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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