Kerr Jacqueline, Anderson Cheryl, Lippman Scott M
Moores Cancer Center, University of California, La Jolla, San Diego, CA, USA; Department of Family Medicine and Public Health, University of California, La Jolla, San Diego, CA, USA.
Moores Cancer Center, University of California, La Jolla, San Diego, CA, USA; Department of Medicine, University of California, La Jolla, San Diego, CA, USA.
Lancet Oncol. 2017 Aug;18(8):e457-e471. doi: 10.1016/S1470-2045(17)30411-4. Epub 2017 Jul 26.
The lifestyle factors of physical activity, sedentary behaviour, and diet are increasingly being studied for their associations with cancer. Physical activity is inversely associated with and sedentary behaviour is positively (and independently) associated with an increased risk of more than ten types of cancer, including colorectal cancer (and advanced adenomas), endometrial cancers, and breast cancer. The most consistent dietary risk factor for premalignant and invasive breast cancer is alcohol, whether consumed during early or late adult life, even at low levels. Epidemiological studies show that the inclusion of wholegrain, fibre, fruits, and vegetables within diets are associated with reduced cancer risk, with diet during early life (age <8 years) having the strongest apparent association with cancer incidence. However, randomised controlled trials of diet-related factors have not yet shown any conclusive associations between diet and cancer incidence. Obesity is a key contributory factor associated with cancer risk and mortality, including in dose-response associations in endometrial and post-menopausal breast cancer, and in degree and duration of fatty liver disease-related hepatocellular carcinoma. Obesity produces an inflammatory state, characterised by macrophages clustered around enlarged hypertrophied, dead, and dying adipocytes, forming crown-like structures. Increased concentrations of aromatase and interleukin 6 in inflamed breast tissue and an increased number of macrophages, compared with healthy tissue, are also observed in women with normal body mass index, suggesting a metabolic obesity state. Emerging randomised controlled trials of physical activity and dietary factors and mechanistic studies of immunity, inflammation, extracellular matrix mechanics, epigenetic or transcriptional regulation, protein translation, circadian disruption, and interactions of the multibiome with lifestyle factors will be crucial to advance this field.
体育活动、久坐行为和饮食等生活方式因素与癌症的关联正越来越多地受到研究。体育活动与十多种癌症风险增加呈负相关，而久坐行为与这些癌症风险增加呈正相关（且独立相关），这些癌症包括结直肠癌（及晚期腺瘤）、子宫内膜癌和乳腺癌。对于癌前和浸润性乳腺癌，最一致的饮食风险因素是酒精，无论在成年早期还是晚期摄入，即使少量摄入也是如此。流行病学研究表明，饮食中包含全谷物、纤维、水果和蔬菜与降低癌症风险相关，其中生命早期（8岁以下）的饮食与癌症发病率的关联最为明显。然而，与饮食相关因素的随机对照试验尚未显示出饮食与癌症发病率之间有任何确凿的关联。肥胖是与癌症风险和死亡率相关的一个关键因素，包括在子宫内膜癌和绝经后乳腺癌的剂量反应关联中，以及在脂肪性肝病相关肝细胞癌的程度和持续时间方面。肥胖会产生一种炎症状态，其特征是巨噬细胞聚集在肿大、肥大、死亡和即将死亡的脂肪细胞周围，形成冠状结构。在体重指数正常的女性中也观察到，与健康组织相比，炎症乳腺组织中芳香化酶和白细胞介素6的浓度增加，巨噬细胞数量增多，这表明存在代谢性肥胖状态。新兴的体育活动和饮食因素随机对照试验，以及关于免疫、炎症、细胞外基质力学、表观遗传或转录调控、蛋白质翻译、昼夜节律紊乱以及微生物群与生活方式因素相互作用的机制研究，对于推动该领域的发展至关重要。
