Surgery, if feasible, is the only curative therapy. If the tumor has metastasized (most commonly, to the liver) and is considered incurable, there are some promising treatment modalities, such as radiolabeled octreotide (e.g. Lutetium (Lu) DOTA-octreotate) or the radiopharmaceutical 131I-mIBG (meta iodo benzyl guanidine) for arresting the growth of the tumors and prolonging survival in patients with liver metastases, though these are currently experimental.

Chemotherapy is of little benefit and is generally not indicated. Octreotide or Lanreotide (somatostatin analogues) may decrease the secretory activity of the carcinoid, and may also have an anti-proliferative effect. Interferon treatment is also effective, and usually combined with somatostatin analogues.

As the metastatic potential of a coincidental carcinoid is probably low, the current recommendation is for follow up in 3 months with CT or MRI, labs for tumor markers such as serotonin, and a history and physical, with annual physicals thereafter.

In general, treatment for PanNET encompasses the same array of options as other neuroendocrine tumors, as discussed in that main article. However, there are some specific differences, which are discussed here.

In functioning PanNETs, octreotide is usually recommended prior to biopsy or surgery but is generally avoided in insulinomas to avoid profound hypoglycemia.

PanNETs in MEN1 are often multiple, and thus require different treatment and surveillance strategies.

Some PanNETs are more responsive to chemotherapy than are gastroenteric carcinoid tumors. Several agents have shown activity. In well differentiated PanNETs, chemotherapy is generally reserved for when there are no other treatment options. Combinations of several medicines have been used, such as doxorubicin with streptozocin and fluorouracil (5-FU) and capecitabine with temozolomide. Although marginally effective in well-differentiated PETs, cisplatin with etoposide has some activity in poorly differentiated neuroendocrine cancers (PDNECs), particularly if the PDNEC has an extremely high Ki-67 score of over 50%.

Several targeted therapy agents have been approved in PanNETs by the FDA based on improved progression-free survival (PFS):

- everolimus (Afinitor) is labeled for treatment of progressive neuroendocrine tumors of pancreatic origin in patients with unresectable, locally advanced or metastatic disease. The safety and effectiveness of everolimus in carcinoid tumors have not been established.

- sunitinib (Sutent) is labeled for treatment of progressive, well-differentiated pancreatic neuroendocrine tumors in patients with unresectable locally advanced or metastatic disease. Sutent also has approval from the European Commission for the treatment of 'unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumors with disease progression in adults'. A phase III study of sunitinib treatment in well differentiated pNET that had worsened within the past 12 months (either advanced or metastatic disease) showed that sunitinib treatment improved progression-free survival (11.4 months vs. 5.5 months), overall survival, and the objective response rate (9.3% vs. 0.0%) when compared with placebo.

Even if the tumor has advanced and metastasized, making curative surgery infeasible, surgery often has a role in neuroendocrine cancers for palliation of symptoms and possibly increased lifespan.

Cholecystectomy is recommended if there is a consideration of long-term treatment with somatostatin analogs.

In secretory tumors, somatostatin analogs given subcutaneously or intramuscularly alleviate symptoms by blocking hormone release. A consensus review has reported on the use of somatostatin analogs for GEP-NETs.

These medications may also anatomically stabilize or shrink tumors, as suggested by the PROMID study (Placebo-controlled prospective randomized study on the antiproliferative efficacy of Octreotide LAR in patients with metastatic neuroendocrine MIDgut tumors): at least in this subset of NETs, average tumor stabilization was 14.3 months compared to 6 months for placebo.

The CLARINET study (a randomized, double-blind, placebo-controlled study on the antiproliferative effects of lanreotide in patients with enteropancreatic neuroendocrine tumors) further demonstrated the antiproliferative potential of lanreotide, a somatostatin analog and recently approved FDA treatment for GEP-NETS. In this study, lanreotide showed a statistically significant improvement in progression-free survival, meeting its primary endpoint. The disease in sixty five percent of patients treated with lanreotide in the study had not progressed or caused death at 96 weeks, the same was true of 33% of patients on placebo. This represented a 53% reduction in risk of disease progression or death with lanreotide based on a hazard ratio of .47.

Lanreotide is the first and only FDA approved antitumor therapy demonstrating a statistically significant progression-free survival benefit in a combined population of patients with GEP-NETS.

