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.

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.

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.

The use of chemotherapy to treat stomach cancer has no firmly established standard of care. Unfortunately, stomach cancer has not been particularly sensitive to these drugs, and chemotherapy, if used, has usually served to palliatively reduce the size of the tumor, relieve symptoms of the disease and increase survival time. Some drugs used in stomach cancer treatment have included: 5-FU (fluorouracil) or its analog capecitabine, BCNU (carmustine), methyl-CCNU (semustine) and doxorubicin (Adriamycin), as well as mitomycin C, and more recently cisplatin and taxotere, often using drugs in various combinations. The relative benefits of these different drugs, alone and in combination, are unclear. Clinical researchers are exploring the benefits of giving chemotherapy before surgery to shrink the tumor, or as adjuvant therapy after surgery to destroy remaining cancer cells.

Chemotherapy has relatively poor curative efficacy in SRCC patients and overall survival rates are lower compared to patients with more typical cancer pathology. SRCC cancers are usually diagnosed during the late stages of the disease, so the tumors generally spread more aggressively than non-signet cancers, making treatment challenging. In the future, case studies indicate that bone marrow metastases will likely play a larger role in the diagnosis and management of signet ring cell gastric cancer.

In SRCC of the stomach, removal of the stomach cancer is the treatment of choice. There is no combination of chemotherapy which is clearly superior to others, but most active regimens include 5-Fluorouracil (5-FU), Cisplatin, and/or Etoposide. Some newer agents, including Taxol and Gemcitabine (Gemzar) are under investigation.

In a single case study of a patient with SRCC of the bladder with recurrent metastases, the patient exhibited a treatment response to palliative FOLFOX-6 chemotherapy.

Surgery remains the only curative therapy for stomach cancer. Of the different surgical techniques, endoscopic mucosal resection (EMR) is a treatment for early gastric cancer (tumor only involves the mucosa) that was pioneered in Japan and is available in the United States at some centers. In this procedure, the tumor, together with the inner lining of stomach (mucosa), is removed from the wall of the stomach using an electrical wire loop through the endoscope. The advantage is that it is a much smaller operation than removing the stomach. Endoscopic submucosal dissection (ESD) is a similar technique pioneered in Japan, used to resect a large area of mucosa in one piece. If the pathologic examination of the resected specimen shows incomplete resection or deep invasion by tumor, the patient would need a formal stomach resection. A 2016 Cochrane review found low quality evidence of no difference in short-term mortality between laparoscopic and open gastrectomy (removal of stomach), and that benefits or harms of laparoscopic gastrectomy cannot be ruled out.

Those with metastatic disease at the time of presentation may receive palliative surgery and while it remains controversial, due to the possibility of complications from the surgery itself and the fact that it may delay chemotherapy the data so far is mostly positive, with improved survival rates being seen in those treated with this approach.

First-line chemotherapy regimens for advanced or metastatic TCC consists of gemcitabine and cisplatin) (GC) or a combination of methotrexate, vinblastine, adriamycin, and cisplatin (MVAC).

Taxanes or vinflunine have been used as second-line therapy (after progression on a platinum containing chemotherapy).

Immunotherapy such as pembrolizumab is often used as second-line therapy for metastatic urothelial carcinoma that has progressed despite treatment with GC or MVAC.

In May 2016 FDA granted accelerated approval to atezolizumab for locally advanced or metastatic urothelial carcinoma treatment after failure of cisplatin-based chemotherapy. The confirmatory trial (to convert the accelerated approval into a full approval) failed to achieve its primary endpoint of overall survival.

Transitional cell carcinoma (TCC) can be very difficult to treat. Treatment for localized stage TCC is surgical resection of the tumor, but recurrence is common. Some patients are given mitomycin into the bladder either as a one-off dose in the immediate post-operative period (within 24 hrs) or a few weeks after the surgery as a six dose regimen.

Localized/early TCC can also be treated with infusions of BCG into the bladder. These are given weekly for either 6 weeks (induction course) or 3 weeks (maintenance/booster dose). Side effects include a small chance of developing systemic tuberculosis or the patient becoming sensitized to the BCG causing severe intolerance and a possible reduction in bladder volume due to scarring.

