pancreatic cancer

Pancreatic Cancer – Its various Causes along with Symptoms, Treatment and Prognosis

Pancreatic cancer is one of the most serious types of cancer occurring. It is a disease which forms malignant or cancerous cells in the tissues of the pancreas.

The pancreas is a gland about 6 inches long that is shaped like a thin pear lying on its side.

The wider end of the pancreas is called the head, the middle section is called the body, and the narrow end is called the tail.

The pancreas lies behind the stomach and in front of the spine. It lies horizontally behind the lower part of the stomach. The pancreas secretes enzymes that aid digestion and hormones that help regulate the metabolism of carbohydrates.

The pancreas has two main jobs in the body:

  • To produce juices that help digest (break down) food.
  • To produce hormones, such as insulin and glucagon, that helps control blood sugar levels. Both of these hormones help the body use and store the energy it gets from food.

The digestive juices are produced by exocrine pancreas cells and the hormones are produced by endocrine pancreas cells. About 95% of pancreatic cancers begin in exocrine cells.

Pancreatic Cancer has been called a “silent” disease because early stages usually does not cause symptoms.

If the tumor blocks the common bile duct and bile cannot pass into the digestive system, the skin and whites of the eyes may become yellow (jaundiced), and the urine darker as a result of accumulated bile pigment called bilirubin.

Comparatively pancreatic cancer spreads rapidly than the other types of cancer and thus is seldom detected in its early stages, which is a major reason why it’s a leading cause of cancer death. Signs and symptoms may not appear until the disease is quite advanced. By that time, the cancer is likely to have spread to other parts of the body and surgical removal is no longer possible.

Earlier studies did not reveal much about pancreatic cancer. But researchers are beginning to understand the genetic basis of the disease. The knowledge that may eventually lead to new and better treatments is attained. Studies lead to conclusions which might reduce the risk of pancreatic cancer with some lifestyle changes.

Smoking and health history can affect the risk of developing pancreatic cancer.

Pancreatic Cancer Causes

The exact as to what damages DNA in the vast majority of cases of pancreatic cancer is not clear. In other words the exact pancreatic cancer causes are not clear. But it is known that a small percentage of people develop the disease as a result of a genetic predisposition. These people who have a close relative, such as a parent or sibling, with pancreatic cancer have a higher risk of developing pancreatic cancer themselves.

A number of genetic diseases have been associated with an increased risk of pancreatic cancer, including familial adenomatous polyposis, nonpolyposis colon cancer, familial breast cancer associated with the BRCA2 gene, hereditary pancreatitis, and familial atypical multiple mole-melanoma syndrome which is a serious type of skin cancer. This means that people who have a hereditary predisposition to develop these cancers are also more likely to develop pancreatic cancer.

Although the above causes are evident only 10 percent of pancreatic cancers result from an inherited tendency. A greater number are caused by environmental or lifestyle factors, such as smoking, diet and chemical exposure.

The actual cause of this disease is unknown but various factors are considered to be increasing the chances of probability of pancreatic cancer occurrence. The presence of a risk factor does not necessarily mean that an individual will develop cancer, nor does the absence of risk factors mean that an individual will not develop cancer. Some of the risk factors are listed below:

  • Age: is also a factor to be considered which increases the incidence of the disease. As age increases the probability of pancreatic cancer also increases. The incidence of Pancreatic Cancer is relatively low in individuals up to age 50, after which it increases significantly. The age group 65 – 79 has the highest incidence of Pancreatic Cancer.
  • Smoking increases the chances of developing Pancreatic Cancer. Study reveals that smokers develop Pancreatic Cancer more than twice as often as nonsmokers.
  • Non vegetarians have a high risk of getting Pancreatic Cancer, if the intakes of meat & fat are high.
  • Medical factors such as cirrhosis (a chronic liver disease), chronic pancreatitis, diabetes and a history of surgery to the upper digestive tract also contribute to the risk
  • Environmental factors such as long-term exposure to certain chemicals, like gasoline and related compounds, as well as certain insecticides, may increase the risk of developing Pancreatic Cancer.
  • Genetic predisposition should also be considered as the possible reason to increase the risk. Possibly 3% of cases of Pancreatic Cancer are related to genetic disorders.

