Chapter 7, Neoplasia

Benign tumors

Not cancerous and easily cured

• No potential to kill host but may be in life threatening location

• Resembles original tissue type

• Grows slowly, little vascularity, no necrotic, retain function and are often encapsulated.

Malignant tumors

months of intensive treatment with uncertain outcomes. Malignant neoplasm is cancer

• Can kill host if left untreated

• Grows rapidly, vascular, necrotic and dysfunctional

• Tissue specific differentiation

• Very invasive and highly metastasizing.

Patterns of spread

• Circulatory or lymphatic systems

• Angiogenesis

• Tumor markers

Angiogenesis

the process where a cancer tumor stimulates the formation of new blood vessels to supply itself with oxygen and nutrients required for growth

Tumor markers

specific substances (ex. proteins) released by tumor cells that help identify the parent tissue of cancer origin

Leukopenia

a deficiency in circulating white blood cells (WBCs), primarily caused by malignant invasion of bone marrow, chemotherapy, or malnutrition, which leaves the host (immunocompromised) vulnerable to severe opportunistic infections

Neutropenia

a deficiency in neutrophils (the primary phagocytic white blood cells), drastically increasing immediate susceptibility to bacterial and fungal infections

Thrombocytopenia

a deficiency in circulating blood platelets. Because platelets mediate clotting, counts dropping below 20,000/mm³ create a severe risk for life-threatening hemorrhage

Anemia

low hemoglobin levels caused by anorexia, chronic tumor bleeding, or bone marrow suppression

Anemia, leukopenia, and thrombocytopenia can all be managed with what?

blood replacement therapy

Cancer Therapies

• Mainstray therapies

  • Surgery

  • Radiation

  • Chemotherapy

• Emerging therapies

  • Immunotherapies

  • Molecular/Targeted therapies

  • Gene therapy

  • Stem cell transplant

Surgery

direct physical removal of the tumor mass; best suited for localized cancers

Radiation

uses targeted high-energy radiation to kill cancer cells and shrink tumors by damaging their DNA

Chemotherapy

systemic administration of cytotoxic drugs to eliminate rapidly dividing cells throughout the body

Immunotherapy

boosting the patient's own immune system to recognize and attack tumor cells

Molecular/Targeted therapy

targeting specific mutated proteins like oncogenes

Genetic mechanisms & risk factors

• Proto-oncogene vs. Oncogene

• Tumor Suppressor Genes

• Cachexia

• Skin Cancer ABCDEs

Proto-oncogene vs. Oncogene

proto-oncogenes normal enhance growth pathways; when mutated, they become overactive oncogenes that drive uncontrolled cellular proliferation

Tumor Suppressor Genes

genes (like p53 or Rb) that normally inhibit cell division or trigger apoptosis; cancer occurs when their function is lost or mutated

Cachexia

severe, systemic tissue wasting, muscle atrophy, anorexia, and elevated metabolic rate caused by advanced malignancy

Skin Cancer ABCDEs

skin cancer signs include

• Asymmetry

• Border irregularity

• Color variation

• Diameter > 6 mm

• Evolution over time