Other medications that block particular secretory effects can sometimes relieve symptoms.

The main treatment modalities are surgery, embolization and radiotherapy.

Radiotherapy alone is reserved only for small lesions not appropriate for either surgery or chemotherapy. Both photon and proton radiotherapy have been used effectively to treat esthesioneuroblastoma. Proton radiotherapy has recently been shown to be effective in a 10-person study with Kadish C tumors, while delivering less toxicity to the nervous system.

The preferred treatment for esthesioneuroblastoma is surgery followed by radiotherapy to prevent reoccurrence of the tumor.

Because LCLC-RP is so rare, no clinical trials have ever been conducted that specifically address treatment of this lung cancer variant. Because LCLC-RP is considered a form of non-small cell lung carcinoma (NSCLC), most physicians adhere to published NSCLC treatment guidelines in rhabdoid carcinoma cases. When possible, radical surgical resection with curative intent is the primary treatment of choice in early stage NSCLC's, and can be administered with or without adjuvant, neoadjuvant, or palliative chemotherapy and/or radiotherapy, depending on the disease stage and performance status of the individual patient.

In numerous clinical trials conducted in NSCLC, several different platinum-based chemotherapy regimens have been shown to be more-or-less equally effective. LCLC's, as a subtype of NSCLC, have traditionally been included in many of these clinical trials, and have been treated like other NSCLC's. More recent trials, however, have shown that some newer agents may have particular effectiveness in prolonging survival of LCLC patients. Pemetrexed, in particular, has shown significant reduction in the hazard ratio for death when used in patients with LCLC. Taxane-based (paclitaxel, docetaxel) chemotherapy was shown to induce a complete and sustained response in a liver metastasis in a case of LCC-RP. A later-appearing metastasis within mediastinal lymph nodes in the same case also showed a durable response to a taxane alone.

There have also been reports of rhabdoid carcinomas expressing vascular endothelial growth factor (VEGF), suggesting that targeted molecular therapy with VEGF blocking monoclonal antibodies such as bevacizumab may be active in these variants. However, evidence suggests that caution must be used when treating a cavitated rhabdoid tumor, one that contains significant components of squamous cell differentiation, or large tumors with containing major blood vessels, due to the potential high risk of life-threatening pulmonary hemorrhage.

A recent study reported a case wherein 2 courses of adjuvant therapy with cisplatin and paclitaxel, followed by oral gefitinib, were used after complete resection. The patient had had no recurrence 34 months later.

As large-volume LCLC-RP may show significant central necrosis and cavitation, prudence dictates that oncologists use extreme caution if contemplating the therapeutic use of bevacizumab, other anti-VEGF compounds, or anti-angiogenesis agents in general, which have been associated with a greatly increased risk of severe hemorrhage and hemoptysis that may be quickly fatal in cavatated pulmonary squamous cell carcinomas. Similar elevated risks have also been noted in tumors located near, or containing, large blood vessels.,

Surgical removal of the tumor, adjuvant chemotherapy prior to tumor removal, and liver transplantation have been used to treat these cancers. Primary liver transplantation provides high, long term, disease-free survival rate in the range of 80%, in cases of complete tumor removal and adjuvant chemotherapy survival rates approach 100%. The presence of metastases is the strongest predictor of a poor prognosis.

The only curative treatment is complete surgical excision of the tumor, which can be performed even in the case of invasion into large blood vessels, such as the renal vein or inferior vena cava. The 5-year survival rate after successful surgery is 50–60%, but unfortunately, a large percentage of patients are not surgical candidates. Radiation therapy and radiofrequency ablation may be used for palliation in patients who are not surgical candidates.

Chemotherapy regimens typically include the drug mitotane, an inhibitor of steroid synthesis which is toxic to cells of the adrenal cortex, as well as standard cytotoxic drugs. A retrospective analysis showed a survival benefit for mitotane in addition to surgery when compared to surgery alone.

The two most common regimens are cisplatin, doxorubicin, etoposide + mitotane and streptozotocin + mitotane. It is unknown which regimen is better. Researchers at Uppsala University Hospital initiated a collaboration between adrenocortical cancer specialists in Europe, USA and Australia, to conduct the first ever randomized controlled trial in adrenocortical cancer (FIRM-ACT study), comparing these two regimens.

