Treatment
Surgery is the initial treatment for GCT, and, in young patients, this can be conservative, with preservation of the uterus and contralateral ovary, because chemotherapy is very effective. Second-look surgery generally is not indicated following initial treatment.
Dysgerminoma
This is the most common malignant GCT and represents 3-5% of all ovarian malignancies. Ninety percent occur in people younger than 30 years, and 75% occur in the second and third decades, with a median age of 22 years.
Dysgerminomas are bilateral in 10-35% of cases. Five percent occur in phenotypic females with abnormal gonads. They may have a 46XY karyotype with pure gonadal dysgenesis or androgen insensitivity syndrome, or, they may have a 45X, 46XY karyotype with mixed gonadal dysgenesis. Dysgerminomas may be large and usually are solid with a smooth external surface and a fleshy pink-tan color inside. The majority are confined to the ovary at diagnosis, but approximately 25% of otherwise stage I dysgerminomas have lymph node metastasis.
Surgery
Surgery is the initial management of a tumor that possibly is a dysgerminoma. Assessment of the abdominal and pelvic contents is made as for EOC (see Surgery for ovarian cancer).
Where no macroscopic disease exists outside the ovary, unilateral oophorectomy should be performed, excising the tumor intact and without rupture. Staging procedures include washings, omental biopsy, and sampling of paraaortic and pelvic lymph nodes. The opposite ovary should be carefully inspected, and a biopsy should be performed if necessary. However, in young patients, the uterus and opposite ovary should be left in situ.
If disease is present outside the ovary, make an attempt to remove all visible tumor while maintaining fertility for the patient. In a young patient, debulking disease from the contralateral ovary, without performing oophorectomy, should be safe.
Many patients present having already undergone a unilateral oophorectomy that uncovered the dysgerminoma. Consideration should be given to staging these patients laparoscopically if possible, if a negative result will spare the patient from receiving chemotherapy. If chemotherapy will be given regardless, initial staging surgery is not warranted.
Postsurgical treatment
Adequately staged patients with stage IA disease can be monitored without further therapy, whatever the size of the primary tumor. However, 15-20% of tumors recur, mostly in the first 2 years after treatment.
All patients at a stage greater than IA require combination chemotherapy, with the most accepted regimen in the United States being bleomycin, etoposide, and cisplatin (BEP). In patients with advanced disease, the combination of vincristine, actinomycin D, and cyclophosphamide (VAC) has been used following BEP as consolidation therapy. Dysgerminoma is very radiosensitive, but radiation rarely is used, especially in young patients, because of its effect on future fertility.
Prognosis
Stage IA disease is associated with a 5-year survival rate of higher than 95%, but even with advanced disease, the 5-year survival rate is good following surgery and chemotherapy.
Immature teratoma
This is the second most common GCT. It occurs mostly in people aged 10-20 years but may occur postmenopausally. Tumor markers are not elevated unless the tumor contains elements of other GCTs. The cardinal histologic feature is immature elements, mostly of neural tissue. The tumor spreads most commonly to peritoneal surfaces.
In the patient who is premenopausal, treatment should include unilateral oophorectomy and surgical staging (see Surgery for ovarian cancer). The contralateral ovary rarely is involved, and biopsy of the other ovary is not necessary. If a patient no longer desires to remain fertile or is postmenopausal, hysterectomy with removal of both ovaries is sensible.
Patients with stage IA grade 1 disease do not need adjuvant therapy postoperatively. The standard of care for high-grade stage I disease postoperatively has been chemotherapy with BEP. Evidence is accumulating that such patients can be treated more conservatively following surgery, provided good follow-up care is maintained. Patients with stage IA grade 2 disease can be monitored only.
The conservative management of stage IA grade 3 is more controversial.
Follow-up
No tumor markers exist for immature teratoma, and follow-up care should include clinical examination together with ultrasound at regular intervals.
Second-look laparoscopy or laparotomy may be considered, particularly in patients who had macroscopic residual disease at the end of surgery. Immature teratoma may be associated with the development of benign teratomatous masses and peritoneal glial implants that may remain for a long time. All masses at second surgery should be removed to be sure that no immature (malignant) elements are present. If such elements are present, the patient should have further chemotherapy with VAC.
The prognosis depends on the extent of the tumor and the grade. Stage I grades 1 and 2 have almost 100% survival. Patients with incompletely resected tumor have a 50% chance of survival.
Other germ cell tumors
Endodermal sinus tumor occurs at a mean age of 18 years, and one third occur before puberty. The tumors secrete alpha-fetoprotein. Following standard surgery, all patients should be treated with BEP. Other chemotherapy regimens may be necessary. Embryonal carcinoma and choriocarcinoma are extremely rare.