Neoplasia Objectives Flashcards
Summarize the 3 fundamental and shared characteristics of cancers
- Cancer is a genetic disorder caused by DNA mutations.
- Genetic alterations in cancer cells are heritable, being passed to daughter cells upon cell division.
- Mutations and epigenetic alterations impart “cancer hallmarks” to cancer cells.
What is a neoplasia?
Neoplastic cells replicate without being constrained by regulating factors that affect normal cells.
What is a papilloma?
Benign epithelial neoplasm
What is a polyp?
Mass that projects above a mucosal surface
What is a chondroma?
Benign cartilaginous tumor.
What is a carcinoma?
Malignant neoplasm of epithelial cells
What is a sarcoma?
Malignant neoplasms of the mesenchymal/connective tissue
Compare and contrast benign and malignant tumors.
BENIGN: mass is mobile, smooth with surrounding fibrous capsule, slow growing, well circumscribed.
MALIGNANT: fixed or ulcerating, irregularly shaped with no capsule, fast growing, metastasis
What are the two basic components of all tumors?
- Parenchyma: determines tumor’s biological behavior.
2. Stroma: supporting non-neoplastic connective tissue such as connective tissue, blood vessels, inflammatory cells
What are the 3 fundamental distinguishing features between benign and malignant tumors?
- Differentiation and anaplasia: benign tumors are well-differentiated and resemble the normal cells, malignant lack differentiation.
- Local invasion: Benign stay local within a capsule, malignant invade and lack capsules.
- Metastasis: Metastasis unequivocally marks a tumor as malignant.
Define anaplasia
“backward formation,” loss of structural and functional differentiation of normal cells
What are the common morphological changes of anaplasia?
- Pleomorphism: variation in size and shape.
- Nuclear abnormalities
- Tumor giant cells: considerably larger than neighboring cells and may include enormous or several nuclei
- Atypical mitosis
- Loss of polarity
What is the difference between dysplasia and carcinoma in situ?
Dysplasia is disorderly proliferation/growth, loss of uniformity of individual cells and architectural orientation, and has possibility of returning to normal. Carcinoma in situ is a preinvasive stage of cancer when dysplastic changes are severe and involve the entire thickness of epithelium.
What are features of invasiveness?
Lack of well defined borders, requires wide margins during surgical excision, allows penetration into blood vessels/lymph/body cavities for metastasis
What are 3 mechanisms of metastasis?
- Seeding within body cavities (e.g. spread over peritoneal surfaces).
- Lymphatic spread
- Hematogenous spread through blood vessels
What is a sentinel lymph node?
First regional lymph node that receives lymph flow from primary tumor.
Identifiable by injecting blue dyes or radioactive tracers into primary tumor.
Sentinel lymph nodes indicate extent of metastasis
What are 3 main factors that affect incidence of cancer?
- Geographic & environmental
- Age
- Genetic/heredity
What are four major classes of cancer genes?
- Oncogenes: promote cell growth.
- Tumor suppressor genes: Prevent uncontrolled growth.
- Genes that regulate apoptosis.
- Genes that regulate interactions between tumor cells and host cells: enhance or inhibit recognition by immune system.
8 hallmarks of cancer?
- Self-sufficiency of growth signals
- Insensitivity to growth-inhibitory signals
- Altered cellular metabolism.
- Evasion of apoptosis.
- Immortality.
- Sustained angiogenesis.
- Invasion and metastasis.
- Evasion of immune surveillance.
What is the RAS gene?
Most commonly mutated oncogene in tumors.
RAS gene encodes for RAS protein, which is activated by receptors turned on by growth factors. Mutated RAS gene creates RAS protein that is always turned “on”
What is TP53?
Most commonly mutated gene in human cancer.
Tumor suppressor gene that functions by blocking progression from G1-S (for DNA repair), causing senescence (prohibiting cell division), or apoptosis
What are 3 classes of carcinogenic agents?
- Chemicals (causes lung cancer, leukemia, bladder cancer).
- Radiant energy (causes skin, thyroid cancers).
- Bacteria and viruses (HPV, EBV, H. Pylori)
What are 5 most common effects of a tumor on the host?
- Impingement on adjacent structures.
- Paraneoplastic syndromes (e.g. tumors produce hormones)
- Bleeding and infection.
- Organ rupture or infarction.
- Cachexia, weakness/wasting
What are the 3 most common neoplastic syndromes?
- HYPERCALCEMIA: Mechanism- PTH released by tumor cells.
- CUSHING’S SYNDROME. Mechanism- ACTH releases by cancer cells.
- HYPERCOAGUABILITY. Mechanism- cancer releases coagulating agents that cause embolisms and non-bacterial endocarditis.
