Anticancer Drugs Practice Questions

Q: Which of the following drugs is used in the adjuvant setting for carcinoma of the colon?

Oxaliplatin. **Explanation:** **Oxaliplatin** is the correct answer because it is a cornerstone of **adjuvant chemotherapy** for Stage III (and high-risk Stage II) colon cancer. The standard adjuvant regimens are **FOLFOX** (5-Fluorouracil, Leucovorin, and Oxaliplatin) or **CAPOX** (Capecitabine and Oxaliplatin). Adjuvant therapy aims to eliminate micrometastases after surgical resection to reduce the risk of recurrence. **Analysis of Incorrect Options:** * **Bevacizumab (Option A):** This is a VEGF inhibitor (angiogenesis inhibitor). While highly effective in the **metastatic** (palliative) setting, clinical trials (like NSABP C-08) showed it provides no survival benefit in the adjuvant setting for colon cancer. * **Cetuximab (Option B):** An EGFR inhibitor used specifically for **metastatic** colorectal cancer in patients with **KRAS wild-type** tumors. Similar to Bevacizumab, it has failed to show benefit in adjuvant trials. * **Irinotecan (Option C):** A Topoisomerase I inhibitor. It is a key component of the **FOLFIRI** regimen used for **metastatic** disease. However, adding Irinotecan to adjuvant 5-FU (IFL regimen) did not improve outcomes compared to 5-FU alone and increased toxicity. **High-Yield Clinical Pearls for NEET-PG:** * **Dose-limiting toxicity of Oxaliplatin:** Peripheral sensory neuropathy (often triggered or exacerbated by **cold exposure**). * **Mechanism:** Platinum compound that forms intra-strand DNA cross-links. * **5-Fluorouracil (5-FU):** Always the "backbone" of colon cancer therapy; its action is enhanced by **Leucovorin** (folinic acid), which stabilizes the binding of 5-dUMP to thymidylate synthase. * **Microsatellite Instability (MSI-H):** Patients with Stage II colon cancer and MSI-H have a good prognosis and generally do *not* benefit from adjuvant 5-FU monotherapy.

Q: Which of the following anticancer drugs can cause a hypercoagulable state?

L-asparaginase. **Explanation:** **L-asparaginase** is the correct answer because its primary mechanism of action involves the depletion of asparagine, which is essential for protein synthesis in leukemic cells. However, this inhibition of protein synthesis is not selective and also affects the liver’s production of endogenous anticoagulants. Specifically, it leads to a significant **decrease in Protein C, Protein S, and Antithrombin III** levels. This deficiency shifts the hemostatic balance toward a **hypercoagulable state**, increasing the risk of venous thromboembolism (VTE) and sagittal sinus thrombosis. **Analysis of Incorrect Options:** * **A. 5-Fluorouracil (5-FU):** Primarily known for causing gastrointestinal toxicity (mucositis), myelosuppression, and a unique **hand-foot syndrome**. While it can cause cardiotoxicity (vasospasm), it is not classically associated with systemic hypercoagulability. * **C. Melphalan:** An alkylating agent (nitrogen mustard) used in multiple myeloma. Its dose-limiting toxicity is **bone marrow suppression**. * **D. Carmustine:** A nitrosourea that is highly lipid-soluble and crosses the blood-brain barrier. Its major toxicities include **delayed myelosuppression** and pulmonary fibrosis. **High-Yield Clinical Pearls for NEET-PG:** * **L-asparaginase** is a mainstay in **Acute Lymphoblastic Leukemia (ALL)** protocols. * **Key Side Effects:** Acute pancreatitis (high-yield), hyperglycemia (due to decreased insulin synthesis), and hypersensitivity reactions (anaphylaxis). * **Monitoring:** Patients on L-asparaginase should be monitored for signs of thrombosis and fibrinogen levels. * **Contrast:** While most anticancer drugs cause bleeding due to thrombocytopenia, L-asparaginase is unique for its **pro-thrombotic** potential.

