Pancreatic cancer is the fourth leading cause of cancer death in the
United States. Unfortunately, because of the location of the pancreas,
deep in the body just in front of the spine, most patients do not
develop symptoms until the disease is advanced. Some people may develop
abdominal or back pain, unexplained weight loss, or become jaundiced
(yellow). Surgery is an option for treatment if there is no evidence of
metastases or tumor spread through the pancreas into the adjacent
organs. Some patients with confined small tumors may a combination
surgery, radiation and chemotherapy. Many patients can not have surgery
because their cancer has already spread beyond the pancreas. For these
patients, alternatives to surgery include chemotherapy and supportive
care.
Because pancreatic cancer is difficult to treat, it is important to
understand risk factors, particularly ones that we can change--such as
environmental exposures (smoking, toxic chemicals). In addition, in
families that appear to inherit pancreatic cancer, it is now possible to
screen this patients for the development of pre-cancerous changes in the
pancreas.
Risk Factors
Pancreatic cancer is usually a cancer of older people (average age of
patients is 71 years), however some patients can develop cancer at an
early age, such as 40. Incidence varies by race, gender, and geography.
The disease occurs more often in African Americans than in whites and in
men more than in women; global incidence rates vary approximately
30-fold. African Americans have the highest pancreatic cancer rate in
the world. The reason for these risk factors is not yet known.
There are four clear risk factors for pancreatic cancer: family
history, cigarette smoking, long-standing diabetes, and hereditary and
chronic pancreatitis.
- Cigarette smoking. This risk factor is associated with
approximately 25 percent of pancreatic cancers. People who smoke for
twenty years or more have double the risk of those who have never
smoked. Smoking has an even greater effect in families that inherit
pancreatic cancer---increasing the odds of developing cancer by up to
7 fold and patients who smoke tend to develop cancer at an earlier
age. This cancerous effect of smoking is also seen in patients with
chronic pancreatitis or hereditary pancreatitis.
- Family history. Pancreatic cancer runs in families, and
people in affected families have about a three-fold risk compared with
the general population. About five percent of patients with pancreatic
cancer report a family history of the disease. Hereditary syndromes
would be seen in families that inherit pancreatic cancer along with
other additional cancers. Examples of these additional cancers
include: cancers of the colon, breast, lung, bladder, uterine, and
melanoma. In addition to the families that inherit cancer, some
families inherit chronic inflammation of the pancreas (hereditary
pancreatitis); these patients are prone to developing pancreatic
cancer. Many families simply inherit pancreatic cancer, with no other
cancers in the family and no history of pancreatitis.
- Long-standing diabetes. There is about a two-fold
increase in risk of pancreatic cancer among people who were diagnosed
with diabetes as adults. This observation suggests that diabetes may
be an independent risk factor for pancreatic cancer, as well as a
possible consequence of the disease. The mechanism involved, however,
is unclear.
- Pancreatitis. Pancreatic cancer risk among individuals
with hereditary pancreatitis or nonhereditary chronic pancreatitis is
about 50 times and 16 to 20 times higher, respectively, than those
without pancreatitis.
Studies also have implicated a number of other factors, including
diet and nutrition, heavy alcohol consumption, other medical conditions,
and certain occupational exposures, but these findings have been
inconsistent.
- Diet and nutrition. Fruit and vegetable intake may have a
protective effect against pancreatic cancer. The effect appears to be
stronger for vegetables, particularly cruciferous vegetables. Folate
is a nutrient is associated with a lower risk of panreatic cancer.
Folate can be found in leafy green vegetables. Increased risk has been
associated with high intake of meat, fat, and carbohydrates and with
elevated body mass index and caloric intake. A recent study found an
interaction between body mass index and caloric intake, suggesting
that caloric intake in excess of that required to maintain energy
balance (e.g. being overweight) may increase risk.
- Alcohol. Alcohol consumption at the level typically
consumed by the U.S. population does not appear to increase risk;
however, approximately 10 studies have reported an increased risk
associated with heavy alcohol consumption.
- Occupational exposures. Organochlorine compounds (DDT,
DDE, and PCBs) have been associated with elevated risk in a small
number of studies. Dry cleaning workers have an increased risk of
pancreatic cancer, possibly due to exposure to chlorinated hydrocarbon
solvents.
Prevention
Smoking cessation appears to reduce risk. A few recent studies
suggest that risk may revert to the level of nonsmokers after long-term
cessation.
Treatment & Surgery
Options for management of pancreatic adenocarcinoma usually involve
combinations of surgery, chemotherapy, and
radiation that must be customized for individual patients, based on
patient factors and the location and extent of the cancer. Of these
three types of treatment, only surgery offers the potential for cure and
then only in a carefully selected subset of patients. Patients who may
be cured with surgery (supported by other, adjunctive therapy) are those
with localized disease that can be completely removed to clear margins.
Unfortunately for many patients, by the time the cancer is detected it
has escaped the local region of the pancreas and spread into adjacent
organs or regional lymph node beds, and/or systemically to the liver,
lungs, and beyond. In such patients, surgery may still be considered to
improve the quality of a patient’s life by controlling complications of
the disease such as bleeding, bile duct, or intestinal obstruction.
