WBR0487
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathophysiology |
| Sub Category | SubCategory::Oncology |
| Prompt | [[Prompt::A 36 year old woman presents to her primary care physician with complaints of fatigue, loss of energy and decreased exercise tolerance. She had noticed she wasn't feeling completely normal for the past 3 to 4 months but points out the past 3 weeks have been very unusual for her. Physical exam is mostly unremarkable except for minor splenomegaly. Lab ordered are shown below. Peripheral blood smear stains very low to absent for leukocyte alkaline phosphatase. Which of the following treatments is most likely to be considered in this patient?
Hb = 9 |
| Answer A | AnswerA::Paclitaxel |
| Answer A Explanation | AnswerAExp::Paclitaxel is a microtubule stabilizer. It is not usually used in the treatment of CML especially in the chronic-phase. |
| Answer B | AnswerB::Cytarabine |
| Answer B Explanation | AnswerBExp::Cytarabine is pyrimidine analog. It is not usually used in the treatment of CML especially in the chronic-phase. |
| Answer C | AnswerC::Methotrexate |
| Answer C Explanation | AnswerCExp::Methotrexate is a folic acid analogue. It is not usually used in the treatment of CML especially in the chronic-phase. |
| Answer D | AnswerD::Cisplatin |
| Answer D Explanation | AnswerDExp::Cisplatin is an agent that causes DNa cross-linking. It is not usually used in the treatment of CML especially in the chronic-phase. |
| Answer E | AnswerE::Dasatinib |
| Answer E Explanation | AnswerEExp::Dasatinib is a tyrosine kinase inhibitor used to treat CML. |
| Right Answer | RightAnswer::E |
| Explanation | [[Explanation::Chronic myelogenous/myeloid leukemia is a myeloproliferative disorder accounting for 20% of adult leukemias that is characterized by the increased and unregulated growth of myeloid cells (neutrophils, eosinophils and basophils) without significant impairment of their differentiating ability. It is classically associated with a chromosomal translocation called the Philadelphia chromosome where a reciprocal translocation between chromosome 9 and 22 occurs, and is specifically designated as t(9;22). The result of the translocation is the bcr-abl gene fusion coding for an oncogenic tyrosine kinase. CML is usually an insidious disease that is often detected incidentally. It is characterized by very low to absent leukocyte alkaline phosphatase staining of peripheral blood and bone marrow aspirates. In 2001, the first tyrosine kinase inhibitor, imatinib, was introduced. It acted by blocking the effects of the bcr-abl gene product. The introduction of tyrosine kinase inhibitors has increased survival rate dramatically. Other drugs similar to imatinib include dasatinib, nilotinib, and bosutinib.
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| Approved | Approved::No |
| Keyword | WBRKeyword::CML, WBRKeyword::Chronic myelogenous leukemia, WBRKeyword::Imatinib, WBRKeyword::bcr-abl, WBRKeyword::Dasatinib |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |