If you’ve had breast cancer, there’s a good chance you take tamoxifen. The medication blocks the effects of estrogen in breast cancer and breast tissue. Taking it after surgery, chemotherapy or radiation therapy helps stop any remaining cancer cells from growing.
“For early-stage breast cancer, tamoxifen is used to decrease the chance of your cancer coming back. For stage IV breast cancer, tamoxifen is used to shrink or stabilize the cancer and to delay its progression,” said Hung Khong, MD, a breast cancer specialist with Banner MD Anderson Cancer Center at Banner Gateway Medical Center. It may also be used to lower the risk of breast cancer in some people.
Your health care provider may recommend that you stop taking tamoxifen if:
- You’ve completed your treatment plan with it. “That’s usually five years, but sometimes up to 10 years,” Dr. Khong said.
- You have advanced cancer that’s no longer responding to it.
- A different treatment approach might be better, based on changes in your health or new medical discoveries.
- Side effects, which can include hot flashes, mood swings and vaginal dryness, are impacting your life and physical or emotional well-being.
Stopping tamoxifen isn’t a decision to take lightly. “Your oncologist is the one who will make recommendations on when to stop tamoxifen. If you do not tolerate the side effects and want to stop tamoxifen, you should notify your oncologist,” Dr. Khong said. In some cases, such as non-invasive breast cancer or a high risk of breast cancer in someone who hasn’t had it, a lower dose of tamoxifen might be an option.
Your oncologist can help you make sure the decision matches your health needs, goals and preferences. It’s important to communicate openly with your oncologist and stay informed about the pros and cons of all your treatment options. Stopping tamoxifen without medical guidance could increase your risk of cancer coming back.
What may happen when you stop taking tamoxifen
“When the decision is made to end tamoxifen, you can stop taking it immediately,” Dr. Khong said. Your health care provider will monitor your health status, evaluate hormone levels, address any new symptoms or concerns and watch for signs of cancer coming back. They may recommend that you transition to another therapy.
Stopping tamoxifen can cause changes in your hormone levels, so you may notice symptoms like hot flashes and mood swings if you are menopausal. However, if tamoxifen was causing these side effects, they may clear up.
“For people who have side effects from tamoxifen, most symptoms usually get better after stopping it for about two weeks,” Dr. Khong said. Talk to your provider about any side effects that continue, since they could be signs of another issue.
You may have changes in menstrual patterns or restart your period if you are premenopausal. You may also notice changes in your body weight when you stop tamoxifen, due to hormonal changes and metabolism adjustments.
Along with helping to keep breast cancer from coming back, tamoxifen may help keep your bones strong and lower your risk of heart disease. So when you stop taking tamoxifen, you should talk to your health care provider about strategies for protecting your bones and heart.
You may face some mental health changes
Transitioning off tamoxifen can also involve emotional adjustments. Women who had early-stage breast cancer have often been taking tamoxifen every day for years.
“People feel more secure knowing that they are taking something to reduce the chance of cancer coming back. When they stop taking tamoxifen, they may feel anxious because they are not taking anything for their cancer anymore,” Dr. Khong said. “For early-stage breast cancer, know that after stopping tamoxifen treatment for the prescribed duration, the benefit in reducing the risk of cancer recurrence can continue for several more years even after you stop taking it.”
It can also help to:
- Remember that feeling anxious or uncertain is normal and these emotions are valid responses.
- Educate yourself about the reasons for stopping tamoxifen. Knowing what to expect can empower you to face the transition with confidence.
- Connect with family members, friends and other breast cancer survivors to share your feelings and get support.
- Talk to your health care team about your emotional concerns.
- Seek professional support from a counselor, therapist or local or online support groups specializing in cancer. They can help with coping strategies and emotional support and give you a safe space to process your feelings.
The follow-up care you may need
After you stop taking tamoxifen, regular checkups and monitoring are important:
- Talk to your provider about any new symptoms or concerns.
- Watch for any signs of cancer coming back.
- Monitor any side effects related to stopping tamoxifen.
- Assess your overall health.
- Manage any long-term effects related to breast cancer treatment or hormonal changes.
- Get any screenings, blood tests, imaging studies or appointments with specialists you may need.
- Make plans for your ongoing preventive health and overall well-being.
Lifestyle habits that can help
Maintaining a healthy lifestyle can support your well-being after breast cancer treatment and after stopping tamoxifen:
- Regular physical activity can improve your cardiovascular fitness and lower the risk of cancer coming back. Aim for at least 150 minutes of exercise like brisk walking, swimming or cycling per week, along with strength training two days per week.
- Choose a balanced, nutritious diet that includes fruits, vegetables, whole grains, lean proteins and healthy fats. Make sure you have foods rich in calcium and vitamin D, such as dairy products, leafy green vegetables and fortified cereals. Limit processed foods, sugary beverages and red or processed meats.
- Maintain a healthy body weight. If managing your weight is hard to do on your own, work with a registered dietitian or a health care provider to develop a plan that works for you.
- Avoid tobacco and excessive alcohol, which can increase your risk of health problems, including cancer.
- Manage stress with techniques such as deep breathing, meditation, yoga, Tai chi or spending time on hobbies or with loved ones.
- Aim for seven to nine hours of quality sleep each night. Follow a consistent sleep schedule, create a relaxing bedtime routine and make sure your bedroom is cool, dark and quiet.
The bottom line
Tamoxifen is an important part of treatment for many people with breast cancer. But the end of the treatment plan, side effects or health changes may mean you need to stop taking it. Knowing what to expect and what can help can make this transition easier.
If you have concerns or questions about your breast cancer treatment plan, reach out to your provider or contact an expert at Banner Health.
