每日一課100天已完結(jié)-04高級篇89講義

Today,cancercausesoneineverysevendeathsworldwide.Buthowdoescancerstart?Andwhatisbeingdonetocombatit?Ourbodiescontaintrillionsofhighlyspecializedcells,andeachcarriesgenesresponsibleforregulatingcellgrowthanddivision.Butwhenageneticchangedisruptsthisprocess,cellsbegintogrowanddivideuncontrollably,thereby ingcancer.Teticchangesthatcausecancerusuallyhappeninthreetypesofgenes:Proto-oncogenes,whichsignalacelltogrowanddivide;TumorSuppressorGenes,whichsignalacelltostopdividing;andDNARepairGenes,whichpreserveandmaintaingeneticcodes.Changesinthesegenesleadtoabnormalcellgrowth,resultinginmassesoftissuescalledTumors.Tumorsmaybebenign,meaningthattheyremaininonearea;ormalignant,whi eansthattheyarecapableofspreading.ThroughaprocesscalledMetastasis,amalignanttumor’scellswilleventuallybreakoff,travelthroughoutthebody,andbeginformingtumorsinotherregions.Whenthishappensthecancerhas emetastaticandismostdangerous.Thecauseofcancerisstillamystery.Inheritedtraitsmaybebehindsomeofteticchangesthatleadtotheformationofcancerouscells,andsomightenvironmentalexposures,suchasexcessiveradiationfromthesun,orchemicalsandcigarettesmoke.IntheUnitedStatestoday,roughly1/3ofallpeoplewilleventuallydevelopcancer.Oftheover100differenttypesofcancer,BreastCanceriscurrentlythemostprevalenttype,andLungCancercausesthemostButourabilitytofightcancerisimproving.Sincejustthe1990s,cancermortalityrateshavedroppedmorethan26percentintheUS,andmorethan2millionliveshavebeensaved.Astreatmentsandmethodsofearlydetectionimprove,anddoctors,scientists,andthepublicbetterunderstandcancer,hoperemainsinthefightagainstthedisease.cancer[‘k?ns?]n.cancerousk?ns?r?sadjcombatk?m?b?tvtkɑmb?tntrilliontr?lj?nndivisiond?’v??(?)nngenetic[d??’net?k]adj.的；遺傳的disrupt[d?s’r?pt]vt.擾亂；使中斷；使[,therebyeer’ba?adv[‘tumor[‘tju:m?(r)]n.腫瘤；腫塊suppressors?’pres?npreserve[pr?’z?v]vt.保存，保留code[k??d]n.代碼，；編tissue[‘t??u?]n.組織；benign[b?’na?n]adj.良性的malignant[m?’l?gn?ntadjmetastasis[m?'t?st?s?s]n.（瘤）轉(zhuǎn)metastaticmet?’st?t?kadj.（癌細胞的）轉(zhuǎn)移性的Inherited[?n’her?t?d]adj.遺傳的；通過繼承得到的trait[tre?t]n.特性，特征formation[f?r’me???n]n.形成excessive?k?ses?vadjradiation[re?d?’e??(?)n]n.輻射chemicalkem?k(?)l]n.化學(xué)制品adjbreast[brest]n.，胸[‘lungl??n.肺mortality[m?r’t?l?ti]n.數(shù)；率treatmenttri?tm(?)ntndetection[d?’tek?(?)n]n.察覺；探測oneineveryseventrillionsofgeneticchangeTumorSuppressorGene腫瘤抑制DNARepairGene遺傳物質(zhì)修復(fù)breakoff分離；脫離inheritedtrait遺傳性狀environmentalexposure環(huán)境excessiveradiation過量輻射BreastCancerthemostprevalenttypeLungCancer肺癌mortalityrate率earlydetection早期檢測thefightagainststh.與某事。在100多種不同類型的中，“”是目前最普遍的類型，“肺癌”導(dǎo)致的人數(shù)最Today,cancercausesoneineverysevendeathsoneineveryseven，意思是“每七個當中就有一個”，這句話是說：全世界每7例，就有1例是Buthowdoescancerstart?但是如何開始的Andwhatisbeingdonetocombatit?