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.

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).

The two major risk factors for esophageal squamous-cell carcinoma are tobacco (smoking or chewing) and alcohol. The combination of tobacco and alcohol has a strong synergistic effect. Some data suggest that about half of all cases are due to tobacco and about one-third to alcohol, while over three-quarters of the cases in men are due to the combination of smoking and heavy drinking. Risks associated with alcohol appear to be linked to its aldehyde metabolite and to mutations in certain related enzymes. Such metabolic variants are relatively common in Asia.

Other relevant risk factors include regular consumption of very hot drinks (over 65 °C)(149 Fahrenheit) and ingestion of caustic substances. High levels of dietary exposure to nitrosamines (chemical compounds found both in tobacco smoke and certain foodstuffs) also appear to be a relevant risk factor. Unfavorable dietary patterns seem to involve exposure to nitrosamines through processed and barbecued meats, pickled vegetables, etc., and a low intake of fresh foods. Other associated factors include nutritional deficiencies, low socioeconomic status, and poor oral hygiene. Chewing betel nut (areca) is an important risk factor in Asia.

Physical trauma may increase the risk. This may include the drinking of very hot drinks.

The median overall survival rate is about 50% in 5 years. Worse prognostic factors include the presence of residual tumor at the margin of the resection specimen (R+), invasion of the peritoneum and metastatic disease.

People with Barrett's esophagus (a change in the cells lining the lower esophagus) are at much higher risk, and may receive regular endoscopic screening for the early signs of cancer. Because the benefit of screening for adenocarcinoma in people without symptoms is unclear, it is not recommended in the United States. Some areas of the world with high rates of squamous-carcinoma have screening programs.

Drinking alcohol excessively is a major cause of chronic pancreatitis, which in turn predisposes to pancreatic cancer. However, considerable research has failed to firmly establish alcohol consumption as a direct risk factor for pancreatic cancer. Overall, the association is consistently weak and the majority of studies have found no association, with smoking a strong confounding factor. The evidence is stronger for a link with heavy drinking, of at least six drinks per day.

Pancreatic cancer is the fifth-most-common cause of cancer deaths in the United States, and the seventh most common in Europe. In 2008, globally there were 280,000 new cases of pancreatic cancer reported and 265,000 deaths. These cancers are classified as endocrine or nonendocrine tumors. The most common is ductal adenocarcinoma. The most significant risk factors for pancreatic cancer are advanced age (over 60) and smoking. Chronic pancreatitis, diabetes or other conditions may also be involved in their development. Early pancreatic cancer does not tend to result in any symptom, but when a tumor is advanced, a patient may experience severe pain in the upper abdomen, possibly radiating to the back. Another symptom might be jaundice, a yellowing of the skin and eyes.

Pancreatic cancer has a poor prognosis, with a five-year survival rate of less than 5%. By the time the cancer is diagnosed, it is usually at an advanced, inoperable stage. Only one in about fifteen to twenty patients is curative surgery attempted. Pancreatic cancer tends to be aggressive, and it resists radiotherapy and chemotherapy.

Compared to other breeds of dog, Scottish terriers have a much increased risk of developing transitional cell carcinoma.

Primary signet ring cell carcinoma of the colon and rectum (PSRCCR) is rare, with a reported incidence of less than 1 percent. It has a poor prognosis because symptoms often develop late and it is usually diagnosed at an advanced stage. Five-year survival rates in previous studies ranged from nine to 30 percent. Average survival was between 20 and 45 months. It tends to affect younger adults with higher likelihood of lymphovascular invasion. It is worth noting that the overall survival rate of patients with SRCC was significantly poorer than that of patients with mucinous or poorly differentiated adenocarcinoma.

In advanced gastric cancers, the prognosis for patients with the SRCCs was significantly worse than for the other histological types, which can be explained by the finding that advanced SRCC gastric cancers have a larger tumor size, more lymph node metastasis, a deeper invasive depth and more Borrmann type 4 lesions than other types.

