Cancrum
Cancrum 共同特徵: 1.失去正常細胞的功能 2.異常增殖 3.侵犯周圍組織 4.轉移
5-year survial rate Thyroid gland (94%), Testis (92%), Melanoma (81%), Urinary bladder (79%), Breast (78%), Hodgkin’s (76%), Prostate (75%), Cervical Cancer (67%), Colon Rectum (57%), Kidney (53%), Non-Hodgkin’s lymphoma (51%), Ovary (39%), Leukemia (36%), Multiple myeloma (26%), Brain (24%), Stomach (16%), Lung (13%), Esophagus (9%), Liver (5%), Pancreas (3%)
<癌症的病因> 一、 遺傳致癌基因 二、 長期接觸致癌物質 三、 長期暴露於紫外線或放射線的照射 四、 病毒感染 五、 治療藥品不良反應
Carcinogenesis
Carcinogenesis Carcinogens Oncogenes Proto-oncogenes
Oncogenesis癌之形成 1.Initiation(誘發期):傷及基因 Oncogen(致癌基因)活性增加,Tumor suppressor gene(腫瘤抑制基因)活性示弱的局面下,正常細胞受到外界的傷害,而傷及染色質之基因層次 外界傷害指的是Carcinogn(致癌因子) 過度之基因傷害會導致細胞之死亡 Mutagenic chemical(基因突變化學物)或稱Initiator(誘發劑)為直接能與細胞DNA相共價結合者,如Alkylating agents( 化物)-以抗癌藥物Cyclophosphamide
Initiator(誘發劑)可以不經由Promotor(促進劑)之煽動,即可致癌,Initiator兼具Promotor之作用 例如將Benzo(a)pyrene塗抹於老鼠皮膚,可以引起腫瘤之形成 一般而言Initiator使正常細胞變成潛在性癌細胞(Initiated cell),在Promotor之存在下,方才轉變成癌細胞(Tumor cell)
2.Promotion(促進期): 細胞開始異常分裂 (1)致癌因子(Chemicals,promotors癌促進劑)一再煽動之下,促進細胞之異常生長與分化,亦即由潛在性癌細胞轉化成癌細胞 (2)食品營養之因素(Nutritional factors)可能在此階段扮演重要角色 (3)Promotor之作用不是破壞細胞DNA,而可能是與細胞膜上之Protein kinase C(蛋白質激媒C)相結合,進而促進細胞內之種種生物活性信息傳遞及激化生長因子 (4)Promotor本身並非Mutagenic(基因突變因素)在無誘發期的狀況下,本身不致癌
3.Progression(惡化期): 具侵襲性 癌細胞變本加厲,轉化為更具侵襲性,迅速增殖蔓延、轉移視為惡性化
Tumor growth A.Rate : doubling time B.Responses to treatment Complete remission (CR) Partial remission (PR) relapse
Variuos Oncogenesis 各類癌之形成 Chemical Carcinogenesis化學性癌形成 (1)Initiators誘發劑 (2)Promotors促進劑 Radiation Carcinogenesis放射性癌形成 Viral oncogenesis病毒性癌形成 (1)RNA oncogenic virus(核醣核酸致癌病毒) Human T-cell leukemia virus type I,HTLV-I (第一型人體T細胞白血病病毒)
(2)DNA oncogenic virus(去氧核醣核酸致癌病毒) Human papilloma virus人體乳突病毒、Cervical CA(子宮頸癌)、Wart(疣) Epstein-Barr virus,E-B virus愛坡斯坦-巴爾病毒、Burkitt’s lymphoma(巴克氏淋巴瘤)、B-cell lymphomas in AIDS(B細胞淋巴瘤)、Hodgkin’s disease(何杰金氏病)、Nasopharyngeal CA(鼻咽癌) Hepatitis B virus,B型肝炎病毒,HBV、 Hepatoma肝癌
Radiation Carcinogenesis 放射性癌形成 過度之紫外線照射X光、鐳等放射性物質,容易導致皮膚癌(Melanoma, Squamous cell carcinoma, Basal cell carcinoma) 因為紫外線傷及DNA形成Pyrimidine dimer(嘧啶複合體) 1946年在日本廣島與長崎原子彈,白血病以AML及CML為主,平均之潛伏期為7年
鐘錶工廠夜光指針塗敷(鐳)之工人,容易得骨癌 放射性物質開採之礦工,其肺癌罹患率為對照組10X 蘇聯Chernoby(車諾比事件),核能發電廠之核能外洩,造成附近居民癌症罹患率增加 嬰兒孩童時期頭頸部接受放射治療者,長大後有9%會發生Thyroid CA 作用機轉:放射性物質可以傷害染色體(Chromosome breakage,translocation,Point mutations)促成癌細胞之形成
