31 - Anticancer Chemotherapy

A set of vocabulary flashcards covering major terms and concepts from the lecture notes on anticancer chemotherapy.

Anticancer chemotherapy

Treatment with cytotoxic drugs aimed at eradicating cancer cells or controlling cancer progression.

Selectivity

Ability of a drug to preferentially target cancer cells over normal cells, enabling a therapeutic window.

Therapeutic index

Ratio of a drug's toxic dose to its effective dose; higher index means a wider safety margin.

Therapeutic window

Range of drug concentrations in which a drug is effective without unacceptable toxicity.

Adjuvant chemotherapy

Chemotherapy given after primary treatment (surgery/radiotherapy) to reduce recurrence.

Neo-adjuvant chemotherapy

Chemotherapy given before primary treatment to shrink tumors.

Maintenance chemotherapy

Non-curative therapy to prolong remission or improve quality of life.

Palliative chemotherapy

Chemotherapy aimed at symptom relief and quality of life rather than cure.

Alkylating agents

Drugs that transfer alkyl groups to DNA, causing cross-links and DNA damage leading to cell death.

Nitrogen mustard

A class of alkylating agents including cyclophosphamide, melphalan, chlorambucil.

Cyclophosphamide

A prodrug activated by liver P450 enzymes; forms DNA cross-links; cell cycle non-specific; used short-term.

Platinum compounds

Alkylating-like agents forming DNA crosslinks (inter- and intra-strand); examples: cisplatin, carboplatin, oxaliplatin.

Cisplatin

Platinum-based DNA crosslinking agent used across multiple cancers.

Antimetabolites

Drugs that resemble natural nucleotide precursors, inhibiting DNA/RNA synthesis by targeting enzymes like thymidylate synthase and dihydrofolate reductase.

Methotrexate

Folate antagonist that inhibits dihydrofolate reductase, blocking thymidylate and purine synthesis; S-phase active.

5-Fluorouracil (5-FU)

Pyrimidine antimetabolite activated to 5-FdUMP; inhibits thymidylate synthase and disrupts DNA synthesis.

Thymidylate synthase

Enzyme converting dUMP to dTMP; inhibited by 5-FU, limiting DNA synthesis.

Dihydrofolate reductase

Enzyme regenerating THF from DHF; inhibited by methotrexate, reducing nucleotide synthesis.

Anthracyclines

DNA-binding antibiotics that intercalate DNA, inhibit repair, generate ROS, and cause DNA breaks.

Epirubicin

Anthracycline that intercalates DNA and inhibits repair, leading to DNA fragmentation and cell death.

Topoisomerase inhibitors

Drugs that inhibit topoisomerase I or II, preventing DNA replication and repair.

Irinotecan

Topo I inhibitor; semisynthetic camptothecin derivative; IV; used in colon cancer.

Topotecan

Topo I inhibitor used in ovarian and other cancers; inhibits DNA repaIr via topo I blockade.

Etoposide

Topo II inhibitor; acts in S and G2; stabilizes DNA-topoisomerase II complex, causing DNA breaks.

Microtubule inhibitors

Drugs that disrupt mitotic spindle function; cell cycle specific (M phase).

Vinca alkaloids

From Catharanthus roseus; vincristine and vinblastine; inhibit microtubule assembly by binding β-tubulin.

Paclitaxel

Taxane that stabilizes microtubules, preventing disassembly and causing mitotic arrest; IV use.

Docetaxel

Taxane similar to paclitaxel; stabilizes microtubules and disrupts mitosis; given IV.

Molecularly targeted therapies

Small molecule inhibitors that block ATP-binding sites of kinases, interrupting signaling pathways.

Imatinib

BCR-ABL tyrosine kinase inhibitor; effective in CML and GIST by inhibiting abnormal kinase activity.

Monoclonal antibodies

Antibodies targeting specific cell-surface proteins to block signaling or deliver therapy; examples trastuzumab, cetuximab, rituximab.

Trastuzumab

Monoclonal antibody against HER2; used in HER2-positive breast cancer.

Tamoxifen

Selective estrogen receptor modulator (SERM); competes with estrogen for ER binding; used in ER-positive breast cancer.

Aromatase inhibitors

Block estrogen synthesis by inhibiting aromatase; examples include anastrozole and letrozole.

SERDs

Selective estrogen receptor downregulators; degrade ER and inhibit signaling (e.g., fulvestrant).

Biological response modifiers

Agents that influence biological responses to cancer, including immunomodulators and checkpoint inhibitors.

Interleukin-2

Cytokine used to stimulate cytolytic T cells against tumors.

PD-1 inhibitors

Immune checkpoint inhibitors that release T-cell inhibition; examples pembrolizumab and nivolumab.

Complications of chemotherapy

Adverse effects such as nausea/vomiting, extravasation injury, bone marrow suppression, infection, alopecia, infertility, teratogenesis, secondary malignancies.

Primary resistance

Intrinsic resistance present before therapy due to tumor heterogeneity and microenvironment.

Acquired resistance

Resistance that develops during treatment due to mutations, altered drug targets, or adaptive pathways.

Multidrug resistance

Resistance via mechanisms like efflux pumps (e.g., P-glycoprotein) reducing intracellular drug levels.

Hallmarks of cancer

Key cancer traits: sustaining proliferative signaling, evading growth suppressors, resisting cell death, inducing angiogenesis, invasion/metastasis, genome instability, and immune evasion.