1.
A 42-year-old man with stage III Hodgkin’s disease received six courses of chemotherapy with the ABVD regimen. Which of the following drugs of this regimen acts mainly in the G2 phase of the tumor cell cycle?
Correct Answer
B. Bleomycin
Explanation
Bleomycin acts mainly in the G2 phase of the tumor cell cycle. It is a cell cycle-specific drug that inhibits DNA synthesis and causes DNA strand breaks. It acts by binding to DNA and inducing oxidative damage, resulting in cell cycle arrest and apoptosis. The other drugs in the ABVD regimen, Doxorubicin, Vinblastine, and Dacarbazine, have different mechanisms of action and do not specifically target the G2 phase of the cell cycle.
2.
A 4-year-old girl presented with increasing weakness and bleeding gums. Physical examination revealed hepatospenomelaly. A CBC with differential showed a WBC count of 65000 with 43% lymphoblasts and a bone marrow biopsy revealed 92% lymphoblasts. The girl received systemic remission chemotherapy and also intrathecal chemotherapy in order to prevent relapse within the CNS. Which of the following drugs was most likely injected intrathecally?
Correct Answer
E. Methotrexate
Explanation
The girl received intrathecal chemotherapy to prevent relapse within the CNS, which suggests that the drug injected intrathecally should have CNS penetration. Methotrexate is a chemotherapy drug that can cross the blood-brain barrier and is commonly used in intrathecal chemotherapy for CNS prophylaxis in leukemia patients. Therefore, Methotrexate is the most likely drug injected intrathecally in this case.
3.
A 45-year-old woman, who had undergone a radical mastectomy for infiltrating ductal carcinoma, started adjuvant combination therapy with CMF cyclophosphamide, methotrexate and fluorouracil). Which of the following statements best explains the mechanism of action of methotrexate?
Correct Answer
A. Inhibition of purine and pyrimidine biosynthesis
Explanation
Methotrexate is a folate antagonist that inhibits the enzyme dihydrofolate reductase, which is involved in the biosynthesis of purines and pyrimidines. By inhibiting this enzyme, methotrexate prevents the synthesis of DNA and RNA, ultimately leading to the inhibition of cell division and growth. Therefore, the best explanation for the mechanism of action of methotrexate is the inhibition of purine and pyrimidine biosynthesis.
4.
A 32-year-old man presented to the hospital with increasing fatigue, anorexia, weight loss, and widespread ecchymoses. A blood examination revealed a white blood cell count of 70000/mm3 with 90% myeloblasts and a bone marrow biopsy showed blast cells that made up about 40% of the nucleated cells in the marrow
normal < 5%). Which of the following drugs was most likely included in the initial chemotherapy of this patient?
Correct Answer
D. Cytarabine
Explanation
The patient's presentation with fatigue, anorexia, weight loss, and widespread ecchymoses, along with a blood examination revealing a high white blood cell count with 90% myeloblasts, suggests a diagnosis of acute myeloid leukemia (AML). A bone marrow biopsy confirmed the presence of blast cells. Cytarabine is a commonly used chemotherapy drug for AML, as it is effective in targeting rapidly dividing cells such as myeloblasts. Therefore, it is most likely that cytarabine would be included in the initial chemotherapy regimen for this patient.
5.
A 67-year-old man underwent surgery to remove an adenocarcinoma of the colon. Since the regional lymph nodes showed evidence of tumor involvement, adjuvant therapy was initiated after surgery. Which of the following drugs was most likely included in the therapeutic regimen of this patient?
Correct Answer
E. Fluorouracil
Explanation
Fluorouracil is a commonly used drug in the adjuvant therapy for colorectal cancer. It is a chemotherapy drug that works by inhibiting the growth of cancer cells. In this case, the patient had evidence of tumor involvement in the regional lymph nodes, indicating a higher risk of recurrence or metastasis. Adjuvant therapy aims to eliminate any remaining cancer cells after surgery and reduce the risk of recurrence. Fluorouracil is often used in combination with other drugs or radiation therapy to enhance its effectiveness and improve patient outcomes.
6.
A 6-year-old girl with acute lymphoblastic leukemia completed her induction therapy with a multidrug regimen. Now she is scheduled for maintenance therapy with a regimen that includes a CCS anticancer drug administered daily, for 7 days every 4 weeks. Which of the following is the drug she is about to receive?
Correct Answer
C. Mercaptopurine
Explanation
The drug the 6-year-old girl is about to receive is Mercaptopurine. This drug is commonly used in maintenance therapy for acute lymphoblastic leukemia. It is a CCS (cell cycle specific) anticancer drug that is administered daily for 7 days every 4 weeks. Mercaptopurine helps to prevent the growth and spread of cancer cells by interfering with their DNA synthesis. It is an important component of the maintenance therapy regimen for this type of leukemia.
7.
A 39-year-old man with acute lymphoblastic leukemia was admitted to the hospital for remission chemotherapy. After three week of therapy the patient started complaining of numbness of his fingers and the soles of his feet. Physical examination showed loss of ankle jerk and depression of deep tendon reflexes. Which of the following drugs most likely caused these patient’s signs and symptoms?