Viral Oncogenesis 病毒性癌形成 (1)RNA oncogenic virus(核醣核酸致癌病毒) HTLV-I (2)DNA oncogenic virus(去氧核醣核酸致癌病毒) 人體乳突病毒,HPV E-B virus Hepatitis B virus
Human Papilloma Virus, HPV 人體乳突狀瘤病毒 1.與下列腫瘤之發生有關: Benign squamous papillomas良性鱗狀乳突瘤 Squamous cell carcinoma of the cervix子宮頸癌 Genital warts性殖器疣,菜花 2.HPV屬於DNA virus
Epstein-Barr Virus,E-B Virus 愛坡斯坦-巴爾病毒 1.與下列4種腫瘤之發生有關 Burkitt’s lymphoma AIDS Hodgkin’s disease何杰金氏病 Nasopharyngeal cancer鼻咽癌 2.EBV侵犯B淋巴球
Hepatitis B Virus, HBV, B型肝炎病毒 1.HBV屬於DNA病毒 2.HBV感染後,肝細胞受阻,部分再生,再生之過程中,再受HBV、Aflatoxin(黃麴毒素)等之作用,而引起基因之變異
Immune 與Cancer行程的關係推論 免疫低下的人容易產生癌症 約5%的人會產生癌症其機率為常人的200X
Oncogenes致癌基因 Michael Bishop與Harold Varmus在1970年代,因為提出Protooncogene(原致癌基因)、Oncogene(致癌基因)之觀念,因而得到1989年諾貝爾醫學獎 Bishop之發現為Retroviral oncogene(反轉錄病毒致癌基因) Protooncogene(原致癌基因)是正常細胞之基因狀態,掌控整個細胞之生長與增殖,並不是預留以後轉化成Oncogene(致癌基因)
Virus病毒,例如Retrovirus(反轉錄病毒)之感染,會傷及細胞核,基因之基本結構DNA,使得原本正常之Protooncogene轉化成Oncogene Viral oncogene, V-oncs其排序與正常細胞DNA之排序相當接近,甚至幾乎相同,病毒感染後,伺機將其DNA傳輸結合至正常細胞之DNA Oncoprotein腫瘤蛋白:Oncogene指使製造之蛋白質(Encodeproteins)稱為Oncoprotein(腫瘤蛋白),包括Growth factors(生長因子)等自我調節素之刺激(Autocrine stimulation)
Activation of Oncogene 致癌基因之活化 由Protooncogene轉變成Oncogene: (1)基因之結構改變,生成Oncoprotein(腫瘤蛋白)導致不正常之功能 (2)改變調節基因,讓基因之表現過度(Overecpression)或異常之表現 由Protooncogene轉變成Oncogene之方式: (1)Point mutation(定點變異) (2)Chromosomal translocation染色體移位 (3)Gene amplification基因放大、膨脹
Clinical Features of Neoplasia 腫瘤之臨床特性 Tumor growth/proliferation腫瘤生長/增殖 Tumor angiogenesis腫瘤血管增生 Tumor progression腫瘤惡化 Tumor metastasis腫瘤 Cachexia惡性體質 Paraneoplastic Syndrome腫瘤外附加症,異性性激素分泌
Tumor Cell Growth 腫瘤細胞之生長 1.腫瘤之發生及擴張大致可以分成下列數期: (1)Neoplastic transformation正常細胞轉化成癌細胞 (2)Clonal expansion細胞族群之擴張 (3)Local invasion局部周遭之侵犯 (4)Distant spread,metastasis遠處播散,轉移
2.影響腫瘤生長之三大因素: (1)腫瘤細胞生長之動態 (2)腫瘤血管形成 (3)腫瘤惡化及多樣性
Tumor Angiogenesis 腫瘤血管形成 腫瘤之血管形成為腫瘤的特點之一,也是腫瘤賴以生存的重要因素
Tumor Progression and Heterogeneity 腫瘤細胞之促進與多樣性 產生異形腫瘤細胞(Tumor cell variants) Nonantigenic不具抗原性 Invasive更具侵襲性 Metastatic更具轉移性 Requiring fewer growth factors更少量之生長因子需求,即可助長生長
Cachexia腫瘤惡性體質 罹患腫瘤後,身體的養份被腫瘤剝奪不少,大量之能源耗損(high calorie expenditure)而成消瘦萎靡的狀態,此種Wasting syndrome(消耗症)稱為Cachexia(惡性體質) Cachexia之程度與腫瘤大小、是否造成重要器官之阻塞或壓迫有關 Cachexia(惡性體質)包括:消瘦、倦怠、噁心、食慾不振、進食減少、貧血
