Leucovorin (Folinic acid)
This describes 5-FU's net cellular effect, and explains why it also damages normal tissues like GI epithelium and bone marrow — not just cancer cells.
What is cell cycle arrest and apoptosis (in rapidly dividing cells)?
This drug class describes 5-FU, since it's a synthetic analog of the natural pyrimidine base uracil.
What is an antimetabolite?
This describes the drug class oxaliplatin belongs to — compounds that damage DNA directly using this heavy metal.
What is a platinum-based (platinum-containing) chemotherapy agent?
This describes the drug class of bevacizumab.
What is a monoclonal antibody?
This is the standard colonoscopy screening interval for an average-risk adult with no prior polyps.
What is every 10 years?
Leucovorin is a reduced, active form of this common vitamin, which normally requires an enzyme to become active — leucovorin bypasses that step.
What is folic acid (vitamin B9)?
This is the active metabolite of 5-FU that irreversibly inhibits thymidylate synthase.
What is FdUMP?
Oxaliplatin's primary mechanism of action involves forming these.
What are platinum-DNA crosslinks (intrastrand/interstrand)?
Bevacizumab works by binding and neutralizing this specific signaling protein.
What is VEGF (Vascular Endothelial Growth Factor)?
This is the diagnostic procedure that provided the definitive tissue diagnosis in this case, as opposed to CT imaging which only stages disease.
What is colonoscopy with biopsy (and CT)?
This is the specific enzyme target that leucovorin helps 5-FU bind to more effectively.
What is thymidylate synthase?
5-FU's second active metabolite, FUTP, disrupts function by incorporating directly into this molecule.
What is RNA?
Unlike 5-FU, oxaliplatin's action is NOT restricted to this.
What is a specific phase (it's not cell-cycle specific)?
This is the overarching term for bevacizumab's mechanism.
What is anti-angiogenesis?
This is the current recommended age to begin routine colonoscopy screening in an average-risk individual, a change from the previous standard.
What is 45?
This is the general pharmacokinetic route of administration and elimination for leucovorin.
What is IV administration with renal excretion?
This describes why 5-FU is typically given as a continuous infusion rather than a single bolus.
What is to maximize exposure time during S-phase (since it's cell-cycle specific and has a short ~10-20 minute half-life)?
This is the notable, dose-limiting toxicity associated with oxaliplatin, occurring in both acute cold-triggered and chronic cumulative forms.
What is peripheral neuropathy?
These are notable toxicities of bevacizumab that connect directly back to its mechanism of disrupting normal blood vessel function.
What are hypertension, impaired wound healing, GI perforation risk, and bleeding?
For a patient with a first-degree relative diagnosed with CRC before age 60 (or more than one first-degree relative at any age), colonoscopy should start at age 40, or this alternative age calculation, whichever is earlier — repeated every 5 years.
What is 10 years younger than the youngest affected relative?
Mechanistically, leucovorin doesn't inhibit thymidylate synthase itself — instead, it does this to 5-FU's active metabolite (FdUMP) and the enzyme.
What is stabilize/strengthen the binding (making the inhibition longer-lasting)?
Patients with a genetic deficiency in this specific enzyme can develop severe, even life-threatening toxicity from standard doses of 5-FU.
What is DPD (dihydropyrimidine dehydrogenase)?
Oxaliplatin is considered this "generation" of platinum-based chemotherapy drug.
What is third-generation?
This is bevacizumab's notably long half-life, which allows for less frequent dosing compared to conventional chemo.
What is approximately 20 days?
This is the surveillance interval recommended after a colonoscopy finds and removes 1–2 small (<10mm) tubular adenomas.
What is 7–10 years?