Frequently Asked Questions about Germ Cell and Stromal Cell Cancers
Germ cell and stromal cell ovarian cancers are rare. They account for about 5-7% of all ovarian cancers.
Germ cell cancers start in cells that form eggs in the ovary. They typically occur in young women and adolescents. Stromal cell cancers start in cells that produce female hormones and hold the ovarian tissues together. They can occur at any age. But they are common in the early thirties and fifties.
Symptoms: Stromal cell cancers are usually slow growing. They can cause pain and discomfort in the early stages. These cancers are known to secrete hormones like estrogen or testosterone. The effects of these hormones include:
- abnormal uterine bleeding
- new onset acne
- facial hair growth
Germ cell cancers usually grow rapidly. They can become very large and cause significant pain or abdominal distension. Some germ cell cancers may produce the pregnancy hormone HCG. This can lead to a false positive pregnancy test.
Risk Factors: There are no known risk factors for these cancers. Recent data suggest that changes in certain chromosomes may be associated with stromal cancers. In germ cell cancers, rare chromosome abnormalities can cause a delay in puberty and menstruation.
Screening/Prevention: There are no known ways to prevent stromal cell or germ cell cancers. Abnormal enlargement of an ovary might be found at the time of an annual pelvic exam. That would increase the chance for diagnosis and treatment. Girls who have not started menstruating by age 15 should be evaluated by their physician. The evaluation should include an analysis of chromosomes. The purpose would be to detect abnormalities that could predispose a girl to a germ cell cancer.
Incidence: Stromal cell cancers account for about five percent of all ovarian cancers. They can be diagnosed at any age. The average age of diagnosis is 45. Stromal cell cancers are the most common hormonally active tumors. Most are diagnosed at an early stage. Stromal cell cancers are slow growing tumors. The prognosis is excellent. The most common stromal cell cancer is the granulosa cell tumor. It accounts for about 80% of all stromal tumors.
Germ cell cancers account for less than five percent of all ovarian cancers. They typically occur in young women and adolescents. The average age of diagnosis is 18 years. In spite of their aggressive nature, germ cell cancers are highly curable. Treatment involves surgery and chemotherapy.
Advances in Germ Cell Ovarian Cancer
In 2007, researchers evaluated results from the National Cancer Institute’s data base for the years 1988 to 2001. They looked at the survival of patients who did not have the uterus and normal ovary removed. It was the same as for patients who had the uterus, tubes, and both ovaries removed. These results suggest that fertility sparing surgery can work for some women. Women who could benefit are those who have an early stage germ cell cancer and wish to still be able to have children.
An important area of concern is a patient’s quality of life. Chemotherapy with platinum agents is a standard treatment for germ cell tumors. A common and disruptive side effect of this treatment is neurologic toxicity. One way to reduce long-term side effects would be a shorter course of treatment. Another option might be close surveillance of women with early stage germ cell cancers. An ongoing study by the Children’s Oncology Group (COG) may shed light on both options.
The COG study involves evaluating the safety and effectiveness of giving fewer patients chemotherapy after surgery. In the trial, patients younger than 19 with early stage germ cell cancers are watched closely after surgery. Blood tests, physical exams, and imaging studies are used to look for signs their cancer has recurred. Only those that show signs of recurrence are treated. Carefully selected patients who who require treatment recieve a shorter course of a three-drug combination. The drug is called BEP. The traditional standard is five days of treatment with each cycle. The hope is this shorter treatment will reduce side effects from chemotherapy. It’s thought that these approaches will improve overall quality of life without affecting outcome. This study will soon be supported by the GOG thereby expanding eligibility to young adults.
Novel approaches to treatment are also being studied. These studies include the use of high-dose chemotherapy with stem cell transplantation. Studies are also focused on other agents. For instance, there are studies of agents that target specific cancer-causing changes. Two agents are sunitinib and bevacizumab. These block angiogenesis. That’s the process of forming new blood vessels. By doing this, they limit tumor growth. They also limit the spread of the cancer. The results of these studies are being eagerly awaited.
Advances in Stromal Ovarian Cancer
Stromal cell cancers of the ovary are rare. They account for about five percent of all ovarian cancers. They tend to be slow growing. While they are less likely to recur, they are less sensitive to chemotherapy when they do. These tumors can recur 10 to 15 years or more after they are first diagnosed.
The most common type of stromal cell cancer is the granulosa cell tumor. It accounts for 80% of all stromal ovarian cancers. The juvenile granulosa cell tumor is a special subtype. It’s seen mainly in young girls. The more common adult type can occur at any age. It is, though, often diagnosed in the postmenopausal age group. The median age of that group is 52 years.
Earlier this year, a study looked at survival in patients who did not have the uterus and unaffected ovary removed. It was the same as for patients who had a hysterectomy and both ovaries removed. This finding is good news for young women with stromal cell tumors who wish to keep the option of pregnancy open.
Inhibin is a blood test used to study the response to therapy. It’s used in patients with ovarian granulosa cell tumors. Rising inhibin levels suggest a granulosa cell tumor may be growing. They also may indicate a tumor has recurred. Scientists have described two different but related inhibin components. They are referred to as inhibin A and inhibin B. Recent studies show inhibin B may be a better indicator for granulosa cell tumor. In blood samples obtained at the time of first diagnosis, inhibin B levels were elevated in 89% of patients. Inhibin A levels were elevated in 67 percent. This was a small study. But it may lead to better diagnostic testing for this rare tumor.
Recent advances in molecular biology have been used in ovarian stromal cell cancers. Novel genetic changes have been found that could aid in early detection, diagnosis, and treatment. One gene of interest is FOXL2. Early data show that FOXL2 has reduced expression in many of these tumors. They also show that in more advanced cancers, expression is reduced compared with early stage cancers. These data suggest that FOXL2 may be a tumor suppressor gene for granulosa cell tumors. This finding suggests that FOXL2 may work to block the growth of this type of cancer cell. Such clues may provide researchers with new strategies to treat granulosa cell tumors and other ovarian stromal cancers.
