研究目的

定量评估2022年全球不同地区、国家因吸烟导致的癌症负担，为后续规划针对性的国家癌症控制措施提供数据支持和科学依据。

数据来源与方法

1. 2022年全球癌症发病和死亡终身风险测算：癌症发病和死亡数据来自GLOBOCAN 2022数据库，全因死亡和人口数据来自联合国世界人口展望。采用“多原发”调整法（Adjusted for Multiple Primaries，AMP）计算2022年全球185个国家所有癌症（不包括非黑色素瘤皮肤癌）以及30种癌症类型的发病及死亡的终身风险。

2. 2022年全球吸烟相关癌症人群归因负担估计：系统收集各个国家具有代表性的吸烟流行率数据。更新吸烟与相关癌症之间的相对风险（Risk Ratios, RRs）：（1）检索PubMed和Embase数据库发表的2020年12月31日前的、关于吸烟和特定癌症风险的荟萃分析和系统综述，提取文献中符合的原始研究信息；（2）检索最新、最全面综述发表年份至2020年12月31日期间，报告吸烟与癌症RRs的前瞻性队列研究；（3）采用纽卡斯尔-渥太华量表（Newcastle-Ottawa Scale, NOS）对文献进行质量评价，NOS评分≥7分的研究被纳入；（4）使用固定效应或随机效应模型估算合并的RRs，Q检验和统计量I²用于评估研究的异质性。根据以上数据采用滞后法估计2022年吸烟导致癌症的人群归因分值（Population Attributable Fractions, PAFs）。结合GLOBOCAN2022 数据库的发病、死亡数据，估计吸烟导致癌症的标化发病/死亡率（Age-standardized Incidence/Mortality Rates，ASIRs/ASMRs）。通过模拟干预分析，假设消除吸烟相关癌症的发病与死亡，运用与第一部分相同的终身风险计算方法，重新估算癌症的发病与死亡终身风险，并与第一部分未干预状态下的基线数据进行对比。

研究结果

1. 2022年从出生到死亡被诊断患癌（不包括非黑色素瘤皮肤癌）的全球终身风险约为22.70%（95%CI：22.67%-22.74%），即每4人中会有1人患癌；因癌症死亡的全球终身风险约为13.89%（95%CI：13.86%-13.92%），即每10人中会有1人因癌症死亡。全球不同地区以及各个国家之间的风险也存在着显著差异。总体来说，随着发展水平的提高，癌症发病和死亡风险也随之增加，在极高发展水平地区，终身患癌风险和癌症死亡风险分别达36.68%（95%CI：36.60%-36.76%）和20.44%（95%CI：20.38%-20.51%）。前列腺癌和乳腺癌分别是全球男性和女性终身发病风险最高的癌症类型，而肺癌和乳腺癌是男性和女性癌症终身死亡风险最高的癌症类型。尽管不同的癌症类型之间年龄条件风险存在很大差异，但癌症发病和死亡的剩余风险均会随着年龄的增长而降低。

2. 2022年，20岁及以上人群中，归因于吸烟的癌症发病数约为275万，死亡人数约为183万，分别占当年癌症病例总数的14.89%和癌症死亡病例总数的19.06%。男性受吸烟影响的程度明显高于女性。男性人群中有23.80%的癌症发病和28.35%的癌症死亡可归因于吸烟，而女性人群中这一比例相对较低，仅有5.64%的癌症发病和7.38%的癌症死亡由吸烟导致。在地理分布方面，发达地区因吸烟导致的PAFs以及归因发病/死亡率明显高于欠发达地区。不论性别，密克罗尼西亚/波利尼西亚地区吸烟相关癌症的PAFs最高。但在男性中，东欧地区的吸烟归因癌症ASIRs最高，密克罗尼西亚/波利尼西亚的吸烟归因癌症ASMRs最高；在女性中，北美地区的吸烟归因癌症ASIRs最高，密克罗尼西亚/波利尼西亚的吸烟归因癌症ASMRs最高。在所有吸烟相关癌症中，喉癌的PAFs最高，肺癌与膀胱癌次之。尽管如此，肺癌的吸烟归因发病与死亡率却是最为沉重，远超其他吸烟相关癌症类型。在模拟研究中，通过消除吸烟暴露可以减少男性19.97%的癌症发病风险和24.89%的癌症死亡风险，女性5.32%的癌症发病风险和7.11%的癌症死亡风险。

结论

1. 2022年无论男性还是女性，每4人中就有1人在其一生中会被诊断出癌症，每10人中有1人会因癌症死亡。在地理分布上，不同地区和国家的终身风险呈现出差异性，随着发展水平的提高，癌症发病和死亡风险也随之增加。癌症的发病和死亡的剩余风险随着年龄的增长而降低，且不同癌症类型呈现出不同的模式。这些结果为全球卫生系统规划以及不同国家/地区的针对性癌症控制干预措施提供了重要信息。

2. 2022年与吸烟相关的癌症负担依旧沉重，且吸烟归因的癌症负担呈现显著地理分布不均衡与癌谱特征分化。发达地区与欠发达地区在吸烟相关癌症发病和死亡风险上存在显著梯度；喉癌、肺癌、膀胱癌等受吸烟影响尤为突出，其中肺癌的吸烟归因疾病负担最为沉重。为有效遏制吸烟相关癌症的危害，亟需针对高负担地区与国家，制定兼具地域适配性与癌种特异性的控烟策略，推动全球癌症防控目标的实现。

Objectives

Quantitatively estimate the cancer burden caused by smoking in different regions and countries globally in 2022, providing data support and scientific basis for subsequent planning of targeted national cancer control measures.

