ORG MED Q4 LEC FINALS

Which statement correctly describes the staging for T2, N1, M0 in this system?

• Large tumor, no lymph node involvement, distant metastasis present

• Moderate sized tumor, limited regional lymph node spread, no distant metastasis

• Small tumor, extensive lymph node involvement, distant metastasis present

• Moderate sized tumor, no lymph node involvement, widespread metastasis

In the cell cycle, which phase is known as the “restriction point” where tumor cells commonly exhibit abnormal checkpoint control?

• G0 phase

• G1 phase

• S phase

• G2 phase

Which positional nucleophilic site on guanine DNA bases is most frequently alkylated by nitrogen mustard alkylating agents?

• N1

• N3

• N7

• O6

Regarding nitrogen mustards, which structural feature primarily distinguishes aliphatic from aromatic mustards, and how does this influence their pharmacokinetics?

• Aromatic mustards have an aryl group at the tertiary amine; they are more orally bioavailable and less reactive

• Aliphatic mustards have additional chlorine atoms making them more oral active

• Aromatic mustards have methyl groups increasing toxicity

• Aliphatic mustards contain an aryl substituent increasing water solubility

What toxic metabolite produced from cyclophosphamide metabolism is responsible for hemorrhagic cystitis, and what adjuvant drug is used to prevent this toxicity?

• Acrolein; Mesna

• Acrolein; Leucovorin

• Phosphoramide mustard; Dexrazoxane

• Phosphoramide mustard; Mesna

Thiotepa exerts cytotoxic effects after oxidative desulfuration to form which active metabolite, and what CNS-related toxicities are commonly seen?

• TEPA; dizziness and blurred vision

• TEPA; peripheral neuropathy and seizures

• Active sulfur mustard; hepatotoxicity and nephrotoxicity

• Phosphoramide mustard; hemolytic anemia

Carmustine’s high lipid solubility allows it to cross the blood-brain barrier. Which clinical condition is this property utilized for, and what dose-limiting toxicity must be monitored?

• Hodgkin’s lymphoma; nephrotoxicity

• Brain tumors; pulmonary toxicity

• Testicular cancer; ototoxicity

• Multiple myeloma; cardiotoxicity

Procarbazine induces O6-methylguanine formation in DNA. How do these lesions affect DNA replication, and what is a notable drug interaction risk unique to procarbazine?

• Cause double-strand DNA breaks; strong interaction with CYP3A4 inhibitors

• Result in mismatch pairing with thymine promoting mutations; inhibit monoamine oxidase causing fatal reactions with tyramine-rich foods

• Inhibit topoisomerase I; increase risk of serotonin syndrome with SSRIs

• Trigger crosslinking; anticholinergic overdose risk

The planar pentacyclic structure of camptothecin is essential for activity. Hydrolysis of which lactone ring leads to inactivation of the drug, and what chemical modifications can stabilize it?

• Ring A; substitution with hydroxyl groups

• Ring C; addition of aromatic side chains

• E-ring lactone; halogenation (Cl, Br, F) to stabilize polarity

• D-ring pyridone; alkylation at C9

The epipodophyllotoxins etoposide and teniposide differ structurally in:

• The number of methoxy groups on ring B

• The configuration of the β-d-glucopyranosyl substituent at C2

• The presence of an additional acetal group on ring D

• The chirality at the pentacyclic lactone