Wide, radical, complete surgical excision is the treatment of choice, with free surgical margins to achieve the best outcome and lowest chance of recurrence. Radiation is only used for palliation. In general, there is a good prognosis, although approximately 50% of patients die from disease within 3–10 years of presentation.

Some benign tumors need no treatment; others may be removed if they cause problems such as seizures, discomfort or cosmetic concerns. Surgery is usually the most effective approach and is used to treat most benign tumors. In some case other treatments may be of use. Adenomas of the rectum may be treated with sclerotherapy, a treatment in which chemicals are used to shrink blood vessels in order to cut off the blood supply. Most benign tumors do not respond to chemotherapy or radiation therapy, although there are exceptions; benign intercranial tumors are sometimes treated with radiation therapy and chemotherapy under certain circumstances. Radiation can also be used to treat hemangiomas in the rectum. Benign skin tumors are usually surgically resected but other treatments such as cryotherapy, curettage, electrodesiccation, laser therapy, dermabrasion, chemical peels and topical medication are used.

The definitive management is surgical removal of the insulinoma. This may involve removing part of the pancreas, as well (Whipple procedure and distal pancreatectomy).

Medications such as diazoxide and somatostatin can be used to block the release of insulin for patients who are not surgical candidates or who otherwise have inoperable tumors.

Streptozotocin is used in islet cell carcinomas which produce excessive insulin. Combination chemotherapy is used, either doxorubicin and streptozotocin, or fluorouracil and streptotozocin in patients where doxorubicin is contraindicated.

In metastasizing tumors with intrahepatic growth, hepatic arterial occlusion or embolization can be used.

The tumor must be removed with as complete a surgical excision as possible. In nearly all cases, the ossicular chain must be included if recurrences are to be avoided. Due to the anatomic site of involvement, facial nerve paralysis and/or paresthesias may be seen or develop; this is probably due to mass effect rather than nerve invasion. In a few cases, reconstructive surgery may be required. Since this is a benign tumor, no radiation is required. Patients experience an excellent long term outcome, although recurrences can be seen (up to 15%), especially if the ossicular chain is not removed. Although controversial, metastases are not seen in this tumor. There are reports of disease in the neck lymph nodes, but these patients have also had other diseases or multiple surgeries, such that it may represent iatrogenic disease.

The first goal of treatment is to correct dehydration. Fluids are often given through a vein (intravenous fluids) to replace fluids lost in diarrhea.

The next goal is to slow the diarrhea. Some medications can help control diarrhea. Octreotide, which is a human-made form of the natural hormone somatostatin, blocks the action of VIP.

The best chance for a cure is surgery to remove the tumor. If the tumor has not spread to other organs, surgery can often cure the condition.

For metastatic disease, peptide receptor radionuclide therapy (PRRT) can be highly effective. This treatment involves attaching a radionuclide (Lutetium-177 or Yttrium-90) to a somatostatin analogue (octreotate or octreotide). This is a novel way to deliver high doses of beta radiation to kill tumours.

Some people seem to respond to a combination chemo called capecitabine and temozolomide but there is no report that it totally cured people from vipoma.

In ES-SCLC, combination chemotherapy is the standard of care, with radiotherapy added only to palliate symptoms such as dyspnea, pain from liver or bone metastases, or for treatment of brain metastases, which, in small-cell lung carcinoma, typically have a rapid, if temporary, response to whole brain radiotherapy.

Combination chemotherapy consists of a wide variety of agents, including cisplatin, cyclophosphamide, vincristine and carboplatin. Response rates are high even in extensive disease, with between 15% and 30% of subjects having a complete response to combination chemotherapy, and the vast majority having at least some objective response. Responses in ES-SCLC are often of short duration, however.

If complete response to chemotherapy occurs in a subject with SCLC, then prophylactic cranial irradiation (PCI) is often used in an attempt to prevent the emergence of brain metastases. Although this treatment is often effective, it can cause hair loss and fatigue. Prospective randomized trials with almost two years follow-up have not shown neurocognitive ill-effects. Meta-analyses of randomized trials confirm that PCI provides significant survival benefits.