Q: What is the primary reason for administering mesna along with cyclophosphamide?

To ameliorate hemorrhagic cystitis. **Explanation:** **1. Why Option C is Correct:** Cyclophosphamide and Ifosfamide are nitrogen mustards that are metabolized in the liver to form **Acrolein**, a toxic metabolite. Acrolein is excreted in the urine and causes direct irritation to the bladder mucosa, leading to **Hemorrhagic Cystitis** (characterized by hematuria and bladder pain). **Mesna** (2-MercaptoEthane Sulfonate Na) is a sulfhydryl compound that acts as a regional detoxifier. It concentrates in the bladder and reacts chemically with acrolein to form a non-toxic, water-soluble stable adduct, thereby preventing bladder damage. **2. Why Other Options are Incorrect:** * **Option A & D:** Mesna does not influence the pharmacokinetics (absorption or metabolism) of cyclophosphamide. Cyclophosphamide is a prodrug activated by hepatic CYP450 enzymes; Mesna does not interfere with this activation. * **Option B:** Mesna does not decrease the excretion of the drug. In fact, it is essential that both Mesna and the toxic metabolites are excreted together in the urine for the protective effect to occur. **3. High-Yield Clinical Pearls for NEET-PG:** * **Hydration:** Vigorous intravenous hydration is the first line of defense against hemorrhagic cystitis to dilute the acrolein. * **Ifosfamide:** While Mesna is optional for low-dose cyclophosphamide, it is **mandatory** when administering Ifosfamide due to higher acrolein production. * **Other Side Effects:** Apart from cystitis, cyclophosphamide is notorious for causing **SIADH** and **Alopecia**. * **Dose-Limiting Toxicity:** For cyclophosphamide, the dose-limiting toxicity is **Bone Marrow Suppression**.

Q: Which of the following drugs is widely used in the management of carcinoma of the breast?

Doxorubicin. **Explanation:** **Doxorubicin** (an Anthracycline antibiotic) is a cornerstone in the management of breast cancer. Its primary mechanism of action involves inhibiting **Topoisomerase II**, intercalating between DNA base pairs, and generating free radicals that cause DNA strand breaks. It is a key component of standard chemotherapy regimens such as **AC** (Adriamycin/Doxorubicin + Cyclophosphamide) and **FAC** (5-FU + Adriamycin + Cyclophosphamide). **Analysis of Incorrect Options:** * **Actinomycin–D (Dactinomycin):** Primarily used for pediatric solid tumors like **Wilms’ tumor**, Ewing’s sarcoma, and Rhabdomyosarcoma, as well as Gestational Choriocarcinoma. It is not a first-line agent for breast carcinoma. * **Bleomycin:** Known for causing pulmonary fibrosis, it is mainly used in **Germ cell tumors** (Testicular cancer), Hodgkin’s lymphoma, and squamous cell carcinomas of the head and neck. * **Dacarbazine:** An alkylating agent that is the drug of choice for **Malignant Melanoma** and is used in the ABVD regimen for Hodgkin’s Lymphoma. **High-Yield Clinical Pearls for NEET-PG:** * **Cardiotoxicity:** The most significant side effect of Doxorubicin is dose-dependent dilated cardiomyopathy. **Dexrazoxane** is an iron-chelating agent used to prevent this toxicity. * **Red Urine:** Doxorubicin can cause a harmless reddish discoloration of urine (not hematuria). * **Other Breast Cancer Drugs:** Remember that **Tamoxifen** (SERM) is used for ER/PR positive cases, and **Trastuzumab** is used for HER2/neu positive cases.

Q: All of the following immunosuppressives cause profound myelosuppression except?

