Lung Cancer Notes

Lung Cancer

Small-cell and Non-small Cell Lung Cancer

Learning Objectives

• Identify populations more at risk for lung cancer, including types of environmental exposure.

• Anticipate patients who meet criteria for annual lung cancer screening.

• Differentiate between Small Cell Lung Cancer (SCLC) and the three types of Non-small Cell Lung Cancer (NSCLC).

• Assess patients for relevant clinical manifestations of lung cancer, both early and advanced.

• Demonstrate knowledge of treatment modalities for lung cancer, including surgical resection, radiation, chemotherapy, targeted therapy, and immunotherapy.

• Understand the difference between palliative, curative, and adjunctive treatments.

Key Terms

• Angiogenesis: The development of new blood vessels.

• Apoptosis: Programmed cell death.

• Chemotherapy: The treatment of disease by the use of chemical substances, especially the treatment of cancer.

• Hemoptysis: Coughing up blood.

• Lymphadenopathy: Disease affecting the lymph nodes.

• Metastasis: The spread of cancer cells from the primary site to other parts of the body.

• Paraneoplastic Syndrome: A syndrome or disorder that is a consequence of cancer in the body but is not directly caused by the physical effects of the tumor.

• PET Scan: A type of nuclear medicine imaging that uses small amounts of radioactive material to visualize and measure changes in metabolic processes.

• Radiation: The emission of energy as electromagnetic waves or as moving subatomic particles.

• Surgical Resection: Surgical removal of tissue or an organ.

• Superior Vena Cava Syndrome: Obstruction of the superior vena cava.

Epidemiology

• Lung Cancer is the leading cause of cancer-related deaths (25%) in the U.S.

• High mortality rate; low cure rate.

• Smoking is responsible for 80%-90% of all lung cancers.

• Female smokers are at a greater risk than male smokers.

• African Americans have the highest incidence of lung cancer and are more likely to die from the disease.

• Asian and Pacific Islanders have the lowest rate of lung cancer.

Etiology

• Assessment of risk falls into 3 categories:

  • Smokers (current & primary exposure)

  • Nonsmokers (former smokers)

  • Never smokers (secondary or tertiary exposure)

    • Never smoker considered person who has had less than 100 cigarettes in their lifetime.

    • Tertiary exposure: Carcinogens leftover on clothes or hair after smoking and someone breathes it in.

• Risk is directly related to total exposure to tobacco smoke

  • Total # of cigs in a lifetime

    • Pack year history

  • Age of smoking onset

  • Depth of inhalation

    • Primary, secondary, tertiary

  • Tar & nicotine content

  • Use of unfiltered cigs

    • Roll own cigarettes

    • Increases carcinogens

• Theory: people have different genetic carcinogen-metabolizing pathways.

  • Has to do with HLAs which live on our cells

• Other causes of lung cancer include exposure to:

  • Pollution

  • Radiation

  • Residential contaminants (old house):

    • Radon Gas

    • Asbestos

  • Industrial agents:

    • Radon, coal dust, asbestos, chromium, arsenic, diesel exhaust

Lung Cancer Screening

• National Lung Screening Trial Criteria for screening (annually):

  • 50-80 years of age

  • Current or former smokers with at least a 20-pack year history

    • Determined by packs per day x # of year smoked.

      • Ex. Half a pack of day for 10 years → 5 years.

  • Former smokers who quit within the last 15 years

  • Spiral CT scan performed if all criteria met → #1 diagnostic.

• Key Points:

  • Lung cancer screening can help find lung cancer at an early stage when it is easier to treat.

  • At this time, studies have shown that low-dose spiral CT scan is the only lung cancer screening tool that reduces the risk of dying from lung cancer.

  • Lung cancer screening is not right for everyone.

Pathophysiology

• Not well understood.

• Most lung cancers arise from mutated bronchial epithelial cells.

  • Located in bronchi (breathing portion of lungs)

• Found more in segmental bronchi and in upper lobes.

• Can take 8-10 years to reach 1 cm nodule.

