neoplasia Flashcards
5 characteristics of anaplasia
- pleomorphism (variation in cell shape and size
- nuclear hyperchromatism (intensely basophilic nuclei)
- increased nuclear/cytoplasmic ratio compared to normal cells
- atypical nuclei (variation in shape and size)
- numerous and atypical mitoses
most severe form of epithelial dysplasia which has all of the microscopic features of cancer, but the atypical cells have not invaded into the host
carcinoma-in-situ
____ tumors tend to have a capsule, which is a compressed band of _____ at the periphery of the tumor
benign; fibrous connective tissue
hemangioma and neurofibroma are common exceptions
the ____ quality is the most reliable means for distinguishing the malignant nature of a tumor
infiltrative
____ is considered the best indicator of malignancy
presence of metastasis
3 ways that malignancies spread
- seeding within body cavities (like the peritoneal cavity)
- lymphatic spread (commonly seen in carcinomas, resulting in lymph node metastases)
- hematogenous spread- favored by sarcomas; lung and liver frequent sites of metastasis in this case
3 well-defined genetic influences on cancer
- inherited cancer syndromes, AD (Rb, MEN)
- defective DNA repair syndromes, AR (xeroderma pigmentosum, ataxia telangiectasia)
- familial cancers (colon, breast, ovarian)
acquired preneoplastic disorders (persistent regenerative cell replication)
- squamous metaplasia and dysplasia of bronchial mucosa
- endometrial hyperplasia and dysplastic proliferations
- leukoplakia of the oral mucosa, vulva, penis
- villous adenomas of the colon
3 classes of normal regulatory genes - principal targets of genetic damage
- protooncogenes
- cancer suppressor genes
- apoptosis regulatory genes
____ are also important in carcinogenesis; if these genes are disabled, the _____ increases and the _____ increases
DNA repair genes; frequency of mutations; rate of neoplastic transformation
6 hallmarks of cancer
- self-sufficiency in growth signals
- insensitivity to growth inhibitory signals
- evasion of cell death
- limitless replicative potential
- development of sustained angiogenesis
- ability to invade and metastasize
factors susceptible to cancer in development of self-sufficiency in growth signals
- growth factors
- growth factor receptors
- signal-transduction proteins
- nuclear transcription factors
- cyclins and cyclin-dependent kinases (CDKs)
growth factor receptor commonly overexpressed
epidermal growth factor receptor family
ERBB-1 in squamous cell carcinoma of the lung
ERBB-2 (HER/NEU) amplified in some breast cancers
most commonly mutated proto-oncogene
RAS gene (normal cytoplasmic signal-transducing protein)
most common overexpressed nuclear transcription factor
MYC gene (activates transcription of cyclin D1, a gene whose product drives cells into the cell cycle)
first tumor suppressor gene to be discovered
retinoblastoma (Rb) gene
single most common target for genetic alteration in human tumors
TP53 tumor suppressor gene
___ loss of ____ is found in virtually every type of cancer; usually due to _____
homozygous loss of TP53; somatic mutation
condition in which families have one aberrant TP53 gene, resulting in a markedly increased rate of cancer for affected individuals
Li-Fraumeni syndrome
____ is the prototypic anti-apoptosis gene activated by ____; found in ____
BCL2; translocation; low-grade lymphomas
2 major phases of metastasis
- invasion of the ECM
2. vascular dissemination and adhesion/homing of tumor cells
steps of invasion of ECM
- detachment of tumor cells from one another
- attachment of tumor cells to matrix components
- degradation of ECM
- migration of tumor cells
once in the circulation, tumor cells adhere to _____, followed by _____
vascular endothelium; basement membrane transmigration
the dist of tumor metastases can generally be predicted by the _____ and _____
location of the primary tumor and its vascular or lymphatic drainage
