Novel Aromatase Inhibitors
Dr.Rashmi Sharma,(MD) 216-A, Last Morh,
Gandhi Nagar, Jammu-Tawi. J&Kâ€“(India).
Oestrogen receptors are expressed in 2/3rd of all breast cancers and the oestrogen mediated growth stimulation through these receptors causes the progression of hormone sensitive breast tumours. Tamoxifen has played a significant role in the treatment of metastatic and early breast cancers, as well as in preinvasive ductal carcinova in situ. The occurance of adverse effects like hot flushes, vaginal dryness, thromboembolism and endometrial cancer with the use of tamoxifen, together with the fact that some patients are refractory to treatment or may develop resistance, generated interest in the inhibition of oestrogen synthesis by aromatase inhibitors (AI) and inactivators . There are two types of AI- irreversible steroidal activators and reversible nonsteroidal imidazole-based inhibitors. The three novel third generation oral AI and inactivators like, anastrozole, letrozole and steroidal exemestane are very effective in reducing oestrogen levels in postmenopausal women, with minimum toxicity. Moreover, their long half life allows once daily administration, leading to better patient compliance. Inhibition of the aromatase system, in particular, with third-generation aromatase inhibitors and inactivators, appears to be associated with statistically significant improved survival of patients with advanced breast cancer, as compared to standard hormonal treatments. Introduction of the novel AI in the treatment of breast cancer has truly increased the hope of longer and better disease-free survival for these patients.