LUNG CANCER

 

INTRODUCTION: Lung cancers arise from a single transformed epithelial cell in the tracheobronchial airways. A carcinogen such as; cigarette smoke, radon gas and other occupational and environmental agents, damages the cell, causing abnormal growth and development into a malignant tumor. Most lung cancers are classified into one of two major categories: small cell lung cancer which contribute 15% to 20% of tumors, and non–small cell lung cancer that contribute approximately 80% of tumors. Most small cell cancers arise in the major bronchi and spread by infiltration along the bronchial wall.

RISK FACTORS OF LUNG CANCER: Risk factors include tobacco smoke and especially second-hand also known as passive smoke, environmental and occupational exposures, gender, genetics, and dietary deficits. Other factors that have been associated with lung cancer include genetic predisposition and underlying respiratory diseases, such as chronic obstructive pulmonary disease (COPD) and tuberculosis (TB).

CLINICAL MANIFESTATIONS: Lung cancer often develops insidiously and is asymptomatic until late in its course. Signs and symptoms depend on location, tumor size, degree of obstruction, and existence of metastases to regional or distant sites.

1.  Most common symptom is cough or change in a chronic cough.

2.  Dyspnea may occur early in the disease.

3.  Hemoptysis or blood-tinged sputum may be expectorated.

4.  Chest pain or shoulder pain may indicate chest wall or pleural involvement. Pain is a late symptom and may be related to bone metastasis.

5.  Recurring fever may be an early symptom.

Chest pain, tightness, hoarseness, dysphagia, head and neck edema, and symptoms of pleural or pericardial infusion exist if the tumor spreads to adjacent structures and lymph nodes.  Common sites of metastases are lymph nodes, bone, brain, contralateral lung, adrenal glands, and liver.  Weakness, anorexia, and weight loss may appear.

ASSESSMENT AND DIAGNOSTIC METHODS: Chest x-ray, CT scans, bone scans, abdominal scans, PET scans, liver ultrasound, and MRI.  Sputum examinations, fiberoptic bronchoscopy, transthoracic fine-needle aspiration, endoscopy with esophageal ultrasound, mediastinoscopy or mediastinotomy, and biopsy.  Pulmonary function tests, ABG analysis scans, and exercise testing.  Staging of the tumor refers to the size of the tumor, its location, whether lymph nodes are involved, and whether the cancer has spread.

MEDICAL MANAGEMENT: The objective of management is to provide a cure if possible. Treatment depends on cell type, stage of the disease, and physiologic status. Treatment may involve surgery, radiation therapy, or chemotherapy—or a combination of these.

RELATED;

1.  THE ORIGIN OF CANCER

2.  GASEOUS EXCHANGE

3.  ACIDITY AND ALKALINITY OF BODY SYSTEMS

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