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.

Although most patients present without any known risk factors evident, a number of risk factors for the development of cholangiocarcinoma have been described. In the Western world, the most common of these is primary sclerosing cholangitis (PSC), an inflammatory disease of the bile ducts which is closely associated with ulcerative colitis (UC). Epidemiologic studies have suggested that the lifetime risk of developing cholangiocarcinoma for a person with PSC is on the order of 10%–15%, although autopsy series have found rates as high as 30% in this population.

Certain parasitic liver diseases may be risk factors as well. Colonization with the liver flukes "Opisthorchis viverrini" (found in Thailand, Laos PDR, and Vietnam) or "Clonorchis sinensis" (found in China, Taiwan, eastern Russia, Korea, and Vietnam) has been associated with the development of cholangiocarcinoma. Patients with chronic liver disease, whether in the form of viral hepatitis (e.g. hepatitis B or hepatitis C), alcoholic liver disease, or cirrhosis of the liver due to other causes, are at significantly increased risk of cholangiocarcinoma. HIV infection was also identified in one study as a potential risk factor for cholangiocarcinoma, although it was unclear whether HIV itself or other correlated and confounding factors (e.g. hepatitis C infection) were responsible for the association.

Infection with the bacteria "Helicobacter bilis" and "Helicobacter hepaticus" species can cause biliary cancer.

Congenital liver abnormalities, such as Caroli's syndrome (a specific type of five recognized choledochal cysts), have been associated with an approximately 15% lifetime risk of developing cholangiocarcinoma. The rare inherited disorders Lynch syndrome II and biliary papillomatosis have also been found to be associated with cholangiocarcinoma. The presence of gallstones (cholelithiasis) is not clearly associated with cholangiocarcinoma. However, intrahepatic stones (called hepatolithiasis), which are rare in the West but common in parts of Asia, have been strongly associated with cholangiocarcinoma. Exposure to Thorotrast, a form of thorium dioxide which was used as a radiologic contrast medium, has been linked to the development of cholangiocarcinoma as late as 30–40 years after exposure; Thorotrast was banned in the United States in the 1950s due to its carcinogenicity.

Cholangiocarcinoma is a relatively rare form of cancer; each year, approximately 2,000 to 3,000 new cases are diagnosed in the United States, translating into an annual incidence of 1–2 cases per 100,000 people. Autopsy series have reported a prevalence of 0.01% to 0.46%. There is a higher prevalence of cholangiocarcinoma in Asia, which has been attributed to endemic chronic parasitic infestation. The incidence of cholangiocarcinoma increases with age, and the disease is slightly more common in men than in women (possibly due to the higher rate of primary sclerosing cholangitis, a major risk factor, in men). The prevalence of cholangiocarcinoma in patients with primary sclerosing cholangitis may be as high as 30%, based on autopsy studies.

Multiple studies have documented a steady increase in the incidence of intrahepatic cholangiocarcinoma over the past several decades; increases have been seen in North America, Europe, Asia, and Australia. The reasons for the increasing occurrence of cholangiocarcinoma are unclear; improved diagnostic methods may be partially responsible, but the prevalence of potential risk factors for cholangiocarcinoma, such as HIV infection, has also been increasing during this time frame.

Urachal cancer is a very rare type of cancer arising from the urachus or its remnants. The disease might arise from metaplasic glandular epithelium or embryonic epithelial remnants originating from the cloaca region.

It occurs in roughly about one person per 1 million people per year varying on the geographical region. Men are affected slightly more often than women mostly in the 5th decade of life but the disease can occur in also in other age groups.

It can involve the urinary bladder, but is not bladder cancer in the usual sense. Urachal cancer can occur at any site along the urachal tract.

Urachal cancer was mentioned by Hue and Jacquin in 1863 followed by an elaborate work by T. Cullen in 1916 about diseases of the umbilicus, while C. Begg further characterized urachal cancer in the 1930s. Detailed diagnostic and staging schemes were proposed by Sheldon et al in 1984, which remain widely used today.

