Guide to Hormone Therapy in Low-Grade Serous Carcinoma
This guide discusses considerations around the use of hormone therapy in low-grade serous ovarian and peritoneal cancer.
We wrote this guide for people who are taking, or have been recommended hormone therapy as part of their LGSOC treatment. It should be read alongside our more comprehensive guide to low-grade serous ovarian cancer.
In this guide
What is hormone therapy?
Hormone therapy is a treatment used in low-grade serous ovarian cancer (LGSOC). It works by limiting the cancer’s access to hormones to slow or stop cancer growth. It can be used to treat newly diagnosed and recurrent LGSOC.
Hormone therapy is also called:
- Hormonal therapy
- Endocrine therapy
- Hormone inhibitors
- Hormone blockers
- Antiestrogen therapy
It is not the same as hormone replacement therapy (HRT) which is generally not recommended in low-grade serous ovarian cancer.
How does it work?
Low-grade serous ovarian cancer cells have receptors (proteins) that allow them to use hormones. Most people with LGSOC are estrogen (also called oestrogen) receptor positive, and about half are also progesterone receptor positive.
When hormones attach to these receptors, the cancer cells grow and multiply. Hormone therapy works by blocking the cancer cells from using hormones, or by reducing the amount of hormones in the body so there is less for the cancer to use.
Where do hormones come from?
Before menopause, the ovaries make most of the body’s estrogen and progesterone. After menopause, the ovaries stop making estrogen but smaller amounts are still made by other parts of the body, like fat cells and the adrenal glands.
What do hormones do?
Estrogen and progesterone are important for reproductive health. They are also used by other areas of the body including our bones, heart and brain.
History of hormone therapy
Hormone therapy has been used for a long time to treat cancers like breast and prostate cancer such as Tamoxifen (1977). But it is only in the past decade that researchers found hormone therapy could help LGSOC.
How long do you take hormone therapy for?
We don’t know how long people with LGSOC should take hormone therapy. In breast cancer, it is usually given for up to ten years. The current recommendation for LGSOC is to take it as long as it helps, meaning until someone either develops unacceptable side effects or their cancer progresses or recurs. That could mean indefinitely if there is no progression or recurrence. Hopefully in the future we will have better data to guide decisions.
Monitoring
If you are taking hormone therapy you usually need your cholesterol, liver function and bone density monitored.
Pregnancy risk
If you still have your uterus and an ovary and are of childbearing age, you should take a pregnancy test before starting treatment. Hormone therapy does not prevent pregnancy, you will need to use non-hormonal contraception.
Non hormonal contraceptive options include:
- Condoms (not all vaginal moisturisers are condom compatible, so read labels)
- Copper intrauterine devices (copper IUDs)
- Tubal ligation (tying tubes)
- Salpingectomy (removal of the fallopian tubes)
- Vasectomy (male steralisation)
- Hysterectomy (removal of the uterus)
Types of hormone therapy
Aromatase inhibitors
Aromatase inhibitors (AIs) block an enzyme called aromatase that stops fat and other tissues producing estrogen. This is the main source of estrogen in post-menopause.
Examples:
- Letrozole: Daily tablet. It is often the first choice in LGSOC hormone therapy.
- Anastrozole: Daily tablet. Thought to be equally as effective as letrozole.
- Exemestane: Daily tablet. Slightly different molecular structure, which may lead to fewer side effects in some people.
Special considerations
Menopause status: Aromatase inhibitors are usually only given post-menopause. This is because they don’t stop the ovaries producing estrogen.
In LGSOC, post-menopause can occur in one of three ways:
- Natural menopause: When menstrual periods have ceased for at least 12 months – on average in one’s early 50s.
- Surgical menopause: When both ovaries are removed prior to the natural age of menopause.
- Medical menopause: When treatments are used to stop normal function of the ovaries with GnRH agonists (see ovarian suppression section).
If an ovary is retained in pre-menopause, a GnRH agonist like Zoladex will be used to induce medical menopause, in addition to an aromatase inhibitor.
Treatments targeting estrogen receptors
Selective estrogen receptor modulator (SERM)
SERMs are also known as estrogen receptor agonist/antagonists (ERAAs). They compete with estrogen to bind to estrogen receptors (ER) on cancer cells. Think of it like leaving a key in a lock to stop another key being inserted. Because it works at the site of tissue where the cancer is, it can be used in both pre- and post-menopause.
Example:
- Tamoxifen – Daily tablet or oral liquid.
Special considerations
Effectiveness: SERMS are generally better tolerated, but less effective than aromatase inhibitors. Researchers think this may be because LGSOC estrogen receptors have multiple shapes in addition to the common one found in breast cancer. More research is needed to confirm this.
