Lung cancer

肺癌肺癌（lung cancer）发生于支气管粘膜上皮，亦称支气管癌。

近50年来许多国家都报道肺癌的发病率明显增高，在男性癌瘤病人中，肺癌已居首位。

肺癌的病因至今尚不完全明确，大量资料表明，长期大量吸纸烟是肺癌的一个重要致病因素。

多年吸纸烟每日40支以上者，肺鳞癌和未分化癌的发病率比不吸烟者高4〜10倍。

城市居民肺癌的发病率比农村高，这可能与大气污染和烟尘中含有致癌物质有关。

因此应该提倡不吸烟，并加强城市环境卫生工作。

【病理改变】肺癌起源于支气管粘膜上皮，局限于基底膜内者称为原位癌。

癌肿可向支气管腔内或/和临近的肺组织生长，并可通过淋巴、血行或经支气管转移扩散。

癌瘤生长速度和转移扩散的情况与癌瘤的组织学类型、分化程度等生物学特性有一定关系。

肺癌的分布情况，右肺多于左肺，上叶多于下叶。

从主支气管到细支气管均可发生癌肿。

起源于主支气管、肺叶支气管的肺癌，位置靠近肺门者，称为中央型肺癌；起源于肺段支气管以下的肺癌，位置在肺的周围部分者，称为周围性肺癌。

（一）分类临床上一般将肺癌分为下列四种类型：1 ．鳞形细胞癌（又称鳞癌）：在各种类型肺癌中最为常见，约占50％，患病年龄大多在50 岁以上，男性占多数。

大多起源于较大的支气管，常为中央型肺癌。

虽然鳞癌的分化程度有所不同，但一般生长发展速度比较缓慢，病程较长，对放射和化学疗法较敏感。

首先经淋巴转移，血行转移发生较晚。

2．未分化癌：发病率仅次于鳞癌，多见于男性，发病年龄较轻。

一般起源于较大支气管，居中央型肺癌。

根据组织细胞形态又可分为燕麦细胞、小圆细胞和大细胞等几种类型，其中以燕麦细胞最为常见。

未分化癌恶性度高，生长快，而且较早地出现淋巴和血行广泛转移，对放射和化学疗法较敏感，在各型肺癌中预后最差。

3．腺癌：起源于支气管粘膜上皮，少数起源于大支气管的粘液腺。

发病率比鳞癌和未分化癌低。

发病年龄较小，女性相对多见。

多数腺癌起源于较小的支气管，为周围型肺癌。

早期一般没有明显的临床症状，往往在胸部x 线检查时被发现，表现为圆形或椭圆形肿块，一般生长较慢但有时早期即发生血行转移，淋巴转移则发生较晚。

肺癌【范围】1．本指南规定了原发性肺癌（简称肺癌)的规范化诊治流程、诊断依据、诊断、鉴别诊断、治疗原则和治疗方案。

2．本指南适用于具备相应资质的市、县级常见肿瘤规范化诊疗试点医院及其医务人员对肺癌的诊断和治疗。

【术语和定义】下列术语和定义适用于本指南。

（一）肺癌(lung cancer)全称为原发性支气管肺癌，起源于支气管粘膜、腺体或肺泡上皮的肺部恶性肿瘤。

1．小细胞肺癌(small cell lung cancer，SCLC)一种特殊病理学类型的肺癌，有明显的远处转移倾向，预后较差，但多数病人对放化疗敏感。

2．非小细胞肺癌(non-small cell lung cancer，NSCLC)除小细胞肺癌以外其他病理学类型的肺癌，包括鳞状细胞癌、腺癌、大细胞癌等。

在生物学行为和临床病程方面具有一定差异。

（二）中心型肺癌(central lung cancer)生长在肺段支气管开口及以上的肺癌。

（三）周围型肺癌(peripheral lung cancer)生长在肺段支气管开口以远的肺癌。

（四）隐性肺癌(occult lung cancer)痰细胞学检查发现癌细胞，影像学和纤维支气管镜未发现病变的肺癌。

【缩略语】下列缩略语适用于本指南。

1．CEA：(carcinoembryonic antigen) 癌胚抗原。

2．NSE：（neurone specific enolase）神经特异性烯醇化酶。

3．CYFRA21-1：（cytokeratin fragment）細胞角蛋白片段19。

【规范化诊治流程】图1 肺癌规范化诊治流程【诊断依据】（一）高危人群有吸烟史和/或肺癌高危职业接触史(如石棉)，年龄在45岁以上者，是肺癌的高危人群。

（二）症状1．肺癌早期可无明显症状，当病情发展到一定程度时，常出现以下症状：(1) 刺激性干咳。

(2) 痰中带血或血痰。

(3) 胸痛。

(4) 发热。

(5) 气促。

当呼吸道症状超过2 周，经对症治疗不能缓解，尤其是痰中带血、刺激性干咳，或原有的呼吸道症状加重，要高度警惕肺癌存在的可能性。

肺癌相关英文词汇小结Chapter 64 Lung Can cer肺癌1. L ung can cer/L ung careino mas 肺癌12.malig nan t tran sformatio n恶性转化2. solid tumor originating from bronchial epithelial cells来源于支气管内皮细胞的实体肿瘤3. N on small cell lu ng can cer (NSCLC) 非小细胞肺癌4. small cell lu ng can cer (SCLC)小细胞肺癌13.overexpression of c-KIT in SCLC 小细胞肺癌细胞c-KIT过表达14. epidermal growth factor receptor (EGFR) in NSCLC非小细胞肺癌表皮生长因子受体15. affect disease prog no sis影响疾病预后5. n atural histories自然病程6. resp on ses to therapy治疗有效7. L ung carci no mas arise from n ormal bron chial epithelial cells that have acquired multiple genetic lesions and are capable of express ing a variety of phe no types 肺癌来源于支气管上皮细胞，这些细胞在后天产生了多种基因缺陷，并且表现出多种表型。

8. Activati on of proto on coge nes原癌基因激活9.i nhibiti on or mutati on of tumor suppressor genes抑癌基因抑制或突变10. product ion of autocri ne growth factors 自分泌产生生长因子11. cellular proliferati on 细胞增殖16. Cigarette smoking is responsible for 〜80% of lung cancer cases80%的肺癌是由于吸烟导致的17. exposure to respiratory carci nogens 暴露于呼吸道致癌物18. asbestos石棉19. Be nzene本20. genetic risk factors基因风险因素21. history of other lung diseases其他肺部疾病病史22. chronic obstructive pulmonary disease [COPD]24. The major cell types are SCLC (〜15%慢性阻塞性肺病23. asthma哮喘of all lung can cers）, ade no carci noma （〜50%）, squamous cell carcinoma （＜30%）, and large cell carci no ma.肺癌主要的类型包括小细胞肺癌（15%）, 腺癌（50%）,鳞癌（＜30%）及大细胞肺癌。

