14). AI Oncogenesis & Cancer Biology Practice Questions

Comprehensive practice flashcards covering oncogenesis, cancer biology, dysplasia grading, invasion mechanisms, and molecular pathways.

What is the definition of neoplasia?

New, abnormal tissue growth.

Which statement best defines a neoplasm?

Growth persists excessively after the initiating stimulus stops.

What does monoclonal tumor origin mean?

Descendants originate from one altered cell.

What distinguishes a malignant tumor from a benign tumor?

The ability to invade surrounding tissues.

Which process best describes the development of cancer over time?

Accumulation and selection of changes that favor abnormal growth.

A tumor that is well circumscribed and compresses adjacent tissue is more likely to be which type?

Benign.

What does the term "metastasis" mean?

Spread to a discontinuous distant site.

What morphological characteristics are hallmarks of malignant cells?

Pleomorphism and hyperchromatic nuclei.

Which mitotic finding is characteristic of many highly malignant neoplasms?

Abnormal mitotic figures.

Why may genetic cancer changes precede visible cancer?

Molecular alterations can develop before obvious clinical or microscopic changes.

Which exposure is highlighted as a preventable cancer risk in the lecture?

Tobacco smoke.

Which environmental exposure is linked to DNA damage and cancer risk?

Ultraviolet radiation.

Which type of infectious agent can contribute to cancer?

Oncogenic viruses.

How does profound immunosuppression affect cancer risk?

It increases risk for some cancers.

Which population is identified as having an elevated cancer risk from immunosuppression?

Organ transplant recipients.

Which clinical pattern may suggest a familial cancer syndrome?

Early-onset cancer and multiple tumors.

Which inherited condition is associated with impaired DNA repair?

Xeroderma pigmentosum.

Which general cancer trend regarding age is emphasized in the lecture?

Incidence rises with age.

Which cultural practice is linked to oral cancer risk in the lecture?

Tobacco chewing.

Which cancer prevention strategy is supported by the lecture?

Avoiding tobacco and chemical carcinogens.

Which finding defines carcinoma in situ?

Full-thickness epithelial atypia without invasion.

In the lecture, mild dysplasia is described as affecting which epithelial layer?

The basal epithelial layer.

How far through the epithelium does moderate dysplasia extend?

From the basal layer to the middle spinous layer.

How far through the epithelium does severe dysplasia extend?

Above the midpoint of the spinous layer.

Which specific histological change marks the transition to invasive carcinoma?

Penetration of the basement membrane.

What does induration indicate clinically?

Firmness that may reflect cancer, scarring, or deep inflammation.

What cellular change promotes the detachment of tumor cells during invasion?

Reduced cadherin-mediated adhesion.

Which enzyme facilitates the breakdown of the basement membrane during invasion?

Type IV collagenase.

Which molecule helps attach epithelial cells to basement membrane components?

Laminin.

Which substance is associated with tumor cell movement through tissue?

Autocrine motility factor.

Which tumor suppressor gene is implicated in Gorlin-Goltz syndrome?

PTCH.

On which chromosome is the PTCH gene located?

Chromosome 9.

Which inherited syndrome is associated with multiple odontogenic keratocysts and basal cell carcinomas?

Gorlin-Goltz syndrome.

Which gene locus is associated with Gardner syndrome?

APC at 5q21.

Which clinical combination is associated with Gardner syndrome?

Colon adenomas, osteomas, and extra or unerupted teeth.

What is the chromosomal translocation associated with the Philadelphia chromosome?

$t(9;22)$.

Which translocation is classically associated with Burkitt lymphoma?

$t(8;14)$.

Loss of the 13q14 chromosomal region is linked to which tumor?

Retinoblastoma.

Loss of the 11p13 chromosomal region is linked to which tumor?

Wilms tumor.

Amplification of N-MYC is associated with which neoplasm?

Neuroblastoma.

How can gene amplification promote oncogenesis?

By increasing expression of a growth-promoting oncogene.

Which tumor suppressor commonly coordinates cell arrest or apoptosis after DNA damage?

TP53.

Which receptor is frequently overexpressed in head and neck squamous cell carcinomas?

EGFR.

Which signaling cascade downstream of growth factor receptors promotes proliferation?

RAS-RAF-MEK-ERK.

Which intracellular pathway can promote tumor cell growth and survival?

PI3K-AKT-mTOR.

Loss of CDKN2A function can favor cancer by disrupting which process?

Cell-cycle checkpoint control.

What is a major cellular consequence of persistent EGFR signaling?

Increased pro-growth signaling.

Which protein promotes the formation of blood vessels to support tumor growth?

VEGF.

What does activation of telomerase help tumor cells achieve?

Maintenance of telomeres across repeated divisions.

Which change can make a cancer cell less responsive to apoptosis?

Increased anti-apoptotic BCL-2 signaling.

Why are multiple pathway alterations often involved in oral carcinogenesis?

Growth, survival, genome stability, and invasion are controlled by distinct interacting mechanisms.

Which fusion gene is associated with the $t(9;22)$ translocation?

BCR-ABL.

How does mild dysplasia differ from moderate dysplasia in terms of epithelial depth?

Mild dysplasia affects the basal epithelial layer, whereas moderate dysplasia extends from the basal layer to the middle spinous layer.

How does severe dysplasia differ from carcinoma in situ?

Severe dysplasia extends above the midpoint of the spinous layer, whereas carcinoma in situ is defined by full-thickness epithelial atypia without invasion.

What boundary must a neoplasm cross to transition from carcinoma in situ to invasive carcinoma?

The basement membrane.

What two morphological features of the cell nucleus are classical hallmarks of malignancy?

Pleomorphism and hyperchromatic nuclei.

What does monoclonal origin imply about the initial cellular genesis of a neoplasm?

All tumor cell descendants originate from a single altered cell.

How does the gross local behavior of a benign neoplasm differ from that of an invasive malignancy?

A benign neoplasm is well circumscribed and compresses adjacent tissue rather than invading it.

Which two specific environmental or lifestyle exposures are cited as causes of DNA damage or preventable cancer risks?

Tobacco smoke and ultraviolet radiation.

Which distinct dental and osseous findings accompany colon adenomas in Gardner syndrome?

Osteomas and extra or unerupted teeth.