A Patient’s Guide to Cancer Immunotherapy
Ovarian Cancer
What You
Need to Know
Hearing the words “You have ovarian cancer” can feel overwhelming. You may feel scared, confused, or uncertain about what comes next. These feelings are not unexpected — and you are not alone. You don’t have to become an expert overnight.
This guide from the Cancer Research Institute (CRI) is designed to help you understand a treatment option called immunotherapy, how it may fit into your ovarian cancer treatment plan, and what questions you may want to ask your health care team along the way.
Take the Next Step with Confidence
Getting a Diagnosis
What is
Ovarian
Cancer?
What are ovaries, and what is ovarian cancer?
The ovaries are two small female reproductive organs that produce eggs and hormones. Ovarian cancer develops when cells in an ovary grow out of control. Some ovarian cancers are now believed to originate in the fallopian tubes, which carry eggs from the ovaries toward the uterus.
A closely related cancer can develop in the peritoneum, the tissue that lines the inside of your abdomen. Because ovarian, fallopian tube, and primary peritoneal cancers share many features and are generally treated in similar ways, they are often discussed together as “ovarian cancer.”
Are there different types of ovarian cancer?
Yes. Knowing the type, or subtype, of ovarian cancer you have can help guide treatment.
- Epithelial ovarian cancer may begin in the ovary or fallopian tube and accounts for about 90% of ovarian cancers. High-grade serous carcinoma is the most common subtype.
- Germ cell tumors begin in the cells that produce eggs and are more common in younger people.
- Stromal tumors begin in the hormone-producing and structural tissues of the ovary.
Most of the immunotherapy information in this guide applies to epithelial ovarian, fallopian tube, and primary peritoneal cancers. Germ cell and stromal tumors may be treated differently. Your health care team can explain which information applies to your diagnosis.
What does staging mean?
Staging describes how far cancer has spread. Ovarian cancer is staged from Stage I to Stage IV. Stage I cancer is limited to your ovaries or fallopian tubes, while more advanced stages may involve other tissues in your pelvis or abdomen, lymph nodes, or distant parts of your body.
Understanding the stage of cancer can help your health care team recommend treatment options.
What type of oncologist treats ovarian cancer?
A gynecologic oncologist is a doctor who specializes in cancers of the female reproductive system and is trained in both cancer treatment and gynecologic surgery.
Because surgery is an important part of treatment for many people with ovarian cancer, people with suspected or newly diagnosed disease should discuss their treatment plan with a gynecologic oncologist whenever possible.
What about fertility, menopause, or sexual health?
Ovarian cancer and its treatment can affect fertility, hormone levels, and sexual health, including causing early menopause, vaginal dryness, discomfort during sex, or changes in sexual desire or body image.
If fertility is important to you, ask whether you should speak with a fertility specialist before treatment begins. Your health care team can also help manage menopause and sexual health concerns or refer you to a specialist.
Making a Decision
Understanding
Immunotherapy
More than 40 immunotherapies have been approved to treat more than 35 different types of cancer. Learning which immunotherapies are available for your specific type of cancer can help you discuss treatment options with your health care team.
What is immunotherapy?
Immunotherapy is a type of cancer treatment that helps your immune system recognize and attack cancer cells.
In ovarian cancer, the currently approved immunotherapies are immune checkpoint inhibitors (ICIs). These treatments block signals cancer can use to suppress immune cells, helping “release the brakes” so your immune system can respond more effectively.
Does immunotherapy work for everyone with ovarian cancer?
No. Immunotherapy has helped some people with ovarian cancer, but it does not work for everyone and is currently used only in certain situations. Whether it may be an option can depend on previous treatment, how the cancer responded to platinum-based chemotherapy, and tumor biomarkers.
For most people with newly diagnosed ovarian cancer, treatment generally begins with surgery and platinum-based chemotherapy rather than immunotherapy.
What genetic and biomarker testing might I need?
Genetic and biomarker testing can help guide treatment and identify hereditary changes that may also be important for your family. Your health care team may recommend germline (hereditary cancer) testing, usually using blood or saliva to look for inherited genetic mutations, as well as tumor testing, which examines features of the cancer itself.
| Test / Biomarker | Why It May Matter |
|---|---|
| BRCA1 and BRCA2 | Can affect hereditary cancer risk and eligibility for some PARP inhibitors, which are a type of targeted cancer treatment |
| Homologous recombination deficiency (HRD) | Can help guide use of PARP inhibitors |
| Folate receptor alpha (FRα) | Can identify some patients who may benefit from certain antibody-drug conjugates (ADCs) |
| PD-L1 | Can help determine eligibility for pembrolizumab (Keytruda®) in platinum-resistant ovarian cancer |
| Microsatellite instability (MSI) / DNA mismatch repair (MMR) / Tumor mutational burden (TMB) | Can identify some tumors that may respond to immune checkpoint inhibitors |
What does “platinum-resistant” ovarian cancer mean?
Platinum-based chemotherapy, such as carboplatin or cisplatin, is a mainstay of ovarian cancer treatment.
Your health care team may describe ovarian cancer as platinum-sensitive or platinum-resistant based on how the cancer responded to platinum chemotherapy and how soon it returned or progressed afterward. Cancer that progresses during platinum treatment or returns within about six months afterwards is often described as platinum-resistant.
This distinction can affect which treatments are recommended, including whether a U.S. Food and Drug Administration (FDA)-approved immunotherapy may be an option.
What immunotherapies are used for ovarian cancer?
