Unit of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
GOS Institute of Child Health, University College London, London, UK.
Cancer Med. 2020 Aug;9(16):6062-6068. doi: 10.1002/cam4.3286. Epub 2020 Jul 6.
Some studies hypothesize that birth month-as a proxy of exposure to ultraviolet radiation in early infancy-is associated with increased risk of skin tumors.
We studied a national cohort of all 5 874 607 individuals born in Sweden to parents of Swedish or Nordic origin as a proxy for Caucasian origin, 1950 to 2014. The cohort was followed for incident skin tumors, including squamous cell carcinomas and melanomas but not basal cell carcinomas, through 2015 from birth up to age 65 for the oldest cohort. Cox regression estimated the association between month of birth and risk of skin tumors in models adjusted for sex, calendar period, and education. Crude observed to expected ratios were also calculated.
There were 33 914 cases of skin tumors, of these, 3025 were squamous cell cancer, 16 968 malignant melanoma and 8493 melanoma in situ/other and 5 428 squamous cell in situ/other in 192 840 593 person-years of follow-up. Observed to expected ratios by month of birth showed no association between month of birth and risk of skin tumors, and the same result was seen when Cox regression analysis was used. Subgroup analyses by sex, educational level, calendar period, or age at follow-up similarly showed no association.
This large register-based cohort study showed no evidence of a higher risk of skin tumors in those born during the spring. Thus, this study lends no support to the hypothesis that birth during spring is a major risk factor for later skin tumors.
一些研究假设出生月份（作为婴儿早期暴露于紫外线辐射的替代指标）与皮肤肿瘤风险增加有关。
我们研究了一个出生于瑞典的父母为瑞典或北欧血统的全国队列，共包括 5874607 人，这是白人血统的代表，出生于 1950 年至 2014 年。该队列从出生到 65 岁（对于最年长的队列），通过 2015 年追踪皮肤肿瘤（包括鳞状细胞癌和黑色素瘤，但不包括基底细胞癌）的发病情况。Cox 回归模型调整性别、日历时间和教育水平后，估计出生月份与皮肤肿瘤风险之间的关联。还计算了粗观察到的预期比值。
共发生 33914 例皮肤肿瘤，其中 3025 例为鳞状细胞癌，16968 例为恶性黑色素瘤，8493 例为原位黑色素瘤/其他，5428 例为原位鳞状细胞癌/其他，随访 192840593 人年。出生月份的观察到的预期比值显示，出生月份与皮肤肿瘤风险之间没有关联，Cox 回归分析也得出了同样的结果。按性别、教育水平、日历时间或随访时的年龄进行的亚组分析也显示没有关联。
这项大型基于登记的队列研究没有证据表明春季出生的人皮肤肿瘤风险较高。因此，这项研究不支持春季出生是皮肤肿瘤后期的主要危险因素的假说。