Pancreatic Cancer Stage

To apt for any treatment option the doctor has to know the exact stage of the pancreatic cancer in the patient. Tests and procedures to stage pancreatic cancer are usually done at the same time as diagnosis.

The following are pancreatic cancer stage descriptions:

Stage 0: In this stage the cancer is found only in the lining of the pancreas. Stage 0 is also called carcinoma in situ.

Stage I: Cancer is found only in the pancreas in this stage. This stage further divided into stage IA and stage IB, based on the size of the tumor.

  • Stage IA: The tumor is 2 centimeters or smaller.
  • Stage IB: The tumor is larger than 2 centimeters.

Stage II: Cancer may have spread to nearby tissue and organs, and may have spread to lymph nodes near the pancreas in this stage. This stage is further divided into stage IIA and stage IIB, based on where the cancer has spread.

  • Stage IIA: Cancer has spread to nearby tissue and organs but has not spread to nearby lymph nodes.
  • Stage IIB: Cancer has spread to nearby lymph nodes and may have spread to nearby tissue and organs.

Stage III: Cancer has spread to the major blood vessels near the pancreas and may have spread to nearby lymph nodes in this stage.

Stage IV: Cancer may be of any size and has spread to distant organs, such as the liver, lung, and peritoneal cavity. It may have also spread to organs and tissues near the pancreas or to lymph nodes.

Recurrent Pancreatic Cancer

Recurrent pancreatic cancer is cancer that has recurred or come back after it has been treated. The cancer may come back in the pancreas or in other parts of the body.

Pancreatic Cancer Symptoms

Pancreatic cancer symptoms often don’t occur until the disease is advanced. The diagnosis of Pancreatic Cancer is usually delayed because symptoms are nonspecific. Jaundice, which causes’ yellowing of the skin is present in approximately 50% of patients at the time of diagnosis and may be associated with less-advanced disease. When symptoms do appear, they may include:

  • Discomfort in abdomen or Upper abdominal pain that may radiate to the middle or upper back
  • Yellowing of the skin and the whites of the eyes (jaundice)
  • Itching
  • Nausea and vomiting
  • Digestive problems
  • Weight loss
  • Fatigue
  • Loss of appetite
  • Glucose intolerance
  • Malnutrition.

In addition, the pancreas may produce too much insulin, causing such symptoms as dizziness, weakness, diarrhea, chills, or muscle spasms.

The patient may not even notice the gradual onset of these relatively nonspecific symptoms. The doctor may interpret them as being caused by something else. Therefore one should be very careful if any of the above symptoms are experienced.

Pancreatic Cancer Treatment

The choice of Pancreatic Cancer treatment depends largely on the stage the pancreatic cancer in the patient.

Possible treatments include surgery, chemotherapy, radiation, and biological therapy. Biological Therapy is also known as immunotherapy. The most common are listed below:

Surgery

During diagnosis, only about 20% of pancreatic tumors can be removed by surgery. This option is usually reserved for Stage 1 patients whose cancer is resectable. The surgeon may perform a resection, which is the removal of a small part of the pancreas.

The standard procedure is called a pancreatic oduodenectomy (Whipple procedure).This surgery for Pancreatic Cancer should be done at centers that perform the procedure frequently. It is the more extensive surgery which is the removal of the pancreas head and nearby structures such as the duodenum. It might be necessary to remove the entire pancreas as well as the spleen, gallbladder, and bile duct.

Sometimes the tumor cannot be completely removed. Most specialists believe that a partial removal does not help the patient.

Sometimes a combination of therapies, such as radiation and chemotherapy given before or after surgery, can increase a patient’s chances of survival.

