Anticancer Drugs — MCQs

Anticancer Drugs Indian Medical PG Practice Questions and MCQs

Question 551: Raloxifene is known to decrease the risk of which type of cancer?

A. Breast cancer (Correct Answer)
B. Cervical cancer
C. Ovarian cancer
D. Endometrial cancer

Explanation: ***Breast cancer*** - **Raloxifene** is a **selective estrogen receptor modulator (SERM)** that acts as an estrogen antagonist in breast tissue, thereby reducing the risk of developing **estrogen receptor-positive breast cancer**. - It is FDA-approved for reducing the risk of invasive breast cancer in **postmenopausal women** at high risk. - The **STAR trial** demonstrated raloxifene's efficacy in breast cancer risk reduction, with fewer side effects than tamoxifen. *Cervical cancer* - **Cervical cancer** is primarily caused by persistent infection with **high-risk human papillomaviruses (HPVs)**. - **Raloxifene** has no known protective effect against **HPV infection** or the development of cervical dysplasia or cancer. *Endometrial cancer* - Unlike breast tissue, **raloxifene** acts as an estrogen antagonist in the **endometrium** and does **not increase** endometrial cancer risk (unlike tamoxifen). - However, it does **not decrease** endometrial cancer risk either; it maintains a neutral effect on endometrial tissue. *Ovarian cancer* - **Ovarian cancer** is a complex disease with various risk factors, but **raloxifene** does not significantly impact its incidence. - While some SERMs have shown varying effects on gynecological cancers, **raloxifene** is not indicated or known to prevent **ovarian cancer**.

Question 552: Which of the following antineoplastic agents is primarily used in the management of small cell carcinoma of the lung?

A. Cisplatin (Correct Answer)
B. Bleomycin
C. Paclitaxel
D. Doxorubicin

Explanation: ***Cisplatin*** - **Cisplatin** is a platinum-based chemotherapy drug that is a cornerstone of treatment for **small cell lung carcinoma (SCLC)**, often used in combination with etoposide. - It works by forming **DNA adducts**, leading to cross-linking and inhibition of DNA synthesis, which is particularly effective against rapidly dividing SCLC cells. *Bleomycin* - **Bleomycin** is an antibiotic antineoplastic agent primarily used in germ cell tumors, lymphomas, and head and neck cancers, but not typically as a first-line agent for SCLC. - Its main dose-limiting toxicity is **pulmonary fibrosis**, which can be severe and is a significant concern. *Paclitaxel* - **Paclitaxel** is a **taxane** chemotherapy drug mainly used in non-small cell lung cancer, ovarian cancer, and breast cancer. - It stabilizes microtubules, preventing depolymerization, which leads to cell cycle arrest and apoptosis, but is not a primary agent for SCLC. *Doxorubicin* - **Doxorubicin** is an **anthracycline antibiotic** used for various cancers including lymphomas, breast cancer, and sarcomas, but not a primary chemotherapy for SCLC. - Its significant side effect is **cardiotoxicity**, which can lead to congestive heart failure.

Question 553: Which drug specifically acts during the 'S' phase of the cell cycle?

A. Chlorambucil
B. Methotrexate (Correct Answer)
C. Vincristine
D. Paclitaxel

Explanation: ***Methotrexate*** - This drug is an **antimetabolite** that acts as a **folate analog**, directly inhibiting **dihydrofolate reductase (DHFR)**. - By blocking DHFR, methotrexate prevents the synthesis of **thymidylate** and other **purine nucleotides**, essential components for DNA synthesis during the **S phase**. *Chlorambucil* - Chlorambucil is an **alkylating agent** that forms **covalent bonds** with DNA, leading to DNA damage and cross-linking. - Its action is **cell cycle non-specific**, meaning it can affect cells in various phases of the cell cycle, not exclusively the S phase. *Vincristine* - Vincristine is a **vinca alkaloid** that acts by binding to **tubulin**, thereby inhibiting its polymerization into **microtubules**. - This disruption prevents the formation of the **mitotic spindle**, arresting cells in **metaphase** during the **M phase** of the cell cycle. *Paclitaxel* - Paclitaxel belongs to the **taxanes** and functions by stabilizing **microtubules**, preventing their depolymerization. - This stabilization also leads to the arrest of cells in **metaphase** during the **M phase**, similar to vincristine but through a different mechanism (stabilizing rather than inhibiting formation).

Question 554: Which of the following is the most characteristic adverse effect of cyclophosphamide?

