Chemotherapy: selective oestrogen receptor degraders: practice question

A Pharmacology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Pharmacology · Chemotherapy: selective oestrogen receptor degraders

Sample item

A postmenopausal woman with ER-positive metastatic breast cancer progresses on tamoxifen and then an aromatase inhibitor. Which intramuscular drug binds the oestrogen receptor and promotes its degradation, with no agonist activity?

AMegestrolBFulvestrantCLetrozoleDRaloxifene

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Fulvestrant

Fulvestrant is a pure oestrogen receptor antagonist that also downregulates the receptor, and is given by intramuscular injection after progression on other endocrine therapy. Letrozole inhibits aromatase, raloxifene is a SERM, and megestrol is a progestin.

Option by option

A. Megestrol
Megestrol is a progestin that acts on progesterone receptors.
B. Fulvestrant (correct)
Correct. A pure antagonist that causes receptor degradation.
C. Letrozole
Letrozole inhibits aromatase, so it lowers oestrogen synthesis and does not bind the receptor.
D. Raloxifene
Raloxifene is a partial agonist SERM and is not used for metastatic disease.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is B, Fulvestrant. Fulvestrant is a pure oestrogen receptor antagonist that also downregulates the receptor, and is given by intramuscular injection after progression on other endocrine therapy.

Why is "Megestrol" not the answer?

Megestrol is a progestin that acts on progesterone receptors.

Why is "Letrozole" not the answer?

Letrozole inhibits aromatase, so it lowers oestrogen synthesis and does not bind the receptor.

Why is "Raloxifene" not the answer?

Raloxifene is a partial agonist SERM and is not used for metastatic disease.

What concept does this question test?

It tests Chemotherapy: selective oestrogen receptor degraders in Pharmacology. Letrozole inhibits aromatase, raloxifene is a SERM, and megestrol is a progestin.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Chemotherapy: selective oestrogen receptor degraders?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.