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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
Squamous cell carcinoma
• 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.
Squamous cell carcinoma
Squamous cell carcinoma
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
Small cell carcinoma
Small cell carcinoma
• 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