Approximately 31,800 people in U.S are diagnosed with pancreatic cancer and 31,200 die of this disease each year. This elevated death rate stems from a lack of curative treatments and the association between pancreatic cancer and risk factors. Pancreatic cancer is considered highly aggressive and often associated with a poor prognosis, even upon early diagnosis. The primary reason for this is that pancreas cancer is usually only detectable in its more advanced and incurable state. Moreover, many pancreatic cancers are relatively resistant to chemotherapy and other medical therapies. In fact, the only potentially curative treatment is surgery, which is often in itself not a viable treatment option.
Even though the symptoms of pancreatic cancer are seldom detected in its early stages, some patients may present with distinct symptoms, including:
- Upper abdominal pain that may radiate to the back
- Jaundice (yellowing of skin, eyes and/or gums
- Loss of appetite
- Weight loss
- Blood clots
Understanding the association between the cancer and its risk factors can help prevent the development of this aggressive and deadly cancer. Moreover, the understanding of these risk factors can help improve the early detection and diagnosis of pancreatic cancer. The prevention and early diagnosis of pancreas cancer will assist in the reduction of the high death rate associated with this disease. Listed below is a brief summary of the major risk factors associated with the development of pancreatic cancer.
Elevated Risk in the Elderly Population
Like most cancers, advanced age is considered to be associated with an elevated risk of developing pancreatic cancer. In fact, before the age of 50 years old the incidence of pancreatic cancer is relatively low. However, this risk elevates significantly in patients over the age of 50 years. The highest incidence of pancreatic cancer has been shown to in patients between the ages of 65 and 79 years. Moreover, the association between risk factors and pancreatic cancer in also elevated in the elderly population. Another study demonstrated that the median age of pancreatic cancer onset was 72 and median age of pancreatic cancer associated death was 73. Moreover, they found that less than 15% of diagnosed pancreatic cancers were in patients under the age of 50 and 90% of pancreatic cancer deaths.
Obesity has been shown to be associated with an increased risk of developing cancers such as those of the colon, breast, endometrium (the lining of the uterus), kidney and esophagus. Some studies have also reported a link between obesity and cancers of the gallbladder ovaries and pancreas. A study examining the incidence of pancreatic cancer in 2170 obese patients and 2209 normal weighted patients demonstrated a strong association between obesity and the potential development of pancreatic cancer. Their results demonstrated that obese patients had an approximately 50% increase risk of pancreatic cancer development.
The incidence of pancreatic cancer is higher in diabetes mellitus population compared to the general population. Moreover, diabetes has been shown to be a risk factor for the pancreatic tumor formation. Studies have demonstrated that approximately 25% of diabetic patients were suffering from pancreatic cancer; where as only 8% of the normal population had pancreatic cancer. Moreover, the age of diagnosis was earlier in the diabetes population (59.4 years) compared to the general population (64.4 years). While an association between diabetes and pancreas cancer has been shown, no associations have been found between diabetes and pancreatic cancer among patients with long-standing diabetes. Moreover, there are some that argue that it is not diabetes that is a risk factor for pancreatic cancer, but pancreatic cancer is a cause of diabetes (i.e. unhealthy pancreas).
Chronic Pancreatic Inflammation
While studies have demonstrated a link between pancreatic inflammation and pancreatic cancer, this association between pancreatic cancer and risk factors have yet to be fully elucidated. These studies have shown an elevated incidence of pancreatic cancers in patients suffering from hereditary pancreatitis, cystic fibrosis, as well as in alcoholic, idiopathic, and tropical chronic pancreatitis. Moreover, genetic diseases leading to chronic pancreatic inflammation are also associated with pancreatic cancer.
Another study evaluated the association between the risks of pancreatic cancer and patient years of pancreatic inflammation. They demonstrated that as the years of pancreatic inflammation increased, the risk of pancreatic cancer also increased. In fact, the incidence of pancreas cancer was 1.8% after 10 years of pancreatic inflammation and 4.0% after 20 years. Furthermore, the risk of pancreatic cancer was more evident in patients over the age of 50 years with an average of 30 years of pancreatic inflammation. An additional study demonstrated that patients with chronic inflammation of the pancreas are 53 times more likely to develop pancreatic cancer than normal patients.
Like most cancers, pancreas cancer is associated with a genetic component. In fact, it has been shown that the risk of developing pancreatic cancer is increased 4 to 5 times for a person with one first-degree relative with pancreatic cancer, 6 to 7 times for a person with two first-degree relatives and 32 times for a person with three first-degree relatives. In addition, patients with hereditary diseases of the pancreas such as hereditary pancreatitis are at a 40% increased risk of pancreatic cancer development. Moreover, mutations in genes such as PRSS1, SPINK1 and CFTR are also associated with the development of pancreas cancer. Furthermore, mutations in the BRCA genes, commonly associated with breast or ovarian cancer, has also been associated with pancreatic cancer. In fact, the risk of pancreatic cancer for families with BRCA2 mutations is estimated to be up to 10 times greater than the average risk. There may also be a small increased risk of pancreatic cancer for families with BRCA1 gene mutations.
Cigarette smoke contains a large number of carcinogens and is associated with a variety of cancers. It is considered the major risk factor associated with the development of pancreatic cancer. In fact, Smoking is estimated to be responsible for 30% of pancreatic cancer. Moreover, it has been shown that patients that smoked while in college have a 2-3 fold increased risk of pancreatic cancer. Another study has demonstrated that the risk of pancreatic cancer is elevated in smokers vs. never smokers. Moreover, patients that smoke over 30 cigarettes per day, smoke for over 50 years and smoked over 40 packs per year have an increased risk of pancreatic cancer. However, smoking cessation has been shown to significantly reduce the risk of pancreatic cancer. In fact, patients that have remained quit for more than 15 years have a similar risk of pancreatic cancer as never smokers.
National Institute of Health – https://www.nih.gov/
National Cancer Institute – https://seer.cancer.gov/statfacts/html/pancreas.html
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Lynch SM et al. Cigarette smoking and pancreatic cancer: a pooled analysis from the pancreatic cancer cohort consortium. AM J Epidemiol. 2009;170:403-13.