癌症是以异常细胞生长为特征的众多疾病的统称，这些异常细胞会失控地分裂，并能浸润和毁坏正常身体组织。癌症通常可以扩散到全身各处。
在正常细胞生长期间经常会发生基因突变。但细胞含有一种可识别何时发生错误并修复错误的机制。有时会漏掉某种错误。这种情况可能导致细胞癌变。
Some option therapies are investigated and demonstrated being ineffective but nonetheless go on to be promoted and promoted. Most cancers researcher Andrew J. Vickers stated, "The label 'unproven' is inappropriate for this sort of therapies; it really is time to assert that many alternative most cancers therapies are 'disproven'."[204]
Radiation to your breast cuts down the flexibility of that breast to generate milk and improves the possibility of mastitis. Also, when chemotherapy is supplied soon after beginning, many of the prescription drugs surface in breast milk, which could damage the baby.[271]
許多預防癌症的想法是根據流行病學的研究而來，分析病患的資料可發現生活方式或是接觸一些環境危險因子的確與特定癌症的發生機率相關。越來越多的證據顯示，根據流行病學研究所提出的建議改善，確實可以讓癌症發病率和死亡率降低。
這種擴散會使治療複雜化，因為轉移性癌症需要更密集和全身的方法。 癌細胞通常通過以下方式擴散：
改善乳腺癌控制，减少可避免的乳腺癌死亡，重点关注健康促进、及时诊断和获得医护，以便通过世卫组织全球乳腺癌倡议加快协调的实施工作；
This is predicated on the blamers' belief that the globe is fundamentally just and so any harmful illness, like most cancers, need to be a form of punishment for poor options, mainly because in a just globe, terrible items wouldn't come about to great people today.[246]
腫瘤較小且尚未擴散/轉移（癌細胞可被定位、手術移除，不需借助循環全身的化學藥物治療）
大约三分之一的癌症死亡源自烟草使用、高体重指数、酒精消费、水果和蔬菜摄入量低以及缺乏身体活动。此外，空气污染是肺癌的一个重要危险因素。
Complementary and option most cancers treatments are a diverse team of therapies, practices and items that are not Component of standard medication.[202] "Complementary drugs" refers to techniques and substances applied along with standard drugs, while "alternative medicine" refers to compounds utilised rather than regular drugs.[203] Most complementary and alternative medicines for cancer have not been researched or tested employing common methods including medical trials.
Individuals that report a higher quality of life tend to outlive lengthier.[209] People with reduce quality of life might be affected by despair and other complications and/or illness development that both of those impairs high-quality and amount of daily life. Furthermore, individuals with even worse prognoses can be depressed or report poorer quality of life given that they perceive that their ailment is likely to be lethal.[citation essential]
Deficient expression of DNA repair service proteins on account of an inherited mutation can boost 癌症 most cancers hazards. People having an inherited impairment in any of 34 DNA maintenance genes (see short article DNA restore-deficiency dysfunction) have improved cancer chance, with some defects making sure a 100% life time possibility of most cancers (e.
方法为基础，通过有针对性的国家支持、区域网络和全球行动，支持各国政府提高儿童癌症的存活率；