Cachexia之原因: (1)Anorexia(噁心),loss of appetite (2)High calorie expenditure能量消耗大 腫瘤之能量消耗增大,推論為Macrophage(巨噬細胞)分泌之物質: TNF-a IL-I:Interleukin I第一號白介質 Proteoglycan一種特殊之“醣化蛋白”曾被發現於腫瘤病人之尿液中,可以裂解肌肉組織
Staging TNM Clinical Classification-by American Joint Committee on Cancer (AJCC) 分類 符號 代表意義 腫 瘤 (tumor) T0 無原發腫瘤跡象 TIS 原位癌 T1 T2 T3 T4 腫瘤的大小及侵犯部位依序增加 TX 腫瘤無法評估
TNM分期系統 (續) 分類 符號 代表意義 淋 巴 結 (nodes) N0 N1 N2 N3 NX 轉 移 (metastasis) 局部淋巴結沒有明顯地不正常 N1 N2 N3 局部淋巴結不正常的程度明顯地增加(對許多原發部位而言,寫在N1下的文字a,例如N1a代表局部淋巴結無轉移,寫在N1下的b,例如N1b代表局部淋巴結疑似轉移或證明轉移) NX 臨床上無法評估局部淋巴結 轉 移 (metastasis) M0 沒有遠端轉移 M1 M2 M3 遠端轉移的程度上升,包括有遠端淋巴結轉移
T1 N0 T2 T3 T4 用TNM分期系統擬訂的治療計劃 治療計劃 符號 治療計劃 原發病變 , 摸不到淋巴結 T1 N0 控制早期的原發病變,放射線治療與手術切除有相同效果,至於選擇哪一種治療方法,則要考慮美容、功能及迅速等因素 T2 中等的向外生長的(exophytic)病變對於放射線治療的效果非常好,放射線治療失敗時,也可以用手術治療 T3 更惡化的病變(advanced lesions)可以採取放射線治療,但是若侵犯骨骼或軟骨時,用手術切除比較好。手術前宜先放射線治療 T4 對於很大的病變,最好合併使用多種方法治療,例如:放射線治療合併化學療法,或手術前先做放射線治療再做根治性手術。也有的病人手術前先做化學治療,使不能手術的病變(inoperable lesions)轉為可手術的(operable)病變,但是這種方法並不常用
分類 符號 治療計劃 原發病變,摸得到淋巴結 T1 N1 T2-3 N2-3 T4 N4 用TNM分期系統擬訂的治療計劃 (續) 有些病人,可以合併使用放射線治療及手術切除,即原發病變用放射線治療,例如,舌癌或頰癌(tongue carcinoma or bucal carcinoma)然後再做頸部分割手術(neck dissection) T2-3 N2-3 如果頸部淋巴結有轉移則需要施行手術切除,即把原發病變及頸部淋巴結一併切除(en bloc dissection) T4 N4 巨大的病變常常是不能手術的,可用姑息性放射線治療,化學治療
Laboratory Diagnosis of Cancer 癌症之實驗診斷 1.大體解剖,手術標本 2.顯微組織(Histology)細胞學(Cytology) Excision or biopsy Fine-needle aspiration Cytologic smear細胞學塗片檢查 Quick-frozen section, Frozen section冰凍緊急切片法
3.分子生物學 (Molecular biology) Immunocytochemistry-免疫細胞化學 Flow cytometry-DNA含量 DNA probe analysis-DNA片段分析 Monoclonal antibodies-單株抗體 Cytokeratin-細胞角質素 P53-P53核基因分析 Antigen receptor-抗原接受體基因
4.生化學分析(Biochemical assays) 腫瘤標記(Tumor markers): 腫瘤標記可以助於診斷及評估療效 CEA:Carcinoembryonic antigen a-FP:a-fetoprotein PSA:Prostate-specific antigen攝護腺特定抗原
5.內視鏡(Endoscopic examinations) 6.超音波(Echography) 7.X光(X-Ray) 8.電腦斷層造影 (CT San:Computerized tomography) 9.核磁共振 (MRI:Magnetic resonance imaging) 10.微生物學(Microbiologic study) Papillomavirus乳突瘤病毒,如應用於子宮頸癌
Characteristics of Malignant Cells Benign Encapsulated Noninvasive Highly differentiated Mitoses rare Slow growth Little or no anaplasia No metastases Malignant Nonencapsulated Invasive Poorly differentiated Mitoses relatively common Rapid growth Anaplastic to varying degrees Metastases
