Lung Cancer Notes

Cancer of the Lung

Anatomic Alterations of the Lungs

• Cancer is characterized by the abnormal new tissue growth via the progressive, uncontrolled multiplication of cells.
• This abnormal growth results in a neoplasm or tumor, which can be localized or invasive, benign or malignant.

Benign Tumors

• Generally do not endanger life unless they interfere with the normal functions of other organs or affect a vital organ.

Malignant Tumors

• Composed of embryonic, primitive, or poorly differentiated cells.
• Grow in a disorganized manner and so rapidly that nutrition of the cells becomes a problem.
• Can cause necrosis, ulceration, and cavity formation.

Lung Cancer

• Arises from the epithelium of the tracheobronchial tree.
• A tumor originating in the bronchial mucosa is called bronchogenic carcinoma.

Major Pathologic or Structural Changes Associated with Lung Cancer

• Inflammation, swelling, and destruction of the bronchial airways and alveoli
• Excessive mucus production
• Tracheobronchial mucus accumulation and plugging
• Airway obstruction
• Atelectasis
• Alveolar consolidation
• Cavity formation
• Pleural effusion

Etiology and Epidemiology

• Lung cancer is the second most common cause of cancer in both men and women.
• Cigarette smoking is the most common cause of lung cancer.
  • Smoking cessation is important
  • Pack-years are calculated as: PackYears = (packs\ per\ day) \times (years\ smoked)
• Radon exposure is the second leading cause of lung cancer.

Exposure to Other Cancer-Causing Agents

• Exposure to asbestos
• Radioactive ores (such as uranium)
• Inhaled chemicals or minerals
• Diesel exhaust
• Air pollution (especially near heavily trafficked roads)
• Arsenic in drinking water
• Radiation therapy to lungs
• Personal or family history of lung cancer

Types of Cancer

• Bronchogenic carcinomas are divided into two major categories:
  • Non–small cell lung carcinoma (NSCLC)
    • Squamous (epidermoid) cell carcinoma
    • Adenocarcinoma (including bronchial alveolar cell carcinoma)
    • Large cell carcinoma
  • Small cell lung carcinoma (SCLC)
    • Small cell carcinoma (also called oat cell carcinoma)
    • Combined small cell carcinoma
    • A mixture of small cell and non–small cell carcinoma

Non–Small Cell Lung Carcinoma (NSCLC)

• The most common type of lung cancer

Squamous Cell Carcinoma

• The tumor originates from the basal cells of the bronchial epithelium and grows through the epithelium before invading the surrounding tissues.
• Has a slow growth rate and a late metastatic tendency.

Adenocarcinoma

• Arises from the mucous glands of the tracheobronchial tree.
• The growth rate is moderate, and the metastatic tendency is early.

Large Cell Carcinoma

• Commonly referred to as undifferentiated large cell anaplastic cancer.
• Commonly arises peripherally but may also be found centrally.
• Has a rapid growth rate and early and widespread metastasis.

Small Cell Lung Carcinoma

• Most of these tumors arise centrally near the hilar region.
• The tumor grows very rapidly, becoming very large, and metastasizes early.
• Has the poorest prognosis.
  • About 90% of patients respond to treatment.
  • But nearly all relapse within 24 months.
• Has the strongest correlation with cigarette smoking.

Other Types of Lung Tumors

• Lung carcinoid tumor
  • A type of cancer that starts in the lungs and is made up of special types of cells called neuroendocrine cells.
  • Four types of neuroendocrine lung tumors:
    • Small cell lung cancer
    • Large cell neuroendocrine carcinoma
    • Typical carcinoids
    • Atypical carcinoids

Carcinoids

• Central carcinoids: Found in the walls of large bronchi near the center of the lungs.
• Peripheral carcinoids: Found in the smaller bronchioles toward the periphery of the lungs.

Cancer that Spreads to the Lungs

• Cancer that begins in other parts of the body can metastasize to lungs (e.g., breast, pancreas, kidney, skin).
• Treatment is based on where the cancer originated.

