Letroz contains letrozole, an oral medication classified as an aromatase inhibitor. It is commonly prescribed in the treatment of hormone receptor-positive breast cancer, especially in postmenopausal women. Letrozole is used either as a first-line treatment or following surgery or other therapies to reduce the risk of cancer recurrence. It plays an essential role in hormone-dependent cancer management by lowering estrogen levels in the body.

Mechanism of Action
Letrozole works by blocking the action of the aromatase enzyme, which is responsible for converting androgens into estrogen in the body. In postmenopausal women, this conversion is the main source of estrogen. By inhibiting aromatase, letrozole significantly reduces estrogen levels, which slows the growth of estrogen-sensitive breast cancer cells and may help to shrink existing tumors.

Uses
Letroz is used to treat early-stage and advanced breast cancer in postmenopausal women whose tumors are hormone receptor-positive. It is also used as an adjuvant treatment following surgery or after completing five years of tamoxifen therapy. In some cases, letrozole may be prescribed for fertility treatment to stimulate ovulation in women with certain conditions like polycystic ovary syndrome, although this is an off-label use.

Adverse Effects
The most commonly reported side effects of letrozole include hot flashes, joint or muscle pain, fatigue, and night sweats. Some women may also experience mood changes, headaches, or an increased risk of osteoporosis due to lowered estrogen levels. Bone mineral density should be monitored during long-term therapy. Rare but serious side effects can include cardiovascular issues and liver enzyme changes, which may require periodic blood tests.