Risk of eye complications: A base-line eye exam (with OCT scan if available) is recommended. There is no global agreement on the need for screening without vision complaints. Ask your local oncologist/optometrist/ophthalmologist.
Risk of uterine (endometrial) cancer: If the uterus is retained there is a small risk (<1%) of uterine cancer. If you experience abnormal bleeding see a doctor. Most uterine cancer is found early when it is curable.
Selective estrogen receptor degrader (SERD)
SERD stands for selective estrogen receptor degrader. SERDs bind to estrogen receptors and break down the receptors. As a result the number of estrogen receptors in the cancer cells are greatly reduced and become less effective at promoting cancer cell growth. It also affects progesterone receptors. Because it works at the site of tissue where the cancer is, it can be used in both pre- and post-menopause.
Examples:
- Fulvestrant (Faslodex) – monthly injection in maintenance phase.
- Elacestrant (Orserdu) – daily tablet (FDA approved for breast cancer but hasn’t been studied in LGSOC)
Special considerations
Effectiveness: Like with SERMs, the LGSOC estrogen receptors have multiple shapes in addition to the common one found in breast cancer, which could affect how well it works but more research is needed to confirm this.
Ovarian suppression
Gonadotropin-releasing hormone (GnRH) agonist
GnRH medications inhibit the secretion of luteinizing hormones involved in the normal ovarian function. They are also known as ovarian suppression drugs and lutenizing hormone-releasing hormone agonists. With long-term use, they stop the ovaries producing estrogen and progesterone inducing medical (chemical) menopause.
Examples:
- Leuprolide (Lupron) – injection 4-12 weekly.
Goserelin (Zoladex) – injection 4-12 weekly.
Special considerations
Diabetes risk: GnRH medications are associated with an increased risk of diabetes. Blood sugars should be monitored periodically.
Side effects and their management
Side effects
It’s common to have some side effects with hormone therapy but the type and intensity can vary a lot from person to person. They are rarely severe or life-threatening from a medical standpoint, but they can impact quality of life. While many side effects improve over time, others, such as sexual side effects, may worsen if not treated. It is important to track any side effects you experience and discuss them with your doctor.
Possible side effects of hormone therapy
- Hot flashes/sweating
- Joint pain and stiffness
- Muscle pain
- Bone pain
- Increased cholesterol
- Headache
- Increased appetite
- Weight gain
- Dizziness
- Edema (fluid retention)
- Osteopenia/osteoporosis
- Low mood and depression
- Anxiety
- Fatigue
- Reduced cognitive function/memory
- Disturbed sleep/insomnia
- Nausea
- Hair thinning
- Skin thinning
- Abnormal blood pressure
- Palpitations
- Vaginal dryness
- Vulvovaginal atrophy
- Pain during sex
- Recurrent urinary tract infections
- Vaginismus
- Hives
- Itching
- Dry mouth
- Dry skin
- Paresthesia (pins and needles sensation)
- Thromboembolism
Management of side effects
There are many non-hormonal treatments and strategies that can help manage symptoms. Support groups, like our LGSOC Peer Support Group, can also be a great resource for learning what has worked for others. However, always consult your doctor before trying any new treatments.
A note on HRT and LGSOC
Systemic HRT (e.g., pills and patches) should usually be avoided in LGSOC because of the risk of stimulating cancer growth. Be cautious with ‘natural’ supplements for menopause, as they may contain compounds that mimic estrogen and carry similar risks.
Bone Density
Estrogen is important for maintaining strong bones. When estrogen levels drop due to hormone therapy, bones can become weaker and more prone to fractures. This risk can be well managed with monitoring and medical treatment when indicated.
Monitoring
Your doctor (usually a primary care physician/GP or endocrinologist) should recommend a DEXA scan (a bone density test) before or shortly after starting hormone therapy. This is usually repeated at regular intervals (often 1-2 years) based on individual risk and treatments.
Prevention and treatment
You may be advised to:
- Take vitamin D supplements and consume adequate dietary calcium.
- Engage in high impact/weight-bearing exercises.
- If bone density is decreasing, medications like bisphosphonates (e.g., zoledronate, alendronate) or bone-modifying agents (e.g., denosumab) may be prescribed.
Cognitive changes (memory and thinking problems)
Some people on hormone therapy report issues with memory, focus, and overall cognitive function. This is a side effect of treatment but can also relate to stress, fatigue, altered sleep habits and situational depression from diagnosis.
Self-help strategies
- Minimise intrusive distractions and focus on one task at a time.
