Cancer Patho

Review of Anatomy/Physiology

Cell Proliferation - healthy cells

• Purpose: growth & development, tissue repair, replacement of old/damaged cells

• Cell Cycle:

  • G₁: Cell grows

  • S: DNA copied

  • G₂: Cell prepares to divide

  • M: Mitosis (cell division)

• Checkpoints: verify DNA integrity, pause division if errors are found, repair damage before proceeding

• Apoptosis: programmed cell death, removes damaged/abnormal cells

• Homeostasis: balance b/w cell growth & cell death

Cell proliferation - cancer cells

• DNA Mutations: damage to genes controlling cell growth

• Loss of Cell Cycle Regulation: ignore normal growth controls, bypass cell cycle checkpoints

• Evasion of Apoptosis: damaged cells survive instead of dying

• Uncontrolled Cell Division: rapid accumulation of abnormal cells

• Angiogenesis: tumor develops its own blood supply

• Invasion & Metastasis: malignant cancer cells spread to surrounding & distant tissues

Benign vs. Malignant Tumors

• Named according to the tissues from which they arise

• Benign: abnormal cells grow slowly & stay confined to their original tissues (lipoma = fat cells; meningioma = meninges of brain)

  • Capsule = boundary b/w tumor & surrounding tissue

  • Isn’t always harmless

• Malignant: cancerous, grow rapidly, less differentiated, do NOT remain confined to original tissue

  • Invades surrounding tissues → metastasizes

Carcinogens

Carcinogens - overview

• Carcinogens = substances or exposures that can damage DNA & contribute to cancer development

• Not all exposures cause cancer → but risk increases w/ the amount & duration of exposure

• 3 categories:

  • 1. Physical: ultraviolet (UV) radiation, ionizing radiation (X-rays, gamma rays)

  • 2. Chemical: tobacco smoke (#1 biggest human carcinogen in the world today), Asbestos, Benzene, Nitrates, environmental pollutants

  • 3. Biological: human papillomavirus (HPV), Hepatitis B & C, Epstein-Barr virus (EBV)

Carcinogenesis

• Process by which a normal cell becomes a cancerous cell

  • Gradual process that happens over many years

• 4 steps:

  • 1. Initiation: DNA damage or mutation occurs

  • 2. Promotion: mutated cells survive & proliferate

  • 3. Progression: additional mutations accumulate, cells become increasingly abnormal

  • 4. Malignant Transformation: invasion of surrounding tissues, metastasis to distant sites

Tumor Grading & Staging

Tumor grading

• Focuses on how abnormal cancer cells look under a microscope

• Predicts how aggressively the cancer is likely to behave

Tumor grades - 1-4

• Grade 1: well differentiated, closely resemble normal cells, slow-growing, least aggressive

• Grade 2: moderately differentiated, some abnormal features, intermediate growth rate

• Grade 3: poorly differentiated, significantly abnormal appearance, few characteristics of normal tissue remain, faster growth & greater potential to spread

• Grade 4: undifferentiated/anaplastic, extremely abnormal appearance, difficult to identify tissue of origin, most aggressive growth pattern, highest metastatic potential

Tumor staging

• Describes how far the cancer cell progressed within the body

• TNM System:

  • T = size of primary tumor (T0-T4)

  • N = lymph node involvement (N0-N3)

  • M = presence of metastasis (M0-M1)

Tumor stages - 0-4

• Stage 0: carcinoma in situ → abnormal cells only, have not invaded surrounding tissue

• Stage 1: small, localized tumor

• Stage 2: larger tumor and/or limited local spread

• Stage 3: significant local spread, often involves regional lymph nodes

• Stage 4: distant metastasis present

Tumor grading vs. tumor staging - summary table

Oncologic Emergencies

Tumor Lysis Syndrome

• Tumor cells burst → release of intracellular contents into bloodstream

• Hyperkalemia = potassium released

• Hyperphosphatemia = phosphate released

• Hyperuricemia = nucleic acids released → converted to uric acid

• Hypocalcemia = phosphate binds calcium

• Leads to electrolyte abnormalities + uric acid crystal formation

• Results: cardiac dysrhythmias, neurologic complications, acute kidney injury (AKI)

Bone marrow suppression

• Decreased bone marrow production of blood cells, particularly common in cancer patients

• Decreased RBCs: anemia, fatigue, weakness, dyspnea

• Decreased WBCs: leukopenia, neutropenia, increased infection risk

• Decreased platelets: thrombocytopenia, increased bleeding risk

• Potentially life-threatening complications: infection/sepsis, severe anemia, hemorrhage

Leukopenia

• Decreased WBC count (<4,000) → normal is 45,00-11,000

• Causes: chemotherapy, radiation therapy, bone marrow suppression

• Decreased immune response: reduced ability to fight infection

• Signs & symptoms: fever (BAD), chills, fatigue, frequent infections

• Major complication: severe infection & sepsis

Neutropenia

• Decreased neutrophil count (ANC <1,500) → normal is 1,500-7,700

• Neutrophils: 1st line of defense against bacterial & fungal infections

• Causes: chemotherapy, radiation therapy, bone marrow suppression

• Neutrophils decreasing = infection risk

• Neutropenic fever = emergency!!

  • Single oral temp >101.°F OR 100.4°F sustained for 1 hour

Thrombocytopenia/Anemia

• Anemia (decreased RBCs):

  • Decreased O₂ carrying capacity, fatigue, weakness, pallor, dyspnea

• Thrombocytopenia (decreased platelets):

  • Impaired clot formation, easy bruising, petechiae, bleeding gums, increased hemorrhage risk

• Key nursing priorities:

  • Monitor CBC, assess for bleeding, assess for fatigue & activity intolerance, implement bleeding precautions as needed

Cancer Overview

Cancer - overview

• What Causes Cancer?