去與搏斗Ourbodiescontaintrillionsofhighlyspecializedcells,我們的身體含有數(shù)萬億個高度專業(yè)化的細andeachcarriesgenes而且每個細胞都攜帶著responsibleforregulatingcellgrowthandButwhenageneticchangedisruptsthisprocess,genetic來自名詞gene（、遺傳因子），作形容詞表示“的、遺傳的”；geneticchange字cellsbegintogrowanddivideuncontrollably,細胞開始不受控制地生長并 ingcancer.從而成為thereby相當于bythere或者bythat，字面意思是“通過那種方式”，強調(diào)“方式”。比如說：Regularexercisestrengthenstheheart,andtherebyreducestheriskofheartattack.（定期鍛煉therefore相當于forthere，自面意思是“為了那里、為了那一點”，強調(diào)“原因”。比如說：Regularexercisestrengthenstheheartandthereforereducestheriskofheartattack.（定期鍛煉另外，therebyhereby（通過這種方式、特此）。比如說：Wordsofmouthbeingnoguarantee,awrittenstatementisherebygiven.（空口無憑，立字為據(jù)。）或者說：Weherebyexpressourthanks.（我們特此致謝。）Teticchangesthatcausecancer導(dǎo)癥的遺傳變usuallyhappeninthreetypesofgenes:通常發(fā)生在三種類型的中型”，英語就叫做prototype；oncogene指的是“腫瘤、”。Proto-oncogenes的字面意思是“原始腫瘤”，因為“”本來就屬于“”，所以我們可以把proto-oncogene理解成“原癌”。這種的作用是什么呢？然后是which引導(dǎo)的定語從句：whichsignalacelltogrowand；tumor是名詞“腫瘤”；suppressor這個詞，來自suppress（抑制、），指的是“抑制物”。TumorSuppressorGenes，也就是“腫瘤抑制”。然后是一個which引導(dǎo)的定語從句，來解釋這whichsignalacelltostopdividing;它們指示細胞停止；andDNARepairGenes,以及“遺傳物質(zhì)修復(fù)whichpreserveandmaintaingeneticcodes.它們保留和遺傳。Teticchangesthatcausecancerusuallyhappeninthreetypesofgenes:導(dǎo)癥的遺傳Proto-oncogenes,whichsignalacelltogrowanddivide;“原癌”，它們指示細胞生長和分TumorSuppressorGenes,whichsignalacelltostopdividing;“腫瘤抑制”，它們指示細胞停andDNARepairGeneswhichpreserveandmaintaingeneticcodesChangesinthesegenes這些的變leadtoabnormalcellgrowth,導(dǎo)致異常的細胞生長，resultinginmassesoftissues結(jié)果會產(chǎn)生大量的組織calledTumors.稱作“腫瘤”Tumorsmaybebenign,腫瘤可能是良性的，meaningthattheyremaininonearea;ormalignant,whieansthattheyarecapableofspreading.這意味著它們能夠,amalignanttumor’scells一個的細willeventuallybreakoff,travelthroughoutthebody,andbeginformingtumorsinotherregions.Whenthishappensthecancer emetastatic就已經(jīng)轉(zhuǎn)移andismostdangerous.而且這是最的。Thecauseofcancerisstillamystery.導(dǎo)癥的原因目前仍然是一個謎Inheritedtraits遺傳的特性maybebehindsomeofteticchanges可能在遺傳變化的背后然后是一個that引導(dǎo)的定語從句，來修飾這種遺傳變化：thatleadtotheformationofcancerouscells,導(dǎo)細胞形成的（遺傳變化formation這個詞，來自form（形成），作名詞表示“形成、組成”。andsomightenvironmentalexposures,環(huán)境也可能如此，suchasexcessiveradiationfromthesun,例如來自的過度輻射，orchemicalsandcigarettesmoke.或者化學(xué)物質(zhì)和香煙煙霧。IntheUnitedStatestoday,在roughly1/3ofallpeoplewilleventuallydevelopcancer.大約1/3的人最終會患上roughly這個詞來自rough（粗略的、大致的），做副詞表示“大約、大致”。Oftheover100differenttypesofcancer,在100多種不同類型的中 的25%，不過發(fā)病的原因還不是特別清楚。而與之相對的肺癌，最大的病因就是因為長期大量吸Butourabilitytofightcancerisimproving.但我們抗擊的能力正在提高Sincejustthe1990s,2090cancermortalityrateshavedroppedmorethan26percentintheUS,在下降了26％以上，andmorethan2millionliveshavebeensaved200多萬人的生命得以挽救。Astreatmentsandmethodsofearlydetectionimprove,隨著治療和早期檢測的改善anddoctorsscientistsandthepublicbetterunderstandcancer,以及醫(yī)生、科學(xué)家和公眾對癌hoperemains希望仍然存在inthefightagainstthedisease.