Overview of cancer chemotherapy Flashcards
What is chemotherapy dhow does it work in cancer treatment?
Chemotherapy is the use of chemical substances, especially cytotoxic drugs, to treat cancer. It works by targeting rapidly dividing cells, a hallmark of cancer, disrupting cell division and leading to cell death.
What is the primary mechanism by which chemotherapeutic drugs act?
They disrupt cell cycle progression, particularly targeting DNA synthesis or mitosis, leading to apoptosis in rapidly dividing cancer cells.
How does this mechanism relate to their therapeutic use?
Since cancer cells divide more rapidly than normal cells, these drugs selectively affect tumor cells, although some normal dividing cells are also impacted.
How are chemotherapeutic drugs classified based on the cell cycle?
Cell cycle-specific (CCS): Act on specific phases (e.g., S or M phase).
Cell cycle-nonspecific (CCNS): Can act at any stage of the cell cycle, including resting cells.
Why is this classification clinically important?
It guides drug choice and scheduling; CCS drugs require scheduling to match the cycle, while CCNS are more broadly effective but often more toxic.
What are the major classes of chemotherapeutic drugs?
Alkylating agents
Antimetabolites
Natural products (e.g., plant alkaloids, antibiotics)
Hormonal agents
Miscellaneous agents
Targeted therapies
How do alkylating agents work?
They add alkyl groups to DNA, causing cross-linking and strand breakage, inhibiting DNA replication and transcription.
What are examples of alkylating agents?
Cyclophosphamide, Chlorambucil, Melphalan.
What are common side effects of alkylating agents?
Myelosuppression, nausea, vomiting, hemorrhagic cystitis.
What is the mechanism of action for antimetabolites?
They mimic normal cellular substrates, interfering with DNA/RNA synthesis.
What are examples of antimetabolites?
Methotrexate, 5-Fluorouracil (5-FU), Cytarabine.
What are major side effects og antimetabolites?
Myelosuppression, mucositis, gastrointestinal toxicity.
How do plant alkaloids function?
They inhibit mitosis by binding to microtubules.
Name examples of plant alkaloids.
Vincristine, Vinblastine, Paclitaxel.
What are key side effects of plant alkaloids?
Neurotoxicity (vincristine), bone marrow suppression (vinblastine), hypersensitivity reactions (paclitaxel).
What is the role of antitumour antibiotics?
They intercalate into DNA, inhibit topoisomerase, and generate free radicals
Name some examples of antitumour antibiotics
Doxorubicin, Daunorubicin, Bleomycin.
What are the key side effects of antitumour antibiotics?
Cardiotoxicity (doxorubicin), pulmonary fibrosis (bleomycin).
How are hormonal agents used in cancer therapy?
They block hormone receptors or reduce hormone production in hormone-sensitive cancers.
What are some examples of hormonal agents?
Tamoxifen (breast cancer), Flutamide (prostate cancer), Aromatase inhibitors.
What are the adverse effects of hormonal agents?
Hot flashes, thromboembolism (Tamoxifen), gynecomastia (Flutamide).
What distinguishes targeted therapies from traditional chemotherapy?
They specifically target molecular abnormalities in cancer cells (e.g., mutated proteins, overexpressed receptors).
Give examples of targeted therapies.
Imatinib (BCR-ABL in CML), Trastuzumab (HER2 in breast cancer), Bevacizumab (VEGF inhibitor).
What are the side effects of targeted therapies?
Diarrhea, skin rash, cardiotoxicity (trastuzumab).