第一章花卉的分类第一节依生态习性和栽培应用特点的分类一、依生活型与生态习性的分类(一)露地花卉在自然条件下，在露地完成其整个生命周期的花卉。

1．一年生花卉：在一年内完成其生长、发育、开花、结实、直至死亡的生命周期。

即春天播种、夏秋开花、结实、后枯死。

故又称春播花卉。

如鸡冠花、波斯菊、百日草、万寿菊、茑萝、千日红、麦杆菊、一串红、半支莲、大花秋葵等。

2．二年生花卉：在二年内完成其生长、发育、开花、结实、直至死亡的生命周期。

即秋天播种、幼苗越冬、翌年春夏开花、结实、后枯死，故又称秋播花卉。

如金鱼草、三色堇、桂竹香、羽衣甘兰、金盏菊、雏菊、风铃草、须苞石竹、矮雪轮、矢车菊等。

3．多年生花卉：指这种花卉它的地下茎和根连年生长，地上部分多次开花、结实，即其个体寿命超过两年。

又因其地下部分的形态不同，可分为两类。

(1)宿根花卉：地下部分的形态正常，不发生变态现象；地上部分表现出一年生或多年生性状，如菊花、萱草、万年青、麦冬、枯梗、蓍草、鸢尾等。

(2)球根花卉：地下部分的根或茎发生变态，肥大呈球状或块状等，如唐菖蒲、郁金香、百合、大理花、美人蕉、风信子等。

又因其形态不同，可分为以下几类。

鳞茎类、球茎类、块茎类、根茎类、块根类。

4．水生花卉：生长在沼泽地或水中及耐水湿的花卉，如荷花、睡莲、萍蓬草、菖蒲、凤眼莲、黄菖蒲等。

5．岩生花卉：指耐旱性强，适合在岩石园栽培的花卉，如虎耳草、香堇、蓍草、景天类等。

(二)温室花卉原产热带、亚热带及南方温暖地区的花卉，在北方寒冷地区栽培必须在温室内培育，或冬季须在温室内保护越冬。

通常可分为下面几类。

1．一、二年生花卉：如瓜叶菊、蒲包花、彩叶草、报春花等。

2．宿根花卉：如非洲紫罗兰、鹤望兰、百子莲、非洲菊、花叶竹芋、蜘蛛抱蛋等。

3．球根花卉：如仙客来、香雪兰、马蹄莲、大岩桐、球根秋海棠、彩叶芋等。

4．兰科植物：依其生态习性不同，又可分为地生兰类：如春兰、蕙兰、建兰、墨兰、寒兰等；附生兰类：如卡特兰、蝴蝶兰、石斛、兜兰等。

What is lung cancer?Cancer of the lung, like all cancers, results from an abnormality in the body's basic unit of life, the cell.Normally, the body maintains a system of checks and balances on cell growth so that cells divide to produce new cells only when new cells are needed. Disruption of this system of checks and balances on cell growth results in an uncontrolled division and proliferation of cells that eventually forms a massknown as a tumor.Tumors can be benign or malignant; when we speak of "cancer," we are referring to those tumors that are malignant. Benign tumors usually can be removed and do not spread to other parts of the body. Malignant tumors, on the other hand, grow aggressively and invade other tissues of the body, allowing entry of tumor cells into the bloodstream or lymphatic system and then to other sites in the body. This process of spread is termed metastasis; the areas of tumor growth at these distant sites are called metastases. Since lung cancer tends to spread or metastasize very early after it forms, it is a very life-threatening cancer and one of the most difficult cancers to treat. While lung cancer can spread to any organ in the body, certain organs -- particularly the adrenal glands, liver, brain, and bone -- are the mostcommon sites for lung cancer metastasis.The lung also is a very common site for metastasis from tumors in other parts of the body. Tumor metastases are made up of the same type of cells as the original (primary) tumor. For example, if prostate cancer spreads via the bloodstream to the lungs, it is metastatic prostate cancer in the lung andis not lung cancer.Lung Cancer PictureThe principal function of the lungs is to exchange gases between the air we breathe and the blood. Through the lung, carbon dioxide is removed from the bloodstream and oxygen from inspired air enters the bloodstream. The right lung has three lobes, while the left lung is divided into two lobes and a small structure called the lingula that is the equivalent of the middle lobe on the right. The major airways entering the lungs are the bronchi, which arise from the trachea. The bronchi branch into progressively smaller airways called bronchioles that end in tiny sacs known as alveoli where gas exchange occurs.The lungs and chest wall are covered with a thin layer of tissue called the pleura.Lung cancers can arise in any part of the lung, but 90%-95% of cancers of the lung are thought to arise from the epithelial cells, the cells lining the larger and smaller airways (bronchi and bronchioles); for this reason, lung cancers are sometimes called bronchogenic cancers or bronchogenic carcinomas. (Carcinoma is another term for cancer.) Cancers also can arise from the pleura (called mesotheliomas) or rarely from supporting tissues within the lungs, for example, the blood vessels.How common is lung cancer?Lung cancer is the most common cause of death due to cancer in both men and women throughout the world. The American Cancer Society estimates that 219,440 new cases of lung cancer in the U.S. will be diagnosed and 159,390 deaths due to lung cancer will occur in 2009. According to the U.S. NationalCancer Institute, approximately one out of every 14 men and women in the U.S. will be diagnosed withcancer of the lung at some point in their lifetime.Lung cancer is predominantly a disease of the elderly; almost 70% of people diagnosed with lung cancer are over 65 years of age, while less than 3% of lung cancers occur in people under 45 years of age.Lung cancer was not common prior to the 1930s but increased dramatically over the following decades as tobacco smoking increased. In many developing countries, the incidence of lung cancer is beginning to fall following public education about the dangers of cigarette smoking and the introduction of effective smoking-cessation programs. Nevertheless, lung cancer remains among the most common types of cancers in both men and women worldwide. In the U.S., lung cancer has surpassed breast cancer as the most common cause of cancer-related deaths in women.Lung cancer is one of the most common cancers in the world. It is a leading cause of cancer death in men and women in the United States.What causes lung cancer?SmokingThe incidence of lung cancer is strongly correlated with cigarette smoking, with about 90% of lung cancers arising as a result of tobacco use. The risk of lung cancer increases with the number of cigarettes smoked and the time over which smoking has occurred; doctors refer to this risk in terms of pack-years of smoking history (the number of packs of cigarettes smoked per day multiplied by the number of years smoked). For example, a person who has smoked two packs of cigarettes per day for 10 years has a 20 pack-year smoking history. While the risk of lung cancer is increased with even a10-pack-year smoking history, those with 30-pack-year histories or