Pancreatic cancer is the fourth most common cause of cancer-related mortality in the Unites States . Approximately 85% of pancreatic cancers are ductal adenocarcinomas, which are discussed here. Less common pancreatic tumors include endocrine tumors, carcinoid tumors, and lymphoma.
The characteristic presentation includes an insidious onset of weight loss, fatigue, anorexia, and gnawing abdominal or back pain. The most common symptom is epigastric pain with radiation to the back, which often improves upon bending forward. In addition, painless jaundice, dark urine, acholic stools, pruritis, migratory thrombophlebitis, or Courvoisier sign (a palpable, nontender gallbladder) may be present.
Unfortunately, by the time symptoms appear, the cancer has often become quite advanced. At the time of diagnosis, more than 80% of patients have advanced tumors marked by either local extension into adjacent organs (such as the liver) or distant metastases, resulting in a poor long-term survival rate. Most patients die within a year of diagnosis.
Age: The condition is rare before age 45, but increases thereafter with age.
Gender: Males have a slightly higher risk than females with a ratio of 1.3-1.
Race: Blacks have a slightly higher incidence of pancreatic cancer than whites.
Smoking: Cigarette smoking is one of the major risk factors for developing pancreatic cancer and accounts for approximately 25% of all cases.
Obesity: Excess weight increases the risk of pancreatic cancer.
Physical inactivity: The lack of physical activity is a risk factor.
Diabetes and insulin resistance: Both diabetes and insulin resistance are associated with an increased risk of pancreatic cancer. , There is also some evidence that diabetes can be a consequence of pancreatic cancer, rather than the cause.
Chronic Pancreatitis: The presence of chronic inflammation of the pancreas increases the risk of pancreatic cancer. One study showed that individuals with chronic pancreatitis had a standardized incidence ratio (the ratio of observed to expected cases) of 26.3.
Family history: About 5%-10% of patients with pancreatic cancer have a first-degree relative with the disease. Most of these cases have no clearly defined gene mutation. However, there are also several clearly defined genetic syndromes, including Peutz-Jeghers syndrome, hereditary breast/ovarian cancer syndrome and familial adenomatous polyposis, that carry a predisposition for pancreatic and other types of cancer. Hereditary pancreatitis (autosomal dominant) is a rare form of chronic pancreatitis which carries an increased risk of pancreatic cancer.
ABO blood type: Having a non-O blood type carries an increased risk for pancreatic cancer.
Alcohol: Heavy alcohol use is also associated with increased pancreatic cancer risk.
Dietary factors: (see Nutritional Considerations).
Patients with unexplained weight loss, painless jaundice or subacute epigastric pain without other obvious cause should undergoing further evaluation with laboratory testing for liver function. Tests for lipase and amylase should also be done if pain is the presenting symptom. In addition, an abdominal CT scan should be performed. Abdominal ultrasound is sometimes used, but is less sensitive.
For patients with a suspicious pancreatic mass who are reasonable surgical candidates, surgical resection is most often recommended. Patients who are not surgical candidates or have a high suspicion of metastatic disease require a biopsy for a definitive diagnosis. This can be done percutaneously or endoscopically. Endoscopic options include cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS).
Once a diagnosis is made, the tumor is staged using the tumor-node-metastasis (TNM) system to determine if it is resectable. This is usually done with CT, MRI, PET scanning or staging laparoscopy, depending on the clinical situation.
Despite advances in treatment, the prognosis for pancreatic cancer remains poor, and surgical resection is the only curative treatment. Only about 15%-20% of pancreatic cancers are found to be potentially resectable at the time of diagnosis. Common surgical procedures include pancreaticoduodenectomy (the Whipple procedure), which involves removal of the duodenum, head of the pancreas, and gallbladder, and t otal or distal pancreatectomy. Treatment with chemotherapy and/or radiation following surgery may improve survival rates.
If the tumor is unresectable, palliation may be attempted via radiation, chemotherapy, or surgical intervention to relieve bile duct and GI tract obstructions. Adequate pain control is also an important part of palliative care.
The risk for pancreatic cancer appears to be significantly related to insulin resistance. Obesity, diabetes, lack of exercise, and diets known to impact insulin resistance and risk for malignancy in general are known to moderate risk. Evidence indicates that the major dietary determinants of increased pancreatic cancer risk include meat and other sources of animal fat, while fruits, vegetables, and whole grains, appear to reduce risk. 19,20
Avoiding animal products. In the NIH-AARP Diet and Health study, the risk for pancreatic cancer was 20% greater in those eating the most meat, compared with those eating the least. Red meat, high-temperature cooked meat, and heme iron from red meat were all associated with roughly 20% greater risk, comparing the highest vs. lowest consumers. Risk increased to over 30% greater in frequent consumers of "well done” or “very well done” meat, compared with those who generally avoid meat cooked in this fashion. Part of this risk has been attributed to the proinflammatory effects of advanced glycation end products found in meat. Conversely, intake of beans, lentils, other plant foods is associated with significantly reduced risk for pancreatic cancer. 
Reducing fat intake. Higher compared with lower intakes of animal fat were associated with a 43% greater risk for pancreatic cancer in the NIH-AARP Diet and Health study. Similarly, in a group of 27,111 male smokers aged 50-69 years who were followed for a 12-year period, those who ate the most saturated fat had a significantly higher risk for pancreatic cancer, compared with nonsmokers who ate the least saturated fat. On the other hand, evidence indicates that individuals consuming the highest amount of polyunsaturated fat have a 13% lower risk for pancreatic cancer, compared with those eating the least.
Increasing consumption of fruits, vegetables, and whole grains. Higher compared with lower fruit and vegetable intakes are associated with a roughly 25% lower risk for pancreatic cancer, and cruciferous vegetables may be especially protective. Consuming the highest dietary amounts of selenium, vitamin C, vitamin E, β-carotene and β-cryptoxanthin was associated with a 30%-53% lower risk for pancreatic cancer. Intake of the highest amount of whole grains was associated with a roughly 25% lower risk for pancreatic cancer, compared to the lowest intakes.
Weight control. Individuals at a body mass index (BMI) of 25 and below are at low risk for pancreatic cancer, but the risk increases by 10% as BMI increases from 25-30, and the risk is greatest at a BMI over 35. Exercise is weakly yet statistically significantly associated with a lower risk for pancreatic cancer.
Limiting or avoiding alcohol. As noted above, heavy alcohol use is associated with pancreatic cancer risk. Avoiding or limiting alcohol use has many potential benefits, in addition to potentially reducing pancreatic cancer risk.
Few studies have examined the effect of dietary changes on survival after diagnosis. One study found a 4-fold increase in median survival (13 months versus 3 months) in patients with pancreatic cancer who followed a macrobiotic diet (composed mainly of whole grains, land and sea vegetables, beans, legumes, and small amounts of fruit) compared with those eating omnivorous diets. Other studies have revealed a longer survival in patients taking an omega-3 fatty acid-containing supplement when compared with those on conventional nutrition therapy. Further studies are needed to establish relationships between diet and pancreatic cancer survival.
Pancreatic cancer typically has a poor prognosis. While dietary factors appear to play a role in risk and possibly in survival, further studies are necessary to clarify these relationships.