Neoplastic Pathophysiology

Question 1

What is the definition of neoplasia?

Answer 1

An abnormal mass of tissue in which the cells deviate from normal with regards to: Growth/Proliferation, Differentiation, Organization and Function

Question 2

Name the general terminology for describing neoplasms of epithelial- and connective tissue

Answer 2

Epithelial
Benign: -oma (Papiloma, adenoma)
Malignant: -carcinoma (adenocarcinoma)

Connective tissue
Benign: -oma (Fibroma, Lipoma)
Malignant: -sarcoma (Fibrosarcoma, Liposarcoma)

Question 3

Differences between benign and malignant tumors in regard to cell characteristics, rate of growth, mode of growth and metastasis

Answer 3

Benign
Cell characteristics: Well differentiated, Looks like origen cells
Rate of Growth: Progressive + slow, Can stop + regress
Mode of Growth: Expansion, Encapsulated
Metastasis: NO

Malignant
Cell characteristics: Undifferentiated, Does not have much resemblance to origen cells
Rate of Growth: Undifferentiated -> Increased growth
Mode of Growth: Invasion, Infiltrates surrounding tissue
Metastasis: Gains access to lymph/ blood -> Metastasize to other areas

Question 4

Properties of cancer cells

Answer 4

Changes in molecular + cellular pathways
- Defect DNA Repair mechanism
- Defects in growth factor signaling pathways
- Evasion of apoptosis
- Sustained proliferation signal (Stabilization of telomers)
- Angiogenesis (in solid tumors)
- Invasive (secrete enzymes) + Metastasis

Question 5

Process of invasion and metastasis

Answer 5

Invasion
Growth of benign tumor in epithelium -> secretion of enzymes -> Intravasation Becomes invasive and enter the capillary

Metastasis
Adhesion to vessel wall -> Extravasation Escape to tissue + form micrometastasis -> Colonize tissue (often liver, bone, brain, lung)
Can be: Lymphatic spread, hematogenous spread and through body cavities (CSF)

Question 6

Properties of oncogenes and tumor suppressors

Answer 6

Oncogenes
Gene overactivity -> Increased risk of cancer
Genes that code for proteins involved in
- Cellular proliferation
- Attenuating (% regulation) differentiation
- Attenuation apoptosis
One mutation is often enough (Can be triggered by radiation, virus)

Tumor suppressors
Gene underactivity -> Increased risk of cancer
Genes that code for proteins normally involved in
- Preventing cell division
- Activation of apoptosis in cells with DNA damage
Mutations in both alleles is usually needed

Question 7

Process of tumor cell transformation

Answer 7

1. Initiation DNA damage + cell mutation in 1 cell (virus, radiation)
2. Promotion Clonal expansion -> Cell gets advantage from stimulus, Activation of oncogenes
3. Progression Autonomous growth
4. Cancer Cells can invade + metastasise

Question 8

Examples of diagnostics and treatments of cancer

Answer 8

Diagnosis
- Screening (Mammography, PAP test)
- Blood tests (Tumor markers)
- Biopsy
- MRI/PET/CT scan

Treatment
- Surgical (local)
- Radiation therapy (local)
- Chemotherapy (systemic)
- Biological therapies