more are considered to have the greatest risk for the development of lung cancer. Among those who smoke two or more packs ofcigarettes per day, one in seven will die of lung cancer.Pipe and cigar smoking also can cause lung cancer, although the risk is not as high as with cigarette smoking. Thus, while someone who smokes one pack of cigarettes per day has a risk for the development of lung cancer that is 25 times higher than a nonsmoker, pipe and cigar smokers have a risk of lung cancer that is about five times that of a nonsmoker.Tobacco smoke contains over 4,000 chemical compounds, many of which have been shown to be cancer-causing or carcinogenic. The two primary carcinogens in tobacco smoke are chemicals known as nitrosamines and polycyclic aromatic hydrocarbons. The risk of developing lung cancer decreases each year following smoking cessation as normal cells grow and replace damaged cells in the lung. In former smokers, the risk of developing lung cancer begins to approach that of a nonsmoker about 15 years aftercessation of smoking.Passive smokingPassive smoking or the inhalation of tobacco smoke by nonsmokers who share living or working quarters with smokers, also is an established risk factor for the development of lung cancer. Research has shown that nonsmokers who reside with a smoker have a 24% increase in risk for developing lung cancer whencompared with nonsmokers who do not reside with a smoker. An estimated 3,000 lung cancer deaths that occur each year in the U.S. are attributable to passive smoking.Asbestos fibersAsbestos fibers are silicate fibers that can persist for a lifetime in lung tissue following exposure to asbestos. The workplace is a common source of exposure to asbestos fibers, as asbestos was widely used in the past as both thermal and acoustic insulation. Today, asbestos use is limited or banned in many countries, including the U.S. Both lung cancer and mesothelioma (cancer of the pleura of the lung as well as of the lining of the abdominal cavity called the peritoneum) are associated with exposure to asbestos. Cigarette smoking drastically increases the chance of developing an asbestos-related lung cancer in workers exposed to asbestos. Asbestos workers who do not smoke have a fivefold greater risk of developing lung cancer than nonsmokers, but asbestos workers who smoke have a risk that is 50- to90-fold greater than nonsmokers.Radon gasRadon gas is a natural, chemically inert gas that is a natural decay product of uranium. Uranium decays to form products, including radon, that emit a type of ionizing radiation. Radon gas is a known cause of lung cancer, with an estimated 12% of lung-cancer deaths attributable to radon gas, or about 20,000 lung-cancer-related deaths annually in the U.S., making radon the second leading cause of lung cancer in the U.S. As with asbestos exposure, concomitant smoking greatly increases the risk of lung cancer with radon exposure. Radon gas can travel up through soil and enter homes through gaps in the foundation, pipes, drains, or other openings. The U.S. Environmental Protection Agency estimates that one out of every 15 homes in the U.S. contains dangerous levels of radon gas. Radon gas is invisible and odorless, but it can be detected with simple test kits.Familial predispositionWhile the majority of lung cancers are associated with tobacco smoking, the fact that not all smokers eventually develop lung cancer suggests that other factors, such as individual genetic susceptibility, may play a role in the causation of lung cancer. Numerous studies have shown that lung cancer is more likely to occur in both smoking and non-smoking relatives of those who have had lung cancer than in the general population. Recently, the largest genetic study of lung cancer ever conducted, involving over 10,000 people from 18 countries and led by the International Agency for Research on Cancer (IARC), identified a small region in the genome (DNA) that contains genes that appear to confer an increased susceptibility to lung cancer in smokers. The specific genes, located the q arm of chromosome 15, code for proteins that interact with nicotine and other tobacco toxins (nicotinic acetylcholine receptor genes).Lung diseasesThe presence of certain diseases of the lung, notably chronic obstructive pulmonary disease (COPD), is associated with an increased risk (four- to sixfold the risk of a nonsmoker) for the development of lung cancer even after the effects of concomitant cigarette smoking are excluded.Prior history of lung cancerSurvivors of lung cancer have a greater risk of developing a second lung cancer than the general population has of developing a first lung cancer. Survivors of non-small cell lung cancers (NSCLCs, see below) have an additive risk of 1%-2% per year for developing a second lung cancer. In survivors of small cell lung cancers (SCLCs, see below), the risk for development of second lung cancers approaches 6%per year.Air pollutionAir pollution from vehicles, industry, and power plants can raise the likelihood of developing lung cancer in exposed individuals. Up to 1% of lung cancer deaths are attributable to breathing polluted air, and experts believe that prolonged exposure to highly polluted air can carry a risk for the development of lungcancer similar to that of passive smoking.What are the types of lung cancer?Lung cancers, also known as bronchogenic carcinomas, are broadly classified into two types: small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC). This classification is based upon the microscopic appearance of the tumor cells themselves. These two types of cancers grow and spread in different ways and may have different treatment options, so a distinction between these two types isimportant.SCLC