• Primary Lung cancers are categorized in 2 broad subtypes

  • Non-small cell (NSCLC) - More Prevelant

    • Accounts for 84% of lung cancers

  • Small cell (SCLC)

    • Accounts for 13% of lung cancers

Non-Small Cell Lung Cancer (NSCLC) → Most Prevalent

• Three Main Types

  1. Squamous cell carcinoma

     • Accounts for 20%-30% of lung cancers

     • Slow growth, metastasis less common

     • Almost always associated with smoking

     • More common in men

     • Tx: Surgical resection (if amenable)

  2. Adenocarcinoma

     • Accounts for 30-40% of lung cancers

     • Moderate growth

     • Most common in never smokers and in women

       • Ex. Cocktail waitresses, flight attendants (when smoking was allowed on plane) - people exposed to smoke

     • Metastatic disease is often present when symptoms occur

       • Urology may need to be consulted because they can show signs related to GU system

     • Surgical resection ( if amenable)– doesn’t respond well to chemotherapy

  3. Large Cell Carcinoma

     • Accounts for 10% of lung cancers

     • Rapid growth of undifferentiated cells (implant wherever they want to in the body) and often arises in the bronchi

     • Usually not treated surgically due to high degree of metastasis

     • Tumor may respond to radiation

       • Decreases size of the tumors and prevents them from pressing on other structures.

Small Cell Lung Cancer (SCLC)

• Accounts for 20% of lung cancers “death sentence” → metastasizes quickly

• Rapid growth with poor prognosis

• Most malignant form of lung cancer with early metastasis, frequently to brain

  • May present with ALOC or AMS (more neurological symptoms than respiratory)

• Chemotherapy and radiation – palliative (supportive, not curative)

Paraneoplastic Syndrome

• Develops as a result of cancer.

• Body-wide and caused by a reaction of hormones, cytokines, enzymes, or antibodies that destroy healthy cells.

  • Excreted by tumor cells (cancer is already existing and it excretes the cells), or

  • Body’s immune response to the cancer

• May manifest before cancer diagnosed

• Associated most with SCLC

• Examples:

  • Hypercalcemia

    • S/S Bone pain, constipation, muscle weakness

  • SIADH

    • Hold onto a lot of water

  • Adrenal Hypersecretion

    • Adrenals release steroids (testosterone, cortisol, and epinephrine) → pts have too much floating around.

    • Elevated cortisol = Cushing’s Syndrome (fatigue, purple striae on abdomen, etc)

  • Polycythemia

    • Overproduction of RBCs

    • RBC and hematocrit elevated

      • Hematocrit shows total volume and percentages of RBCs

  • Cushing’s syndrome

    • From too much cortisol

Clinical Manifestations

• Common to all lung cancers: symptoms are non-specific and appear late in the disease process.

  • BIG 3 SIGNS AND SYMPTOMS:

    • Persistent Cough

    • Blood-tinged sputum

      • Because blood going to area or cough breaking open some capillaries

    • Lobar pneumonia refractory (resistant) to antibiotic tx

      • Where pt has a blocked off patch of pneumonia in the lobes of a lung and has gotten 1-2 rounds of abx but pt still has symptoms and pneumonia.

  • Dyspnea

  • Wheezing

  • Chest pain

    • More pleuritic (off to side of lungs)

• Late Signs:

  • Anorexia, unexpected weight loss, fatigue, nausea, vomiting (main)

  • Hoarseness

    • Tumor pressing on laryngeal nerve

  • Unilateral paralysis of diaphragm

    • May cause respiratory distress (part of the diaphragm is pushed down)

  • Dysphagia

  • Superior vena cava obstruction

    • Affects upper body (may feel fullness in face or head)

  • Palpable lymph nodes

• Metastasis – through direct extension, or blood and lymph system

  • Common sites: lymph nodes, liver, brain, bones, adrenal glands

    • Pts often come in for a different symptoms (ex. Bone pain) that ends up being related to lung cancer

  • Small cell lung cancer can metastasize quickly

Diagnostic Studies

• CT scan → best diagnostic tool

  • How big tumor is and if there’s blood flow into it.

• CXR

• PET/Bone Scans

  • Looks for metastasis

• Sputum cytology – only 20-30% positive (more of a centralized lung cancer like primary or secondary bronchus which show up with a positive cytology)

  • Looks at cells under a microscope for abnormal cells

  • The other lung cancers live further down closer to the alveoli and don’t come up with sputum.

