(A) P is a steroidal aromatase inhibitor that has androgenic activates
(B) Q is an imidazole aromatase inhibitor
(C) R is a steroid and irreversible aromatase inhibitor
(D) S is indicated for pre and postmenopausal breast cancer.
Aromatase inhibitors can be classified in to steroidal and non-steroidal category. Steroidal aromatase inhibitors include exemestane and aminoglutethimide. Letrozole and anastrazole are no-steroidal and belongs to imidazole category. Exemestane is an irreversible steroidal aromatase inhibitor. Steroidal aromatase inhibitors are non-specific and inhibit adrenal synthesis and also show androgenic activity. Aromatase inhibitors play important role in post menopausal breast cancer where estrogens are synthesized from andostanedione by aromatase enzyme. Their role in premenopausal women is less significant. Hence letrozole and anastrazole are used in postmenopausal but not in premenopausal breast cancer.
(A) Exemestane is an irreversible aromatase inhibitor
(B) Anastrazole requires hydrocortisone as supplement
(C) Aromatase inhibitors are mainly indicated for postmenopausal breast cancer
(D) Letrozole is more potent than aminoglutethimide
aminoglutethimide, anastrazole and letrozole are aromatase inhibitors. Among these, aminoglutethimide inhibits hydrocortisone synthesis and hence requires hydrocortisone supplementation. Anastrazole and letrozole doesn’t inhibit corticosteroid synthesis hence doesn’t require hydrocortisone supplementation.
(A) Imatinib, tyrosine kinase inhibitor
(B) Gefitinib, Epidermal growth factor receptor
(C) Trastuzumab, HER2 growth receptor
(D) Etoposide, Topoisomerase I
Etoposide inhibits topoisomerase II.
(A) Aminoglutethimide, adrenal hormone synthesis inhibitor, postmenopausal breast cancer
(B) Anastrazole, aromatase inhibitor, breast cancer
(C) Bicalutamide, antiandrogen, prostate cancer
(D) Rituximab, monoclonal antibody, colorectal cancer
Rituximab inhibits CD20 antigen which is expressed in non-Hodgkin’s B lymphoma cells. Bevacizumab and cetuximab are indicated for colorectal cancer.
(A) Cytarabine, Inhibition of DNA polymerase
(B) Nitrogen mustard, Inter/intra chain cross linking in DNA
(C) Etoposide, Inhibition of topoisomerase I
(D) Pentostatin, Inhibition of adenosine deaminase
Etoposide inhibits topoisomerase II whereas topotecan and irinotecan inhibit topoisomerase I.