Cyclosporine. ### Explanation The core concept in this question is distinguishing between **cytotoxic immunosuppressants** and **calcineurin inhibitors**. **Why Cyclosporine is the Correct Answer:** Cyclosporine is a **calcineurin inhibitor**. It works by binding to cyclophilin, which inhibits the phosphatase activity of calcineurin. This prevents the translocation of Nuclear Factor of Activated T-cells (NFAT), ultimately blocking the production of IL-2 and T-cell proliferation. Because its mechanism is highly specific to T-lymphocyte signaling and does not involve the inhibition of DNA synthesis or cell division in rapidly dividing cells, it is **not myelosuppressive**. Its primary toxicities are nephrotoxicity, gingival hyperplasia, and hirsutism. **Analysis of Incorrect Options:** * **Azathioprine & Mercaptopurine:** These are antimetabolites (purine analogs) that interfere with DNA synthesis. Since bone marrow cells are rapidly dividing, these drugs inherently cause significant **myelosuppression** (leukopenia and thrombocytopenia) as a primary side effect. * **Sirolimus (Rapamycin):** While it is not a calcineurin inhibitor (it is an mTOR inhibitor), it is well-known for causing **thrombocytopenia** and anemia as common side effects, making it more myelosuppressive than cyclosporine. **High-Yield NEET-PG Pearls:** * **Calcineurin Inhibitors (Cyclosporine, Tacrolimus):** Mnemonic for Cyclosporine side effects: **"6 H's"** — **H**ypertension, **H**yperlipidemia, **H**yperkalemia, **H**irsutism, **H**yperplasia of gums, and **H**epatotoxicity (plus Nephrotoxicity). * **Tacrolimus vs. Cyclosporine:** Tacrolimus is more potent and does *not* cause hirsutism or gingival hyperplasia (it may cause alopecia instead). * **Drug Interaction:** Azathioprine/6-MP levels increase dangerously when co-administered with **Allopurinol** (due to Xanthine Oxidase inhibition), leading to life-threatening bone marrow suppression.

Q: Which of the following blocks DNA replication by getting incorporated into the DNA strand?

Cytarabine. **Explanation:** **Correct Option: A. Cytarabine** Cytarabine (Ara-C) is a pyrimidine analog (antimetabolite) that acts specifically during the **S-phase** of the cell cycle. Its mechanism involves two primary steps: 1. It is phosphorylated intracellularly into its active form, **cytarabine triphosphate**. 2. This active form competes with deoxycytidine triphosphate to be **incorporated into the DNA strand**. Once incorporated, it acts as a DNA chain terminator and inhibits **DNA polymerase**, thereby blocking DNA synthesis and repair. **Incorrect Options:** * **B & C (Nalidixic acid and Ciprofloxacin):** These are Quinolone/Fluoroquinolone antibiotics. They inhibit **DNA Gyrase** (Topoisomerase II) and **Topoisomerase IV** in bacteria. They do not get incorporated into the DNA strand. * **D (Paclitaxel):** This is a Taxane that acts on microtubules. It **stabilizes microtubules** by preventing depolymerization (freezing them in the polymerized state), leading to cell cycle arrest in the **M-phase**. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** Cytarabine is a cornerstone in the induction therapy of **Acute Myeloid Leukemia (AML)**. * **Specific Toxicity:** High-dose Cytarabine is associated with **Cerebellar toxicity** (ataxia, dysarthria) and **conjunctivitis** (prophylactic steroid drops are often used). * **Resistance:** Resistance to Cytarabine often occurs due to a decrease in the activating enzyme **deoxycytidine kinase**.

Q: Which of the following drugs is specifically for HER2-positive breast carcinoma?

