Lung Cancer
Overview
• Most common cause of cancer mortality in U.S. and world • American Cancer Society estimates 160,440 deaths in U.S. in 2004, compared to 127,200 combined deaths from colorectal, breast, prostate cancer
Risk Factors
• • • • • Cigarette smoking 2nd hand smoke Asbestos Radon Arsenic • Ionizing radiation • Haloethers • Polycyclic aromatic hydrocarbons • Nickel
Types
• 4 major cell types make up 88% of all primary lung cancers 1. Squamous cell = 20-30% 2. Adenocarcinoma = 30-40% 3. Large cell = 10% 4. Small cell = 20% • Remainder include undifferentiated, carcinoids, bronchial gland tumors • Each different type has different natural histories and responses to therapy
Squamous Cell
• Arises in proximal portions of tracheobronchial tree 60-80% cases • Histopathology:
– presence of keratin (produced by tumor cells) – presence of intracellular bridges
Adenocarcinoma
• 75% cases occur peripherally • Can be localized, multinodular, or diffuse • Most common lung ca in nonsmokers, women, and young patients (<45 yrs) • Histopathology:
– neoplastic gland formation – intracytoplasmic mucin production
Large cell
• Usually large peripheral mass with necrosis • Histopathology:
– sheets of round to polygonal cells with prominent nucleoli and pale staining cytoplasm without differentiating features
Small cell
• Central location or widespread • Histopathology:
– pleomorphic population of small cells with variable amounts of cytoplasm
Clinical presentation
• Majority are symptomatic at presentation (> 85%) 1. Symptoms related to lung lesion 2. Symptoms from intrathoracic spread 3. Symptoms from distant mets 4. Symptoms from paraneoplastic syn.
Symptoms of lung lesion
• • • • • • Cough with or without sputum Dyspnea Hemoptysis Chest pain Wheezing Weight loss
Symptoms of intrathoracic spread
• Pleural or pericardial effusion • Compression of recurrent laryngeal nerve (hoarseness), phrenic nerve palsy (elevated diaphragm), brachial plexus involvement (Pancoast tumor) • Tracheal obstruction, esophageal compression, SVC syndrome
Symptoms of distant mets
• May occur in almost every organ system • Bone mets (vertebrae, ribs, pelvis most popular) • Hepatic mets (usually indicate poor prognosis) • Brain mets (can have HA, nausea/vomiting, seizures, confusion, personality changes)
Symptoms of paraneoplastic syndromes
• Production of parathyroid hormone-related peptide (squamous cell) • SIADH (small cell) • Ectopic ACTH production (small cell) • Peripheral neuropathy, cortical cerebellar degeneration, Eaton-Lambert syndrome (small cell) • Migratory venous thrombophlebitis • Digital clubbing (non-small cell) • Hypertrophic palm osteoarthopathy (adenocarcinoma)
Diagnosis and Treatment
• Histopathology • Staging 1. Anatomic staging—determining location of tumor (TNM method for non-small cell, whether or not disease is restricted to hemithorax for small cell) 2. Physiologic staging--assessment of a patient’s ability to withstand various antitumor treatments
Pretreatment staging procedures for all pts
• H&P • Performance status and weight loss • Basic labs • EKG • TB skin test • CXR • CT chest, abd, pelvis • CT brain and/or Bone scan if findings suggest metastases • X-rays of suspicious bony lesions • Barium swallow if dysphagia history • PFT’s and ABG if respiratory problems • Histology
Additional tests once have diagnosis
NON-SMALL CELL • Bronch with BAL, brushing, biopsies • PFT’s and ABG • Coags • CT Brain • Evaluation of mediastinum during surgery • Thoracentesis if present with effusion
SMALL CELL • Bronch with BAL, brushing, biopsies • CT Brain • Bone marrow Bx (if abnormal CBC)
Treatment for Non-small cell
• Stage I a/b = surgical resection • Stage II a/b = surgical resection +/- XRT or chemo • Stage IIIa = initial chemo, surgery, +/- XRT (no surgery if contralateral or bilateral mediastinal nodes, extrascapular nodes, or fixed nodes) • Stage IIIb = ranges from palliation to chemo to chemo and XRT • Stage IV = chemo or palliation
Treatment for Small cell
• Chemotherapy and/or XRT • Usually advanced disease at time of discovery and therefore not surgical candidates except if single nodule