Screening and Diagnosis

• Most lung cancers are not diagnosed until after the patient presents with symptoms.

  • A progressively worsening cough, often includes blood or rust -colored sputum
  • Chest pain
  • Hoarse voice
  • Poor appetite and weight loss
  • Dyspnea
  • Fatigue
  • Frequent bronchial infection or pneumonia episodes
  • Sudden onset of wheezing

• When lung cancer spreads to others parts of the body, the patient may have other symptoms of cancer that include:

  • Bone pain (e.g., back or hips)
  • Neurologic problems (e.g., headache)
  • Arm and leg weakness or numbness
  • Dizziness or balance problems
  • Seizures
  • Jaundice
  • Enlarged lymph nodes

• In addition, the patient may demonstrate a group of very specific syndromes associated with lung cancer, such as:

  • Homer’s syndrome
  • Superior vena cava syndrome
  • Paraneoplasic syndromes

• The primary goals of diagnostic procedures:

  • Confirm the presence of a lung carcinoma
  • Establish the cancer cell type
  • Confirm the stage of the cancer

Staging of Non–Small Cell Lung Carcinoma (NSCLC)

• The tumor node metastasis (TMN) staging system

• The staging of lung cancer confirms the:

  • Cell type
  • Size of the tumor
  • Level of lymph node involvement
  • Extent to which the cancer has spread

• The stage of a patient’s cancer is determined by a combination of all of the following factors:

  • T—represents the size and location of the primary tumor
  • N—denotes the regional lymph node involvement
  • M—signifies the extent of metastasis (e.g., common sites are the brain, bones, adrenal glands, liver, kidneys, and other lung)

• The letters after the T, N, and M provide more information about each of these factors

• The numbers 0 through 4 represent increasing severity

Stage Grouping for Lung Cancer

• Once the T, N, and M categories have been established, information is grouped together to determine the overall stage of the lung cancer.
• Stages 0, I, II, III, and IV are used to identify the overall stage of the lung cancer:
  • Stage 0 and I being the least advanced
  • Stage IV the most advanced

Staging of Small Lung Carcinoma (SCLC)

• For treatment reasons, SCLC is usually classified as a limited stage, or an extensive stage:
  • Limited stage—means the cancer is confined to only one lung and to its neighboring lymph nodes.
    • It can be treated with a single radiation field.
    • In some cases, the lymph nodes at the center of the chest (mediastinal lymph nodes) may be included, even when the cancer is close to the other lung.
    • About 1 out of 3 patients with small cell lung cancer have limited stage SCLC

Overview of the Cardiopulmonary Clinical Manifestations

• The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by:
  • Atelectasis
  • Alveolar consolidation
  • Excessive bronchial secretions

The Physical Examination

• Vital signs:
  • Increased respiratory rate (tachypnea)
  • Increased heart rate (pulse)
  • Increased blood pressure
• Cyanosis
• Cough, sputum production, and hemoptysis
• Chest assessment findings:
  • Crackles and wheezing

Pulmonary Function Test (PFT) Findings

• Depending on where the malignancy originates, the PFT results may show either obstructive or restrictive values.
• When large amounts of pulmonary tissue, chest wall, and/or diaphragm are involved:
  • The pathology may show restrictive PFT values.

Radiologic Findings

• Chest radiograph:
  • Small oval or coin lesion
  • Large irregular mass
  • Alveolar consolidation
  • Atelectasis
  • Pleural effusion
  • Involvement of the mediastinum or diaphragm

General Management of Lung Cancer

Treatment options for non–small cell lung cancer (NSCLC)

• Surgery
  • Pneumonectomy, Lobectomy, Segmentectomy or wedge resection, Sleeve resection, VATS
• Radiofrequency ablation (RFA)
• Radiation therapy
  • External beam rations therapy (EBRT)
  • Brachytherapy
• Chemotherapy
• Targeted therapies

Treatment options for small cell lung cancer (SCLC)

• Chemotherapy
• Radiation therapy
• Surgery