The most common and most effective treatment is surgical removal of the gallbladder (cholecystectomy) with part of liver and lymph node dissection. However, with gallbladder cancer's extremely poor prognosis, most patients will die within a year of surgery. If surgery is not possible, endoscopic stenting of the biliary tree can reduce jaundice and a stent in stomach may relieve vomiting. Chemotherapy and radiation may also be used with surgery. If gall bladder cancer is diagnosed after cholecystectomy for stone disease (incidental cancer), reoperation to remove part of liver and lymph nodes is required in most cases. When it is done as early as possible, patients have the best chance of long-term survival and even cure.

Some areas of ongoing medical research in cholangiocarcinoma include the use of newer targeted therapies, (such as erlotinib) or photodynamic therapy for treatment, and the techniques to measure the concentration of byproducts of cancer stromal cell formation in the blood for diagnostic purposes. Changes in CA19-9 tumor marker are being assessed in a clinical trial of oral vaccine Immunitor V3-X.

The cancer commonly spreads to the liver, bile duct, stomach, and duodenum.

Apart from not smoking, the American Cancer Society recommends keeping a healthy weight, and increasing consumption of fruits, vegetables, and whole grains, while decreasing consumption of red and processed meat, although there is no consistent evidence this will prevent or reduce pancreatic cancer specifically. A 2014 review of research concluded that there was evidence that consumption of citrus fruits and curcumin reduced risk of pancreatic cancer, while there was possibly a beneficial effect from whole grains, folate, selenium, and non-fried fish.

In the general population, screening of large groups is not currently considered effective, although newer techniques, and the screening of tightly targeted groups, are being evaluated. Nevertheless, regular screening with endoscopic ultrasound and MRI/CT imaging is recommended for those at high risk from inherited genetics.

The majority of cases of cholangiocarcinoma present as inoperable (unresectable) disease in which case patients are generally treated with palliative chemotherapy, with or without radiotherapy. Chemotherapy has been shown in a randomized controlled trial to improve quality of life and extend survival in patients with inoperable cholangiocarcinoma. There is no single chemotherapy regimen which is universally used, and enrollment in clinical trials is often recommended when possible. Chemotherapy agents used to treat cholangiocarcinoma include 5-fluorouracil with leucovorin, gemcitabine as a single agent, or gemcitabine plus cisplatin, irinotecan, or capecitabine. A small pilot study suggested possible benefit from the tyrosine kinase inhibitor erlotinib in patients with advanced cholangiocarcinoma.

Risk factors for pancreatic adenocarcinoma include:

- Age, gender, and ethnicity; the risk of developing pancreatic cancer increases with age. Most cases occur after age 65, while cases before age 40 are uncommon. The disease is slightly more common in men than women, and in the United States is over 1.5 times more common in African Americans, though incidence in Africa is low.

- Cigarette smoking is the best-established avoidable risk factor for pancreatic cancer, approximately doubling risk among long-term smokers, the risk increasing with the number of cigarettes smoked and the years of smoking. The risk declines slowly after smoking cessation, taking some 20 years to return to almost that of non-smokers.

- Obesity; a BMI greater than 35 increases relative risk by about half.

- Family history; 5–10% of pancreatic cancer cases have an inherited component, where people have a family history of pancreatic cancer. The risk escalates greatly if more than one first-degree relative had the disease, and more modestly if they developed it before the age of 50. Most of the genes involved have not been identified. Hereditary pancreatitis gives a greatly increased lifetime risk of pancreatic cancer of 30–40% to the age of 70. Screening for early pancreatic cancer may be offered to individuals with hereditary pancreatitis on a research basis. Some people may choose to have their pancreas surgically removed to prevent cancer developing in the future.

- Chronic pancreatitis appears to almost triple risk, and as with diabetes, new-onset pancreatitis may be a symptom of a tumor. The risk of pancreatic cancer in individuals with familial pancreatitis is particularly high.

- Diabetes mellitus is a risk factor for pancreatic cancer and (as noted in the Signs and symptoms section) new-onset diabetes may also be an early sign of the disease. People who have been diagnosed with Type 2 diabetes for longer than ten years may have a 50% increased risk, as compared with non-diabetics.

- Specific types of food (as distinct from obesity) have not been clearly shown to increase the risk of pancreatic cancer. Dietary factors for which there is some evidence of slightly increased risk include processed meat, red meat, and meat cooked at very high temperatures (e.g. by frying, broiling or barbecuing).

Treatment is variable, both due to its rarity and to its frequently slow-growing nature. Treatment ranges from watchful waiting to debulking and hyperthermic intraperitoneal chemotherapy (HIPEC, also called intraperitoneal hyperthermic chemotherapy, IPHC) with cytoreductive surgery.