在與此類疾病作的過程中常生活入手，提高預(yù)防的意識，因為大約80%的和我們的環(huán)境和生活有關(guān)，尤其是戒Today,cancercausesoneineverysevendeathsworldwide.Buthowdoescancerstart?Andwhatisbeingdonetocombatit?Ourbodiescontaintrillionsofhighlyspecializedcells,andeachcarriesgenesresponsibleforregulatingcellgrowthanddivision.Butwhenageneticchangedisruptsthisprocess,cellsbegintogrowanddivideuncontrollably,thereby ingcancer.Teticchangesthatcausecancerusuallyhappeninthreetypesofgenes:Proto-oncogenes,whichsignalacelltogrowanddivide;TumorSuppressorGenes,whichsignalacelltostopdividing;andDNARepairGenes,whichpreserveandmaintaingeneticcodes.Changesinthesegenesleadtoabnormalcellgrowth,resultinginmassesoftissuescalledTumors.Tumorsmaybebenign,meaningthattheyremaininonearea;ormalignant,whi eansthattheyarecapableofspreading.ThroughaprocesscalledMetastasis,amalignanttumor’scellswilleventuallybreakoff,travelthroughoutthebody,andbeginformingtumorsinotherregions.Whenthishappensthecancerhas emetastaticandismostdangerous.Thecauseofcancerisstillamystery.Inheritedtraitsmaybebehindsomeofteticchangesthatleadtotheformationofcancerouscells,andsomightenvironmentalexposures,suchasexcessiveradiationfromthesun,orchemicalsandcigarettesmoke.IntheUnitedStatestoday,roughly1/3ofallpeoplewilleventuallydevelopcancer.Oftheover100differenttypesofcancer,BreastCanceriscurrentlythemostprevalenttype,andLungCancercausesthemostButourabilitytofightcancerisimproving.Sincejustthe1990s,cancermortalityrateshavedroppedmorethan26percentintheUS,andmorethan2millionliveshavebeensaved.Astreatmentsandmethodsofearlydetectionimprove,anddoctors,scientists,andthepublicbetterunderstandcancer,hoperemainsinthefightagainstthedisease.。在100多種不同類型的中，“”是目前最普遍的類型，“肺癌”導(dǎo)致的人數(shù)最cancer[‘k?ns?]n.也因此得名。cancer的形容詞，叫做：cancerousk?ns?r?batk?m?b?tvt.與……[‘kɑmb?bat是beat（打擊）的簡寫。combat說：Wemusttrytocombatpoverty.（須努力與貧困作。）betweenthetwosides.（雙方展開了激烈的戰(zhàn)斗。）trilliontr?lj?nn.billion1million1有一個就是trillion，本來是million的三次方（tri+million的簡寫），后來變成了“萬億”，也就是billion的1千倍。divisiond?’v??(?)nn這個詞來自divide（分開），作名詞可以表示“分配、分割”。比如說：thedivisionoflaborbetweenthesexes（男女分工），afairdivisionoftimeandresources（時間和資源的合理分配）說：salesdivision（銷售部門），technicaldivision（技術(shù)部門）等等。disruptd?s’r?ptvt.前綴dis-表示“分開”；后面的-rupt-是詞根“打破”，我們之前學(xué)過bankrupt（），字面意思就是“打破了經(jīng)濟狀況”。disrupt的字面意思，是“分開打破”，作動詞表示“擾亂、使中斷”。比如說：heavysnowdisruptedtravelintothecity.（大雪擾亂了入城交通系統(tǒng)的正常運行。）或者說：Hisspeechwasdisruptedbyagroupofers.（他的被一群者打斷了。）tumortju:m?(rn.這個詞前面的-tum-和thumb（大拇指）相關(guān)，大拇指相比一只手上的其它四根手指，肉，tum的本意也是“膨脹、鼓起、多出來”，而tumor這個詞，指的就是“多出來的一塊肉”，專指身體上的“腫瘤、腫塊”。比如說：Thesurgeonremovedthepaitent’stumor.（外科醫(yī)生摘除了的腫preservepr?’z?vvt.前綴好”，作動詞表示“保護、保留”。比如說：Weneedtopreservetheenvironment.（我們需要保護環(huán)境。）這個時候preserve更突出的是“提前應(yīng)對可能的”，而不是“壞事發(fā)生了再采取措施彌之前我們還學(xué)過一個詞，叫做rrve。這個詞的前綴rerrve。比如：I’dieorveableorwo（約一個人桌。）code[k??d]n.代碼，；編或者passcode，也就是“可以通過的詞或代碼”。“破譯”，英語就叫做breakacode或者crackacode。前綴ab-表示“離開”；后面的normal是形容詞“正常的”。abnormal的字面意思，是“離開正常的”，作形容詞表示“反常的、的”。比如說：Hisbehaviorwasabitabnormal.