- Stick to a daily routine to stay organised.
- Use a diary or phone calendar with reminder alarms to record upcoming commitments, appointments and deadlines.
- Rely on physical reminders to remember to do things.
Try to focus on what is most important. It is probably better to do fewer things well than many things poorly. If you can’t keep up with everything, try to eliminate nonessential or less enjoyable tasks, say “no” more, delegate, and ask for help.
If you are struggling, reach out to a primary care physician,/GP counsellor, psychologist or clinical neuropsychologist.
For more information see: “Managing cognitive side effects”.
Weight and appetite
Many people experience an increase in appetite and some weight gain due to hormone therapy.
Healthy eating
Eating a variety of whole foods, including a foundation of plant-based foods such as vegetables, fruit, whole grains, nuts and seeks, will support optimal cholesterol levels, help maintain satiety to regulate appetite, and ensure optimal intake of vitamins and minerals.
Exercise
Regular exercise (20-30 minutes daily, 4-5 times a week) will help maintain a stable body weight and aid in improving HDL cholesterol (the body’s good cholesterol).
A nutritionist or dietician can provide further advice.
Sleep problems
Most people have sleep problems at some point after being diagnosed with cancer. This can mean trouble falling asleep, staying asleep, waking up too early, or feeling tired even after sleep. Poor sleep at night often leads to feeling sleepy and worn out during the day, which can be upsetting.
Improving sleep
- Avoid caffeine in the afternoon and evening.
- Limit screen time before bed.
- Keep your bedroom a comfortable temperature, quiet, and dark. A comfortable mattress and clean bedding also help you sleep better.
- Try light exercise during the day and get some natural sunlight.
- Avoid naps during the day.
Further help
For acute sleep disruption, for example, hospitalisation or medical procedures, short-term use of sleep medication may be helpful. However, if sleep problems persist, a treatment called Cognitive Behavioral Therapy for Insomnia (CBT-I) can be very effective. Talk to your primary care physician/GP or a psychologist for more advice.
Additional resources
Mood changes (depression and anxiety)
Hormone therapy and the stress of cancer diagnosis can impact your mood, causing anxiety and depression.
Coping mechanisms
- Very mild symptoms may improve with regular exercise, meditation, or talking to supportive friends and family.
- Mental health apps may also be helpful. Examples include Elly (our free code: COOC100), Headspace, All Right?, Aunty Dee, Breathe2Relax, Groov, Happify, Just a Thought, Mindshift, Calm, and oVRcome (Virtual Reality platform).
Professional help
For mild to moderate symptoms counselling, psycho-education, exercise, meditation, and/or focussed psychological treatments like Cognitive Behavioural Therapy (CBT) and Acceptance Commitment Therapy (ACT) can help.
If symptoms are moderate to severe, your doctor may recommend medication alongside counselling/pyschological support.
Speak with your doctor about the best approach for your situation.
Hot flashes
Hot flashes (sudden feelings of warmth, often with sweating) and night sweats are common side effects of hormone therapy.
Lifestyle changes
- Keep your environment cool, wear layered clothing, and use fans to stay comfortable.
- Identify and avoid triggers like spicy foods, and smoking.
- Relaxation techniques, cognitive behavioural therapy, acupuncture, or clinical hypnosis can also help.
Medication
Veozah (fezolinetant) is a new targeted treatment for hot flashes but it is not yet widely available. Low doses of certain antidepressants (like SSRIs or SNRIs) and other medications, such as gabapentin and clonidine, may also help reduce hot flashes.
Read more about managing hot flashes.
Joint and muscle pain
Aromatase inhibitors (AIs) can cause joint stiffness and muscle pain, often referred to as aromatase inhibitor musculoskeletal syndrome (AIMSS).
Pain relief
- Over-the-counter pain medications like ibuprofen or acetaminophen can provide relief for short-term pain.
- Regular exercise, particularly gentle stretching and strengthening exercises, can help reduce stiffness.
- Acupuncture has also shown benefits in managing joint pain and stiffness.
- Low doses of certain antidepressants and other medications, such as gabapentin can also help.
Switching medications
If your symptoms are significant, speak with your doctor about trying a different hormone therapy. Some people are able to tolerate a different AI even though they discontinued the first AI because of side effects.
Read more about managing joint pain.
Sexual health concerns
Hormone therapy, chemotherapy, and radiation can lead to issues like vaginal dryness, painful sex, and low sex drive. These may be worsened by pelvic floor muscle problems.
