The usual chemotherapy regimen has limited efficacy in tumours of this type, although Imatinib has shown some promise. There is no current role for radiotherapy.

The usual treatment is surgery. The surgery for females usually is a fertility-sparing unilateral salpingo-oophorectomy. For malignant tumours, the surgery may be radical and usually is followed by adjuvant chemotherapy, sometimes by radiation therapy. In all cases, initial treatment is followed by surveillance. Because in many cases Leydig cell tumour does not produce elevated tumour markers, the focus of surveillance is on repeated physical examination and imaging.

In males, a radical inguinal orchiectomy is typically performed. However, testes-sparing surgery can be used to maintain fertility in children and young adults. This approach involves an inguinal or scrotal incision and ultrasound guidance if the tumour is non-palpable. This can be done because the tumour is typically unifocal, not associated with precancerous lesions, and is unlikely to recur.

The prognosis is generally good as the tumour tends to grow slowly and usually is benign: 10% are malignant. For malignant tumours with undifferentiated histology, prognosis is poor.

The usual treatment is surgery. The surgery usually is a fertility-sparing unilateral salpingo-oophorectomy. For malignant tumours, the surgery may be radical and usually is followed by adjuvant chemotherapy, sometimes by radiation therapy. In all cases, initial treatment is followed by surveillance. Because in many cases Sertoli–Leydig cell tumour does not produce elevated tumour markers, the focus of surveillance is on repeated physical examination and imaging. Given that many cases of Sertoli–Leydig cell tumor of the ovary are hereditary, referral to a clinical genetics service should be considered.

The prognosis is generally good as the tumour tends to grow slowly and usually is benign: 25% are malignant. For malignant tumours with undifferentiated histology, prognosis is poor.

Women with benign germ cell tumors such as mature teratomas (dermoid cysts) are cured by ovarian cystectomy or oophorectomy. In general, all patients with malignant germ cell tumors will have the same staging surgery that is done for epithelial ovarian cancer. If the patient is in her reproductive years, an alternative is unilateral salpingoophorectomy, while the uterus, the ovary, and the fallopian tube on the opposite side can be left behind. This isn't an option when the cancer is in both ovaries. If the patient has finished having children, the surgery involves complete staging including salpingoophorectomy on both sides as well as hysterectomy.

Most patients with germ cell cancer will need to be treated with combination chemotherapy for at least 3 cycles. The chemotherapy regimen most commonly used in germ cell tumors is called PEB (or BEP), and consists of bleomycin, etoposide, a platinum-based antineoplastic (cisplatin).

If ovarian cancer recurs, it is considered partially platinum-sensitive or platinum-resistant, based on the time since the last recurrence treated with platins: partially platinum-sensitive cancers recurred 6–12 months after last treatment, and platinum-resistant cancers have an interval of less than 6 months. Second-line chemotherapy can be given after the cancer becomes symptomatic, because no difference in survival is seen between treating asymptomatic (elevated CA-125) and symptomatic recurrences.

For platinum-sensitive tumors, platins are the drugs of choice for second-line chemotherapy, in combination with other cytotoxic agents. Regimens include carboplatin combined with pegylated liposomal doxorubicin, gemcitabine, or paclitaxel. Carboplatin-doublet therapy can be combined with paclitaxel for increased efficacy in some cases. Another potential adjuvant therapy for platinum-sensitive recurrences is olaparib, which may improve progression-free survival but has not been shown to improve overall survival. (Olaparib, a PARP inhibitor, was approved by the US FDA for use in BRCA-associated ovarian cancer that had previously been treated with chemotherapy.) For recurrent germ cell tumors, an additional 4 cycles of BEP chemotherapy is the first-line treatment for those tho have been treated with surgery or platins.

If the tumor is determined to be platinum-resistant, vincristine, dactinomycin, and cyclophosphamide (VAC) or some combination of paclitaxel, gemcitabine, and oxaliplatin may be used as a second-line therapy.

For platinum-resistant tumors, there are no high-efficacy chemotherapy options. Single-drug regimens (doxorubicin or topotecan) do not have high response rates, but single-drug regimens of topotecan, pegylated liposomal doxorubicin, or gemcitabine are used in some cases. Topotecan cannot be used in people with an intestinal blockage. Paclitaxel used alone is another possible regimen, or it may be combined with liposomal doxorubicin, gemcitabine, cisplatin, topotecan, etoposide, or cyclophosphamide. ( See also Palliative care below.)

The 1997 International Germ Cell Consensus Classification is a tool for estimating the risk of relapse after treatment of malignant germ cell tumor.

A small study of ovarian tumors in girls reports a correlation between cystic and benign tumors and, conversely, solid and malignant tumors. Because the cystic extent of a tumor can be estimated by ultrasound, MRI, or CT scan before surgery, this permits selection of the most appropriate surgical plan to minimize risk of spillage of a malignant tumor.

Access to appropriate treatment has a large effect on outcome. A 1993 study of outcomes in Scotland found that for 454 men with non-seminomatous (non-germinomatous) germ cell tumors diagnosed between 1975 and 1989, 5-year survival increased over time and with earlier diagnosis. Adjusting for these and other factors, survival was 60% higher for men treated in a cancer unit that treated the majority of these men, even though the unit treated more men with the worst prognosis.

