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• Perrier, Flavie; Ahimbisibwe, Ashley; Valberg, Morten; Green, Adele C.; Ghiasvand, Reza & Rueegg, Corina Silvia [Show all 10 contributors for this article] (2026). Exploring the paradoxical association of sun exposure and melanoma-specific mortality: The Norwegian Women and Health (NOWAC) Study. European Journal of Cancer. ISSN 0959-8049. 241. doi: 10.1016/j.ejca.2026.116787. Full text in Research Archive Show summary

  Background Paradoxically, some studies have found that high sun exposure, a well-known cause of melanoma, is associated with lower mortality among melanoma patients. In the Norwegian Women and Health cohort, we aimed to investigate associations between pre-diagnosis sun exposure and melanoma-specific and overall death, and the potential impact of unmeasured confounding and selection bias (conditioning on melanoma diagnosis) on any observed association between markers of high sun exposure and death. Methods We estimated hazard ratios (HRs) by Cox regression, observed covariate E-values, bias-adjusted HRs, and performed frailty analysis. Results Among 2234 patients with a first melanoma (311 deaths, 168 from melanoma; mean follow-up 8.0 years), we found significantly reduced risk of melanoma-specific (HR=0.41, 95% confidence interval (CI)=0.24–0.68) and overall (HR=0.49, 95%CI=0.33–0.72) death for ever- versus never-sunburn and a negative trend for cumulative number of sunburns (ptrend≤0.001), but not for sunbathing vacations (HR=0.69, 95%CI=0.37–1.27, melanoma-specific death). Neither the E-value approach nor bias-adjusted HRs suggested a large degree of unmeasured confounding for the sunburn-death association. However, frailty analysis suggested that selection may partly explain the association. Conclusion While sunburns appear protective, this association might reflect unobserved heterogeneity in melanoma risk and selection bias, and the associations may not represent a true causal effect.

• Perrier, Flavie; Ahimbisibwe, Ashley; Ghiasvand, Reza; Rueegg, Corina Silvia; Green, Adele C. & Borch, Kristin Benjaminsen [Show all 11 contributors for this article] (2025). Physical activity and mortality in melanoma patients within the Norwegian Women and Cancer study (NOWAC). International Journal of Cancer. ISSN 0020-7136. 157(5), p. 846–857. doi: 10.1002/ijc.35430. Full text in Research Archive Show summary

  Pre- and post-diagnosis physical activity (PA) have been associated with decreased mortality and recurrence in cancer patients, but its effect is under-studied in patients with cutaneous melanoma. We investigated the association between pre-diagnosis PA (most recent level and long-term trajectories) and melanoma-specific, other-cause, and overall mortality. Additionally, PA levels before and after a melanoma diagnosis were compared. We used information at recruitment and follow-ups in the prospective population-based Norwegian Women and Cancer cohort linked to the Cancer Registry of Norway. In total 1829 women were diagnosed with a first primary melanoma in 1991─2020, aged 34–93 years. We used Cox regression adjusted for age at diagnosis, education, smoking status, region of residence, melanoma thickness, and summary stage. Most recent pre-diagnosis PA was non-significantly associated with lower risk of melanoma-specific mortality (hazard ratio (HR) = 0.69, 95% confidence interval (CI) = 0.44─1.07, high vs. low) and significantly associated with other-cause (HR = 0.50, 95% CI = 0.28─0.89) and overall mortality (HR = 0.59, 95% CI = 0.42─0.82). Four pre-diagnosis PA trajectory classes were identified using a latent class mixed model (low, decreasing, moderate, and high). The PA trajectory classes were not significantly associated with melanoma-specific mortality. However, significantly decreased risks of other-cause (HR = 0.51, 95% CI = 0.30─0.87) and overall mortality (HR = 0.59, 95% CI = 0.42─0.84) were found in the moderate versus low class. Only 275 patients reported both pre- and post-diagnosis PA, and among those, 69% had a similar PA level before and after melanoma diagnosis. Our results suggest that pre-diagnosis PA reduces mortality in middle-aged Norwegian women with melanoma.