Correct Answer
A. Vincristine
Explanation
Vincristine is a chemotherapeutic drug that is known to cause peripheral neuropathy, which is consistent with the patient's symptoms of numbness in the fingers and soles of the feet. Additionally, vincristine can also cause loss of ankle jerk and depression of deep tendon reflexes, which were also observed in the physical examination. Therefore, vincristine is the most likely drug to have caused these signs and symptoms in the patient.
8.
A 66-year-old man came to his physician complaining of a persistent backache. He was found on rectal examination to have a single, hard, irregular nodule within his prostate. Subsequent exams found his prostatic specific antigen to be 100 ng/mL ( normal: < 3.0 ) and a CT scan showed several enlarged pelvic lymph nodes and multiple sclerotic lesions in his spine. Which of the following pairs of drugs would be most appropriate for that patient?
Correct Answer
C. Leuprolide and flutamide
Explanation
Leuprolide and flutamide would be the most appropriate drugs for this patient. The patient's symptoms, including a persistent backache and the presence of a hard, irregular nodule within the prostate, along with an elevated prostate-specific antigen (PSA) level and imaging findings of enlarged lymph nodes and sclerotic lesions in the spine, are consistent with advanced prostate cancer. Leuprolide is a luteinizing hormone-releasing hormone (LHRH) agonist that suppresses the production of testosterone, which can help slow the growth of prostate cancer. Flutamide is an antiandrogen that blocks the effects of testosterone, further inhibiting the growth of the tumor. Together, these drugs can be effective in managing advanced prostate cancer.
9.
A 42-year-old woman presented with fever, night sweats, cough and a 8 kg weight loss. Chest x-rays displayed a mediastinal mass and a CT scan of the abdomen showed multiple enlarged lymph nodes. A biopsy of an inguinal node revealed Reed-Sternberg cells. The patient was scheduled for a combination ABVD anticancer chemotherapy (doxorubicin, bleomycin vinblastine and dacarbazine). Which of the following malignancies was the patient most likely to suffer from?
Correct Answer
C. Hodgkin’s disease
Explanation
Based on the symptoms described (fever, night sweats, cough, weight loss), as well as the findings on chest x-rays and CT scan (mediastinal mass, enlarged lymph nodes), and the presence of Reed-Sternberg cells in the biopsy of an inguinal node, the patient is most likely suffering from Hodgkin's disease. Hodgkin's disease is a type of lymphoma characterized by the presence of Reed-Sternberg cells, which are large abnormal cells found in the lymph nodes. Treatment for Hodgkin's disease often involves a combination of anticancer chemotherapy drugs, such as ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine).
10.
A 67-year-old man presents to his physician with a 10-day history of fatigue, bleeding gums, perirectal cellulitis and ringing in the ears. He has recently lost 9kg. He shows no evidence of hepatosplenomegaly or lymphadenopathy, but he is pale and weak.
Results from blood tests:
White blood cell count: 18, 300/mm3(normal 4000-11000/mm3)
(75%leukemic blastocytes(normal: none), 20% lymphocytes
Hemoglobin: 9.1g/dL(normal 11-14g.dL)
Hematocrit: 29%(normal 40-44%)
Platelet count:98, 000/mm3(normal 150,00-400,000)
He is diagnosed with Acute Myelogenous leukemia (sometimes called ANLL acute non lymphocytic leukemia). After induction therapy with daunorubicin and cytarabine, followed by etoposide 7 days later, further tests were performed: the patient’s K+ and creatinine levels significantly increased, together with seriously increased uric acid levels. Further test data indicate that the patient now has Tumor lysis
Syndrome(TLS).
Which of the following best explains his current condition?
Correct Answer
D. Cytotoxic drugs actions on a high growth fraction cancer, may result in TLS
Explanation
Cytotoxic drugs, such as daunorubicin and cytarabine, are commonly used in the treatment of acute myelogenous leukemia (AML). These drugs work by targeting and killing rapidly dividing cancer cells. However, their action can also affect normal cells, including the kidneys. Tumor lysis syndrome (TLS) is a potential complication of cytotoxic therapy, characterized by the release of intracellular contents from dying cancer cells. This can lead to metabolic abnormalities, such as increased levels of potassium, creatinine, and uric acid. Therefore, the best explanation for the patient's current condition is that cytotoxic drugs' actions on a high growth fraction cancer, like AML, may result in TLS.
11.