Trastuzumab. **Explanation:** **1. Why Trastuzumab is correct:** Trastuzumab is a **recombinant humanized monoclonal antibody** that specifically targets the extracellular domain of the **HER2/neu (ErbB2)** receptor. HER2 is a proto-oncogene (tyrosine kinase receptor) that is overexpressed in approximately 20–30% of breast cancer cases. By binding to this receptor, Trastuzumab inhibits cell proliferation and promotes antibody-dependent cellular cytotoxicity (ADCC), making it the gold standard for HER2-positive breast carcinoma. **2. Why the other options are incorrect:** * **Tamoxifen:** This is a **Selective Estrogen Receptor Modulator (SERM)**. It acts as an antagonist in the breast and is used for **ER/PR-positive** breast cancer, not specifically for HER2-positive cases. * **Exemestane:** This is an **Irreversible Aromatase Inhibitor (Type I)**. It works by blocking the peripheral conversion of androgens to estrogens. It is used in postmenopausal women with hormone-sensitive (ER+) breast cancer. * **Fulvestrant:** This is a **Selective Estrogen Receptor Downregulator (SERD)**. It binds to and degrades the estrogen receptor. It is used in advanced ER-positive breast cancer that has progressed after anti-estrogen therapy. **3. High-Yield Clinical Pearls for NEET-PG:** * **Cardiotoxicity:** The most significant side effect of Trastuzumab is **reversible cardiomyopathy** (decrease in LVEF). Unlike Doxorubicin, it does not cause structural damage (no myofibrillar dropout). * **Combination Warning:** Never co-administer Trastuzumab with Anthracyclines (like Doxorubicin) due to the high risk of synergistic cardiotoxicity. * **Other HER2 Drugs:** Lapatinib (dual TKI for EGFR/HER2) and Pertuzumab (inhibits HER2 dimerization) are also used in HER2+ cases.

Question 1

Which of the following drugs is used in the adjuvant setting for carcinoma of the colon?

Accepted Answer

Oxaliplatin

Answer

Bevacizumab

Answer

Cetuximab

Answer

Irinotecan

Question 2

Which of the following is an aromatase inhibitor used in breast cancer therapy?

Accepted Answer

Letrozole

Answer

Anastrozole

Answer

Exemestane

Answer

Tamoxifen

Question 3

Which of the following anticancer drugs can cause a hypercoagulable state?

Accepted Answer

L-asparaginase

Answer

5-FU

Answer

Melphalan

Answer

Carmustine

Question 4

What is the primary reason for administering mesna along with cyclophosphamide?

Accepted Answer

To ameliorate hemorrhagic cystitis

Answer

To increase absorption

Answer

To decrease excretion

Answer

To decrease metabolism

Question 5

Imatinib used in CML acts by which mechanism?

Accepted Answer

Competitive inhibition of the ATP binding site of ABL kinase

Answer

Inhibiting BCR/ABL translocation tyrosine kinase

Answer

Blocking the action of P glycoprotein

Answer

C-Kit kinase inhibition

Question 6

Which of the following drugs is widely used in the management of carcinoma of the breast?

Accepted Answer

Doxorubicin

Answer

Actinomycin–D

Answer

Bleomycin

Answer

Dacarbazine

Question 7

All of the following immunosuppressives cause profound myelosuppression except?

Accepted Answer

Cyclosporine

Answer

Sirolimus

Answer

Azathioprine

Answer

Mercaptopurine

Question 8

Which of the following blocks DNA replication by getting incorporated into the DNA strand?

Accepted Answer

Cytarabine

Answer

Nalidixic acid

Answer

Ciprofloxacin

Answer

Paclitaxel

Question 9

Fulvestrant is used in the treatment of which of the following conditions?

Accepted Answer

HR positive metastatic breast cancer in postmenopausal women

Answer

Male breast cancer

Answer

Paget's disease

Answer

Acute myeloid leukemia associated with Down's syndrome

Question 10

Which of the following drugs is specifically for HER2-positive breast carcinoma?

Accepted Answer

Trastuzumab

Answer

Tamoxifen

Answer

Exemestane

Answer

Fulvestrant

Anticancer Drugs — MCQs

Anticancer Drugs — MCQs

On this page

Practice by Chapter

Want unlimited practice?