Examples of cancers where adenocarcinomas are a common form:

- esophageal cancer; most cases in the developed world are adenocarcinomas.

- pancreas; over 80% of pancreatic cancers are ductal adenocarcinomas.

- prostate cancer is nearly always adenocarcinoma

- cervical cancer: most is squamous cell cancer, but 10–15% of cervical cancers are adenocarcinomas

- stomach cancer

Adenocarcinoma (; plural adenocarcinomas or adenocarcinomata ) is a type of cancerous tumor that can occur in several parts of the body. It is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or both. Adenocarcinomas are part of the larger grouping of carcinomas, but are also sometimes called by more precise terms omitting the word, where these exist. Thus invasive ductal carcinoma, the most common form of breast cancer, is adenocarcinoma but does not use the term in its name—however, esophageal adenocarcinoma does to distinguish it from the other common type of esophageal cancer, esophageal squamous cell carcinoma. Several of the most common forms of cancer are adenocarcinomas, and the various sorts of adenocarcinoma vary greatly in all their aspects, so that few useful generalizations can be made about them.

In the most specific usage (narrowest sense), the glandular origin or traits are exocrine; endocrine gland tumors, such as a VIPoma, an insulinoma, or a pheochromocytoma, are typically not referred to as adenocarcinomas but rather are often called neuroendocrine tumors. Epithelial tissue sometimes includes, but is not limited to, the surface layer of skin, glands, and a variety of other tissue that lines the cavities and organs of the body. Epithelial tissue can be derived embryologically from any of the germ layers (ectoderm, endoderm, or mesoderm). To be classified as adenocarcinoma, the cells do not necessarily need to be part of a gland, as long as they have secretory properties. Adenocarcinoma is the malignant counterpart to adenoma, which is the benign form of such tumors. Sometimes adenomas transform into adenocarcinomas, but most do not.

Well differentiated adenocarcinomas tend to resemble the glandular tissue that they are derived from, while poorly differentiated adenocarcinomas may not. By staining the cells from a biopsy, a pathologist can determine whether the tumor is an adenocarcinoma or some other type of cancer. Adenocarcinomas can arise in many tissues of the body owing to the ubiquitous nature of glands within the body, and, more fundamentally, to the potency of epithelial cells. While each gland may not be secreting the same substance, as long as there is an exocrine function to the cell, it is considered glandular and its malignant form is therefore named adenocarcinoma.

Oesophagogastric junctional adenocarcinoma is a cancer of the lower part of the oesophagus, often linked to a Barrett's oesophagus.

The incidence of oesophagogastric junctional adenocarcinoma is rising rapidly in western countries, in contrast to the declining frequency of distal gastric adenocarcinoma. Treatment options for adenocarcinomas involving the oesophagogastric junction are limited and the overall prognosis is extremely poor.

Bladder cancer in cats and dogs usually is transitional cell carcinoma, which arises from the epithelial cells that line the bladder. Less often, cancer of the urinary bladder is squamous cell carcinoma, adenocarcinoma, or rhabdomyosarcoma.

OGJ adenocarcinoma is a highly mutated and heterogeneous disease. Microsatellite instability (MSI) can be observed and coincides with an elevated number of somatic mutations. Potentially actionable coding mutations have been identified in 67 genes, including those in CR2, HGF, FGFR4 and ESRRB. Numerous genes harbouring somatic coding mutations and copy number changes in the microsatellite stable (MSS) OGJA are also known to be altered with similar predicted functional consequence in other tumour types. TP53, SYNE1, and ARID1A are among the most frequently mutated genes.

The overall incidence is 0.5 to 1 cases per 100,000 people per year. It is slightly more common in women than men (male:female ratio = 9:11). The median age at presentation is typically about 50 years with a range of 20–25 years.

There are two primary types of vaginal cancer: squamous-cell carcinoma and adenocarcinoma.