    

• Biopsy – definitive diagnosis

  • Fine needle aspiration

    • Insert needle through the chest wall and into lung (risk of pneumothorax)

  • Bronchoscopy

    • Camera into bronchi through throat

  • Thoracoscopy

    • Make an incision to go in and look through the chest cavity

  • Thoracentesis

    • Pleural effusion may develop from cancer itself → this allows provider to grab a sample and send it to lab.

• Staging

  • Non-small cell uses the TNM staging system

    • T = Tumor

      • T0 means no evidence of a primary tumor, so it may be that the cells are cancerous but they haven’t developed a tumor.

      • T1-4 means an ascending degree of tumor size and involvement. (Know that 1 is small and 4 is big)

      • TX means tumor can’t be measured or undifferentiated (can’t tell what type of cells are there)

      • TIS (carcinoma in situ) means it’s a very new, small tumor still within its bounds it originally grew. Pts with carcinoma in situ have a better outcome due to surgical resection.

    • N = Lymph nodes

      • N0 means no evidence of disease in lymph nodes

      • N1-4 know that 1 is small and 4 is big)

      • NX means unable to be assessed

    • M = Metastasis

      • M0 means no evidence

      • M1-4 means degree of metastasis (is it generalized or close to where it’s at vs. widespread)

      • MX how far it has grown

  • Small cell; staging unnecessary because this cancer is always considered systemic

    • Go straight into treatment

Interprofessional Care

• Surgical Resection

  • Treatment of choice in earlier stages of non-small cell lung cancer

  • Smaller tumors/better outcome

    • Potentially curative (especially if tumors are small)

  • 50% of tumors are not resectable at the time of diagnosis

  • Types of Resection:

    • Pneumonectomy

      • Take the lung

    • Lobectomy

      • Remove lobe of lung (we have 5 lobes)

    • Segmental or wedge resection

      • Take segment of lung out (smaller than lobe)

    • Video-assisted thoracoscopic surgery (VATS)

      • Most surgeries performed with this

      • Go in and remove what they need to with a few incisions

Interprofessional Care: Radiation

• Treatment for both types

• Curative (giving in hopes to cure the disease), palliative (wont cure but helps feels better), or adjunctive (they do this with something else in hopes to cure the pt)

  • Primary treatment in non-surgical patients

  • Relief of symptoms/pain from bronchial obstructive tumors, SVC syndrome, bone pain (bone hyperplasia)

  • Treat metastatic bone pain or cerebral involvement

  • Performed preoperatively to reduce tumor mass for surgical removal.

  • Never radiate a child’s brain younger than 5.

    • Over 5: the tissues are produced but not the functionality.

• SBRT

  • delivers a targeted radiation dose directly to a tumor (Focuses directly on the tumor, unlike radiation)

  • therapy over 1-3 days

Interprofessional Care: Chemotherapy

• Primary treatment in SCLC, or for nonresectable NSCLC

• Often done in a combination of 2 or more drugs

  • Want cell cycle phase nonspecific

  • Can target cells where they are growing at different stages (cancer cells can go dormant and if we leave them alone, they will grow again).

  • Helps decrease likelihood of tolerance

• Goal: to eliminate or reduce the number of cancer cells

  • Performed in adjunction with radiation to help shrink tumors, diminish cells, and stop ells from growing, and to eradicate cancer cells.

• Two categories of Chemo drugs:

  • Cell cycle phase non-specific

  • Cell cycle phase specific

Interprofessional Care: Targeted Therapy

• Inhibits tumor growth rather than directly killing cancer cells

  • Aims to prevent tumor growth

    • Types:

      • Blocks growth signals

      • Blocks kinase protein (responsible for cancer development and growth)

      • Blocks angiogenesis (A property the body has to create a new blood supply because cancer cells create their own blood supply)

Interprofessional Care: Immunotherapy

• Monoclonal Antibodies (“-mabs”)

  • Take a pre-made antibody and continue producing it until identical

• Block PD-1 (T cell protein) to prevent cancer cell from attacking other cells

• Boosts immune response against cancer cells; shrinks tumor overtime or slows growth

  • Utilizes a horse antibody and causes pt to go into an anaphylactic reaction, which we want to shrink their anaphylactic reaction → Allows T cells to work at destroying cancer cells. Interferes with PD-1 and PD-L1.