Hormone therapy is one of the most effective treatments for certain breast and prostate cancers that are fuelled by hormones. These cancers are called hormone receptor–positive, meaning the cancer cells rely on hormones such as oestrogen or testosterone to grow.
Hormone therapy works by blocking these hormones or reducing their production, helping slow or stop cancer growth.
Hormone Therapy in Breast Cancer
In women, oestrogen is mainly produced by the ovaries before menopause and after menopause by other body tissues that convert hormones from the adrenal glands.
Adjuvant hormone therapy (AHT) helps slow or stop the growth of oestrogen-dependent cancer by either blocking the effects of oestrogen or reducing its production.
Common treatments include:
Tamoxifen A selective oestrogen receptor modulator (SERM) that blocks oestrogen receptors in breast tissue.
Aromatase inhibitors (AIs) These medications reduce oestrogen production in postmenopausal women. Examples include anastrozole, letrozole, and exemestane.
Ovarian suppression therapy This lowers oestrogen levels in premenopausal women and may be combined with aromatase inhibitors.
Hormone Therapy in Prostate Cancer
In men, prostate cancer often depends on testosterone for growth. Treatment typically involves androgen deprivation therapy (ADT), which reduces or blocks testosterone activity.
Common medications include:
Gonadotropin-releasing hormone (GnRH) agonists such as leuprolide, which suppress testosterone production.
Second-generation androgen receptor antagonists, including enzalutamide, apalutamide, and darolutamide, which prevent testosterone from binding to its receptor.
Androgen biosynthesis inhibitors, such as abiraterone, which reduce androgen production by blocking the enzyme CYP17.
Hormone therapy may be used before surgery or radiation to shrink tumours, after treatment to reduce recurrence risk, or in advanced disease to slow progression and control symptoms.
Side Effects
Although hormone therapy is effective and generally well tolerated, long-term hormone suppression can cause physical, cognitive, and emotional side effects. Managing these effects is important for maintaining quality of life and treatment adherence.
Physical Side Effects
Musculoskeletal symptoms Joint pain, stiffness, and muscle aches are common, particularly with aromatase inhibitors in women and ADT in men.
Vasomotor symptoms Hot flashes and night sweats affect both men and women and may disrupt sleep. Fatigue is one of the most common side effects of cancer treatment and can persist even after treatment ends.
Sleep disturbance Difficulty falling or staying asleep can contribute to fatigue, reduced concentration, and mood changes.
Cognitive impairment (“brain fog”) People with cancer may experience memory lapses, slower thinking, and difficulty concentrating.
Weight gain and body composition changes Loss of muscle mass and increased fat can alter body shape and self-esteem. Men receiving ADT are particularly at risk of central adiposity and insulin resistance.
Bone health Hormone suppression can accelerate bone loss and increase the risk of osteoporosis and fractures. Preventive treatments such as bisphosphonates or denosumab may be recommended.
**Emotional and Psychosocial Side Effects ** Mood changes Fatigue, sleep disruption, and hormonal changes can lead to low mood, irritability, and emotional distress.
Body image changes Weight gain, bloating, joint stiffness, and hair thinning may affect confidence and self-perception.
Social impacts Pain, fatigue, and emotional distress can reduce participation in social activities and affect quality of life.
Sexual health and fertility Women may experience low libido, vaginal dryness, or painful intercourse, while men may have reduced libido or erectile difficulties. For younger women, treatment-induced menopause and fertility loss can cause significant emotional distress.
Many emotional effects are closely linked to the physical side effects of treatment, highlighting the importance of effective management.
**Managing Side Effects ** Managing hormone therapy side effects often requires a multimodal approach, including:
Pharmacologic treatments (such as SSRIs for hot flashes or bisphosphonates for bone health) Exercise and physical therapy to maintain strength and mobility Cognitive and behavioural support for fatigue and brain fog Psychosocial support to address mood changes and improve treatment adherence
Open communication with healthcare providers is essential. Patients should report side effects honestly, as underreporting symptoms may lead to premature discontinuation of therapy.
Further research is needed to improve personalised side-effect management, ensuring patients receive strategies tailored to their individual needs.
Read more on: https://oncologybuddies.com/2025/12/01/hormonal-therapy-and-side-effects/