Choriocarcinoma of the testicles has the worst prognosis of all germ cell cancers

Dysgerminomas are most effectively treated with radiation, though this can cause infertility and is being phased out in favor of chemotherapy. Radiation therapy does not improve survival in people with well-differentiated tumors.

In stage 1c and 2 cancers, radiation therapy is used after surgery if there is the possibility of residual disease in the pelvis but the abdomen is cancer-free. Radiotherapy can also be used in palliative care of advanced cancers. A typical course of radiotherapy for ovarian cancer is 5 days a week for 3–4 weeks. Common side effects of radiotherapy include diarrhea, constipation, and frequent urination.

Germinomas, like several other types of germ cell tumor, are sensitive to both chemotherapy and radiotherapy. For this reason, treatment with these methods can offer excellent chances of longterm survival, even cure.

Although chemotherapy can shrink germinomas, it is not generally recommended alone unless there are contraindications to radiation. In a study in the early 1990s, carboplatinum, etoposide and bleomycin were given to 45 germinoma patients, and about half the patients relapsed. Most of these relapsed patients were then recovered with radiation or additional chemotherapy.

Since Krukenberg tumors are secondary (metastatic), management might logically be driven by identifying and treating the primary cancer. The optimal treatment of Krukenberg tumors is unclear. The role of surgical resection has not been adequately addressed but if metastasis is limited to the ovaries, surgery may improve survival. The role of chemotherapy and/or radiotherapy is uncertain but may sometimes be beneficial.

A retrospective study of 83 women with sex cord–stromal tumours (73 with granulosa cell tumour and 10 with Sertoli-Leydig cell tumour), all diagnosed between 1975 and 2003, reported that survival was higher with age under 50, smaller tumour size, and absence of residual disease. The study found no effect of chemotherapy. A retrospective study of 67 children and adolescents reported some benefit of cisplatin-based chemotherapy.

The initial approach to tubal cancer is generally surgical and similar to that of ovarian cancer. As the lesion will spread first to the adjacent uterus and ovary, a total abdominal hysterectomy is an essential part of this approach and removes the ovaries, the tubes, and the uterus with the cervix. Also, peritoneal washings are taken, the omentum is removed, and pelvic and paraaortic lymph nodes are sampled. Staging at the time of surgery and pathological findings will determine further steps. In advanced cases when the cancer has spread to other organs and cannot be completely removed cytoreductive surgery is used to lessen the tumor burden for subsequent treatments. Surgical treatments are typically followed by adjuvant usually platinum-based chemotherapy.

Also radiation therapy has been applied with some success to patients with tubal cancer for palliative or curative indications

Usually the lesion is surgically removed. Primarily, there is concern that the lesion identified in a patient could be cancerous, but there is also the risk of torsion, and possibly the development of symptoms. A stable lesion, however, could be clinically followed.

Colorectal cancer patients with peritoneal involvement can be treated with Oxaliplatin or Irinotecan based chemotherapy. Such treatment is not expected to be curative, but can extend the lives of patients. . Some patients may be cured through Hyperthermic intraperitoneal chemotherapy but the procedure entails a high degree of risk for morbidity or death.

International Federation of Gynecology and Obstetrics (FIGO) staging is done at the time of surgery:

Benign fibromas may, but need not be, removed. Removal is usually a brief outpatient procedure.

For malignant teratomas, usually, surgery is followed by chemotherapy.

Teratomas that are in surgically inaccessible locations, or are very complex, or are likely to be malignant (due to late discovery and/or treatment) sometimes are treated first with chemotherapy.

Dysgerminomas, like other seminomatous germ cell tumors, are very sensitive to both chemotherapy and radiotherapy. For this reason, with treatment patients' chances of long-term survival, even cure, is excellent.

The treatment of choice is complete surgical removal ("i.e.," complete resection). Teratomas are normally well-encapsulated and non-invasive of surrounding tissues, hence they are relatively easy to resect from surrounding tissues. Exceptions include teratomas in the brain, and very large, complex teratomas that have pushed into and become interlaced with adjacent muscles and other structures.

Prevention of recurrence does not require "en bloc" resection of surrounding tissues.

A prospective study of ovarian sex cord–stromal tumours in children and adolescents began enrolling participants in 2005.

For more general information, see ovarian cancer.

For advanced cancer of this histology, the US National Cancer Institute recommends a method of chemotherapy that combines intravenous (IV) and intraperitoneal (IP) administration. Preferred chemotherapeutic agents include a platinum drug with a taxane.

A number of medications may be used to control symptoms. NSAIDs can be used to reduce painful menstrual periods. Oral contraceptive pills may be prescribed to reduce uterine bleeding and cramps. Anemia may be treated with iron supplementation.

Levonorgestrel intrauterine devices are effective in limiting menstrual blood flow and improving other symptoms. Side effects are typically few as the levonorgestrel (a progestin) is released in low concentration locally. While most levongestrel-IUD studies concentrated on treatment of women without fibroids a few reported good results specifically for women with fibroids including a substantial regression of fibroids.