Cancer of the stomach, also called gastric cancer, is the fourth-most-common type of cancer and the second-highest cause of cancer death globally. Eastern Asia (China, Japan, Korea, Mongolia) is a high-risk area for gastric cancer, and North America, Australia, New Zealand and western and northern Africa are areas with low risk. The most common type of gastric cancer is adenocarcinoma, which causes about 750,000 deaths each year. Important factors that may contribute to the development of gastric cancer include diet, smoking and alcohol consumption, genetic aspects (including a number of heritable syndromes) and infections (for example, "Helicobacter pylori" or Epstein-Barr virus) and pernicious anemia. Chemotherapy improves survival compared to best supportive care, however the optimal regimen is unclear.

Chemotherapy (typically the agent Mitomycin C) may be infused directly into the abdominal cavity after cytoreductive surgery to kill remaining microscopic cancerous tumors and free floating cells. The heated chemotherapy (HIPEC) is perfused throughout the abdominal cavity for an hour or two as the last step in the surgery, or ports are installed to allow circulation and/or drainage of the chemicals for one to five days after surgery, known as early postoperative intraperitoneal chemotherapy (EPIC). EPIC may be given in multiple cycles for several months after surgery.

Systemic chemotherapy may be administered as additional or adjuvant treatment. Due to the increased availability of new chemotherapies developed for colon and colorectal cancer patients, some patients have experienced stability in tumor growth with systemic chemotherapy. Systemic chemotherapy is reserved for patients with advanced disease, recurrent disease, or disease that has spread to the lymph nodes or distant sites.

This disease may recur following surgery and chemotherapy. Periodic post operative CT scans and tumor marker laboratory tests are used to monitor the disease for any tumor regrowth.

Gastrointestinal cancer refers to malignant conditions of the gastrointestinal tract (GI tract) and accessory organs of digestion, including the esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The symptoms relate to the organ affected and can include obstruction (leading to difficulty swallowing or defecating), abnormal bleeding or other associated problems. The diagnosis often requires endoscopy, followed by biopsy of suspicious tissue. The treatment depends on the location of the tumor, as well as the type of cancer cell and whether it has invaded other tissues or spread elsewhere. These factors also determine the prognosis.

Overall, the GI tract and the accessory organs of digestion (pancreas, liver, gall bladder) are responsible for more cancers and more deaths from cancer than any other system in the body. There is significant geographic variation in the rates of different gastrointestinal cancers.

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.

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.

Women are almost twice as likely as men to form gallstones especially during the fertile years; the gap narrows after the menopause. The underlying mechanism is female sex hormones; parity, oral contraceptive use and estrogen replacement therapy are established risk factors for cholesterol gallstone formation. Female sex hormones adversely influence hepatic bile secretion and gallbladder function. Estrogens increase cholesterol secretion and diminish bile salt secretion, while progestins act by reducing bile salt secretion and impairing gallbladder emptying leading to stasis. A new 4th generation progestin, drospirenone, used in some oral contraceptives may further heighten the risk of gallstone disease and cholecystectomy; however, the increased risk is quite modest and not likely to be clinically meaningful.

A retrospective (historical) cohort study was performed on a very large data base including 1980 and 1981 Medicaid billing data from the states of Michigan and Minnesota in which 138,943 users of OCs were compared with 341,478 nonusers. Oral contraceptives were shown as risk factors for gallbladder disease, although the risk is of sufficient magnitude to be of potential clinical importance only in young women.

The 1984 Royal College of General Practitioners' Oral Contraception Study suggests that, in the long-term, oral contraceptives are not associated with any increased risk of gallbladder disease, although there is an acceleration of the disease in those women susceptible to it.

Newer research suggests otherwise. A 1993 meta-analysis concludes that oral contraceptive use is associated with a slightly and transiently increased rate of gallbladder disease, but laters confirms that modern low-dose oral contraceptives are safer than older formulas, though an effect cannot be excluded.

A 2001 comparative study of the IMS LifeLink Health Plan Claims Database interpreted that in a large cohort of women using oral contraceptives, there was found a small, statistically significant increase in the risk of gallbladder disease associated with desogestrel, drospirenone and norethisterone compared with levonorgestrel. No statistically significant increase in risk was associated with the other formulations of oral contraceptive (etynodiol diacetate, norgestrel and norgestimate).

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.

A prospective study in 1994 noted that body mass index remains the strongest predictor of symptomatic gallstones among young women. Other risk factors are having over four pregnancies, weight gain, and cigarette smoking. Alcohol was shown to have an inverse relationship between use and gallbladder disease.

A Krukenberg tumor refers to a malignancy in the ovary that metastasized from a primary site, classically the gastrointestinal tract, although it can arise in other tissues such as the breast. Gastric adenocarcinoma, especially at the pylorus, is the most common source. Krukenberg tumors are often (over 80%) found in both ovaries, consistent with its metastatic nature.

