Neoplasia III Flashcards
What are carcinogens?
Carcinogens are agents that inflict genetic damage by damage to DNA
Direct-Acting Carcinogens
They require no metabolic conversion to enact their negative effects.
Indirect Acting Carcinogens
They require metabolic conversion to become ultimate
carcinogens.
What are promoters?
Promoters are compounds, which themselves are nontumorigenic, however they facilitate the induction of cell proliferation.
Carcinogen: Vinyl chloride
Angiosarcoma of the liver
Carcinogen: Nitrosamine in smoked foods
Stomach cancer
Carcinogen: Asbestos
Mesothelioma and bronchogenic carcinoma
Carcinogen: Arsenic
Squamous cell carcinoma of the skin
Carcinogen: Aflatoxin B
Hepatocellular carcinoma
Carcinogen: Cigarette smoke
Carcinoma of the oropharynx, lung, esophagus, kidney, bladder
What are some radiation carcinogens?
- Ionizing radiation (X-rays)
- UV light
What does Human T-cell lymphotropic virus (HTLV-1) cause?
T cell leukemia/lymphoma
What does Human papillomavirus (HPV) cause?
Cervical cancer
What does Epstein Barr Virus (EBV) cause?
Burkitt Lymphoma and nasopharyngeal carcinoma
What does Hepatitis B and C virus cause?
Hepatocellular carcinoma
What are some mechanisms that tumors enact to evade the immune system?
Failing to express HLA class I and escaping CTL attack
Eliminating strongly immunogenic subclones
Suppressing the host immune response; examples: by secreting TGF-beta
Expressing FasL and inducing immune cell apoptosis
Producing a thicker coat of glycocalyx molecules blocking access to immune cells
What is cancer cachexia?
This results on the loss of body fat, lean body mass, weakness, anorexia, anemia.
What are Paraneoplastic Syndromes?
They are symptom complexes that cannot be readily explained by local or distant spread of the neoplasms. They may be mediated by hormone elaboration which is not indigenous to the tumor parenchyma.
Examples are Cushing’s Syndrome from a tumor cells in the lung producing ACTH
How does grading of cancer work?
Based on the cytologic differentiation (anaplasia, pleomorphism, loss of normal architecture, mitoses) of the tumor cells
Well-differentiated = low grade; poorly differentiated = high grade
How does the staging of cancer work?
Staging of a cancer is based on the size of the primary tumor, extent of spread to regional lymph nodes, and the presence or absence of metastases.
What is “homing?”
Specific cancers have shown an ability to metastasize to areas of the body far away that show no direct path
