Staging:
International Federation of Gynecology and Obstetrics (FIGO) staging
Stage I - Limited to ovaries
Ia - Limited to one ovary
Ib - Limited to both ovaries
Ic - Ascites with malignant cells on peritoneal washings or extension beyond the capsule in either Ia or Ib
Stage II - Pelvic extension
IIa - Involvement of uterus or fallopian tubes
IIb - Extension to the bladder or rectum
IIc - Stage IIa or IIb but with positive peritoneal washings
Stage III - Peritoneal implants outside of pelvis
IIIa - Microscopic seeding of abdominal surfaces
IIIb - Abdominal peritoneal implants smaller than 2 cm
IIIc - Abdominal implants larger than 2 cm or positive lymph nodes
Stage IV - Distant metastases
Pleural effusions - Must confirm with positive cytology to be deemed stage IV
Any involvement of the liver parenchyma
During laparotomy, obtain a biopsy from the contralateral ovary because 5% of all stage Ia cancers established by gross inspection have occult microscopic disease on the opposite ovary. Some advocate leaving the opposite ovary undisturbed if it is of normal size or appearance.
MEDICAL TREATMENT :
A preponderance (75-80%) of dysgerminomas present as stage I cancers and, therefore, can be treated by surgical resection alone with a unilateral salpingo-oophorectomy. This is preferred when attempting to preserve fertility; however, diligent follow-up care, with serial pelvic examinations and tumor markers (ie, hCG, AFP, LDH) is mandatory if resection is the only treatment modality.
The role of adjuvant therapy should be reserved for resectable yet advanced tumors. Chemotherapy usually is the adjuvant therapy of choice to spare fertility and is used in cases of recurrence after radiation therapy. Radiation therapy can be administered to patients with stage I-III tumors.
Adjuvant chemotherapy: The 4 regimens for chemotherapy are as follows: (1) vincristine, actinomycin D, and cyclophosphamide (VAC); (2) methotrexate, actinomycin D, and chlorambucil (MAC); (3) vincristine, bleomycin, and cisplatin (VBP); and (4) bleomycin, etoposide, and cisplatin (BEP). Although the efficacy has been analyzed for each protocol, advanced disease or recurrent dysgerminoma is more responsive to the BEP protocol.
Bleomycin, etoposide, and cisplatin protocol
Bleomycin - Maximum 30 U IV per week for 9 weeks; dose at 20 U/m2
Etoposide (ie, VP-16) - 100 mg/m2 on days 1-5 q3wk for 3 courses; reduced 20% for granulocytic fever or previous radiotherapy
Cisplatin - 20 mg/m2 on days 1-5 q3wk for 3 courses
Vincristine, actinomycin D, and cyclophosphamide protocol
Vincristine - 1.5 mg/m2; maximum 2.5 mg qwk for 12 weeks
Actinomycin - 0.5 mg IV over 5 days q4wk
Cyclophosphamide - 5-7 mg/kg over 5 days q4wk
Vincristine, bleomycin, and cisplatin protocol
Vinblastine - 12 mg/m2 q3wk for 4 courses
Bleomycin - 20 U/m2 (maximum 30 U) qwk for 7 weeks, with an 8th course administered in week 10
Cisplatin - 20 mg/m2 qd for 5 days q3wk for 3-4 courses
Antiemetics
Chlorpromazine - 25-50 mg PO/IM/PR q4h
Lorazepam 1-2 mg PO/IV q6h
Dexamethasone 8 mg IV prior to cisplatin and 4 mg q4h for 2 doses
Radiation therapy
Radiation is used to treat periaortic and pelvic lymph node metastases. Shielding the remaining ovary in an attempt to preserve fertility is not uncommon. Oophoropexy may be used to mechanically hold the remaining ovary away from the radiation field.
Radiation therapy is recommended for any dysgerminomas staged Ib-III. The field of exposure extends from T11 to L5, with shielding of the contralateral ovary and the femur head.
The use of radiation in stage Ia cancers is considered precautionary. Most patients present with stage I disease and usually can be treated with simple resection (eg, unilateral salpingo-oophorectomy).
De Palo, Freed, and Lawson developed the 3 major radiation therapy protocols. These protocols differ mainly in their treatment of the abdomen for node-positive disease and in prophylactic treatment of the mediastinum.
Primary therapy with radiation is reserved for patients who cannot tolerate chemotherapy or surgical resection.
Surgical Care: Patients undergoing surgery for ovarian cancer require a mechanical and/or antibiotic bowel preparation before surgery. This contingency planning is critical in the case of unsuspected GI spread requiring bowel resection. Additionally, nutritional supplementation may be necessary, depending on the status of the patient.
Dysgerminoma disease staged below Ia (ie, confined within the capsule of only one ovary) is best treated with simple unilateral salpingo-oophorectomy.
A biopsy should be performed on the contralateral ovary at the time of surgery if the ovary is enlarged or appears abnormal. Otherwise, performing a biopsy of a normal contralateral ovary only diminishes fertility by adhesion formation postbiopsy.
Thorough studies have questioned the prophylactic removal of both ovaries. Current recommendations advise against removal of the normal ovary because this does not reduce the risk of ovarian cancer and commits patients to early menopause and infertility.
Residual microscopic disease is extinguished readily with chemotherapy and radiation therapy, to which these cells are highly responsive. Clinical oncologists and women wishing to preserve fertility have accepted adjuvant therapy and sparing of the healthy contralateral ovary. Recurrence after chemotherapy and radiation therapy is highly uncommon, although the literature reports one case.
Bilateral disease is justification for bilateral salpingo-oophorectomy. A total abdominal hysterectomy is not mandatory but may be performed concurrently if patients are no longer interested in bearing children.
Full staging is completed with peritoneal washings, infracolic omentectomy, and lymph node biopsy before closure. A biopsy for unilateral disease may be performed on the ipsilateral pelvic lymph nodes. Periaortic lymph node sampling should be performed in both circumstances. Take great care to observe carefully the retroperitoneal lymph nodes because these are the most common sites of metastasis for this disease.
According to current American College of Obstetricians and Gynecologists (ACOG) recommendations, second-look laparotomies are not considered the standard of care for dysgerminomas.
DRUG THERAPY :
1. ANTINEOPLASTIC AGENTS : Treatment entails chemotherapy and radiation therapy. Lesions staged higher than stage Ia require a combination of VAC, VBP, or BEP.
- VINCRISTINE
- ACTINOMYCIN-D
- CYCLOPHOSPHAMIDE
- ETOPOSIDE
- BLEOMYCIN
- CISPLATIN
- VINBLASTINE