Moan Johan, Grigalavicius Mantas, Baturaite Zivile, Juzeniene Asta, Dahlback Arne
Department of Radiation Biology; Institute for Cancer Research; Oslo, Norway ; Department of Physics; University of Oslo; Oslo, Norway.
Department of Radiation Biology; Institute for Cancer Research; Oslo, Norway.
Dermatoendocrinol. 2013 Jan 1;5(1):186-91. doi: 10.4161/derm.23791.
Incidence rates of skin cancer increase with decreasing latitude in Norway, as in many other countries with white populations. The latitudinal trends of the incidence rates of skin cancer were studied and compared with data for vitamin D-induced by UV and for vitamin D intake. The north-south gradient for CMM incidence rates on sun exposed skin is much smaller than those for BCC and SCC, and that for BCC is smaller than that for SCC. This indicates that SCC and BCC are mainly due to solar UVB, while UVA may play a significant role for CMM and a smaller role for BCC, since the north-south gradient of annual UVB fluences is larger than that of UVA fluences. However, there is an inverse latitudinal gradient of skin cancer in central Europe. This is probably due to a gradient of skin color, since white skin is an important determinant of increased risk of skin cancer. The role of vitamin D for skin cancer risk is difficult to evaluate, since serum levels of 25-hydroxyvitamin D, as well as vitamin D intakes, are widely different from country to country. Still, epidemiological evidence indicates a role: for melanomas arising on non-sun exposed body localizations (uveal melanomas, melanomas arising in the vulva and perianal/anorectal regions) there appears to be no latitudinal gradient, or, a negative gradient, i.e., increasing rates with decreasing latitude as would be expected if UV-generated vitamin D plays a protective role. Both skin cancer risk and vitamin D photosynthesis decrease with increasing skin darkness.
与许多其他白人人口众多的国家一样，挪威皮肤癌的发病率随纬度降低而上升。对皮肤癌发病率的纬度趋势进行了研究，并与紫外线诱导的维生素D及维生素D摄入量的数据进行了比较。暴露于阳光下皮肤的黑色素瘤发病率的南北梯度远小于基底细胞癌和鳞状细胞癌，且基底细胞癌的梯度小于鳞状细胞癌。这表明鳞状细胞癌和基底细胞癌主要归因于太阳紫外线B，而紫外线A可能对黑色素瘤起重要作用，对基底细胞癌起较小作用，因为年度紫外线B通量的南北梯度大于紫外线A通量。然而，在中欧存在皮肤癌的反向纬度梯度。这可能是由于肤色梯度所致，因为白皮肤是皮肤癌风险增加的一个重要决定因素。维生素D对皮肤癌风险的作用难以评估，因为不同国家的25-羟基维生素D血清水平以及维生素D摄入量差异很大。尽管如此，流行病学证据表明其有一定作用：对于非阳光暴露身体部位出现的黑色素瘤（葡萄膜黑色素瘤、外阴及肛周/肛管直肠区域出现的黑色素瘤），似乎不存在纬度梯度，或者存在负梯度，即发病率随纬度降低而上升，这正如紫外线产生的维生素D起保护作用时所预期的那样。皮肤癌风险和维生素D光合作用均随皮肤颜色加深而降低。