Pelvic floor health
Pelvic floor muscles, when weak or tight, can impact sexual enjoyment. Pelvic health physical therapists may recommend tools, exercises, and massage therapy to help. However, exercises like Kegels can worsen painful sex for some cancer survivors and should only be done if advised by a professional. Pelvic health physiotherapy can also help with issues like incontinence, pain, and fatigue.
Vaginal dryness and pain during sex
Hormone therapy can cause vaginal dryness, making sex uncomfortable or painful. Regular use of non-hormonal vaginal moisturisers and silicone-based lubricants can help (check compatibility with condoms). The safety of vaginal estrogen in LGSOC is unknown but there is a theoretical risk that local absorption through the vaginal wall could lead to cancer growth.
Low libido
Hormone changes can reduce sexual desire. Addressing physical discomfort can improve libido. Open communication, regular exercise, and in some cases, medication adjustments may also help. Always consult your doctor for advice.
Specialist support
It’s important to talk to your healthcare team about these concerns. Specialists like gynaecologists, pelvic health physical therapists, and sex counsellors can provide additional support.
Read more about sexual side effects and their treatment.
Evidence for use in low-grade serous ovarian cancer
The following research studies give information about hormone therapy in LGSOC but there is still a lot more to learn.
Frontline (newly diagnosed)
Letrozole after chemotherapy compared to letrozole on its own:
First results released on the NRG Oncology website as of 10th April 2026. Listen to a Podcast with clinical trial lead Dr Amanda Fader on YouTube or Spotify discussing the findings.
After chemotherapy:
Hormonal maintenance therapy for women with low-grade serous cancer of the ovary or peritoneum (2017)
Instead of chemotherapy:
Ongoing research
Hormone therapy is being studied in clinical trials, both on its own and in combination with other treatments. Below are some of the clinical trials currently happening in low-grade serous ovarian cancer.
Learn more about LGSOC clinical trials.
Glossary of terms
Acceptance commitment therapy (ACT) is a mindfulness-based “contextual cognitive behavioral therapy” that can be especially helpful in the context of cancer. It teaches people mental tools to help them accept the things that are outside of their control and engage in actions that bring greater meaning and richness to life.
Medical (chemical) menopause is a temporary (and reversible) menopausal state created with the use medications used to suppress ovulation and production of ovarian hormones.
Cognitive behavioral therapy for insomnia (CBT-I) is a science-based approach to change what patients do with sleep and how they think about sleep. It has been shown to effectively improve sleep in cancer patients, with good long-term benefits.
A DEXA scan is an imaging test that measures bone density (strength).
Nonsteroidal anti-inflammatory drugs (NSAIDS) is a type of pain medication that blocks the production of certain body chemicals that cause inflammation.
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants. Prescribed to ease symptoms of moderate to severe depression, they work by increasing levels of serotonin in the brain.
Serotonin and norepinephrine reuptake inhibitors (SNRIs) are a class of medications used to treat depression and sometimes other conditions, such as anxiety disorders and long-term (chronic) pain, especially nerve pain. They work by blocking the reabsorption (reuptake) of the neurotransmitters serotonin and norepinephrine in the brain.
Surgical menopause occurs after an oophorectomy, a surgery that removes the ovaries.
Acknowledgements
Thank you to the following individuals for their support in developing this guide.
- Professor David Gershenson (Gynecological Oncologist, The University of Texas MD Anderson Cancer Center)
- Dr Rachel Grisham (Medical Oncologist, Memorial Sloan Kettering Cancer Center)
- Dr K K Wong PhD (Scientist, The University of Texas MD Anderson Cancer Center)
Thank you to the experts who contributed to specific sections:
- Sexual health: Dr Kristin Rojas (@kristinrojasmd, breast cancer surgeon and board certified gynaecologist, Director of the MUSIC Sexual Health After Cancer Program at University of Miami)
- Mental health: Dr Pleayo Tovaranonte (MBChB, LLB (Hons), LLM (Medical Law & Ethics), Medical Practitioner, New Zealand)
- Hot flashes and joint pain: Dr Katelyn Tondo-Steele (DO, Gynaecological Oncology Fellow, University of Michigan)
- Hot flashes and joint pain: Dr Karen McLean (Gynaecological Oncologist, MD, PhD, University of Michigan)
- Cognitive function: Associate Professor Laurie Miller (Clinical Neuropyschologist, University of Sydney)
- Bone density: Dr Susannah O’Sullivan (Endocrinologist, MBCHB PhD, New Zealand)
- Sleep: Associate Professor Darren Mansfield (deputy director of Monash Lung and Sleep)
- Sleep: Dr Bei Bei (Research Lead and Clinical Psychologist, Monash University)
- Weight: Lisa Smith (Dietician)
- Editing – Jennifer Boyer