饮酒是公认的癌症危险因素。尽管对饮酒与癌症风险之间的关系进行了广泛的研究，但少量饮酒对癌症风险的影响仍然是一个争论的话题。为了促进这一讨论，我们进行了全面的系统回顾和荟萃分析。我们的系统回顾旨在调查不同饮酒水平与几种癌症类型风险之间的关联。我们重点使用 139 项队列研究的数据来分析前瞻性关联。其中，106项研究经过定量综合后纳入荟萃分析。我们的分析没有发现少量饮酒与全因癌症风险之间存在显着关联（相对风险[RR]=1.02；95%置信区间[CI] ] 0.99-1.04），但我们观察到剂量反应关系。少量饮酒与食道癌、结直肠癌和乳腺癌的较高风险显着相关。轻度至中度饮酒与食道癌、结直肠癌、喉癌和乳腺癌的风险升高相关。研究还发现，大量饮酒会增加患胃癌、肝癌、胰腺癌和前列腺癌的风险，从而增加几乎所有类型癌症的风险。此外，与男性相比，女性的癌症风险通常较低。我们的研究结果强调，癌症风险不仅限于大量饮酒，还包括少量饮酒。这些发现表明，不存在与癌症风险相关的安全饮酒水平。我们的结果强调了公共卫生干预措施解决饮酒问题以降低癌症风险的重要性。

Alcohol consumption is a well-established risk factor for cancer. Despite extensive research into the relationship between alcohol consumption and cancer risk, the effect of light alcohol consumption on cancer risk remains a topic of debate. To contribute to this discourse, we conducted a comprehensive systematic review and meta-analysis.Our systematic review aimed to investigate the associations between different levels of alcohol consumption and the risk of several cancer types. We focused on analyzing prospective associations using data from 139 cohort studies. Among them, 106 studies were included in the meta-analysis after a quantitative synthesis.Our analysis did not find a significant association between light alcohol consumption and all-cause cancer risk (relative risk [RR]=1.02; 95% confidence interval [CI] 0.99-1.04), but we observed a dose-response relationship. Light alcohol consumption was significantly associated with higher risks of esophageal, colorectal, and breast cancers. Light to moderate drinking was associated with elevated risks of esophageal, colorectal, laryngeal, and breast cancers. Heavy drinking was also found to contribute to the risk of stomach, liver, pancreas, and prostate cancers, thereby increasing the risk of almost all types of cancer. Additionally, women generally had lower cancer risks compared to men.Our findings highlight that cancer risks extend beyond heavy alcohol consumption to include light alcohol consumption as well. These findings suggest that there is no safe level of alcohol consumption associated with cancer risk. Our results underscore the importance of public health interventions addressing alcohol consumption to mitigate cancer risks.