GCNIS is generally treated by radiation therapy and/or orchiectomy. Chemotherapy used for metastatic germ cell tumours may also eradicate GCNIS.

Most treatments involve some combination of surgery and chemotherapy. Treatment with cisplatin, etoposide, and bleomycin has been described.

Before modern chemotherapy, this type of neoplasm was highly lethal, but the prognosis has significantly improved since.

When endodermal sinus tumors are treated promptly with surgery and chemotherapy, fatal outcomes are exceedingly rare.

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).

NUT midline carcinoma is very resistant to standard chemotherapy treatments. The tumor may initially respond to therapy, and then rapid recurrence is experienced, followed by death. A multimodality approach to treatment is advocated, especially since most patients present with advanced disease. Treatment must be tailored to the individual patient, with several promising new targeted molecular therapies in clinical trials. Specific molecular targeted therapies (BET inhibitors and histone deacetylase inhibitors (HDACi)) may help to yield growth arrest of the neoplastic cells. Overall, there is a mean survival of 6–9 months.

This cancer is typically aggressive, presents at an advanced stage when the cancer has already metastasized, and is resistant to chemotherapy. It therefore poses a significant management challenge. Current treatment options include surgical resection and chemotherapy with a variety of agents, including (but not limited to) ifosfamide, etoposide, carboplatin, and topotecan. A recent study looked at the use of methotrexate, vinblastine, doxorubicin, and cisplatin in 3 patients and saw a partial response and longer survival than historical reports. Carboplatin, gemcitibine, and paclitaxel provided a complete response in a patient with advanced disease. The role of radiation is unclear; some tumors have shown a response to radiation. Due to the apparent propensity for the tumor to spread to the central nervous system, it has been suggested that prophylactic craniospinal irradiation should be considered.

Unlike classical seminoma, spermatocytic seminomas rarely metastasise, so radical orchidectomy alone is sufficient treatment, and retroperitoneal lymph node dissection and adjuvant chemotherapy or radiotherapy are generally not required.

Treatment of rhabdomyosarcoma is a multidisciplinary practice involving the use of surgery, chemotherapy, radiation, and possibly immunotherapy. Surgery is generally the first step in a combined therapeutic approach. Resectability varies depending on tumor site, and RMS often presents in sites that don't allow for full surgical resection without significant morbidity and loss of function. Less than 20% of RMS tumors are fully resected with negative margins. Fortunately, rhabdomyosarcomas are highly chemosensitive, with approximately 80% of cases responding to chemotherapy. In fact, multi-agent chemotherapy is indicated for all patients with rhabdomyosarcoma. Before the use of adjuvant and neoadjuvant therapy involving chemotherapeutic agents, treatment solely by surgical means had a survival rate of <20%. Modern survival rates with adjuvant therapy are approximately 60–70%.

There are two main methods of chemotherapy treatment for RMS. There is the VAC regimen, consisting of vincristin, actinomyocin D, and cyclophosphamide, and the IVA regimen, consisting of ifosfamide, vincristin, and actinomyocin D. These drugs are administered in 9–15 cycles depending on the staging of the disease and other therapies used. Other drug and therapy combinations may also show additional benefit. Addition of doxorubicin and cisplatin to the VAC regimen was shown to increase survival rates of patients with alveolar-type, early-stage RMS in IRS study III, and this same addition improved survival rates and doubled bladder salvage rates in patients with stage III RMS of the bladder.

Radiation therapy, which kill cancer cells with focused doses of radiation, is often indicated in the treatment of rhabdomyosarcoma, and the exclusion of this treatment from disease management has been shown to increase recurrence rates. Radiation therapy is used when resecting the entirety of the tumor would involve disfigurement or loss of important organs (eye, bladder, etc.). Generally, in any case where a lack of complete resection is suspected, radiation therapy is indicated. Administration is usually following 6–12 weeks of chemotherapy if tumor cells are still present. The exception to this schedule is the presence of parameningeal tumors that have invaded the brain, spinal cord, or skull. In these cases radiation treatment is started immediately. In some cases, special radiation treatment may be required. Brachytherapy, or the placement of small, radioactive “seeds” directly inside the tumor or cancer site, is often indicated in children with tumors of sensitive areas such as the testicles, bladder, or vagina. This reduces scattering and the degree of late toxicity following dosing. Radiation therapy is more often indicated in higher stage classifications.