Any form of surgery has potential side effects. In many cases, the surgery for Pancreatic Cancer will involve a large incision in the abdomen. The healing process for such major surgery can be very involved.

When the tumor is confined to the pancreas but cannot be removed, a combination of radiation therapy and chemotherapy may be recommended.

Radiation therapy

Certain substances emit invisible, high-energy rays, or radiation. These substances are called radioactive. The energy of the rays can kill cells. Special machines aim the rays at the parts of the body with cancerous tumors, so as to kill the cancer cells while minimizing damage to healthy tissue.

Unlike chemotherapy, radiation is not necessarily carried throughout the body. As such, it is known as a local therapy, rather than as a systemic therapy. However, there are still potential side effects of radiation including fatigue, localized hair loss, changes to appearance of skin, and digestive problems. Medicines and other treatments can reduce the intensity of the side effects. As with other cancer treatments, the incidence of side effects varies with patient health and the exact nature of the treatment.

Chemotherapy

When the tumor has spread to other organs (metastasized) such as the liver, chemotherapy alone is usually used.

The standard chemotherapy agent is gemcitabine, but other drugs may be used. Gemcitabine provides clinical improvement in approximately 25% of patients.

For patients who have biliary obstruction (blockage of the vessels that transport bile) and the tumor cannot be totally removed, the obstruction must be relieved. There are generally two approaches to this, surgery and placement of a biliary stent (similar to stents placed in the arteries of the heart to relieve blockages) during ERCP.

Immunotherapy

This form of therapy involves using drugs to boost the body’s natural immune response (its ability to fight disease). Examples of these drugs are interferon and monoclonal antibodies. They work with the body’s immune system to block the growth of cancer cells. Biological therapy can be used on its own or in conjunction with other therapies.

Immunotherapy can result in side effects that are reminiscent of the flu: fever, aches, weakness, fatigue, and chills. Patients may also experience skin problems such as easy bruising or rashes, as well as diarrhea and nausea.

Mortality of Pancreatic Cancer

Cigarette smoking is considered an important risk factor for pancreatic cancer, but other purported risk factors are less well established. The associations with a variety of possible risk factors for death from pancreatic cancer are large.

Cigarette smoking at baseline is associated with fatal pancreatic cancer among men and less fatal among women. A trend in risk was observed with increasing number of cigarettes smoked per day among current smokers at baseline. With several variables included in separate models for men and women, additional factors to be predictive of mortality of pancreatic cancer, including family history of pancreatic cancer, black race, diabetes, and increased body mass index were found.

History of gallstones was predictive of pancreatic cancer among men. An inverse association with vegetable consumption was observed among men that were not statistically significant. Findings confirm that cigarette smoking is an important predictor of pancreatic cancer mortality, and identify several other factors that may contribute to increased risk.

Pancreatic Cancer Prognosis

Pancreatic Cancer patients are resectable (can be surgically removed), some patients are cured. Pancreatic cancer prognosis differs from patient to patient depending on the stage & condition of the patient. However, cure rates are significantly less than 50%.

Most commonly chemotherapy and radiation are often given after surgery to attempt to increase the cure rate. Patients with Pancreatic Cancer that can be removed successfully with surgery should consider enrollment in a clinical trial (a medical research study to determine the best treatment).

For patients with Pancreatic Cancer that cannot be removed completely with surgery or cancer that has spread beyond the pancreas, cure is not currently possible. The average (median) survival is generally less than 1 year.

Pancreatic Cancer Survival Rate

Pancreatic Cancer is rarely curable. The overall pancreatic cancer survival rate is less than 4%. The cure rates are highest (although still usually under 25%) if the tumor is small (less than 2 cm in diameter) and is truly localized to the pancreas but, unfortunately, such cases account for fewer than 20% of all cases of Pancreatic Cancer. For patients with advanced cancers, the overall survival rate of all stages is less than 1% at 5 years with most patients dying within 1 year.