Materials and methods

1. Calculation of the lifetime risk of developing and dying from cancer globally in 2022: The data on cancer incidence and mortality were sourced from the GLOBOCAN 2022 database, while the data on all-cause mortality and population were obtained from the United Nations World Population Prospects. The "Adjusted for Multiple Primaries (AMP)" method was employed to calculate the lifetime risk of developing and dying from all cancers (excluding non-melanoma skin cancer) and 30 types of cancer in 185 countries worldwide in 2022.

2. Estimation of the population-attributable burden of smoking-related cancers globally in 2022: Representative data on the prevalence of smoking in various countries were systematically collected. The relative risks (RRs) between smoking and related cancers were updated as follows: (1) Meta-analyses and systematic reviews on the risk of smoking and specific cancers published before December 31, 2020, in the PubMed and Embase databases were retrieved, and the original research information meeting the criteria was extracted from the literature; (2) Prospective cohort studies reporting the RRs between smoking and cancers from the year of the latest and most comprehensive review to December 31, 2020, were retrieved; (3) The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the literature, and studies with a NOS score of ≥ 7 were included; (4) Fixed-effect or random-effect models were used to estimate the pooled RRs, and the Q-test and the statistic I² were used to assess the heterogeneity of the studies. Based on the above data, the Population attributable fractions (PAFs) of cancers caused by smoking in 2022 were estimated using the lag method. Combining the incidence and mortality data from the GLOBOCAN 2022 database, the age-standardized incidence/mortality rates (ASIRs/ASMRs) of cancers caused by smoking were estimated. Through simulation intervention analysis, assuming the elimination of smoking, the lifetime risk of developing and dying from cancer was re-estimated using the same calculation method as in the first part, and compared with the baseline data in the non-intervention state of the first part.

Results

1. In 2022, the global lifetime risk of being diagnosed with cancer (excluding non-melanoma skin cancer) was approximately 22.70% (95% CI: 22.67%-22.74%), which means that about 1 in every 4 people would develop cancer. The global lifetime risk of dying from cancer was approximately 13.89% (95% CI: 13.86%-13.92%), equivalent to more than 1 in every 10 people dying from cancer. There were significant differences in risks among different regions globally and across various countries. Generally, with the improvement of the development level, the risks of cancer incidence and mortality increased. In regions with extremely high development levels, the risks of developing and dying from cancer reached 36.68% (95% CI: 36.60%-36.76%) and 20.44% (95% CI: 20.38%-20.51%), respectively. Prostate cancer and breast cancer were the cancer types with the highest lifetime risks of developing for men and women, respectively, while lung cancer and breast cancer were the cancer types with the highest lifetime risks of dying. Although there were significant differences in age-conditional risks among different cancer types, the lifetime risks of developing and dying from cancer decreased with increasing age.

2. In 2022, among adults aged 20 and above, the number of cancer incidences attributable to smoking was approximately 2.75 million, and the number of deaths was about 1.83 million, accounting for 14.89% of the total cancer cases and 19.06% of the total cancer deaths in that year, respectively. Men were significantly more affected by smoking than women. In the male population, 23.80% of cancer cases and 28.35% of cancer deaths were attributable to smoking, while in the female population, the proportions were relatively lower, with only 5.64% of cancer cases and 7.38% of cancer deaths caused by smoking. In terms of geographical distribution, the PAFs and attributable incidence/mortality rates of cancers caused by smoking in developed regions were significantly higher than those in underdeveloped regions. Regardless of gender, the PAFs of smoking-related cancers in the Micronesia/Polynesia region were the highest. Among men, the ASIRs of cancers attributable to smoking in the Eastern Europe region were the highest, and the ASMRs of cancers attributable to smoking in the Micronesia/Polynesia region were the highest. Among women, the ASIRs of cancers attributable to smoking in the North American region were the highest, and the ASMRs of cancers attributable to smoking in the Micronesia/Polynesia region were the highest. Among all smoking-related cancers, the PAFs of laryngeal cancer were the highest, followed by lung and bladder cancer. Nevertheless, the ASIRs/ASMRs of lung cancer attributable to smoking were the most burdensome, far exceeding those of other smoking-related cancer types. In the simulation study, eliminating smoking exposure could reduce the lifetime risk of developing cancer by 19.97% and the lifetime risk of dying from cancer by 24.89% in men, and by 5.32% and 7.11% in women.

Conclusions

1. In 2022, for both men and women, about 1 in every 4 people will be diagnosed with cancer in their lifetime, and about 1 in every 10 people will die from cancer. Geographically, there were differences in the lifetime risks among different regions and countries. With the improvement of the development level, the lifetime risks of developing and dying from cancer increased. The lifetime risks decreased with increasing age, and different cancer types showed different patterns. These results provide important information for planning the global health system and formulating targeted cancer control intervention measures in different countries/regions.

2. In 2022, the burden of smoking-related cancers remained heavy, and there were significant imbalances in the geographical distribution and differentiation in the cancer spectrum of the cancer burden attributable to smoking. There was a significant gradient in the risks of smoking-related cancer incidence and mortality between developed and underdeveloped regions. Laryngeal cancer, lung cancer, bladder cancer, etc., were particularly affected by smoking, and the disease burden of lung cancer attributable to smoking was the most severe. To effectively curb the harm of smoking-related cancers, it is urgent to formulate tobacco control strategies that are both regionally adaptable and cancer-specific for regions and countries with a high burden and to promote the achievement of global cancer prevention and control goals.