicion Sensitivity of Nodular and Superficial Spreading Melanoma

In Norway, nodular melanoma is the most fatal melanoma subtype and superficial spreading melanoma the most common, indicating diagnostic challenges. The aim of this study was to assess the clinical suspicion sensitivity of nodular melanoma and superficial spreading melanoma, by diagnosing physician, using randomly selected 100 nodular melanomas and 100 superficial spreading melanomas from the Norwegian Melanoma Registry, diagnosed in 2014 to 2015. Information about suggested diagnoses and diagnosing physician was collected from pathology request forms. Suspicion sensitivity was defined as the proportion (%) of cases with “melanoma” as a suggested diagnosis, estimated with 95% confidence interval (95% CI). Most melanomas (74.5%) were diagnosed by non-dermatologists, with a suspicion sensitivity of 23% (95% CI 15–34) for nodular melanoma and 24% (95% CI 16–35) for superficial spreading melanoma. Corresponding estimates for dermatologists were 50% (95% CI 32–68) and 96% (95% CI 80–99), respectively (pinteraction=0.007). The low suspicion sensitivity for both subtypes among non-dermatologists calls for educational efforts

Ultraviolet radiation and skin cancer risk in offshore workers

Background: Excess skin cancer mortality and incidence have been reported among both land-based and offshore petroleum workers. The association between skin cancer and ultraviolet radiation (UVR) exposure has not been examined in these workers, although they have long off-duty periods and high average income that may allow travelling to sunny destinations. In addition, they have access to solariums free of charge on many accommodation platforms. Aims: To prospectively examine risk of incident cutaneous melanoma (CM) and non-melanoma skin cancer (NMSC), according to sun-tanning habits with adjustment for aromatic hydrocarbon exposure. Methods: A cohort of men employed offshore from 1965 to 1999 was linked through the Cancer Registry of Norway 1999–2012. Cox regression adapted to a stratified case-cohort design was used to estimate hazard ratios with 95% confidence intervals. Results: The cohort included 24917 men. During 13.5 years of follow-up, 112 CMs and 70 NMSCs occurred. A positive dose–response relationship was seen between sunburn frequency and risk of CM (Ptrend < 0.05) and NMSC (Ptrend < 0.01). Solarium use both before and after age 20 was related to increased risk of NMSC. Sunscreen use was associated with increased risk of NMSC (Ptrend < 0.001). Conclusions: UVR exposure seems to be a significant contributor to the elevated risk of skin cancer observed in North Sea offshore workers. The positive association between solarium use and NMSC risk adds to the growing body of literature on artificial UV devices as carcinogenic. This research has been published in Occupational Medicine. © 2017 Oxford University Pres