Tumor Basics
What does the suffix -oma generally indicate in tumor names?
A benign tumor
Define contact inhibition.
The ability of normal cells to stop dividing when they touch other cells; cancer cells lose this property.
What is a proto-oncogene?
The normal form of a gene that directs cell growth and division; when mutated, it becomes an oncogene.
What is the term for growth of new blood vessels that tumors need to survive?
Angiogenesis.
Which type of chemotherapy is given before surgery to shrink a tumor?
A) Adjuvant
B) Neoadjuvant
C) Induction
D) Palliative
B) Neoadjuvant.
What is the difference between a benign and malignant tumor?
Benign = localized and non-invasive; Malignant = invasive and can metastasize.
Which of the following is not a property of cancer cells?
A) Immortality
B) Lack of contact inhibition
C) Anchorage dependence
D) Anaplasia
C) Anchorage dependence (they are anchorage independent).
Which gene is known as the “guardian of the genome”?
A) ras
B) TP53
C) BRCA1
D) Myc
B) TP53.
A tumor must develop its own blood supply once it grows larger than:
A) 1 micron
B) 1 millimeter
C) 1 centimeter
D) 10 centimeters
B) 1 millimeter.
Name one major side effect of chemotherapy on the bone marrow.
Anemia, leukopenia, or thrombocytopenia.
Which of the following is an example of a malignant tumor?
A) Adenocarcinoma
B) Lipoma
C) Leiomyoma
D) Chondroma
A) Adenocarcinoma
What does it mean for cancer cells to be immortal?
They divide indefinitely, often due to activation of telomerase.
How do oncogenes differ from tumor suppressor genes?
Oncogenes promote cell growth when mutated; tumor suppressor genes normally inhibit growth but, when mutated, allow uncontrolled growth.
What is the difference between Stage 1 and Stage 4 cancer?
Stage 1 = confined to organ of origin; Stage 4 = metastasized to distant sites.
Explain how CAR-T cell therapy works.
Patient’s T cells are engineered with chimeric antigen receptors to better recognize and kill cancer cells.
What is a carcinoma in situ?
A pre-invasive malignant tumor that has not invaded the basement membrane.
Differentiate between anaplasia and pleomorphism.
Anaplasia = loss of cell differentiation and organization; Pleomorphism = variability in cell size and shape.
Explain the concept of loss of heterozygosity.
When both copies of a tumor suppressor gene are inactivated, leading to unregulated cell growth.
Define organ tropism.
The tendency of cancer cells to preferentially grow in certain organs due to local growth factors, receptors, or chemokines.
What is cachexia?
A severe form of malnutrition seen in cancer patients, including anorexia, weight loss, and weakness.
Explain why tumor classification is important in cancer biology.
It helps determine prognosis, treatment options, and biological behavior of the tumor.
What is meant by multipotency of tumor stem cells?
Their ability to differentiate into multiple different cell types.
Which is an example of a caretaker gene disorder?
A) Hepatitis B infection
B) Xeroderma pigmentosum
C) HPV infection
D) Kaposi sarcoma
B) Xeroderma pigmentosum.
Explain how cancer cells detach and invade new tissues.
They use proteases to digest extracellular matrix, reduce adhesion molecules, and spread via circulation/lymph.
Differentiate between adjuvant, neoadjuvant, and induction chemotherapy.
Adjuvant = after surgery to eliminate micrometastases; Neoadjuvant = before surgery to shrink tumor; Induction = initial therapy to reduce tumor burden.