comprise about 20% of lung cancers and are the most aggressive and rapidly growing of all lung cancers. SCLC are strongly related to cigarette smoking, with only 1% of these tumors occurring in nonsmokers. SCLC metastasize rapidly to many sites within the body and are most often discovered after they have spread extensively. Referring to a specific cell appearance often seen when examining samples of SCLC under the microscope, these cancers are sometimes called oat cell carcinomas.NSCLC are the most common lung cancers, accounting for about 80% of all lung cancers. NSCLC can be divided into three main types that are named based upon the type of cells found in the tumor:Adenocarcinomas are the most commonly seen type of NSCLC in the U.S. and comprise up to 50% of NSCLC. While adenocarcinomas are associated with smoking, like other lung cancers, this type is observed as well in nonsmokers who develop lung cancer. Most adenocarcinomas arise in the outer, or peripheral, areas of the lungs. Bronchioloalveolar carcinoma is a subtype of adenocarcinoma that frequently develops at multiple sites in the lungs and spreadsalong the preexisting alveolar walls.Squamous cell carcinomas were formerly more common than adenocarcinomas; at present, they account for about 30% of NSCLC. Also known as epidermoid carcinomas, squamous cell cancers arise most frequently in the central chest area in the bronchi.Large cell carcinomas, sometimes referred to as undifferentiated carcinomas, are the leastcommon type of NSCLC.Mixtures of different types of NSCLC are also seen.Other types of cancers can arise in the lung; these types are much less common than NSCLC and SCLC and together comprise only 5%-10% of lung cancers:Bronchial carcinoids account for up to 5% of lung cancers. These tumors are generally small(3-4 cm or less) when diagnosed and occur most commonly in people under 40 years of age.Unrelated to cigarette smoking, carcinoid tumors can metastasize, and a small proportion ofthese tumors secrete hormone-like substances that may cause specific symptoms related to the hormone being produced. Carcinoids generally grow and spread more slowly than bronchogenic cancers, and many are detected early enough to be amenable to surgicalresection.Cancers of supporting lung tissue such as smooth muscle, blood vessels, or cells involved inthe immune response can rarely occur in the lung.As discussed previously, metastatic cancers from other primary tumors in the body are often found in the lung. Tumors from anywhere in the body may spread to the lungs either through the bloodstream, through the lymphatic system, or directly from nearby organs. Metastatic tumors are most often multiple, scattered throughout the lung, and concentrated in the peripheral rather than central areas of the lung.What are the signs and symptoms of lung cancer?Symptoms of lung cancer are varied depending upon where and how widespread the tumor is. Warning signs of lung cancer are not always present or easy to identify. A person with lung cancer may have thefollowing kinds of symptoms:No symptoms: In up to 25% of people who get lung cancer, the cancer is first discovered on a routine chest X-ray or CT scan as a solitary small mass sometimes called a coin lesion, since ona two-dimensional X-ray or CT scan, the round tumor looks like a coin. These patients withsmall, single masses often report no symptoms at the time the cancer is discovered.Symptoms related to the cancer: The growth of the cancer and invasion of lung tissues and surrounding tissue may interfere with breathing, leading to symptoms such as cough, shortness of breath, wheezing, chest pain, and coughing up blood (hemoptysis). If the cancer has invaded nerves, for example, it may cause shoulder pain that travels down the outside of the arm (calledPancoast's syndrome) or paralysis of the vocal cords leading to hoarseness. Invasion of theesophagus may lead to difficulty swallowing (dysphagia). If a large airway is obstructed, collapse of a portion of the lung may occur and cause infections (abscesses, pneumonia) in theobstructed area.Symptoms related to metastasis: Lung cancer that has spread to the bones may produceexcruciating pain at the sites of bone involvement. Cancer that has spread to the brain maycause a number of neurologic symptoms that may include blurred vision, headaches, seizures, or symptoms of stroke such as weakness or loss of sensation in parts of the body.Paraneoplastic symptoms: Lung cancers frequently are accompanied by symptoms that result from production of hormone-like substances by the tumor cells. These paraneoplastic syndromes occur most commonly with SCLC but may be seen with any tumor type. A common paraneoplastic syndrome associated with SCLC is the production of a hormone calledadrenocorticotrophic hormone (ACTH) by the cancer cells, leading to oversecretion of the hormone cortisol by the adrenal glands (Cushing's syndrome). The most frequent paraneoplastic syndrome seen with NSCLC is the production of a substance similar to parathyroid hormone, resulting in elevated levels of calcium in the bloodstream.Nonspecific symptoms: Nonspecific symptoms seen with many cancers, including lungcancers, include weight loss, weakness, and fatigue. Psychological symptoms such asdepression and mood changes are also common.When should one consult a doctor?One should consult a health-care provider if he or she develops the symptoms associated with lungcancer, in particular, if they havea new persistent cough or worsening of an existing chronic cough,blood in the sputum,persistent bronchitis or repeated respiratory infections,chest pain,unexplained weight loss and/or fatigue,breathing difficulties such as shortness of breath or wheezing.How is lung cancer