In patients with evidence of early muscular invasion, radical curative surgery in the form of a cysto-prostatectomy usually with lymph node sampling can also be performed. In such patients, a bowel loop is often used to create either a "neo-bladder" or an "ileal conduit" which act as a place for the storage of urine before it is evacuated from the body either via the urethra or a urostomy respectively.

Cetuximab is the first-line therapy for Ménétrier disease. Cetuximab is a monoclonal antibody against epidermal growth factor receptor (EGFR), and has been shown to be effective in treating Ménétrier disease.

Several medications have been used in the treatment of the condition, with variable efficacy. Such medications include: anticholinergic agents, prostaglandins, proton pump inhibitors, prednisone, and H2 receptor antagonists. Anticholinergics decrease protein loss. A high-protein diet should be recommended to replace protein loss in patients with low levels of albumin in the blood (hypoalbuminemia). Any ulcers discovered during the evaluation should be treated in standard fashion.

Severe disease with persistent and substantial protein loss despite cetuximab may require total removal of the stomach. Subtotal gastrectomy is performed by some; it may be associated with higher morbidity and mortality secondary to the difficulty in obtaining a patent and long-lasting anastomosis between normal and hyperplastic tissue. In adults, there is no FDA approved treatment other than gastrectomy and a high-protein diet. Cetuximab is approved for compassionate use in the treatment of the disease.

Pediatric cases are normally treated for symptoms with the disease clearing up in weeks to months.

treatment to be directed towards the findings in investigation if it is found to be AMAG immunosupressive drugs and chemotherapy with antineoplastic drugs.

In case of confirmed malignancy of stomach complete or step ladder or stage ladder resection of gastric or stomach to be done.

Diffuse large B-cell lymphomas of the stomach are primarily treated with chemotherapy with CHOP (cyclophosphamide+doxorubicine+vincristine+prednisone) with or without rituximab being a usual first choice.

Antibiotic treatment to eradicate H. pylori is indicated as first line therapy for MALT lymphomas. About 60% of MALT lymphomas completely regress with eradication therapy. Radiation treatment for H. pylori negative gastric malt lymphoma, has a high success rate, 90% or better after 5 years. Second line therapy for MALT lymphomas is usually chemotherapy with a single agent, and complete response rates of greater than 70% have been reported.

Subtotal gastrectomy, with post-operative chemotherapy is undertaken in refractory cases, or in the setting of complications, including gastric outlet obstruction.

There is a risk of development of cancer with fundic gland polyposis, but it varies based on the underlying cause of the polyposis. The risk is highest with congenital polyposis syndromes, and is lowest in acquired causes. As a result, it is recommended that patients with multiple fundic polyps have a colonoscopy to evaluate the colon. If there are polyps seen on colonoscopy, genetic testing and testing of family members is recommended.

In the gastric adenocarcinoma associated with proximal polyposis of the stomach (GAPPS), there is a high risk of early development of proximal gastric adenocarcinoma.

It is still unclear which patients would benefit with surveillance gastroscopy, but most physicians recommend endoscopy every one to three years to survey polyps for dysplasia or cancer. In the event of high grade dysplasia, polypectomy, which is done through the endoscopy, or partial gastrectomy may be recommended. One study showed the benefit of NSAID therapy in regression of gastric polyps, but the efficacy of this strategy (given the side effects of NSAIDs) is still dubious.

Radiotherapy is a valid first option for "MALT lymphoma". It provides local control and potential cure in localized gastric stage IE and II 1E disease with 5-year EFS of 85-100% reported in retrospective studies. However, the irradiation field is potentially large as it must include the whole stomach, which can vary greatly in size and shape. Irradiation techniques have improved considerably in the last 20 years, including treating the patient in a fasting state, decreasing the irradiated field and required dose. The moderate dose of 30 Gray (Gy) of involved-field radiotherapy administered in 15 fractions (doses) can be associated with tolerable toxicity and excellent outcomes. Hence, radiotherapy is the preferred approach for local disease where antibiotic therapy has failed, or is not indicated. Evidence also suggests that radiotherapy can be utilized to control localized relapses outside the original radiation field.