• Rao-Skirbekk, Shilpa; Zhang, Siqi; Ahimbisibwe, Ashley; Bekkevold, Terese; Ruscio, Francesco Di & Palomares, Alfonso Diz-Lois [Show all 10 contributors for this article] (2024). Short-term effects of temperature and air pollution on mortality in Norway: a nationwide cohort-based study. Frontiers in Environmental Health. ISSN 2813-558X. 3. doi: 10.3389/fenvh.2024.1419261. Full text in Research Archive
• Ahimbisibwe, Ashley; Valberg, Morten; Green, Adele C.; Ghiasvand, Reza; Rüegg, Corina Silvia & Rimal, Raju [Show all 10 contributors for this article] (2023). Nevus Count, Pigmentary Characteristics, and Melanoma-specific Mortality among Norwegian Women with Melanoma >1.0 mm Thick. Acta Dermato-Venereologica. ISSN 0001-5555. 103. doi: 10.2340/actadv.v103.4403. Full text in Research Archive Show summary

  Little is known about if and how nevi and pigmentation are associated with melanoma-specific mortality. However, increased melanoma awareness in people with lighter pigmentation and many nevi may result in earlier diagnosis of thinner less-lethal tumors. The aim of this study was to investigate associations between nevus count (asymmetrical > 5 mm and small symmetrical), pigmentary characteristics (hair colour, eye colour, skin colour, freckling, pigmentary score), and melanoma-specific mortality in subjects with melanomas > 1 mm. Data from the Norwegian Women and Cancer cohort, established in 1991, with complete follow-up of melanoma patients until 2018 through the Cancer Registry of Norway, were used to estimate hazard ratios with 95% confidence intervals for the associations between nevus count, pigmentary characteristics, and melanoma-specific mortality, stratified by tumor thickness using Cox regression. Estimated hazard ratios consistently indicated a higher risk of melanoma death for those with darker vs lighter pigmentary characteristics in patients with tumors > 1.0–2.0 mm and > 2.0 mm thick (e.g. pigmentary score hazard ratio 1.25, 95% confidence interval (0.74–2.13)). Among women with melanomas >1.0 mm thick, lighter pigmentation and asymmetrical nevi may be associated with lower melanoma-specific mortality, suggesting that factors that increase the risk of melanoma may also be associated with decreased risk of death from melanoma.

• Gåsnes, Siri Kristine; Oliveira, Victor Henrique Silva de; Gismervik, Kristine; Ahimbisibwe, Ashley; Tørud, Brit & Jensen, Britt Bang (2021). Mortality patterns during the freshwater production phase of salmonids in Norway. Journal of Fish Diseases. ISSN 0140-7775. 44(12), p. 2083–2096. doi: 10.1111/jfd.13522. Full text in Research Archive Show summary

  Mortality in Norwegian salmonid aquaculture has a major influence on fish welfare and represents economic losses for producers. We reviewed the estimated monthly mortality for freshwater farms with Atlantic salmon and rainbow trout between 2011 and 2019. We built a regression model for mortality which included the variables year, weight group, season, region and farm. Additionally, we distributed questionnaires to farmers to gather information regarding potential causes of mortalities. The analysis of data for Atlantic salmon showed that median monthly mortality increased from 0.15% in 2011 (interquartile range [IQR]: 0.06–0.39) to 0.25% (IQR: 0.1–0.67) in 2019. Mortality was highest in the North (0.27%, IQR: 0.11–0.72) and lowest in the Southwest region (0.16%, IQR: 0.07–0.4). The season with highest mortality was summer (0.24%, IQR: 0.1–0.64), while winter had the lowest (0.12%, IQR: 0.05–0.35). The smallest fish (3–12 g) showed highest mortality (0.31%, IQR: 0.14–0.69) compared to heavier fish. Results from the questionnaire showed that infectious or non-infectious diseases were the most commonly reported causes of mortality. The mortality patterns described in this study identifies several important risk factors. Highlighting causal links is an important step to reducing mortality and improving welfare in the freshwater production phase of salmonids in Norway.

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• Ahimbisibwe, Ashley; Perrier, Flavie; Valberg, Morten; Green, Adele C; Ghiasvand, Reza & Rueegg, Corina Silvia [Show all 10 contributors for this article] (2024). The counterintuitive association of sun exposure and melanoma-specific mortality in a cohort of Norwegian women. Full text in Research Archive
• Gåsnes, Siri Kristine Sollien; Oliveira, Victor Henrique Silva De; Gismervik, Kristine; Ahimbisibwe, Ashley; Tørud, Brit & Jensen, Britt Bang (2022). Dødelighet i settefiskfasen. Full text in Research Archive
• Gåsnes, Siri Kristine; Oliveira, Victor Henrique Silva de; Gismervik, Kristine; Ahimbisibwe, Ashley; Tørud, Brit & Jensen, Britt Bang (2021). Mortality during the freshwater production phase of salmonids in Norway. Full text in Research Archive

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