Immunotherapy is a more recent treatment modality that is still in development. This method involves recruiting and training the patient's immune system to target the cancer cells. This can be accomplished through administering small molecules designed to pull immune cells towards the tumors, taking immune cells pulled from the patient and training to attack tumors through presentation with tumor antigen, or other experimental methods. A specific example here would be presenting some of the patient's dendritic cells, which direct the immune system to foreign cells, with the PAX3-FKHR fusion protein in order to focus the patient's immune system to the malignant RMS cells. All cancers, including rhabdomyosarcoma, could potentially benefit from this new, immune-based approach.

Cancers often grow in an unbridled fashion because they are able to evade the immune system. Immunotherapy is a method that activates the person's immune system and uses it to their own advantage. It was developed after observing that in some cases there was spontaneous regression. Immunotherapy capitalises on this phenomenon and aims to build up a person's immune response to cancer cells.

Other targeted therapy medications inhibit growth factors that have been shown to promote the growth and spread of tumours. Most of these medications were approved within the past 10 years. These treatments are:

- Nivolumab

- Axitinib

- Sunitinib

- Cabozantinib

- Everolimus

- Lenvatinib

- Pazopanib

- Bevacizumab

- Sorafenib

- Temsirolimus

- Interleukin-2 (IL-2) has produced "durable remissions" in a small number of patients, but with substantial toxicity.

- Interferon-α

Activity has also been reported for ipilimumab but it is not an approved medication for renal cancer.

More medications are expected to become available in the near future as several clinical trials are currently being conducted for new targeted treatments, including: atezolizumab, varlilumab, durvalumab, avelumab, LAG525, MBG453, TRC105, and savolitinib.

Chemotherapy and radiotherapy are not as successful in the case of RCC. RCC is resistant in most cases but there is about a 4–5% success rate, but this is often short lived with more tumours and growths developing later.

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

Based on a survey of >800, surgical removal of the entire involved kidney plus the peri-renal fat appeared curative for the majority of all types of mesoblastic nephroma; the patient overall survival rate was 94%. Of the 4% of non-survivors, half were due to surgical or chemotherapeutic treatments. Another 4% of these patients suffered relapses, primarily in the local area of surgery rare cases of relapse due to lung or bone metastasis.. About 60% of these recurrent cases had a complete remission following further treatment. Recurrent disease was treated with a second surgery, radiation, and/or chemotherapy that often vincristine and actinomycin treatment. Removal of the entire afflicted kidney plus the peri-renal fat appears critical to avoiding local recurrences. In general, patients who were older than 3 months of age at diagnosis or had the cellular form of the disease, stage III disease, or involvement of renal lymph nodes had a higher recurrence rate. Among patients with these risk factors, only those with lymph node involvement are recommended for further therapy.

It has been suggested that mesoblastic nephroma patients with lymph node involvement or recurrent disease might benefit by adding the ALK inhibitor, crizotinib, or a tyrosine kinase inhibitor, either larotrectinib or entrectinib, to surgical, radiation, and/or chemotherapy treatment regimens. These drugs inhibit NTRK3's tyrosine kinase activity. Crizotinib has proven useful in treating certain cases of acute lymphoblastic leukemia that are associated with the "ETV6-NTRK3" fusion gene while larotrectinib and entrectinib have been useful in treating various cancers (e.g. a metastatic sarcoma, papillary thyroid cancer, non-small-cell lung carcinoma, gastrointestinal stromal tumor, mammary analog secretory carcinoma, and colorectal cancer) that are driven by mutated, overly active tyrosine kinases. Relevant to this issue, a 16-month-old girl with infantile fibrosarcoma harboring the "ETV6–NTRK3" fusion gene was successfully trated with larotrectinib. The success of these drugs, howwever, will likely depend on the relative malignancy-promoting roles of ETV6-NTRK3 protein's tyrosine kinase activity, the lose of ETV6-related transcription activity accompanying formation of ETV6-NTRK3 protein, and the various trisomy chromosomes that populate mesoblastic nephroma.

Total resection of the tumour, followed by radiation therapy is the standard treatment modality. Medulloepithelioma of the ciliary body may necessitate enucleation of the eye. Radiation therapy alone may prolong survival. Aggressive chemotherapy with autologous bone marrow transplant is used for metastatic medulloepitheliomas.

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.

Renal medullary carcinoma is extremely rare and it is not currently possible to predict those individuals with sickle cell trait who will eventually develop this cancer. It is hoped that early detection could result in better outcomes but screening is not feasible.

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.

Prophylactic mastectomy to reduce the risk of breast cancer is an option.