diagnosed?Doctors use a wide range of diagnostic procedures and tests to diagnose lung cancer. These include...The history and physical examination may reveal the presence of symptoms or signs that are suspicious for lung cancer. In addition to asking about symptoms and risk factors for cancerdevelopment such as smoking, doctors may detect signs of breathing difficulties, airwayobstruction, or infections in the lungs. Cyanosis, a bluish color of the skin and the mucousmembranes due to insufficient oxygen in the blood, suggests compromised function due to chronic disease of the lung. Likewise, changes in the tissue of the nail beds, known as clubbing,also may indicate chronic lung disease.The chest X-ray is the most common first diagnostic step when any new symptoms of lungcancer are present. The chest X-ray procedure often involves a view from the back to the front of the chest as well as a view from the side. Like any X-ray procedure, chest X-rays expose the patient briefly to a small amount of radiation. Chest X-rays may reveal suspicious areas in the lungs but are unable to determine if these areas are cancerous. In particular, calcified nodulesin the lungs or benign tumors called hamartomas may be identified on a chest X-ray and mimiclung cancer.CT (computerized tomography, computerized axial tomography, or CAT) scans may be performed on the chest, abdomen, and/or brain to examine for both metastatic and lung tumors.A CT scan of the chest may be ordered when X-rays do not show an abnormality or do not yield sufficient information about the extent or location of a tumor. CT scans are X-ray procedures that combine multiple images with the aid of a computer to generate cross-sectional views of the body. The images are taken by a large donut-shaped X-ray machine at different angles around the body. One advantage of CT scans is that they are more sensitive than standard chestX-rays in the detection of lung nodules, that is, they will demonstrate more nodules. Sometimes intravenous contrast material is given prior to the scan to help delineate the organs and their positions. A CT scan exposes the patient to a minimal amount of radiation. The most common side effect is an adverse reaction to intravenous contrast material that may have been given prior to the procedure. This may result in itching, a rash, or hives that generally disappear rather quickly. Severe anaphylactic reactions (life-threatening allergic reactions with breathing difficulties) to contrast material are rare. CT scans of the abdomen may identify metastatic cancer in the liver or adrenal glands, and CT scans of the head may be ordered to reveal the presence and extent of metastatic cancer in the brain.A technique called a low-dose helical CT scan (or spiral CT scan) is sometimes used in screening for lung cancers. This procedure requires a special type of CT scanner and has been shown to be an effective tool for the identification of small lung cancers in smokers and former smokers. However, it has not yet been proven whether the use of this technique actually saves lives or lowers the risk of death from lung cancer. The heightened sensitivity of this method is actually one of the sources of its drawbacks, since lung nodules requiring further evaluation will be seen in approximately 20% of people with this technique. Of the nodules identified by low-dose helical screening CTs, 90% are not cancerous but require up to two years of costly and often uncomfortable follow-up and testing. Trials are underway to further determine the utility of spiral CT scans in screening for lung cancer.Magnetic resonance imaging (MRI) scans may be appropriate when precise detail about a tumor's location is required. The MRI technique uses magnetism, radio waves, and a computer to produce images of body structures. As with CT scanning, the patient is placed on a moveable bed which is inserted into the MRI scanner. There are no known side effects of MRI scanning, and there is no exposure to radiation. The image and resolution produced by MRI is quite detailed and can detect tiny changes of structures within the body. People with heart pacemakers, metal implants, artificial heart valves, and other surgically implanted structures cannot be scanned with an MRI because of the risk that the magnet may move the metal partsof these structures.Positron emission tomography (PET) scanning is a specialized imaging technique that uses short-lived radioactive drugs to produce three-dimensional colored images of those substances in the tissues within the body. While CT scans and MRI scans look at anatomical structures, PET scans measure metabolic activity and the function of tissues. PET scans can determinewhether a tumor tissue is actively growing and can aid in determining the type of cells within a particular tumor. In PET scanning, the patient receives a short half-lived radioactive drug, receiving approximately the amount of radiation exposure as two chest X-rays. The drug accumulates in certain tissues more than others, depending on the drug that is injected. The drug discharges particles known as positrons from whatever tissues take them up. As the positrons encounter electrons within the body, a reaction producing gamma rays occurs. A scanner records these gamma rays and maps the area where the radioactive drug has accumulated. For example, combining glucose (a common energy source in the body) with a radioactive substance will show where glucose is rapidly being used, for example, in a growingtumor.Bone scans are used to create images of bones on a computer screen or on film. Doctors may order a bone scan to determine whether a lung cancer has metastasized to the bones. In a bone scan, a small amount of radioactive material is injected into