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Colorectal cancer (also known as colon cancer,rectal cancer or bowel cancer) is when cancerdevelops in the colon or rectum (parts of the large intestine).[1] It is due to the abnormal growth of cells that have the ability to invade or spread to other parts of the body.[2] Symptoms may include blood in the stool, a change in bowel movements, weight loss, and feeling tired all the time.[3]
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’’’大腸直腸癌’’’，又稱為’’’大腸癌’’’、’’’直腸癌’’’、或’’’腸癌’’’，為源自[[結腸]]或[[直腸]]（為[[大腸]]的一部份）的[[癌症]][1]。因為[[細胞]]不正常的生長，可能侵犯或[[遠端轉移|轉移]]至身體其他部[2]。症狀可能包括{{link-en|糞便中帶血|Lower_gastrointestinal_bleeding}}、排便習慣改變、[[體重減輕]]、以及疲倦感[3]。
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Most colorectal cancers are due to lifestyle factors and increasing age with only a small number of cases due to underlying genetic disorders.[4][5] Risk factors include: diet, obesity, smoking and not enoughphysical activity.[4][5] Dietary factors that increase the risk include: red and processed meat as well asalcohol.[4] Another risk factor is inflammatory bowel disease, which includes Crohn’s disease and ulcerative colitis.[4] Some of the inherited conditions that can cause colorectal cancer include: familial adenomatous polyposis and hereditary non-polyposis colon cancer; however, these represent less than 5% of cases.[4][5] It typically starts as a benign tumor which over time becomes cancerous.[4]
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大部份的大腸直腸癌起因為生活習慣及老化，少部分則因為遺傳疾病[4][5]。風險因子包括飲食、[[肥胖]]、[[吸菸|抽煙]]、[[體能鍛鍊|運動]]量不足[4][5]。增加罹癌風險的飲食包含[[紅肉]]或[[肉类食物#.E8.82.89.E7.B1.BB.E9.A3.9F.E7.89.A9.E7.9A.84.E5.8A.A0.E5.B7.A5.E5.92.8C.E8.82.89.E5.88.B6.E5.93.81|加工肉品]]、以及[[酒精]][4]。其他風險因子包含[[炎症性肠病|發炎性腸道疾病]]（分為[[克隆氏症]]和[[潰瘍性結腸炎|潰瘍性大腸炎]][4]）。某些可能造成大腸直腸癌的遺傳疾病為家族性結直腸瘜肉{{link-en|綜合症|Familial_adenomatous_polyposis}}和{{link-en|遺傳性非瘜肉症結直腸癌|Hereditary_nonpolyposis_colorectal_cancer}}，然而這些遺傳性疾病占大腸直腸癌所有病例中的比例不到5%[4][5]。大腸直腸癌通常源自[[良性腫瘤]]，然而隨時間進展變成[[惡性腫瘤]][4]。
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Bowel cancer may be diagnosed by biopsy during asigmoidoscopy or colonoscopy.[3] This is than followed by medical imaging to determine if the disease has spread.[1] Screening is effective at decreasing the chance of dying from colorectal cancer and is recommended starting at the age of 50 and continuing until the age of 75.[6]Aspirin and other non-steroidal anti-inflammatory drugs decrease the risk.[7][4] There general use is not recommended for this purpose; however, do to side effects.[8]
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腸癌的診斷可藉由{{link-en|乙狀結腸鏡|Sigmoidoscopy}}或{{link-en|大腸鏡|Colonoscopy}}檢查[[切片]][3]。接著由[[醫學影像|影像檢查]]查看是否轉移[1]。進行大腸直腸癌的{{link-en|篩檢|Cancer_screening}}可有效降低死亡率，目前建議50歲以上至75歲規則接受篩檢[6]。阿斯匹靈及其他[[非類固醇消炎止痛藥|非類固醇抗發炎藥物]]可降低罹癌風險[4][7]，但由於藥物的副作用，目前並不建議常規使用它們來預防大腸直腸癌的發生[8]。
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Treatments used for colorectal cancer may include some combination of surgery, radiation therapy, chemotherapy and targeted therapy.[1] Cancers that are confined within the wall of the colon may be curable with surgery while cancer that has spread widely are usually not curable with management focusing on improving quality of life and symptoms.[1] Five year survival rates in the United States are around 65%.[9] This; howeverm depends on how advanced the cancer is, whether or not all the cancer can be removed with surgery, and the person’s overall health.[3] Globally, colorectal cancer is the third most common type of cancer making up about 10% of all cases.[10] In 2012 it resulted in 1.4 million new cases and caused 694,000 deaths.[10] It is more common in developed countries were more than 65% of occur.[4] It is less common in women than men.[4]
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治療方式包括[[外科手術|手術]]、[[放射線治療]]、[[化學治療]]、及[[標靶治療]]或是合併使用以上療法[1]。侷限在腸壁的大腸直腸癌可能藉由手術治癒，然而當癌症已擴散或轉移時則不然，此時則以改善[[生活品質]]及症狀為治療目標[1]。在美國，{{link-en|五年存活率|Five year survival rates}}約65%[9]，然而主要取決於病人健康狀況與癌症分期，而分期又關係到是否能藉由手術移除[3]。整體來說，大腸直腸癌為第三常見癌症，約占10%[10]。在2012年，有140萬例新診斷的大腸直腸癌，且造成69.4萬人死亡[10]。大腸直腸癌在[[已開發國家]]較為常見，占全世界總案例數的65％。而在女性較男性少見[4]。