Overview
Clear cell adenocarcinoma of the ovary (also called ovarian clear cell carcinoma or OCCC) is a rare subtype of epithelial ovarian cancer. It gets its name from the way the cancer cells look under a microscope — they appear clear or "hobnail-shaped" because of their high glycogen content. This cancer develops in the tissue that covers the outside of the ovary or lines cysts within the ovary. It is often associated with endometriosis, a condition where tissue similar to the uterine lining grows outside the uterus. Symptoms can include pelvic or abdominal pain, bloating, feeling full quickly when eating, changes in urination, and sometimes abnormal vaginal bleeding. Many women are diagnosed at an earlier stage compared to other ovarian cancers because the tumor can grow large and cause noticeable symptoms sooner. However, clear cell adenocarcinoma is known for being more resistant to standard platinum-based chemotherapy than other types of ovarian cancer. Treatment typically involves surgery to remove the tumor, often including removal of the ovaries, fallopian tubes, and uterus, followed by chemotherapy. Because this subtype does not respond as well to traditional chemotherapy, researchers are actively studying new targeted therapies and immunotherapy approaches. Early detection and treatment by a gynecologic oncologist experienced with this rare subtype are important for the best possible outcomes.
Also known as:
Key symptoms:
Pelvic or lower abdominal painAbdominal bloating or swellingFeeling full quickly when eatingFrequent or urgent need to urinateUnexplained weight loss or weight gainAbnormal vaginal bleedingFatigue and low energyBack painConstipation or changes in bowel habitsA noticeable mass or lump in the pelvisPain during intercourseBlood clots in the legs (deep vein thrombosis)High calcium levels in the blood (hypercalcemia)
Sporadic
Usually appears on its own, not inherited from a parent
Adult
Begins in adulthood (age 18 or older)
FDA & Trial Timeline
10 eventsSun Yat-Sen Memorial Hospital of Sun Yat-Sen University — PHASE2
Tongji Hospital — PHASE3
Dana-Farber Cancer Institute — PHASE2
M.D. Anderson Cancer Center — PHASE1, PHASE2
Tongji Hospital
Elizabeth K. Lee MD — PHASE2
Xencor, Inc. — PHASE2
Nuvectis Pharma, Inc. — PHASE1
Novartis Pharmaceuticals — PHASE1, PHASE2
National Cancer Institute (NCI) — PHASE2
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Clear cell adenocarcinoma of the ovary.
8 clinical trialsare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Rare Disease Specialist
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Financial Resources
1 resourcesHexalen
Medimmune Oncology, Inc.
Travel Grants
No travel grants are currently matched to Clear cell adenocarcinoma of the ovary.
Community
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Start the conversation →Latest news about Clear cell adenocarcinoma of the ovary
1 articlesCaregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.What stage is my cancer, and has it spread beyond the ovary?,Was the surgeon able to remove all visible cancer during my operation?,Given that clear cell carcinoma can be resistant to standard chemotherapy, what treatment plan do you recommend for me specifically?,Has my tumor been tested for molecular markers like ARID1A, PIK3CA, or microsatellite instability that might guide targeted therapy?,Should I have genetic testing for hereditary cancer syndromes like BRCA mutations or Lynch syndrome?,Are there any clinical trials available for clear cell ovarian cancer that I might be eligible for?,What is my expected prognosis, and what follow-up monitoring schedule will I need?
Common questions about Clear cell adenocarcinoma of the ovary
What is Clear cell adenocarcinoma of the ovary?
Clear cell adenocarcinoma of the ovary (also called ovarian clear cell carcinoma or OCCC) is a rare subtype of epithelial ovarian cancer. It gets its name from the way the cancer cells look under a microscope — they appear clear or "hobnail-shaped" because of their high glycogen content. This cancer develops in the tissue that covers the outside of the ovary or lines cysts within the ovary. It is often associated with endometriosis, a condition where tissue similar to the uterine lining grows outside the uterus. Symptoms can include pelvic or abdominal pain, bloating, feeling full quickly whe
How is Clear cell adenocarcinoma of the ovary inherited?
Clear cell adenocarcinoma of the ovary follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Clear cell adenocarcinoma of the ovary typically begin?
Typical onset of Clear cell adenocarcinoma of the ovary is adult. Age of onset can vary across affected individuals.
Are there clinical trials for Clear cell adenocarcinoma of the ovary?
Yes — 8 recruiting clinical trials are currently listed for Clear cell adenocarcinoma of the ovary on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Clear cell adenocarcinoma of the ovary?
20 specialists and care centers treating Clear cell adenocarcinoma of the ovary are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.
What treatment and support options exist for Clear cell adenocarcinoma of the ovary?
1 patient support program are currently tracked on UniteRare for Clear cell adenocarcinoma of the ovary. See the treatments and support programs sections for copay assistance, eligibility, and contact details.