（他的行為有點tissuet??u?n.這個詞前面的-tis-和text（編織、編制）有關(guān)。tissue統(tǒng)”，作名詞可以表示內(nèi)的“組織”。比如說muscletissue（肌肉組織），braintissue（大腦組生活當中，tissue作名詞，也可以表示“”，因為是“木漿纖維編織的產(chǎn)物”。比如說aboxoftissue，就是“一盒”的意思。benignb?’na?nadj.這個詞前面的beni表示“好”，我們熟悉的benifit（-beni-好+-fic-做），字面意思是“做出來有好處”，也就是“利益”的意思。benign后面的-gn-是gene（）的簡寫，表示“”。這個時候我們就會發(fā)現(xiàn)，benign醫(yī)學(xué)術(shù)語。和benign（良性的）相對的，是：malignantm?’l?gn?ntadj.這個詞前面的mal(i)-是“壞的”，我們之前學(xué)過malice表示“”；中間的-gn-表示“”；最后是形容詞后綴-ant。malignant腫瘤”和“”，英語就分別叫做benigntumor和malignanttumor。這個詞前面的meta-和move（移動）相關(guān)，表示“改變位置”；中間的-st-是詞根“站立”。說：Patientswithkidneymetastasistypicallyhavecancerouscellgrowthinbothkidneys.（如果“轉(zhuǎn)移性腫瘤細胞”，英語就叫做Metastatictumorcells。Inherited?n’her?t?dadj.遺傳的；通過繼承得到的inherit?n’her?tvt.&vi前綴in-表示“注入”；后面的-her-是詞根“粘附、依附”，長相很像here（這里），也就是說“就粘在這里哪兒也不去”的意思。inherit的字面意思，是“依附于”，突出的是“通過得到”，作動詞表示“繼承”。比如說：Sheinheritedafortunefromherfather.（她從父親那里繼承了一大筆遺產(chǎn)。）或者說：Allhischildrenwillinheritequally.（他所有的將平分遺產(chǎn)。）heirerntraittre?tn.trait這個詞和drag（拉、拽）相關(guān)，作名詞指的“線條勾勒出來的輪廓”，后來延伸成了“特性、特做inheritedtrait。excessive?k?ses?vadj.過量的，過度的excess?k’sesn.過量；過度adj前綴ex-表示“向外”；后面的-cess-是詞根“走”。excess的字面意思，是“走出去”，專門指的是“超出了范圍”，作名詞表示“過量、過度”。比如說：Hestarteddrinkingtoexcessafterlosinghisjob.（他失業(yè)之后開始了過度飲酒。）或者說：Wecovercostsupto$600andthenyoupaytheexcess.（我們最多支付600的費用，超過的部分由你支付。）excess也可以作形容詞，表示“過量的、過度的”，這個時候和excessive沒有區(qū)別。比如說：Themajorreasonforexcessweightisexcesseating.（體重的主要原因是飲食過量。）我們也可以說成：Themajorreasonforexcessiveweightisexcessiveeating.radiationre?d?’e??(?)nn.輻射radiatere?d?e?tvt.&vi（火能發(fā)射出熱量。）或者說：Abeamoflightradiatedfromthelighthouse.（一束光從燈塔上射了.前綴pre-表示“在……之前”；中間的-val-是value（價值）的簡寫；最后是一個形容詞后綴-ent。prevalent示“盛行的、普遍的”。比如說：Thesediseasesaremoreprevalentamongyoungchildren.（這些疾病在幼兒中更普遍。）或者說：Thecolorisprevalentinsomecountries.（這種顏色在一些國家很lungl??n..這個詞來自treat（對待），作名詞可以表示“醫(yī)生對待的辦法”，也就是“治療、療法”。比如說：Theearlierthetreatmentisgiven,thebetterthepatient’schances.（越早接受治療，康待），或者說specialtreatment（特殊待遇）等等。detectiond?’tek?(?)nn.察覺；探測detectd?’tektvtn前綴de-是dis-的變體表示否定；中間的-tect-是詞根“覆蓋”，我們之前學(xué)過一個詞叫做deck（甲測”。比如說：Thetestsaredesignedtodetectthediseaseearly.（這些檢查旨在早期查出疾病。）或者說：Radarisusedtodetectobjectsintheairoratsea.（被用來探測空中或海上的detective[d?’tekt?v]n.adj.To'day,'cancer↗causesonein'every↗sevendeathsBut'how↗doescancers'tart↘?And'what↗isbeing'donetocom'bat'Our↗bodiescontain'trillions↗of'highly↗s'pecialized'cells,and'eachcarries'genesres'ponsiblefor'regulating'cell↗'growth↗anddi'vision↘.But'when↗age'neticchangedis'rupts↗this'process,‘cellsbeginto'grow↗anddi'vide'uncon'trollably,there'by↗be'coming↗'cancer↘.語音：Buttwhenage’neticc（全文標出）Tetic↗changesthat'causecancer/'usually↗happenin'three↗typesof語音：that弱讀+尾音t不讀（全文標出）；typesof連讀。'Proto-'oncogeneswhichsignalacelltogrowanddi'vide;語調(diào)：2處升調(diào)。'