the bloodstream and collects in the bones, especially in abnormal areas such as those involved by metastatic tumors. The radioactive material is detected by a scanner, and the image of the bones is recorded on aspecial film for permanent viewing.Sputum cytology: The diagnosis of lung cancer always requires confirmation of malignant cells by a pathologist, even when symptoms and X-ray studies are suspicious for lung cancer. The simplest method to establish the diagnosis is the examination of sputum under a microscope. If a tumor is centrally located and has invaded the airways, this procedure, known as a sputumcytology examination, may allow visualization of tumor cells for diagnosis. This is the most risk-free and inexpensive tissue diagnostic procedure, but its value is limited since tumor cells will not always be present in sputum even if a cancer is present. Also, noncancerous cells may occasionally undergo changes in reaction to inflammation or injury that makes them look likecancer cells.Bronchoscopy: Examination of the airways by bronchoscopy (visualizing the airways through a thin, fiberoptic probe inserted through the nose or mouth) may reveal areas of tumor that can be sampled (biopsied) for diagnosis by a pathologist. A tumor in the central areas of the lung or arising from the larger airways is accessible to sampling using this technique. Bronchoscopy may be performed using a rigid or a flexible fiberoptic bronchoscope and can be performed in a same-day outpatient bronchoscopy suite, an operating room, or on a hospital ward. The procedure can be uncomfortable, and it requires sedation or anesthesia. While bronchoscopy is relatively safe, it must be carried out by a lung specialist (pulmonologist or surgeon) experienced in the procedure. When a tumor is visualized and adequately sampled, an accurate cancer diagnosis usually is possible. Some patients may cough up dark-brown blood for one to two days after the procedure. More serious but rare complications include a greater amount of bleeding, decreased levels of oxygen in the blood, and heart arrhythmias as well ascomplications from sedative medications and anesthesia.Needle biopsy: Fine needle aspiration (FNA) through the skin, most commonly performed with radiological imaging for guidance, may be useful in retrieving cells for diagnosis from tumor nodules in the lungs. Needle biopsies are particularly useful when the lung tumor is peripherallylocated in the lung and not accessible to sampling by bronchoscopy. A small amount of localanesthetic is given prior to insertion of a thin needle through the chest wall into the abnormalarea in the lung. Cells are suctioned into the syringe and are examined under the microscopefor tumor cells. This procedure is generally accurate when the tissue from the affected area isadequately sampled, but in some cases, adjacent or uninvolved areas of the lung may be mistakenly sampled. A small risk (3%-5%) of an air leak from the lungs (called a pneumothorax,which can easily be treated) accompanies the procedure.Thoracentesis: Sometimes lung cancers involve the lining tissue of the lungs (pleura) and lead to an accumulation of fluid in the space between the lungs and chest wall (called a pleuraleffusion). Aspiration of a sample of this fluid with a thin needle (thoracentesis) may reveal the cancer cells and establish the diagnosis. As with the needle biopsy, a small risk of apneumothorax is associated with this procedure.Major surgical procedures: If none of the aforementioned methods yields a diagnosis, surgical methods must be employed to obtain tumor tissue for diagnosis. These can include mediastinoscopy (examining the chest cavity between the lungs through a surgically inserted probe with biopsy of tumor masses or lymph nodes that may contain metastases) orthoracotomy (surgical opening of the chest wall for removal or biopsy of a tumor). With a thoracotomy, it is rare to be able to completely remove a lung cancer, and both mediastinoscopy and thoracotomy carry the risks of major surgical procedures (complications such as bleeding,infection, and risks from anesthesia and medications). These procedures are performed in anoperating room, and the patient must be hospitalized.Blood tests: While routine blood tests alone cannot diagnose lung cancer, they may revealbiochemical or metabolic abnormalities in the body that accompany cancer. For example, elevated levels of calcium or of the enzyme alkaline phosphatase may accompany cancer that is metastatic to the bones. Likewise, elevated levels of certain enzymes normally present within liver cells, including aspartate aminotransferase (AST or SGOT) and alanine aminotransferase(ALT or SGPT), signal liver damage, possibly through the presence of tumor metastatic to the liver. One current focus of research in the area of lung cancer is the development of a blood testto aid in the diagnosis of lung cancer. Researchers have preliminary data that has identifiedspecific proteins, or biomarkers, that are in the blood and may signal that lung cancer is present in someone with a suspicious area seen on a chest X-ray or other imaging study.What is staging of lung cancer?The stage of a cancer is a measure of the extent to which a cancer has spread in the body. Staging involves evaluation of a cancer's size and its penetration into surrounding tissue as well as the presence or absence of metastases in the lymph nodes or other organs. Staging is important for determining how a particular cancer should be treated, since lung-cancer therapies are geared toward specific stages.Staging of a cancer also is critical in estimating the prognosis of a given patient, with higher-stage cancers generally having a worse prognosis than lower-stage cancers.。