Immune checkpoint inhibitors may be an option for certain people with ovarian cancer based on factors such as prior treatment, platinum resistance, and tumor biomarkers.
| Your situation | What immunotherapy may be used |
|---|---|
| PD-L1-positive, platinum-resistant cancer after one or two previous systemic treatments | Pembrolizumab with paclitaxel chemotherapy, with or without bevacizumab |
| Certain advanced tumors with MSI-H, dMMR, or TMB-H | Pembrolizumab |
| Certain recurrent or advanced dMMR tumors after previous treatment | Dostarlimab (Jemperli®) |
Immunotherapies may also become available through future FDA approvals or clinical trials.
What is a clinical trial, and when should I consider participating?
Clinical trials are carefully monitored research studies that test new treatments or new ways of using existing treatments. They may provide access to promising therapies that are not yet approved by the FDA.
Clinical trials can be worth considering at different points in your care, including when you are first diagnosed, if the cancer comes back, or if standard treatments are no longer working. Ask your doctor about trials at your treatment center or use CRI’s Clinical Trial Finder to explore options that you may be eligible for.
what to Expect
Starting
Treatment
How is immunotherapy for ovarian cancer given?
Pembrolizumab can be given by IV (intravenous) infusion or as a subcutaneous injection, while dostarlimab is given by IV infusion. Immunotherapy is typically given every three to six weeks, depending on the type and treatment plan.
For PD-L1-positive, platinum-resistant ovarian cancer, pembrolizumab is given with weekly paclitaxel chemotherapy, with or without bevacizumab. Your health care team can explain which form and schedule are appropriate for you.
What side effects should I expect?
Many people tolerate immunotherapy well, but side effects can occur because the immune system becomes more active and may affect healthy tissues. Common side effects may include fatigue, skin changes (such as rash or itching), and diarrhea. Less commonly, immune-related side effects can affect the colon, liver, lungs, hormone-producing glands, or other organs.
If you receive immunotherapy with chemotherapy or bevacizumab, you may also experience side effects from those treatments. Tell your health care team about new or worsening symptoms as soon as possible, even if they seem minor.
How will I know if immunotherapy treatment is working?
Your health care team may use imaging scans, physical exams, blood tests, and changes in your symptoms to determine how well treatment is working.
For some people with ovarian cancer, levels of a blood protein called CA-125 may also help monitor treatment response. Your doctor will consider CA-125 results alongside scans, symptoms, and other information rather than relying on the blood test alone.
Looking and Living Forward
Post-Treatment
Support
What ongoing care will I need?
Regular follow-up care helps monitor for recurrence and manage ongoing side effects. It may include physical exams, imaging, blood tests such as CA-125, and conversations about your physical and emotional well-being.
Some immune-related side effects can develop or continue after immunotherapy has stopped, so tell your health care team about new symptoms even after treatment ends.
What if immunotherapy doesn’t work or the ovarian cancer comes back?
Not everyone responds to immunotherapy, and it can be difficult if treatment does not work as hoped. If immunotherapy isn’t effective or the cancer returns, your doctor may recommend additional chemotherapy, targeted therapy, immunotherapy, surgery, or a clinical trial.
Where can I find support from others affected by ovarian cancer?
Connecting with other people affected by ovarian cancer can provide practical and emotional support. You can explore personal stories and resources for people affected by cancer and immunotherapy.
Organizations such as the Ovarian Cancer Research Alliance (OCRA) and National Ovarian Cancer Coalition (NOCC) also offer additional educational resources, support programs, and peer connections for patients and caregivers.
What comes next?
No matter where you are in your journey — newly diagnosed, in treatment, or considering next steps — your questions matter. Keep asking. Bring support when you can. And let your health care team know how you’re feeling, both physically and emotionally.
conversational cues
10 Questions to Ask Your Doctor
Being diagnosed with ovarian cancer can feel overwhelming, and understanding your treatment options can make a big difference. Asking questions can help you take an active role in your care, make informed decisions, and feel more prepared as you move forward.
Here are 10 questions you may want to ask your health care team:
1
What exact type and stage of ovarian, fallopian tube, or primary peritoneal cancer do I have?
2
Should I be treated by or get a second opinion from a gynecologic oncologist?
3
Have I had both genetic testing and tumor biomarker testing?
4
Which of my genetic or biomarker results affect my treatment options, and do they have any implications for my family?
5
Is my cancer considered platinum-sensitive or platinum-resistant, and how does that affect my options?
6
Is immunotherapy a recommended option for me right now, and if so, which treatment or combination would I receive?
7
What side effects should I watch for, and when should I call you?
8
How will we monitor whether treatment is working, and what role will scans and CA-125 testing play?
9
Are there clinical trials I should consider now or in the future?
10
What support is available for me and my family, including emotional support, fertility or menopause care, financial resources, and help managing treatment?
Continue Your Immunotherapy Journey
Review Patient Resources
Find trusted answers about cancer immunotherapy, treatment options, explanations for medical terms, and more.
Find Immunotherapy Clinical Trials
Explore immunotherapy clinical trials and learn how participation works, with support from CRI’s clinical trial navigators.
Explore Patient Journeys
Hear directly from patients and survivors who have received immunotherapy and learn how they navigated diagnosis, treatment, and decision-making.
Keep Up-To-Date with Educational Programs & Ongoing Research
Stay informed through CRI’s patient-focused educational programs, webinars, and research.
Acknowledgements
We extend our sincere gratitude to the CRI ImmunoAdvocates, a group of patients treated with immunotherapy, who generously shared their experiences, insights, and time to help shape this guide. By telling your stories and offering your perspectives, you’ve helped ensure that people newly diagnosed with cancer feel seen, supported, and empowered as they begin their immunotherapy journey.
Disclaimer: This information is intended for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always talk with your health care team about questions or decisions related to your care.