A. Hemorrhagic cystitis (Correct Answer)
B. Infertility
C. Bone marrow suppression
D. Diabetes insipidus

Explanation: ***Hemorrhagic cystitis*** - **Hemorrhagic cystitis** is a unique and characteristic adverse effect of cyclophosphamide due to the accumulation of its metabolite, **acrolein**, in the bladder. - This toxicity can be prevented by adequate hydration and co-administration of **mesna**. *Infertility* - While **cyclophosphamide** can cause **infertility** due to its cytotoxic effects on gonadal cells, this is a less specific and less immediate adverse effect compared to hemorrhagic cystitis. - Infertility is a common side effect of many chemotherapeutic agents, but hemorrhagic cystitis is particularly associated with **cyclophosphamide** and **ifosfamide**. *Bone marrow suppression* - **Bone marrow suppression**, leading to **myelosuppression** (leukopenia, anemia, thrombocytopenia), is a very common and expected dose-limiting toxicity of most chemotherapy drugs, including cyclophosphamide. - Although serious, it is not the most *characteristic* or unique adverse effect of cyclophosphamide in the way **hemorrhagic cystitis** is. *Diabetes insipidus* - **Diabetes insipidus** is not a known or characteristic adverse effect of cyclophosphamide. - Other drugs, such as **lithium**, are more commonly associated with nephrogenic diabetes insipidus.

Question 555: Which of the following conditions is Cetuximab primarily used to treat?

A. Basal cell carcinoma
B. Crohn's disease
C. Adamantinoma of bone
D. Colorectal cancer (Correct Answer)

Explanation: ***Colorectal cancer*** - **Cetuximab** is an **epidermal growth factor receptor (EGFR) inhibitor** primarily used in the treatment of metastatic colorectal cancer. - It is particularly effective in patients with **RAS wild-type tumors**, as mutations in RAS can confer resistance to anti-EGFR therapies. *Basal cell carcinoma* - This is a **skin cancer** typically treated with local excision, topical therapies, or hedgehog pathway inhibitors like vismodegib or sonidegib. - **Cetuximab** is not a standard treatment for basal cell carcinoma. *Crohn's disease* - This is an **inflammatory bowel disease** treated with anti-inflammatory drugs, immunomodulators, and biologics like anti-TNF agents (e.g., adalimumab, infliximab). - **Cetuximab** targets EGFR and is not indicated for Crohn's disease. *Adamantinoma of bone* - This is a rare, low-grade malignant **bone tumor** that is typically treated with surgical resection. - There is no established role for **Cetuximab** in the management of adamantinoma.

Question 556: Pemetrexed in combination with cisplatin is the first-line chemotherapy for which of the following conditions?

A. Non small cell lung carcinoma
B. Ewings sarcoma
C. Mesothelioma (Correct Answer)
D. Osteosarcoma

Explanation: ***Mesothelioma*** - **Pemetrexed in combination with cisplatin** is the **first-line standard chemotherapy** for **malignant pleural mesothelioma**. - This was pemetrexed's **first FDA approval** (2004) and represents its most characteristic indication. - It acts as a **folate analog metabolic inhibitor**, targeting rapidly dividing cells. - Pemetrexed-cisplatin combination significantly improves survival compared to cisplatin alone in mesothelioma. *Non small cell lung carcinoma* - While pemetrexed is also approved for **non-squamous NSCLC**, it is used in various regimens (first-line with cisplatin/carboplatin, maintenance therapy, or second-line monotherapy). - However, in NSCLC, the pemetrexed-cisplatin combination is **one of several options**, not the definitive first-line standard as it is in mesothelioma. - The question specifically asks about the condition where pemetrexed-cisplatin is the **first-line standard**. *Ewings sarcoma* - **Ewing's sarcoma** is a bone cancer primarily affecting children and young adults. - Standard treatment involves **vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide**. - **Pemetrexed** is not used in Ewing's sarcoma treatment. *Osteosarcoma* - **Osteosarcoma** is treated with regimens involving **methotrexate, doxorubicin, cisplatin, and ifosfamide**. - **Pemetrexed** is not a standard component of osteosarcoma treatment protocols.

Question 557: Estramustine is a combination of ?

A. Estradiol + normustine (Correct Answer)
B. Estriol + normustine
C. Estriol + mechloroethamine
D. Estriol + cyclophosphamide

Explanation: ***Estradiol + normustine*** - **Estramustine** is a **cytotoxic drug** used in the treatment of **prostate cancer**. - It is a chemical conjugate of **estradiol** (an estrogen) and **normustine** (a nitrogen mustard alkylating agent). *Estriol + normustine* - **Estriol** is a weaker estrogen compared to **estradiol** and is not the estrogen component in estramustine. - The combination of estriol with normustine does not form estramustine. *Estriol + mechloroethamine* - **Mechlorethamine** is another type of **nitrogen mustard** alkylating agent, but it is not the specific cytotoxic component of estramustine. - **Estriol** is also incorrect as the estrogen component. *Estriol + cyclophosphamide* - **Cyclophosphamide** is a different **alkylating agent** from the nitrogen mustards, and it is not part of the estramustine structure. - As with previous options, **estriol** is not the correct estrogen component.