Pancreatic neuroendocrine tumors (PanNETs, PETs, or PNETs), often referred to as "islet cell tumors", or "pancreatic endocrine tumors" are neuroendocrine neoplasms that arise from cells of the endocrine (hormonal) and nervous system within the pancreas.

PanNETs are a type of neuroendocrine tumor, representing about one third of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Many PanNETs are benign, while some are malignant. Aggressive PanNET tumors have traditionally been termed "islet cell carcinoma".

PanNETs are quite distinct from the usual form of pancreatic cancer, the majority of which are adenocarcinomas, which arises in the exocrine pancreas. Only 1 or 2% of clinically significant pancreas neoplasms are PanNETs.

Antacids are a common treatment for mild to medium gastritis. When antacids do not provide enough relief, medications such as H blockers and proton-pump inhibitors that help reduce the amount of acid are often prescribed.

Cytoprotective agents are designed to help protect the tissues that line the stomach and small intestine. They include the medications sucralfate and misoprostol. If NSAIDs are being taken regularly, one of these medications to protect the stomach may also be taken. Another cytoprotective agent is bismuth subsalicylate.

Several regimens are used to treat "H. pylori" infection. Most use a combination of two antibiotics and a proton pump inhibitor. Sometimes bismuth is added to the regimen.

Primary signet-ring cell carcinoma of the urinary bladder is extremely rare and patient survival is very poor and occurs mainly in men ages 38 to 83. However, one such patient treated with a radical cystectomy followed by combined S-1 and Cisplatin adjuvant chemotherapy did demonstrate promising long-term survival of 90 months.

Surgical removal of the stomach (gastrectomy) is typically recommended after for people after 20 years of age, and before 40 years of age.

Digestive system neoplasms are tumors which affect the digestive system. Types include:

- esophageal cancer

- gastric cancer

- small intestinal cancer

- colorectal cancer

- anal cancer

In most people with peptic ulcer disease, the oedema will usually settle with conservative management with nasogastric suction, replacement of fluids and electrolytes and proton pump inhibitors.

Treatment focuses on addressing the underlying cause of symptoms.

Treatment of gastritis that leads to pernicious anemia consists of parenteral vitamin B-12 injection. Associated immune-mediated conditions (e.g., insulin dependent diabetes mellitus, autoimmune thyroiditis) should also be treated. However, treatment of these disorders has no known effect in the treatment of achlorhydria.

Achlorhydria associated with "Helicobacter pylori" infection may respond to H pylori eradication therapy, although resumption of gastric acid secretion may only be partial and it may not always reverse the condition completely.

Antimicrobial agents, including metronidazole, amoxicillin/clavulanate potassium, ciprofloxacin, and rifaximin, can be used to treat bacterial overgrowth.

Achlorhydria resulting from long-term proton-pump inhibitor (PPI) use may be treated by dose reduction or withdrawal of the PPI.

A health care provider may prescribe octreotide acetate (Sandostatin) injections to treat dumping syndrome symptoms. The medication works by slowing gastric emptying and inhibiting the release of insulin and other GI hormones.

Surgery is indicated in cases of gastric outlet obstruction in which there is significant obstruction and in cases where medical therapy has failed. Endoscopic balloon therapy may be attempted as an alternative to surgery, with balloon dilation reporting success rates of 76% after repeat dilatons. The operation usually performed is an antrectomy, the removal of the antral portion of the stomach. Other surgical approaches include: vagotomy, the severing of the vagus nerve, the Billroth I, a procedure which involves anastomosing the duodenum to the distal stomach, or a bilateral truncal vagotomy with gastrojejunostomy.

It is diagnosed and treated endoscopically; however, endoscopic ultrasound or angiography can be of benefit.

Endoscopic techniques used in the treatment include epinephrine injection followed by bipolar or monopolar electrocoagulation, injection sclerotherapy, heater probe, laser photocoagulation, hemoclipping or banding. Alternatively, in patients with refractory bleeding Interventional Radiology may be consulted for an angiogram with subselective embolization.