笔记《病理生理学》呼吸系统常见恶性肿瘤一、肺癌（lung cancer）（一）发病概况（二）病因：肺癌与下列因素有关：1、吸烟2、大气污染3、职业因素4、电离辐射（三）肺癌的组织发生：绝大多数肺癌均起源于各级支气管粘膜上皮，源于支气管腺体或肺泡上皮细胞者较少。

因而肺癌实为支气管源性癌。

小细胞肺癌来自支气管粘膜及腺体的Kultschitzky细胞（嗜银细胞），属于APUD瘤。

支气管粘膜上皮可以经过两种途径癌变（1）由基底细胞直接癌变；（2）经上皮增生、鳞状上皮化生、非典型增生、原位癌，逐渐演化为浸润癌。

（四）病理变化：1、肉眼类型：（1）中央型：癌块位于肺门部，由主支气管和叶支气管发生。

形成环绕癌变支气管的巨大癌块，形状不规则或呈分叶状，与肺组织的界限不清，有时比较清晰。

癌块周围可有卫星灶。

有时癌块内也可见坏死空腔。

（2）周围型：位于肺叶周边部，癌发生在段或亚段支气管，往往在近脏层胸膜的肺组织内形成球形或结节状无包膜的癌块，与周围肺组织的界限较清晰，而与支气管的关系不明显。

（3）弥漫型：此型罕见，癌组织沿肺泡管、肺泡弥漫性浸润生长，呈肺炎样外观，或呈大小不等的结节散布于多个肺叶内。

2、组织学类型：（1）鳞状细胞癌：约占30-50%。

肿瘤由支气管粘膜上皮经鳞状上皮化生恶变而来。

肉眼通常是中央型，按组织血分化程度不同可分为高分化、中分化、低分化三级；为肺癌中最常见的类型。

（2）小细胞癌：约占20-25%，肉眼多为中央型，又叫燕麦细胞癌。

起源于支气管粘膜和粘液腺内Kultschitzky细胞，是一种具有异源性内分泌功能的肿瘤。

（3）腺癌：约占35%，发生率在肺癌中占第三位。

肉眼多为周边型，亚型：肺泡细胞癌，又称细支气管—肺泡细胞癌，可能源于终末细支气管和肺泡上皮细胞，肿瘤细胞沿肺泡壁扩散，成单层或多层排列。

肉眼多呈弥漫型。

（4）大细胞癌：主由胞浆丰富的大细胞组成，癌细胞高度异型。

此型恶性程度颇高，生长快，容易侵入血管形成广泛转移。

nsclc的分类非小细胞肺癌（Non-Small Cell Lung Cancer，NSCLC）是肺癌的一种常见类型，占据了肺癌病例的大部分。

NSCLC根据肿瘤细胞类型和组织学特征的不同，可以被进一步细分为多个亚型。

这些分类对于诊断和治疗的选择至关重要。

本文将介绍NSCLC的常见分类方法，以便增进对这种类型肺癌的了解。

1. 腺癌（Adenocarcinoma）腺癌是NSCLC最常见的亚型之一，约占所有NSCLC的40%。

腺癌主要来源于肺组织中粘液腺体、气道腺体和表面上皮细胞等，并呈现出腺泡或腺管结构。

腺癌通常发生在肺的外周部位，也可能侵犯邻近组织。

对于早期腺癌，手术切除往往是首选的治疗方法。

2. 鳞癌（Squamous Cell Carcinoma）鳞癌约占NSCLC的25-30%。

它起源于肺的上皮细胞，通常在大气道内形成不同程度的角化。

鳞癌可以分为鳞状细胞生长型、梁细胞生长型等亚型。