Determination of treatment options depends on certain factors, some of which affect internal organs and others that affect personal appearance. When determining treatment, oncologists consider the initial location the tumor, the likelihood of body function deterioration, the effect on appearance, and the patient's potential response to chemotherapy and radiation. Surgery is the least successful of the treatment options; the tumor cannot be completely removed because it develops within the cells. Chemotherapy follows surgery to shrink or eliminate the remaining cancer cells.

Stem cell research under clinical trial shows promise to replace lost cells.

The aggressiveness of this cancer requires the response of a large team of specialists, possibly including a pediatric surgeon, oncologist, hematologist, specialty nurse, and rehabilitation specialists. Social workers and psychologists aid recovery by building a system of emotional support. Treatment is harsh on the body and may result in side effects including mood swings, learning difficulties, memory loss, physical deformations or restrictions, and potential risk of secondary cancers.

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 three basic types of treatment are surgery, radiation therapy, and chemotherapy.

Surgery is performed by urologists; radiation therapy is administered by radiation oncologists; and chemotherapy is the work of medical oncologists. In most patients with testicular cancer, the disease is cured readily with minimal long-term morbidity. While treatment success depends on the stage, the average survival rate after five years is around 95%, and stage 1 cancers cases, if monitored properly, have essentially a 100% survival rate.

Immunotherapy research suggests that treatment using "Euphorbia peplus", a common garden weed, may be effective. Australian biopharmaceutical company Peplin is developing this as topical treatment for BCC. Imiquimod is an immunotherapy but is listed here under chemotherapy.

Radiation therapy can be delivered either as external beam radiotherapy or as brachytherapy (internal radiotherapy). Although radiotherapy is generally used in older patients who are not candidates for surgery, it is also used in cases where surgical excision will be disfiguring or difficult to reconstruct (especially on the tip of the nose, and the nostril rims). Radiation treatment often takes as few as 5 visits to as many as 25 visits. Usually, the more visits scheduled for therapy, the less complication or damage is done to the normal tissue supporting the tumor. Radiotherapy can also be useful if surgical excision has been done incompletely or if the pathology report following surgery suggests a high risk of recurrence, for example if nerve involvement has been demonstrated. Cure rate can be as high as 95% for small tumor, or as low as 80% for large tumors. Usually, recurrent tumors after radiation are treated with surgery, and not with radiation. Further radiation treatment will further damage normal tissue, and the tumor might be resistant to further radiation. Radiation therapy may be contraindicated for treatment of nevoid basal-cell carcinoma syndrome. The 2008 study reported that radiation therapy is a good treatment for primary BCCs and recurrent BCCs, but not for BCCs that have recurred following previous radiation treatment.

The initial treatment for testicular cancer is surgery to remove the affected testicle (orchiectomy). While it may be possible, in some cases, to remove testicular cancer tumors from a testis while leaving the testis functional, this is almost never done, as the affected testicle usually contains pre-cancerous cells spread throughout the entire testicle. Thus removing the tumor alone without additional treatment greatly increases the risk that another cancer will form in that testicle.

Since only one testis is typically required to maintain fertility, hormone production, and other male functions, the afflicted testis is almost always removed completely in a procedure called inguinal orchiectomy. (The testicle is almost never removed through the scrotum; an incision is made beneath the belt line in the inguinal area.) In the UK, the procedure is known as a radical orchidectomy.

Medulloepithelioma carries a dismal prognosis with a median survival of 5 months.

Recommendations for individuals from families affected by the syndrome include:

- Avoidance of radiation therapy to reduce risk of secondary radiation induced malignancies,

- Children and adults undergo comprehensive annual physical examination,

- Women undergo age specific breast cancer monitoring beginning at age 25 years, and

- All patients should consult a physician promptly for evaluation of lingering symptoms and illnesses.

Since gestational choriocarcinoma (which arises from a hydatidiform mole) contains paternal DNA (and thus paternal antigens), it is exquisitely sensitive to chemotherapy. The cure rate, even for metastatic gestational choriocarcinoma, is around 90–95%.

At present, treatment with single-agent methotrexate is recommended for low-risk disease, while intense combination regimens including EMACO (etoposide, methotrexate, actinomycin D, cyclosphosphamide and vincristine (Oncovin) are recommended for intermediate or high-risk disease.

Hysterectomy (surgical removal of the uterus) can also be offered to patients > 40 years of age or those for whom sterilisation is not an obstacle. It may be required for those with severe infection and uncontrolled bleeding.

Choriocarcinoma arising in the testicle is rare, malignant and highly resistant to chemotherapy. The same is true of choriocarcinoma arising in the ovary. Testicular choriocarcinoma has the worst prognosis of all germ-cell cancers.