观察到不同国家间癌症诊断平均年龄的差异。因此，我们旨在评估全球常见癌症的中位数诊断年龄在国际上的变化，同时调整人口年龄结构的差异。我们使用了国际癌症研究机构（IARC）的五大洲癌症发病情况（CI5）第十一卷数据库，该数据库包括来自65个国家的基于人口的癌症登记处于2008年至2012年之间的癌症诊断。我们计算了每个国家肺癌、结肠癌、乳腺癌和前列腺癌的原始的诊断中位年龄，然后使用间接标准化方法调整了年龄差异。我们发现，在标准化之后，诊断中位年龄变化了最多10年，通常是在低收入和中等收入国家中增加，在高收入国家中减少，这是由于相对年轻和年长的人口。在标准化后，肺癌的诊断年龄范围为12年（中位数年龄61岁的保加利亚 vs 73岁的巴林），结肠癌为12年（中位数年龄60岁的伊朗伊斯兰共和国 vs 72岁的秘鲁），女性乳腺癌为10年（中位数年龄49岁的阿尔及利亚、伊朗伊斯兰共和国、韩国 vs 59岁的美国和其他国家），前列腺癌为10年（中位数年龄65岁的美国、立陶宛 vs 75岁的菲律宾）。与高收入国家相比，低收入和中等收入国家的人群患结肠癌的年龄较小，但患前列腺癌的年龄较大（p值LMICs-vs-HICs< 0.001）。吸烟率较高的国家中，肺癌在男性和女性中的发病年龄较小（p值矫正< 0.001）。女性乳腺癌在东亚、中东和非洲地区被倾向于在较小的年龄被诊断。我们的研究结果表明，全球癌症诊断中位年龄的差异可能反映了人群水平的危险因素和癌症控制措施的差异，包括筛查。本文已经由美国政府雇员共同完成，并且在美国是公有领域的作品。

Differences in the average age at cancer diagnosis are observed across countries. We therefore aimed to assess international variation in the median age at diagnosis of common cancers worldwide, after adjusting for differences in population age structure. We used IARC's Cancer Incidence in Five Continents (CI5) Volume XI database, comprising cancer diagnoses between 2008 and 2012 from population-based cancer registries in 65 countries. We calculated crude median ages at diagnosis for lung, colon, breast and prostate cancers in each country, then adjusted for population age differences using indirect standardization. We showed that median ages at diagnosis changed by up to 10 years after standardization, typically increasing in low- and middle-income countries (LMICs) and decreasing in high-income countries (HICs), given relatively younger and older populations, respectively. After standardization, the range of ages at diagnosis was 12 years for lung cancer (median age 61-Bulgaria vs 73-Bahrain), 12 years for colon cancer (60-the Islamic Republic of Iran vs 72-Peru), 10 years for female breast cancer (49-Algeria, the Islamic Republic of Iran, Republic of Korea vs 59-USA and others) and 10 years for prostate cancer (65-USA, Lithuania vs 75-Philippines). Compared to HICs, populations in LMICs were diagnosed with colon cancer at younger ages but with prostate cancer at older ages (both pLMICS-vs-HICs  < 0.001). In countries with higher smoking prevalence, lung cancers were diagnosed at younger ages in both women and men (both pcorr  < 0.001). Female breast cancer tended to be diagnosed at younger ages in East Asia, the Middle East and Africa. Our findings suggest that the differences in median ages at cancer diagnosis worldwide likely reflect population-level variation in risk factors and cancer control measures, including screening.© 2023 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.