鳞癌常常出现在大气道附近，容易引发咳嗽、咳痰等呼吸系统症状。

对于本地化的鳞癌，外科手术是常见的治疗选择。

3. 大细胞癌（Large Cell Carcinoma）大细胞癌是NSCLC的一种罕见亚型，约占NSCLC的10-15%。

大细胞癌的命名源于其细胞形态没有明显的特征，通常没有腺泡或角化。

大细胞癌发展迅速且侵袭性较强，常迅速转移至其他部位。

化疗和放疗是治疗大细胞癌的主要方式。

4. 腺鳞癌（Adenosquamous Carcinoma）腺鳞癌是一种罕见的混合型NSCLC，同时具有腺癌和鳞癌的组织学特征。

腺鳞癌的发病率相对较低，约占所有NSCLC的3-4%。

由于其与其他亚型的混合，腺鳞癌的治疗策略通常结合多种方法，如手术切除、化疗和放疗等。

尽管NSCLC的分类方法众多，但这些分类仅仅是分类系统的一种，旨在帮助医生更好地了解肺癌的特征及其治疗方案。

同时，这种分类方法虽然在临床上有一定的指导意义，但其作用仍在不断发展。

各种肿瘤名称肿瘤是当今世界面临的重要健康问题之一。

据统计，全球每年约有数百万人被诊断出患有不同类型的肿瘤。

不同的肿瘤在病因和发展方式上存在差异，因此渴望拥有更深入的了解是非常必要的。

本文将介绍一些常见肿瘤的名称和它们所代表的意义。

1. 骨肉瘤 (Osteosarcoma)骨肉瘤是一种最常见的骨肿瘤，通常发生在青少年和年轻成年人的长骨中。

这种肿瘤来源于骨组织中的恶性肿瘤细胞，并具有高度侵袭性。

它常常导致骨骼的破坏和身体功能的丧失，需要进行综合治疗，包括手术切除、放疗和化疗。

2. 卵巢癌 (Ovarian Cancer)卵巢癌是女性生殖系统中最常见的恶性肿瘤之一。

由于卵巢位于盆腔较深位置，通常在早期难以被发现。

这导致了卵巢癌的高度死亡率。

然而，早期诊断和治疗的进步有助于提高预后。

因此，及早进行定期检查对于女性的健康至关重要。

3. 胰腺癌 (Pancreatic Cancer)胰腺癌是一种高度侵袭性的肿瘤，常常在早期阶段无明显症状。

当肿瘤已扩散至其他器官时，患者的生存率显著降低。

胰腺癌的治疗主要包括手术切除、化疗和放疗。

然而，由于胰腺的位置及其组织特点，手术治疗往往具有一定的挑战性。

4. 鼻咽癌 (Nasopharyngeal Cancer)鼻咽癌是一种罕见但具有高度侵袭性的头颈部肿瘤。

它主要发生在鼻咽部的粘膜上，通常导致颈部淋巴结的肿大。

鼻咽癌的主要治疗方式是放疗和化疗，手术的角色相对较小。

此外，由于病因与人类乳头瘤病毒（HPV）的感染有关，疫苗的预防措施也很重要。

5. 乳腺癌 (Breast Cancer)乳腺癌是女性最常见的恶性肿瘤之一。

它通常发生在乳房组织中，但男性也有罹患乳腺癌的可能。

乳腺癌的治疗方式包括手术切除、放疗、化疗和内分泌治疗。

早期发现和早期治疗对于预防疾病的进展至关重要。

6. 结肠癌 (Colorectal Cancer)结肠癌是消化系统最常见的恶性肿瘤之一。

它发生在结肠或直肠的组织中，常常由结肠息肉的变态生长导致。