Granulosa cell tumors (GCT) are a rare form of ovarian cancer, accounting for a small percentage of all ovarian malignancies. While GCT is classified as cancer and carries risk, the outlook is generally more favorable compared to the more common types of epithelial ovarian cancer. The long-term prognosis depends heavily on how early the tumor is discovered and its biological behavior.
What Are Granulosa Cell Tumors
Granulosa cell tumors are the most common type of sex cord-stromal tumor, arising from the hormone-producing tissues surrounding the ovarian follicles. Unlike epithelial tumors, GCTs originate internally from specialized cells that regulate reproductive function. This unique origin dictates the tumor’s most distinctive clinical feature: its ability to secrete hormones.
The tumor cells often produce large amounts of estrogen, acting as a functional endocrine mass. This excess estrogen triggers notable symptoms, frequently leading to an early diagnosis. In postmenopausal women, this hormonal activity often manifests as postmenopausal or abnormal uterine bleeding. For younger patients, the estrogen surge may cause menstrual irregularities or, in children, precocious puberty.
These clinical signs prompt medical investigation before the mass grows too large or spreads. This hormonal signature is a defining difference from many other ovarian cancers, which often remain clinically silent until advanced stages. The tumor is typically slow-growing, which contributes to a generally positive prognosis.
The Outcome: Survival Rates and Staging
While death from a granulosa cell tumor is possible, the likelihood is significantly lower than for most other ovarian malignancies. The lethality of GCT is directly tied to the stage of the disease at diagnosis. Because these tumors often cause hormonal symptoms, up to 90% are diagnosed at Stage I, meaning the cancer is confined entirely to the ovary.
For patients diagnosed at Stage I, the long-term outlook is excellent, with 10-year survival rates ranging from approximately 88% to 96%. The majority of deaths from GCT occur only after the cancer has recurred multiple times or if the disease was already advanced when first discovered.
The International Federation of Gynecology and Obstetrics (FIGO) staging system classifies the extent of the disease, which is the most reliable predictor of outcome. When the tumor has spread beyond the ovary to other pelvic or abdominal structures (Stages II-IV), the prognosis changes considerably. For these advanced stages, the 5-year and 10-year survival rates drop to a range of 33% to 44%. The risk of mortality is primarily a factor of the tumor’s physical extent at the time of initial treatment.
Treatment Approaches for GCT
The primary and most effective treatment for a granulosa cell tumor is surgical removal. The goal of the initial operation is to completely remove the tumor and accurately determine the stage of the disease. This procedure often involves a hysterectomy and the removal of both fallopian tubes and ovaries, known as a total abdominal hysterectomy with bilateral salpingo-oophorectomy.
For younger patients with Stage IA disease who wish to preserve their fertility, a unilateral salpingo-oophorectomy, which removes only the affected ovary and tube, may be safely performed. Complete surgical staging is crucial, as it involves taking biopsies from various abdominal sites to ensure the cancer is truly confined to the ovary. Leaving residual tumor tissue is associated with a poorer prognosis.
Systemic treatments like chemotherapy or radiation therapy are generally reserved for cases that are high-risk, advanced, or recurrent. A common chemotherapy regimen used is a platinum-based combination, such as bleomycin, etoposide, and cisplatin (BEP). Chemotherapy is typically administered following surgery to eliminate any microscopic disease that may have spread.
Hormonal therapies, including aromatase inhibitors, are also sometimes utilized, particularly for recurrent or metastatic disease, as the tumor cells are hormone-sensitive. The selection of adjuvant treatment is determined by the tumor’s size, its stage, and the presence of certain high-risk pathological features.
Managing the Risk of Recurrence
A defining characteristic of granulosa cell tumors is their potential for late recurrence, which can happen many years or even decades after the initial successful treatment. This propensity for a delayed return is the main factor driving the need for long-term, specialized follow-up care. Recurrence can sometimes be found 10, 15, or even 20 years after the primary diagnosis.
Patients are advised to undergo lifelong surveillance, which involves a combination of physical examinations, imaging, and tumor marker monitoring. The most valuable tool for monitoring is a blood test for a specific tumor marker called Inhibin B. GCT cells often secrete this hormone, and a rising level in the blood can indicate a recurrence months before it is visible on imaging or causes symptoms.
Anti-Mullerian Hormone (AMH) is another reliable serum marker that can be measured alongside Inhibin B to enhance the detection sensitivity. If a recurrence is detected, it is typically managed with a combination of repeat surgery to remove the new tumor, potentially followed by chemotherapy or hormonal therapy. While a recurrence complicates the overall prognosis, aggressive intervention can still lead to prolonged survival.