lung carcinoma

Lung Carcinoma6

Carcinoma of the Lung

• In United States:-

• 6.5 % of all deaths & 29% of cancer -related death.

• #1 cause of cancer deaths in males & females– 31% of male cancer deaths in 2008– 26% of female cancer deaths

Annual Age-adjusted Cancer Death Rates for Selected Cancers, United States, 1930-2004

MalesFemales

CA Cancer J Clin 2008;58:81-82

Smoking-related diseases

Causes of Lung Cancer

• 85-90% smoking • Industrial hazards :- Asbestos , Uranium Rare arsenic, chromium, mustard gas, nickel,

vinyl chloride .• Air pollution :- Radon• Molecular genetics:- KRAS, c-MYC,EGFR,

p53

Classification of Lung Carcinoma (Major Types)

Non-Small Cell Carcinoma:

- Adenocarcinoma 42%

- Squamous cell carcinoma 28%

- Large cell carcinoma 14%

Small cell carcinoma 16%

Precursor lesions:-(1)Squamous dysplasia & Ca.in situ.(2)Atypical adenomatous hyperplasia.(3)Diffuse idiopathic pulmonary neuroendocrine hyperplasia.

Adenocarcinoma

• Frequency: 42%• Smoking: X 3 (increased risk)• Males < females• Survival (5 years): 15 - 20%• Peripheral

Adenocarcinoma

• Malignant epithelial tumors with tubular, acinar, or papillary growth patterns, and/or mucus production by the tumor cells.

• Adenocarcinoma is the predominant histological subtype of lung carcinoma in most countries (40-50% of all cases).

• Most prevalent form of lung cancer in younger males (<50 yr) and in women of all ages, in never smokers, and in former smokers

• Adenocarcinoma has flipped with squamous tumors as most common over the past 20 years. Why? Thought that smoking with filters, light tobacco, profound inhalation favor the development of distal bronchiolar and alveolar adenocarcinomas

AdenocarcinomaBronchioloalveolar type

• Frequency: 2 %• Smoking: yes• Males = females• Survival (5 years): 25 a 40 %.• Presentation:

– Single or multiple tumor nodules– Miliary tumor– “Pneumonic form”

Bronchioalveolar carcinoma – Mucinous type

Pneumonic presentation (40%) – Poor prognosis

1. Definition: noninvasive tumors with bland cytology and lepidic spread (line alveolar surfaces)

2. New proposal to classify these as “adenocarcinoma in situ” or atypical adenomatous hyperplasia

AdenocarcinomaBronchioloalveolar type

Squamous cell carcinoma

• Frequency: 28%• Smoking: X 25 (increased risk)• Males > females• Survival (5 years): 15 - 20%• Arises in bronchial squamous

metaplasia• Centrally located• May cavitate


• Malignant epithelial tumor with morphologic evidence of keratinization, intercellular bridges or both.

• Second most common type of lung cancer.

• 2/3 central 1/3 peripheral.



Large Cell Carcinoma• Frequency: 14%

• Gross– Peripheral lesion

• Microscopic– group of tumors that do not fit the criteria of a

squamous cell carcinoma, adenocarcinoma, or small cell carcinoma

• Prognosis– Similar to adenocarcinoma

Small cell carcinoma

• Frequency: 16%• Smoking: 95% of patients• Survival (5 years): 1 - 5 %

• Malignant epithelial tumor consisting of small cells with minimal/scant cytoplasm, finely granular nuclear chromatin, absent or inconspicuous nucleoli, displaying prominent nuclear molding, high mitotic/apoptotic activity and extensive necrosis

• Highly associated with cigarette smoking, central location, early spread, common paraneoplastic syndromes



• Still a dismal lesion: over 75% of cases present with stage III or IV disease

• In many series long term survival is less than 5%

• Takes one importance because it essentially removes a patient from consideration of resection in most cases

Presenting Symptoms of Lung Cancer

• Potentially curable– asymptomatic– cough– hemoptysis

• Usually incurable– dyspnea & chest pain– anorexia & weight loss– hoarseness– bone pain– Horner’s syndrome (Pancoast tumor)

Bronchogenic carcinoma + bronchectasis.

Mesothelioma• Mesothelioma:

– Malignant tumor of mesothelial cells

– Highly malignant neoplasm with short survival

– Most patients (70%) have an asbestos exposure history

• Asbestos exposure also increases the risk of pulmonary cancer

• Smoking is not related to mesothelioma

Health & Medicine

lung carcinoma