Shifting Paradigms In Hormonal Therapy Of Breast Cancer

Until recently tamoxifen occupied the central stage ininhibitors are currently FDA approved and available
adjuvant (post operative) hormonal treatment offor treatment of breast cancer. These drugs are
breast cancer. Tamoxifen has been the unchallengedanastrozole (Arimidex), letrozole (Femara) and
hormonal therapy of choice for adjuvant treatmentexemestane (Aromasin). All these are active drugs
of early stage breast cancer for over two decades.are generally considered to be equally effective.
Things have changed now. A new group of hormonalAromatase inhibitors may be useful even if a woman
drugs that has been introduced few years ago hashas already been started on tamoxifen. Aromatase
almost replaced tamoxifen as the treatment ofinhibitors can be taken for five years after
choice for early stage breast cancer. This new groupcompletion of five years of tamoxifen. A clinical trial
of drugs known as aromatase inhibitors has been(MA-17) has shown that if Femara is taken for
shown to be more effective than tamoxifen overanother extra five years after completion of five
and over again.years of treatment with tamoxifen, this would result
This new group of drugs however is not effective inin improved outcome. Other trials (ABCSG trial, ARNO
premneopausal women who have been diagnosedtrial 95, and ITA trial) have shown that it is beneficial
with breast cancer. Tamoxifen still remains theto switch from tamoxifen to aromatase inhibitors
hormonal treatment of choice for women withafter two to three years of treatment with
breast cancer who have hormone receptor positivetamoxifen.
early stage breast cancer.Aromatase inhibitors have already shown to be
This new group of drugs known as aromatasesuperior to tamoxifen in the treatment of hormone
inhibitors acts by inhibiting an enzyme calledreceptor positive metastatic (cancer that has spread
aromatase, which is responsible for production ofto distant organs) breast cancer. In this situation
small amounts of estrogen in post-menopausalFemara is currently the drug of choice and tamoxifen
women. Estrogen production from the ovaries inhave moved to second or third position as an option
premneopausal women is not depended onfor hormonal therapy.
aromatase hormone, and that is the reason why thisOne thing is clear. The very foundation of tamoxifen
drug is not effective in premneopausal women.as the hormonal treatment of choice is shaking and
Three drugs belonging to the group of aromatasethe aromatase inhibitors are here to stay.