Long-term Ultraviolet Flux, Other Potential Risk Factors, and Skin Cancer Risk: A Cohort Study
Cancer Epidemiol Biomarkers Prev; 23(6); 1080–9. ©2014 AACR.
Shaowei Wu1,2, Jiali Han1,2,3,5, Francine Laden2,3,4, and Abrar A. Qureshi1,2,6 abrar_qureshi@brown.edu
1Department of Dermatology; 2Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School; Departments of 3Epidemiology and 4Environmental Health, Harvard School of Public Health, Boston, Massachusetts; 5Department of Epidemiology, Fairbanks School of Public Health, Simon Cancer Center, Indiana University, Indianapolis, Indiana; and 6Department of Dermatology, Warren Alpert Medical School, Brown University, Providence, Rhode Island
Background: Few prospective studies have examined the relationship between sun exposure, other potential risk factors, and risk of different skin cancers [including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma] simultaneously.
Methods: We evaluated the association between a number of potential risk factors and skin cancer risk in a cohort of 108,916 US women, the Nurses' Health Study II (1989–2009).
Results: During 2.05 million years of follow-up, we identified 6,955, 880, and 779 diagnoses of BCC, SCC, and melanoma, respectively.
Compared with participants in the lowest quintile of cumulative ultraviolet flux in adulthood, participants in the highest quintile had multivariable-adjusted relative risks (RR) of
- 2.35 (Ptrend < 0.0001) for BCC,
- 2.53 (Ptrend = 0.009) for SCC, and
- 0.68 (Ptrend = 0.38) for melanoma.
In contrast, the RRs were
- 1.68 (95% CI, 1.55–1.82) for BCC,
- 1.68 (95% CI, 1.34–2.11) for SCC, and
- 1.80 (95% CI, 1.42–2.28) for melanoma
for participants with ≥5 blistering sunburns when compared with participants without sunburn between ages 15 and 20 years. We found significant interactions between family history of melanoma, number of blistering sunburns between ages 15 and 20 years and BCC risk, and between sunburn reaction as a child/adolescent and SCC risk (all Pinteraction < 0.05).
Conclusion: In a cohort of U.S. women, we found that sun exposures in both early life and adulthood were predictive of BCC and SCC risks, whereas melanoma risk was predominantly associated with sun exposure in early life.
Impact: Our results may have potential implications for the prevention of skin cancers.
See also VitaminDWiki
- Melanoma might be suppressed by Vitamin D - many studies
- Vitamin D protects DNA against UV skin damage – 5 studies 2012-2013 the body can deal with UVB – provided it is not overloaded – e.g. sunburn
- Sunny side of the hill is the healthiest – 400BC
- Getting sunshine improves your health provided you do not sunburn - Grant Dec 2012
- Interview with transcript concerning UVA, UVB, and health – Grant Dec 2012
Effects of UVB radation, like that from radioactive materials, are NOT Linear
Well described in WikiPedia
Linear no-threshold modelLinear no-threshold model which has the following chart
Alternative assumptions for the extrapolation of the cancer risk vs. radiation dose to low-dose levels, given a known risk at a high dose:
supra-linearity,
linear
linear-quadratic,
hormesis