A 15-year-old boy suffering from Acute Lymphoblastic Leukemia, had induction therapy with vincristine, prednisone, and asparaginase. To try to achieve complete remission, he was given a fourth drug IV, which was a cytotoxic antibiotic. To prevent CNS metastases, a chemotherapeutic agent was introduced intrathecally (IT). Identify the additional IV drug and the IT drug which were added to his regimen
Correct Answer
B. IV daunorubicin and IT methotrexate
Explanation
The additional IV drug added to the patient's regimen is daunorubicin. Daunorubicin is a cytotoxic antibiotic commonly used in the treatment of acute lymphoblastic leukemia. It works by inhibiting DNA and RNA synthesis, leading to the death of cancer cells. The IT drug added to prevent CNS metastases is methotrexate. Methotrexate is a chemotherapeutic agent that inhibits the synthesis of DNA, RNA, and proteins, thereby preventing the growth of cancer cells. It is administered intrathecally to target cancer cells in the central nervous system.
12.
Which of the following antimalignant drugs is correctly matched with the tissue to which it shows dose-limiting toxicity?
Correct Answer
B. Vincristine –nervous tissue
Explanation
Vincristine is correctly matched with nervous tissue as the tissue to which it shows dose-limiting toxicity. This means that Vincristine has the potential to cause toxic effects specifically in the nervous tissue when given in high doses.
13.
A 35-year-old woman was recently diagnosed with a breast cancer, identified as an invasive ductal carcinoma. After a lumpectomy followed by radiotherapy, a combination chemotherapy strategy was initiated using CMF (Cyclophosphamide, Methotrexate, 5-Fluorouracil). Why treat this patient with this combination of drugs rather than with a single drug?
Correct Answer
C. CMF attacks cells in different pHases of the cell cycle, thus maximizing kill
Explanation
The reason for treating this patient with the combination of CMF drugs rather than a single drug is because CMF attacks cells in different phases of the cell cycle, thus maximizing kill. This means that the combination therapy targets cancer cells at various stages of their growth and division, increasing the likelihood of effectively killing them. Using a single drug may not be as effective in targeting all the cancer cells, especially those that are in different phases of the cell cycle.
14.
MW presents to his doctor with a painless swelling in his left testicle. Laboratory tests showed Alfa fetoprotein (AFP) 300ng/ml. After orchiectomy, persistent elevations of AFP were found. Abdominal CT revealed a 6x10cm mass. Further tests for pulmonary function, an audiogram, 24h creatinine clearance and CBC’s’s with differential and platelet counts were done to establish his current normal blood levels. Why were these further laboratory tests selected to be done?
Correct Answer
B. To establish base-line functioning of these organs prior to initiation of appropriate cytotoxic combination chemotherapy
Explanation
The further laboratory tests were selected to establish the baseline functioning of these organs before starting the appropriate cytotoxic combination chemotherapy. This is important because it helps the doctors determine the current normal blood levels and functioning of these organs, which can be used as a reference point to monitor any changes or potential side effects caused by the chemotherapy. By establishing the baseline, doctors can make informed decisions about the dosage and selection of antimalignant drugs to be used in combination chemotherapy.
15.
The following diagram shows the intracellular signaling mechanisms involved in T-cell proliferation. Pharmacological agents affect T-cell proliferation by acting at different sites in this signaling pathway. The immunosuppressant drug sirolimus acts on substance Y in the diagram.
What is substance Y?
Correct Answer
B. MTOR
Explanation
Sirolimus, an immunosuppressant drug, acts on mTOR (mammalian target of rapamycin), which is substance Y in the diagram. mTOR is a protein kinase that plays a crucial role in regulating cell growth, proliferation, and metabolism. By inhibiting mTOR, sirolimus suppresses T-cell proliferation and immune responses. The other options, immunophillin FKBP-12 and calcineurin phosphatase, are not directly related to sirolimus or T-cell proliferation in this context.
16.
Your patient has been diagnosed and treated for bladder cancer with IV glucocorticoids and another chemotherapeutic agent, an antimetabolite. His wife brings him a week later to the ER, stating that he has been increasingly confused over the past several days. Normally a very active and athletic man, your 44-year-old male patient did not want to get out of bed this morning. Examination reveals a drowsy man with markedly decreased motor activity when asked to lift his arm or extend his leg. Temp is 37o C, BP 105/75. Laboratory evaluation of liver enzymes reveals hepatotoxicity. Your patient's symptoms could be associated with what chemotherapeutic agent?
Correct Answer
B. Methotrexate
Explanation
GLUCOCORTICOIDS: CNS (psychosis, insomnia, and tremor)Muscle (myopathy)
METHOTREXATE: CNS (aseptic meningitis and transverse myelopathy acutely with intrathecal injections; stroke-like and/or encephalopathic syndrome with IV administration as a delayed syndrome)
CISPLATIN: PNS (most common with an axonal sensory peripheral neuropathy) CNS (ototoxicity with high-frequency hearing loss. Seizures are uncommon along with focal brain dysfunction)
VINCRISTINE: PNS (primarily axonal sensory-motor neuropathy, rarely cranial and autonomic neuropathies) CNS (occasional seizures)
5-FLUROURACIL: CNS (pancerebellar syndrome and encephalopathy)
BCNU & CCNU: CNS (ocular toxicity and encephalopathy)
CYTOSINE ARABINOSIDE: PNS (cerebellar dysfunction; rarely encephalopathy and an extra-pyramidal syndrome)