The exact cause of pancreatic cancer in an individual is still being researched upon. However, the most important risk factor for pancreatic cancer is increasing age, with risk rising to 1 in 61 by the age of 85 years. Other factors that increase the risks may include:
- Smoking (usually considered the most common cause of pancreatic cancer)
- Obesity (body mass index >30 kg/m2)
- Heavy alcohol use (more than four standard drinks/day)
- Long-standing diabetes (>5 years)
- Severe pancreatitis: Patients who have chronic or severe pancreatitis are five times more likely to develop pancreatic cancer.
- Previous surgeries such as gastrectomy or cholecystectomy: People who have had certain types of surgery such as a gastrectomy (portion of the stomach removed) to treat stomach ulcers or cholecystectomy (gallbladder removal) may be at an increased risk of pancreatic cancer. There is conflicting evidence that specific types of bacteria that can produce carcinogenic chemicals called nitrosamines as a result of these types of surgery may increase the risk of pancreatic cancer.
- Diet: Diets with a high intake of meat and/or saturated fat and reduced intake of fruits and vegetables can increase the risk of pancreatic cancer.
- People frequently exposed to certain pesticides and petroleum products may have an increased risk of pancreatic cancer. High rates of pancreatic cancer have been noted among industrial workers, for example, those working in chemical manufacturing and metal industries.
- One first-degree relative (FDR) with pancreatic cancer: Approximately, 5-10% of patients with pancreatic cancer have a family history of the pancreatic disease.
- African Americans tend to be more likely to acquire cancer of the pancreas than their Caucasian counterparts. Causes of this are not entirely clear but may have to do with diet, smoking, diabetes rates, and obesity.
- Pancreatic cancer is caused by mutations or changes in a person’s DNA.
- These genetic mutations may be inherited, meaning that we are born with them, or they may be acquired throughout a lifetime.
- In most cases of pancreatic cancer, mutations are caused by environmental, lifestyle, and aging factors.
- Approximately, 5-10% of all pancreatic cancers are the result of inherited changes, which explains why pancreatic cancer appears to run in some families.
- Breast cancer 2 (BRCA2) gene: Mutations in the BRCA2 gene may also account for 6-16% of hereditary pancreatic cancer cases. It is estimated that the lifetime risk of pancreatic cancer for those carrying a BRCA2 gene mutation is 5%.
- Peutz-Jeghers syndrome: This syndrome is caused by mutations in the STK11 gene. It is associated with the growth of polyps (usually benign) in the stomach and intestines and pigmentation on the lips and nose. The lifetime risk of pancreatic cancer is 36%.
- Hereditary pancreatitis: It is rare and can be caused by mutations in the PRSS1 or SPINK1 gene. This condition is characterized by frequent episodes of chronic pancreatitis (long-term inflammation of the pancreas) beginning from a relatively young age. The lifetime risk of pancreatic cancer is estimated to be as high as 40%.
- Familial atypical multiple mole melanomas (FAMMM): FAMMM is caused by mutations in the CDKN2A gene, and affected individuals develop numerous skin moles and melanomas at a young age. They may also be susceptible to cancer of the pancreas.
- Lynch syndrome or hereditary non-polyposis colorectal cancer (HNPCC): It is an inherited predisposition to developing bowel cancer due to mismatch repair gene mutations (MLH1, MSH2, MSH6, and PMS2). It is also associated with an increased risk of pancreas cancer.
- Familial adenomatous polyposis (FAP): It is characterized by multiple colorectal adenomas at a significantly younger age. Benign and malignant tumors can also be found in other sites such as the duodenum, stomach, and skin. FAP is a result of mutations in the APC gene and is associated with an increased risk of pancreatic cancer.
What are the treatment options for pancreatic cancer?
Treatment for pancreatic cancer is determined by the stage of the disease. Localized pancreatic cancer is treated with surgery and chemotherapy. Chemotherapy can be given before or after the surgery. Advanced pancreatic cancer is not removed by surgery and instead is treated with chemotherapy and radiation.
- Surgery: Surgery to remove pancreatic cancer can be part of pancreaticoduodenectomy (Whipple procedure), partial pancreatectomy, or total pancreatectomy depending on the location of the cancer within the pancreas. The goal of the surgery is to remove all the cancer in the pancreas and surrounding tissues.
- Chemotherapy: Chemotherapy is a systemic treatment (a drug is dispersed throughout the entire body) that is designed to kill the cancer cells. Typically, it is administered intravenously (through a vein). Chemotherapy may be administered before surgery (neoadjuvant therapy), after surgery (adjuvant therapy), or in the setting of advanced disease.
- Radiation therapy: Radiation uses high-energy X-rays to destroy the cancer cells. Radiation therapy can be used to relieve symptoms (called palliative treatment) of advanced pancreatic cancer. Sometimes, chemotherapy will be given concurrently with radiation because the addition of systemic chemotherapy renders the cancer cells more susceptible to the killing effects of radiation.