Medullary carcinoma may refer to one of several different tumors of epithelial origin. As the term "" is a generic anatomic descriptor for the mid-layer of various organ tissues, a medullary tumor usually arises from the "mid-layer tissues" of the relevant organ.

Medullary carcinoma most commonly refers to:

- Medullary thyroid cancer

- Medullary carcinoma of the breast

Medullary carcinoma may also refer to tumors of:

- Pancreas

- Ampulla of Vater

- Gallbladder

- Stomach

- Large intestine

- Kidney — Renal medullary carcinoma

Resection is sometimes a part of a treatment plan, but duodenal cancer is difficult to remove surgically because of the area that it resides in—there are many blood vessels supplying the lower body. Chemotherapy is sometimes used to try to shrink the cancerous mass. Other times intestinal bypass surgery is tried to reroute the stomach to intestine connection around the blockage.

A 'Whipple' procedure is a type of surgery that is sometimes possible with this cancer. In this procedure, the duodenum, a portion of the Pancreas (the head), and the gall bladder are usually removed, the small intestine is brought up to the Pylorus (the valve at the bottom of the stomach) and the Liver and Pancreas digestive enzymes and bile are connected to the small intestine below the Pylorus.

The removal of part of the Pancreas often requires taking Pancreatic Enzyme supplements to aid digestion. These are available in the form of capsules by prescription.

It is not unusual for a patient having received a Whipple procedure to feel perfectly well, and to lead his/her normal life without difficulty.

It is important for the procedure to be performed by a surgeon with extensive experience having done and observed the procedure, as specific competence makes a big difference.

Some patients need to be fitted with tubes to either add nutrients (feeding tubes) or drainage tubes to remove excess processed food that can not pass the blockage.

The cancerous mass tends to block food from getting to the small intestine. If food cannot get to the intestines, it will cause pain, acid reflux, and weight loss because the food cannot get to where it is supposed to be processed and absorbed by the body.

Patients with duodenal cancer may experience abdominal pain, weight loss, nausea, vomiting, and chronic GI bleeding.

Due to the increased risk for gallbladder cancer, the recommended treatment is cholecystectomy which usually includes pre-operative or intra-operative imaging of the biliary tree. Cholecystectomy may be performed via an open incision or via laparoscopic methods, but gallbladder anatomy and consistency may complicate the operation.

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.

Alcohol is a risk factor for liver cancer, through cirrhosis. "Cirrhosis results from scar formation within the liver, most commonly due to chronic alcohol use."

"Approximately 5 percent of people with cirrhosis develop liver cancer. Cirrhosis is a disease that develops when liver cells are replaced with scar tissue after damage from alcohol abuse, …"

The NIAAA reports that "Prolonged, heavy drinking has been associated in many cases with primary liver cancer." However, it is liver cirrhosis, whether caused by alcohol or another factor, that is thought to induce the cancer."

"The chances of getting liver cancer increase markedly with five or more drinks per day" (NCI).

A study concluded that for every additional drink regularly consumed per day, the incidence of liver cancer increases by 0.7 per 1000.

In the United States, liver cancer is relatively uncommon, afflicting approximately 2 people per 100,000, but excessive alcohol consumption is linked to as many as 36% of these cases by some investigators "Overall, 61% of HCC were attributable to HCV [hepatitis C virus], 13% to HBV [hepatitis B virus], and 18% to heavy alcohol drinking." A study in the province of Brescia, northern Italy concluded, "On the basis of population attributable risks (AR), heavy alcohol intake seems to be the single most relevant cause of HCC in this area (AR: 45%), followed by HCV (AR: 36%), and HBV (AR: 22%) infection."

Any alcohol intake is associated with the development of malignant melanoma.

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 assertion that porcelain gallbladder increases the incidence of gallbladder cancer is widely taught in medical schools but is based on studies from 1931 and 1962. A prominent study aid for surgical residents even states that the risk of cancer in a porcelain gallbladder is 15%. The precise nature of the association between gallbladder cancer and porcelain gallbladder is uncertain. Two articles published in 2001 examined the association between cancer of the gallbladder and calcified gallbladder. The first study reviewed 10,741 cholecystectomies and found that the 88 patients with gallbladder cancer did not have calcified gallbladders while the 15 patients with porcelain gallbladders did not have gallbladder cancer. The second study reviewed 25,900 gallbladder specimens and found 150 patients with cancer and 44 patients with calcified gallbladders of two types (intramural calcification and selective mucosal calcification). The selective mucosal calcification group showed a 7% incidence of cancer with a significant odds ratio of 13.89.

An article published in 2013 reviewed 111 studies and found 340 patients with gallbladder wall calcification showed a 21% overall rate of gallbladder malignancy; however, when studies with obvious selection bias were excluded the rate of gallbladder malignancy fell to 6%. Comparatively, a matched cohort without gallbladder calcification showed a 1% rate of gallbladder malignancy.