Question 558: What is the preferred method for the disposal of cytotoxic drugs?

A. Autoclaving
B. Chemical disinfection
C. Incineration (Correct Answer)
D. Microwaving

Explanation: ***Incineration*** - **High-temperature incineration** (typically 1,000°C to 1,200°C) is the most effective method for rendering cytotoxic drugs **harmless** by breaking down their chemical structure. - This method ensures the complete destruction of active cytotoxic compounds and minimizes environmental contamination. *Autoclaving* - **Autoclaving** uses high-pressure steam for sterilization, primarily effective against **microorganisms**, but it does not chemically inactivate cytotoxic drugs. - Many cytotoxic drugs are heat-stable and simply autoclaving them would not destroy their **pharmacological activity**. *Chemical disinfection* - **Chemical disinfection** methods are generally not sufficient to completely inactivate the complex chemical structures of most cytotoxic drugs. - Some cytotoxic agents can react with disinfectants to form other hazardous byproducts, or the disinfection process may not ensure **complete degradation**. *Microwaving* - **Microwaving** is primarily used for heating and has no significant role in the **destruction or inactivation** of cytotoxic compounds. - It does not generate the necessary temperatures or conditions to break down the chemical structure of **cytotoxic waste**.

Question 559: Anticancer drug with disulfiram-like action?

A. Procarbazine (Correct Answer)
B. Nitrosourea
C. 5 FU
D. Methotrexate

Explanation: ***Procarbazine***- **Procarbazine** inhibits **aldehyde dehydrogenase**, leading to an accumulation of acetaldehyde when alcohol is consumed.- This accumulation results in symptoms similar to those experienced with **disulfiram-alcohol reactions**, such as flushing, headache, nausea, and vomiting.*Nitrosourea*- **Nitrosoureas** like carmustine and lomustine are **alkylating agents** that cross the blood-brain barrier and are primarily used in brain tumors. [1]- They do not exhibit a recognized disulfiram-like reaction with alcohol.*5 FU*- **5-Fluorouracil (5-FU)** is a **pyrimidine analog** that acts as an antimetabolite, interfering with DNA and RNA synthesis. [2]- While it has various side effects, a disulfiram-like reaction is not among its common or significant adverse drug interactions.*Methotrexate*- **Methotrexate** is an **antifolate drug** that inhibits dihydrofolate reductase, thereby blocking DNA synthesis. [2]- It is known for side effects like myelosuppression and mucositis but does not have disulfiram-like properties.

Question 560: Mechanism of action of actinomycin D is ?

A. Inhibits RNA-dependent DNA synthesis
B. Activates RNA-dependent DNA synthesis
C. Inhibits DNA-dependent RNA synthesis (Correct Answer)
D. Activates DNA-dependent RNA synthesis

Explanation: ***Inhibits DNA-dependent RNA synthesis*** - **Actinomycin D** (dactinomycin) is a chemotherapeutic agent that primarily acts by intercalating into the **DNA double helix** [1]. - This intercalation selectively inhibits the movement of **RNA polymerase**, thereby blocking **DNA-dependent RNA synthesis** (transcription) and subsequently protein synthesis [1]. *Inhibits RNA-dependent DNA synthesis* - This mechanism describes the action of drugs targeting **reverse transcriptase**, such as those used in **HIV treatment** [2]. - Actinomycin D does not affect enzymes involved in synthesizing DNA from an RNA template [1]. *Activates RNA-dependent DNA synthesis* - There are no known therapeutic drugs that deliberately activate **RNA-dependent DNA synthesis**. - Such an action would typically promote viral replication in the context of **retroviruses**. *Activates DNA-dependent RNA synthesis* - Activating **DNA-dependent RNA synthesis** (transcription) would increase gene expression and protein synthesis. - Actinomycin D is an **anti-cancer drug** designed to suppress cell growth by *inhibiting* this process, not activating it [1].

Practice by Chapter

Principles of Cancer Chemotherapy

Practice Questions

Alkylating Agents

Practice Questions

Antimetabolites

Practice Questions

Antitumor Antibiotics

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Plant Alkaloids

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Topoisomerase Inhibitors

Practice Questions

Hormonal Agents

Practice Questions

Targeted Therapy

Practice Questions

Immunotherapy

Practice Questions

Management of Chemotherapy Side Effects

Practice Questions

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