TumorSup'pressor'Genes,which'signal↗acelltos'top↗and'DNARe'pair'Genes,whichpre'serve↗andmain'tainge'netic'Changesinthesegenesleadto'abnormalcellgrowth,resultingin'masses↗of'tissuescalled'Tumors↘.Tumorsmaybebe∨nign,'meaning↗thattheyremaininone'area;'or↗ma'lignant,which'meansthattheyare'capable↗ofs'preading↘.Througha'process↗calledMe'tastasis,ama'lignant↗tumor’scellswille'ventuallybreak'off,'travelthroughoutthe'body↗,andbe'gin↗forming'tumorsin'other↗只讀一個Whenthis'happens/the'cancer↗ emetas'tatic/andis'most↗語音：cancerhasandismosttThe'cause↗ofcanceriss'till↗aIn'herited'traitsmaybebe'hindsomeoftetic'changesthat'lead↗tothefor'mationof'cancerous'cells,for'mationofcancerouscellssand'so↗mighten'viron'mentalex'posures,suchasex'cessive'radi'ationfromthe'sun,or'chemicalsand'cigarettes'moke↘.語音：suchasex’cessivecigarettetIntheU'nited↗S'tatesto'day,roughly'1/'3of'allpeoplewille'ventuallydevelopOfthe'over'100↗'different↗'types↗ofcancer,'Breast↗Canceris'currentlythemost'prevalent'type,and'Lung↗Cancercauses↗themost'deaths↘.mosttdeathsthsdz]（ths）But'our↗abilityto'fight↗cancerisSince'just↗the'19'90s,'cancer↗mor'talityrateshave'droppedmorethan'26per'centinthe'US,and'morethan'2million'liveshavebeen'saved↘.As'treatments/and'methodsof'early↗de'tectionim'prove,and'doctors↗,'scientists↗,andthe'publicbetterunder'stand↗cancer↗,'hope↗re'mainsinthe'fightagainst↗theTo'day,'cancer↗causesonein'every↗sevendeathsworld'wide↘.But'how↗doescancers'tart↘?And'what↗isbeing'donetocom'batit↘?'Our↗bodiescontain'trillions↗of'highly↗s'pecialized'cells,and'eachcarries'genesres'ponsiblefor'regulating'cell↗'growth↗anddi'vision↘.But'when↗age'neticchangedis'rupts↗this'process,‘cellsbeginto'grow↗anddi'vide'uncon'trollably,there'by↗be'coming↗'cancer↘.Tetic↗changesthat'causecancer/'usually↗happenin'three↗typesof'genes:'Proto-'oncogenes,which'signal↗acellto'grow↗anddi'vide;'TumorSup'pressor'Genes,which'signal↗acelltos'top↗di'viding;and'DNARe'pair'Genes,whichpre'serve↗andmain'tainge'netic'codes↘.'Changesinthesegenesleadto'abnormalcellgrowth,resultingin'masses↗of'tissuescalled'Tumors↘.Tumorsmaybebe∨nign,'meaning↗thattheyremaininone'area;'or↗ma'lignant,which'meansthattheyare'capable↗ofs'preading↘.Througha'process↗calledMe'tastasis,ama'lignant↗tumor’scellswille'ventuallybreak'off,'travelthroughoutthe'body↗,andbe'gin↗forming'tumorsin'other↗'regions↘.Whenthis'happens/the'cancer↗has emetas'tatic/andis'most↗The'cause↗ofcanceriss'till↗a'mystery↘.In'herited'traitsmaybebe'hindsomeofthege'netic'changesthat'lead↗tothefor'mationof'cancerous'cells,and'so↗mighten'viron'mentalex'posures,suchasex'cessive'radi'ationfromthe'sun,or'chemicalsand'cigarettes'moke↘.IntheU'nited↗S'tatesto'day,roughly'1/'3of'allpeoplewille'ventuallydevelop'cancer↘.Ofthe'over'100↗'different↗'types↗ofcancer,'Breast↗Canceris'currentlythemost'prevalent'type,and'Lung↗Cancercauses↗themost'deaths↘.But'our↗abilityto'fight↗cancerisim'proving↘.Since'just↗the'19'90s,'cancer↗mor'talityrateshave'droppedmorethan'26per'centinthe'US,and'morethan'2million'liveshavebeen'saved↘.As'treatments/and'methodsof'early↗de'tectionim'prove,and'doctors↗,'scientists↗,andthe'publicbetterunder'stand↗cancer↗,'hope↗re'mainsinthe'fightagainst↗thedis'ease↘. ()causesoneineverysevendeathsworldwide.Buthowdoescancerstart?Andwhatisbeingdoneto (抑制；與之作)it?Ourbodiescontain s(萬億)ofhighlyspecializedcells,andeachcarriesgenesresponsibleforregulatingcellgrowthanddivision( ).Butwhena (的)change thisprocess,cellsbegintogrowanddivide (控制不住地),thereby( cancer.Teticchangesthatcausecancerusuallyhappeninthreetypesofgenes:Proto-oncogenes( ),whichsignalacelltogrowanddivide;Tumor( )Suppressor GeneswhichsignalacelltostopdividingandDNARepairGenes 存；保留)andmaintaingenetic s().Changesinthesegenesleadto growth,resultinginmassesoftissues( )calledTumors.Tumorsmaybe meaningthattheyremaininonearea;ormalignant,whi eansthattheyarecapableofspreading.ThroughaprocesscalledMetastasis,a (惡性的)tumor’scellswilleventuallybreakoff,travelthroughoutthebody,andbeginformingtumorsinotherregions.Whenthishappensthecancerhas emetastatic( )andismostdangerous.Thecauseofcancerisstillamystery.Inherited( s(特征；特性)maybebehindsomeofteticchangesthatleadtothe (形成)ofcancerouscells,andsomightenvironmentalexposures,such (過量的；過度的)radiation )fromthesun,s(化學(xué)制品)andcigarettesmoke.IntheUnitedStatestoday,roughly1/3ofallpeoplewilleventuallydevelopcancer.Oftheover100differenttypesofcancer,Breast( )Canceriscurrentlythemost (盛行的)type,andLung( )Cancercausesthemostdeaths.Butourabilitytofightcancerisimproving.Sincejustthe1990s,cancer (數(shù))rateshavedroppedmorethan26percentintheUS,andmorethan2millionliveshavebeensaved. s(治療)andmethodsofearlydetection( )improve,anddoctors,scientists,andthepublicbetterunderstandcancer,hoperemainsinthefightagainstthedisease.cancer；combat與……戰(zhàn)斗；防止，抑 division分配，分開 genetic的；遺傳的 disrupt擾亂；使中斷；tumorsuppressorcode代碼，；編abnormal反常的；tissuebenignmalignantinheritedtraitexcessiveradiationchemicalbreast，胸lungmortality數(shù)；detection；探Today,cancercausesoneineverysevendeathsworldwide.Buthowdoescancerstart?Andwhatisbeingdonetocombatit?Ourbodiescontaintrillionsofhighlyspecializedcells,andeachcarriesgenesresponsibleforregulatingcellgrowthanddivision.Butwhenageneticchangedisruptsthisprocess,cellsbegintogrowanddivideuncontrollably,thereby ingcancer.Teticchangesthatcausecancerusuallyhappeninthreetypesofgenes:Proto-oncogenes,whichsignalacelltogrowanddivide;TumorSuppressorGenes,whichsignalacelltostopdividing;andDNARepairGenes,whichpreserveandmaintaingeneticcodes.Changesinthesegenesleadtoabnormalcellgrowth,resultinginmassesoftissuescalledTumors.Tumorsmaybebenign,meaningthattheyremaininonearea;ormalignant,whi eansthattheyarecapableofspreading.ThroughaprocesscalledMetastasis,amalignanttumor’scellswilleventuallybreakoff,travelthroughoutthebody,andbeginformingtumorsinotherregions.Whenthishappensthecancerhas emetastaticandis