- Vaginal squamous-cell carcinoma arises from the squamous cells (epithelium) that line the vagina. This is the most common type of vaginal cancer. It is found most often in women aged 60 or older.

- Vaginal adenocarcinoma arises from the glandular (secretory) cells in the lining of the vagina that produce some vaginal fluids. Adenocarcinoma is more likely to spread to the lungs and lymph nodes.

- Clear cell adenocarcinoma occurs in a small percentage of women (termed "DES-Daughters") born between 1938 and 1973 (later outside the United States) that were exposed to the drug diethylstilbestrol (DES) in utero. DES was prescribed to 5 to 10 million mothers period to prevent possible miscarriages and premature births. Typically, women develop DES-related adenocarcinoma before age 30, but increasing evidence suggests possible effects or cancers (including other forms of vaginal glandular tumors) at a later age. DES-exposure in women is also linked to various infertility and pregnancy complications. Daughters exposed to DES in utero may also have an increased risk of moderate/severe cervical squamous cell dysplasia and an increased risk of breast cancer. Approximately one in 1,000 (0.1%) DES Daughters will be diagnosed with clear cell adenocarcinoma. The risk is virtually non-existent among premenopausal women not exposed to DES.

- Vaginal germ cell tumors (primarily teratoma and endodermal sinus tumor) are rare. They are found most often in infants and children.

- Sarcoma botryoides, a rhabdomyosarcoma also is found most often in infants and children.

- Vaginal melanoma, a melanoma that appears in the vagina.

Clear-cell adenocarcinoma is a type of adenocarcinoma that shows clear cells.

Types include:

- Clear-cell adenocarcinoma of the vagina

- Clear-cell ovarian carcinoma

- Uterine clear-cell carcinoma

- Clear-cell adenocarcinoma of the lung (which is a type of Clear-cell carcinoma of the lung)

See also:

- Clear-cell squamous cell carcinoma of the lung

Accurate incidence statistics on MCACL are unavailable. It is a very rare tumor, with only a few dozen cases reported in the literature to date.

In the few cases described in the literature to date, the male-to-female ratio is approximately unity, and right lung lesions occurred twice as commonly as left lung lesions. Approximately 2/3 of cases have been associated with tobacco smoking. Cases have been reported in patients as young as 29.

MCACL has a much more favorable prognosis than most other forms of adenocarcinoma and most other NSCLC's. Cases have been documented of continued growth of these lesions over a period of 10 years without symptoms or metastasis. The overall mortality rate appears to be somewhere in the vicinity of 18% to 27%, depending on the criteria that are used to define this entity.

Periampullary cancer is a cancer that forms near the ampulla of Vater, an enlargement of the ducts from the liver and pancreas where they join and enter the small intestine.It consists of:

1. ampullary tumour from ampulla of Vater,

2. cancer of lower common bile duct, and

3. duodenal cancer adjacent to ampulla.

4. carcinoma head of pancreas

It presents with painless jaundice which may have waxing and waning nature because at times the sloughing of the tumor tissue relieves the obstruction partially.

Taken as a class, long-term survival rates in BAC tend to be higher than those of other forms of NSCLC. BAC generally carries a better prognosis than other forms of NSCLC, which can be partially attributed to localized presentation of the disease. Though other factors might play a role. Prognosis of BAC depends upon the histological subtype and extent at presentation but are generally same as other NSCLC.

Recent research has made it clear that nonmucinous and mucinous BACs are very different types of lung cancer. Mucinous BAC is much more likely to present with multiple unilateral tumors and/or in a unilateral or bilateral pneumonic form than nonmucinous BAC. The overall prognosis for patients with mucinous BAC is significantly worse than patients with nonmucinous BAC.

Although data are scarce, some studies suggest that survival rates are even lower in the mixed mucinous/non-mucinous variant than in the monophasic forms.

In non-mucinous BAC, neither Clara cell nor Type II pneumocyte differentiation appears to affect survival or prognosis.