  • Cancer develops when DNA mutations cause cells to grow and divide uncontrollably

• Risk Factors

  • Tobacco use, UV radiation (sun exposure), environmental exposures, certain viruses (HPV, Hepatitis B & C), family history/genetics, increasing age, lifestyle factors (diet, obesity, physical inactivity)

• Important Facts

  • Cancer can develop in any tissue or organ

  • Most cancers result from multiple mutations over time

  • Not all cancers are inherited

  • Early detection improves outcomes

Carcinoma - Pathophysiology

• Cancers that arise from epithelial tissue

• Most common type of cancer → 80-90% of all cancer diagnoses

• 3 types:

  • 1. Basal Cell Carcinoma (BCC)

    • Most common skin cancer

    • Arises from basal cells of the epidermis, slow growing, rarely metastasizes

    • **Melanoma is NOT a carcinoma**

  • 2. Squamous Cell Carcinoma (SCC)

    • Arises from squamous epithelial cells → can occur in skin, mouth, esophagus, & cervis

    • More likely to invade & metastasize than BCC

  • 3. Adenocarcinoma

    • Arises from grandular epithelial tissue

    • Common in → breast, colon, lung, prostate

Basal Cell Carcinoma of the Skin

Skin cancer - core characteristics

• Most common skin cancer

• Arises from basal cells of the epidermis

• Associated w/ chronic UV exposure

• Slow growing, rarely metastasizes

Skin cancer - clinical presentation

• Pearly or waxy papule/nodule

• Visible blood vessels (telangiectasia)

• Non-healing sore or ulcer

• Commonly found on sun-exposed areas (face, ears, scalp, neck)

BCC of skin - treatment & priorities

• Treatment: surgical excision, Mohs surgery, cryotherapy, topical therapies

  • Mohs = cut off layer by layer → funnel-like, heals a lot better

  • Cryotherapy = freezing off (like a wart)

• Nursing priorities: educate on sun protection, encourage routine skin exams, monitor surgical site healing, report new/changing skin lesions

Colorectal Adenocarcinoma

Colorectal cancer - core characteristics

• Cancer of the colon or rectum

• Often develops from precancerous polyps (growths)

• Increased risk w/ COPD

• Risk increased w/ age

• One of the most common cancers worldwide

Colorectal cancer - clinical presentation

• Change in bowel habits → diarrhea/constipation, narrow stools/blood in stools

• Abdominal pain/cramping

• Unexplained weight loss

• Fatigue (may indicate anemia)

Colorectal cancer - detection/screening

• Colonoscopy → both a screening & diagnostic tool

• Flexible sigmoidoscopy → similar to colonoscopy, but doesn’t go through whole colon

• If these are positive, a colonoscopy is completed:

  • CT Colonography

  • Fecal Occult Blood Test (FOBT)

  • Fecal Immunochemical Test

Colonoscopy

• Visual exam of the colon & rectum using a flexible scope

• Why is it important?

  • Detects precancerous polyps (growths) → allows removal of polyps before they become cancerous

  • Detects colorectal cancer early → reduces colorectal cancer mortality

• Patient Preparation

  • Bowel prep required, clear liquid diet, NPO as ordered, sedation

Colorectal cancer - treatment & priorities

• Treatment

  • Surgical resection, chemotherapy, target therapy/immunotherapy, radiation therapy (more common for rectal cancer)

• Nursing priorities

  • Monitor bowel function, assess surgical incision & ostomy (if present), promote nutrition & hydration, monitor for infection, patient education on screening & follow-up care (ostomy care)

Adenocarcinoma of the Lung

Lung cancer - core characteristics

• Cancer originating in lung tissue

• Strongly associated w/ tobacco smoking → may also occur in nonsmokers

• Leading cause of cancer-related death → often caused metastasis in other areas of the body

• Often diagnosed at an advanced stage

Lung cancer - clinical presentation

• Persistent cough, new or worsening cough

• Hemoptysis (coughing up blood)

• Dyspnea

• Chest pain

• Hoarseness

• Unexplained weight loss

• Recurrent respiratory infections

Lung cancer - risk factors

• Cigarette smoking/second-hand smoking

• Radon exposure

• Occupational/job exposures (asbestos, silica)

• Family history

• Air pollution

Lung cancer - detection & screening

• Low-dose CT (LDCT)

• Chest X-ray (may detect abnormalities)

• Bronchoscopy

• Sputum cytology

• Tissue biopsy

Bronchoscopy

• Visual exam of the airways using a flexible scope

• Why is it important?

  • Visualizes the trachea & bronchi

  • Identifies tumors, obstructions, & abnormal tissue

  • Allows collection of tissue biopsies

  • Helps diagnose lung cancer

• Patient prep

  • NPO as ordered, sedation commonly used, remove dentures

• Post-procedure

  • Do not eat or drink until gas reflex returns (b/c throat spray numbs throat), monitor respiratory status, assess for bleeding

Lung cancer - treatment & priorities

• Treatment

  • Surgical resection (4 types), chemotherapy, radiation therapy, targeted therapy, immunotherapy

• Nursing priorities

  • Assess respiratory status, monitor oxygenation (Spo₂), promote smoking cessation, encourage pulmonary hygiene, coughing/deep breathing, incentive spirometry, monitor for infection, promote nutrition