Clear Cell Ovarian Cancer: Overview, Diagnosis, Treatments and Risk Factors

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What is Clear Cell Ovarian Cancer

Clear cell ovarian cancer is a subtype of epithelial carcinoma. Epithelial carcinomas occur on the surface of the ovaries. Clear cell ovarian cancer gets its name because the center of the cells appear clear when viewed through a microscope. According to the Atlas of Genetics and Cytogenetics in Oncology and Haematology, ovarian epithelial carcinomas “account for 75% of all ovarian tumors, and 90-95% of ovarian malignancies.” The subtype clear cell ovarian cancer is much more rare. Only about 7.4 percent of ovarian carcinomas are clear cell, estimates Johns Hopkins Pathology.

Signs and Symptoms

Like all forms of ovarian cancer, clear cell ovarian cancer is often asymptomatic, meaning it does not cause any noticeable symptoms. This is especially true during early stages of the cancer, when it is most treatable. Even when signs of ovarian cancer are present, they are often overlooked and disregarded as common ailments. Some symptoms that may be present with clear cell ovarian cancer include abdominal bloating, abdominal discomfort, lack of appetite, feeling full after only eating a small amount of food, fatigue, weight gain or loss, frequent need to urinate, difficulty urinating, constipation, menstrual changes, pain during sex and back pain.


A positive CA-125 ovarian cancer screening test or possible symptoms present in the woman may lead a doctor to investigate for signs of ovarian cancer. Imaging tests such as an ultrasound may be used to spot the presence of a tumor. A laparoscopy, which is an exploratory surgery done with small cameras inserted through small incisions in the body, may be performed to spot a tumor and possibly obtain a sample of cells. A diagnosis of clear cell ovarian cancer is not made until either a biopsy of cells or of the removed tumor is done in a laboratory where the cells can be identified.


The main treatments for clear cell ovarian cancer are surgery and chemotherapy. Depending on how large the tumor is and how far it has spread, it is either completely removed or a large portion of the tumor is removed. The affected ovary or ovaries, fallopian tubes and uterus may be removed as well. Chemotherapy is administered to kill remaining cancer cells and to shrink any remaining tumors. Johns Hopkins Pathology states that there is some discrepancy in medical research on the survival rates of women with clear cell ovarian cancer, with some research showing the outcome of treatment being similar to other types of epithelial cell ovarian cancers and other research suggesting that the treatment outcome is slightly less successful. Assuming the outcome of treatment for clear cell ovarian cancer is less successful than other epithelial ovarian cancers, the differences are not significant, says Johns Hopkins Pathology.

Risk Factors

The risk factors that increase a woman’s chance of getting clear cell ovarian cancer are:

  • A familial history of ovarian cancer.
  • Endometriosis
  • Post-menopausal
  • Obesity
  • Caucasian
  • Jewish descent

Genetic Link to Ovarian Cancer

Research cited in “Frequent Mutations of Chromatin Remodeling Gene ARID1A in Ovarian Cell Carcinoma”, published in the “Science Magazine.” linked mutations in the AR1D1A and PPP2R1A genes to clear cell ovarian cancer.


Johns Hopkins Pathology: Ovarian Cancer

UConns Virtual Pathology Museum: Clear Cell Carcinoma of Ovary

Frequent Mutations of Chromatin Remodeling Gene ARID1A in Ovarian Clear Cell Carcinoma; Science Magazine; Johns Hopkins University; Sian Jones et. al.; September 8, 2010

Endometrioid and Clear Cell Ovarian Cancers - A Comparative Analysis of Risk Factors; European Journal of Cancer, Vol. 44, Issue 16; Christina M. Nagel et. al.; November 2008