Patients treated with complete surgical excision can expect an excellent long term outcome without any problems. Recurrences may be seen in tumors which are incompletely excised.

Radiotherapy is commonly used to treat Merkel-cell cancers. The radiotherapy fields used are usually very large so as to cover sufficient areas of skin. This is necessary because of MCC's aggressive local and regional metastatic behavior.

Adjuvant radiotherapy has been shown to be effective in reducing the rates of recurrence and in increasing the survival of patients with MCC. Patients who present with no distant metastases and a negative sentinel lymph node biopsy have a very good prognosis when treated with both surgery and radiotherapy (approximately 90% survival rate at five years).

Metastatic MCC may respond to treatment with chemotherapy and/or radiation, but current multimodal therapies are usually not curative. Intensive treatment can be effective in shrinking the tumor and improving operability when tumors are too large to be removed or located in a place where removal would be difficult or dangerous, or in palliation of signs and symptoms caused by metastatic tumors.

Because of its rarity, there have been no randomized clinical trials of treatment of GCCL, and all information available derives from small retrospective institutional series or multicenter metadata.

In cases of LS-SCLC, combination chemotherapy (often including cyclophosphamide, cisplatinum, doxorubicin, etoposide, vincristine and/or paclitaxel) is administered together with concurrent chest radiotherapy (RT).

Chest RT has been shown to improve survival in LS-SCLC.

Exceptionally high objective initial response rates (RR) of between 60% and 90% are seen in LS-SCLC using chemotherapy alone, with between 45% and 75% of individuals showing a "complete response" (CR), which is defined as the disappearance of all radiological and clinical signs of tumor. However, relapse rate remains high, and median survival is only 18 to 24 months.

Because SCLC usually metastasizes widely very early on in the natural history of the tumor, and because nearly all cases respond dramatically to chemotherapy and/or radiotherapy, there has been little role for surgery in this disease since the 1970s. However, recent work suggests that in cases of small, asymptomatic, node-negative SCLC's ("very limited stage"), surgical excision may improve survival when used prior to chemotherapy ("adjuvant chemotherapy").

Proton pump inhibitors (such as omeprazole and lansoprazole) and histamine H2-receptor antagonists (such as famotidine and ranitidine) are used to slow acid secretion. Once gastric acid is suppressed, symptoms normally improve.

Surgery is usually the first treatment that a patient undergoes for Merkel-cell cancer. Lesions usually appear purple-red in color, and there is little else to distinguish this variant of skin cancer from other types. Its identity usually comes as a surprise after surgery and pathologic examination.

As with surgery for most other forms of cancer, it is normal for the surgeon to remove a border of healthy tissue surrounding the tumor. While it has been thought that leaving this margin may not be as critical as it is in the surgical resection of melanoma, studies also reveal that local recurrences are fairly common in MCC near the site of the surgery.

Local or regional lymph nodes are usually removed if the lesion is more than 1 cm in diameter, due to a high risk that they will contain cancer cells (micrometastasis) that could develop into a new tumor or spread further. Sometimes, however, the doctor will first perform a sentinel lymph node biopsy. In this procedure, the doctor injects a dye or radioactive substance near the tumor. This material flows into adjacent lymph nodes, which are identified, removed, and checked for cancer cells, indicating the sites where cancer is most likely to spread (the "sentinel" nodes). This procedure has been demonstrated to be an important prognostic indicator. Results help dictate the use of appropriate adjuvant therapies. Usually, however, surgery alone is insufficient to control Merkel-cell carcinoma.

Most patients with benign insulinomas can be cured with surgery. Persistent or recurrent hypoglycemia after surgery tends to occur in patients with multiple tumors. About 2% of patients develop diabetes mellitus after their surgery.

Surgery can usually cure VIPomas. However, in one-third to one-half of patients, the tumor has spread by the time of diagnosis and cannot be cured.

Heightened glucagon secretion can be treated with the administration of octreotide, a somatostatin analog, which inhibits the release of glucagon. Doxorubicin and streptozotocin have also been used successfully to selectively damage alpha cells of the pancreatic islets. These do not destroy the tumor, but help to minimize progression of symptoms.

The only curative therapy for glucagonoma is surgical resection, where the tumor is removed. Resection has been known to reverse symptoms in some patients.