癌症有超過一百個種類，一般可依據癌細胞原發部位來分類，例如肺癌、乳癌等；另外能根據不同組織或細胞做以下分類：
癌症复发。癌症幸存者有癌症复发的风险。有些癌症比其他癌症更容易复发。请咨询医生如何降低癌症复发的风险。治疗后，医生可能会为您设计一份随访护理计划。该计划可能包括在治疗后的几个月和几年里定期进行扫描和检查，以寻找癌症复发的迹象。
In non-human beings, some types of transmissible most cancers have also been explained, whereby the most cancers spreads involving animals by transmission of your tumor cells them selves.
某些癌症的成長會受某些荷爾蒙的增加或減少而抑制。對荷爾蒙敏感的腫瘤常見的例子有乳癌和前列腺癌，減低或增加體內雌激素或雄激素往往可用來做為補充治療的一種。
Upper body X-ray displaying lung cancer while in the still left lung Most cancers are originally recognized either as a result of visual appearance of signals or indicators or via screening.[125] Neither of those causes a definitive prognosis, which necessitates the examination of a tissue sample by a pathologist.
筛查旨在确认尚未出现症状但已具有暗示特定癌症或癌症前期迹象的个体。如在筛查中发现异常，则应进行进一步检测以作出明确诊断，如果证明存在癌症，还应转诊进行治疗。
Qualified therapy is actually a sort of chemotherapy that targets specific molecular variances involving cancer and standard cells. The main targeted therapies blocked the estrogen receptor molecule, inhibiting the growth of breast cancer. Yet another prevalent illustration is The category of Bcr-Abl inhibitors, which happen to be applied to treat Continual myelogenous leukemia (CML).
疼痛。尽管不是所有癌症都会引起疼痛，但癌症或癌症治疗会引起疼痛。药物和其他方法可以有效地治疗癌性疼痛。
Minimized expression of DNA repair genes disrupts DNA mend. This is often shown within the figure with the 4th stage with the top. (Within the figure, pink wording indicates the central function of DNA injury and defects in DNA mend from the progression to cancer.) When DNA fix is deficient DNA injury remains in cells at a greater than normal degree (5th amount) and results in amplified frequencies of mutation and/or epimutation (sixth degree).
放射線治療（也稱放療、輻射療法）是使用輻射線殺死癌細胞，縮小腫瘤。放射治療可經由體外放射治療（英语：external beam radiotherapy）或體內近接放射治療。由於癌細胞的生長和分裂都較正常細胞快，藉由輻射線破壞細胞的遺傳物質，可阻止細胞生長或分裂，進而控制癌細胞的生長。不過放射治療的效果僅能侷限在接受照射的區域內。放射治療的目標則是要儘可能的破壞所有癌細胞，同時盡量減少對鄰近健康組織影響。雖然輻射線照射對癌細胞和正常細胞都會造成損傷，但大多數正常細胞可從放射治療的傷害中恢復。因此通常在臨床上，醫師與放射專家會小心計算需要的放射線劑量，同時放射治療也會分成許多次進行，讓健康的組織在每次輻射線照射的間隔中能有機會恢復。
The central role of DNA harm and epigenetic defects in DNA fix genes in carcinogenesis The classical look at of cancer is actually a set of ailments driven by progressive genetic abnormalities that include mutations in tumor-suppressor genes and oncogenes, As well as in chromosomal abnormalities. A task for epigenetic alterations was recognized inside the early 21st century.[103]
Human immunodeficiency virus (HIV) does in a roundabout way lead to cancer but it surely triggers immune deficiency which can Enlarge the chance as a result of other bacterial infections, at times nearly numerous thousandfold (in the situation of Kaposi's sarcoma). Importantly, vaccination against the hepatitis B virus along with the human papillomavirus have been proven to almost reduce the risk 癌症 of cancers due to these viruses in folks successfully vaccinated just before infection.
戒烟。如果您抽烟，请戒烟。如果您不吸烟，请勿开始抽烟。抽烟与多种癌症有关，而不仅仅是肺癌。立即停止吸烟会降低您将来患癌症的风险。
烟草使用、酒精消费、不健康饮食、缺乏身体活动和空气污染是癌症（以及其他非传染性疾病）的危险因素。