Cabergoline in a moderate and well-tolerated dose has been shown in two studies to shrink fibroids effectively. The mechanism of action responsible for how cabergoline shrinks fibroids is unclear.

Ulipristal acetate is a synthetic selective progesterone receptor modulator (SPRM) that has tentative evidence to support its use for presurgical treatment of fibroids with low side-effects. Long-term UPA-treated fibroids have shown volume reduction of about 70%. In some cases UPA alone is used to relieve symptoms without surgery.

Danazol is an effective treatment to shrink fibroids and control symptoms. Its use is limited by unpleasant side effects. Mechanism of action is thought to be antiestrogenic effects. Recent experience indicates that safety and side effect profile can be improved by more cautious dosing.

Gonadotropin-releasing hormone analogs cause temporary regression of fibroids by decreasing estrogen levels. Because of the limitations and side effects of this medication, it is rarely recommended other than for preoperative use to shrink the size of the fibroids and uterus before surgery. It is typically used for a maximum of 6 months or less because after longer use they could cause osteoporosis and other typically postmenopausal complications. The main side effects are transient postmenopausal symptoms. In many cases the fibroids will regrow after cessation of treatment, however, significant benefits may persist for much longer in some cases. Several variations are possible, such as GnRH agonists with add-back regimens intended to decrease the adverse effects of estrogen deficiency. Several add-back regimes are possible, tibolone, raloxifene, progestogens alone, estrogen alone, and combined estrogens and progestogens.

Progesterone antagonists such as mifepristone have been tested, there is evidence that it relieves some symptoms and improves quality of life but because of adverse histological changes that have been observed in several trials it can not be currently recommended outside of research setting. Fibroid growth has recurred after antiprogestin treatment was stopped.

Aromatase inhibitors have been used experimentally to reduce fibroids. The effect is believed to be due partially by lowering systemic estrogen levels and partially by inhibiting locally overexpressed aromatase in fibroids. However, fibroid growth has recurred after treatment was stopped. Experience from experimental aromatase inhibitor treatment of endometriosis indicates that aromatase inhibitors might be particularly useful in combination with a progestogenic ovulation inhibitor.

Variants with edema can be associated with Meigs' syndrome. They may be a part of nevoid basal cell carcinoma syndrome (Gorlin syndrome).

Fertility subsequent to treatment of surface epithelial-stromal tumors depends mainly on histology and initial

staging to separate it into early borderline (or more benign) versus advanced stages of borderline (or more malignant). Conservative management (without bilateral oophorectomy) of early stage borderline tumors have been estimated to result in chance of over 50% of spontaneous pregnancy with a low risk of lethal recurrence of the tumor (0.5%). On the other hand, in cases of conservative treatment in advanced stage borderline tumors, spontaneous pregnancy rates have been estimated to be 35% and the risk of lethal recurrence 2%.

Treatment of Meigs' syndrome consists of thoracentesis and paracentesis to drain off the excess fluid (exudate), and unilateral salpingo-oophorectomy or wedge resection to correct the underlying cause.

Most fibroids do not require treatment unless they are causing symptoms. After menopause fibroids shrink and it is unusual for them to cause problems.

Symptomatic uterine fibroids can be treated by:

- medication to control symptoms

- medication aimed at shrinking tumors

- ultrasound fibroid destruction

- myomectomy or radio frequency ablation

- hysterectomy

- uterine artery embolization

In those who have symptoms uterine artery embolization and surgical options have similar outcomes with respect to satisfaction.

Almost all patients require multidrug chemotherapy (often including ifosfamide and etoposide), as well as local disease control with surgery and/or radiation. An aggressive approach is necessary because almost all patients with apparently localized disease at the time of diagnosis actually have asymptomatic metastatic disease.

Treatment often consists of neoadjuvant chemotherapy, which may include vincristine, doxorubicin, and cyclophosphamide with ifosfamide and etoposide. After about three months of chemotherapy, the remaining tumor is surgically resected, irradiated, or both. The surgical resection may involve limb salvage or amputation. Complete excision at the time of biopsy may be performed if malignancy is confirmed at the time it is examined.

Treatment lengths vary depending on location and stage of the disease at diagnosis. Radical chemotherapy may be as short as six treatments at 3-week cycles, but most patients undergo chemotherapy for 6–12 months and radiation therapy for 5–8 weeks.

Radiotherapy has been used for localized disease. The tumor has a unique property of being highly sensitive to radiation, sometimes acknowledged by the phrase "melting like snow", but the main drawback is that it recurs dramatically after some time. Antisense oligodeoxynucleotides have been proposed as possible treatment by down-regulating the expression of the oncogenic fusion protein associated with the development of Ewing's sarcoma resulting from the EWS-ETS gene translocation. In addition, the synthetic retinoid derivative fenretinide (4-hydroxy(phenyl)retinamide) has been reported to induce high levels of cell death in Ewing's sarcoma cell lines "in vitro" and to delay growth of xenografts in "in vivo" mouse models.