Survival Rates are influenced by: 1.the type of cancer 2.the stage of disease at diagnosis 3.the response to treatment
Factors influence “increase” of survival rate 1.Diagnosis tests improved 2.Early detection Early found 3.More treatment technology (eg: BMT; Bone marrow transplantation, BRM; Biological Response modifiers) 4.More Risk factors detected
Cancer Prevention & Risk Reduction A. Risk Factors 1.Tobacco 2.Alcohol – oral cavity, pharyns, larynx, esophagus, liver 3.Occupational Exposure 石綿、鉻、鎳、醚砷 – lung 芳香劑 – bladder 苯 – leukemia 聚乙烯 - liver
(續) 4.Viruses Epstein-Barr virus – nasopharyngeal cancer & Burkitt’s lymphoma Herpes – cervical cancer Human T-cell lymphotropic virus (HTLV-I) – children lymphoma Human immunodeficiency virus – AIDS Hepatitis – Hepatoma Human papillomavirus
(續) 5.Radiation – ionizing (X ray) - ultraviolet ray 6.Hormones – estrogen 7.Focds – fat - smoked
Nurse Role assessment, counseling, teaching, screening, planning, advocate
Levels of Prevention Primary prevention – reduce or eliminate risks of cancer Secondary prevention – early detection and screening, prompt treatment, and limited disability Tertiary prevention – rehabilitation, symptom control
Cancer Prevention Tips Don’t smoke or use tobacco in any form (including cigarettes, pipes, cigars, or chewing tobacco) Drink alcohol in moderation (one to two drinks per day) Know, and follow health and safety rules at your work place Avoid unnecessary x-ray exposure. If the x-ray is necessary, wear a shield to protect other parts of your body
(續) 5. Take estrogens only as long as necessary and be sure to discuss dosage with your physician 6. Avoid overexposure to the sun by using sunscreens (as SPF about 15) and wearing protective clothing. Be particularly cautious between 11 a.m. and 3 p.m. 7. Eat a diet high in fiber and low in fat (fruits, vegetables, and whole-grain breads and cereals) 8. Stress coping 9. Life style
Cancer Screening/ Detection/ and Diagnosis Cancer’s Seven Warning Signals (CAUTION) Change in bowel or bladder habits A sore that does not heal Unusual bleeding or discharge Thickening or lump in breast or elsewhere Indigestion or difficulty in swallowing Obvious change in wart or mole Nagging cough or hoarseness