What causes pancreatic cancer? symptoms, types, Treatment

Table of content

1. Meaning, location, function and functional disorder of pancreas:

Before focusing on the issues relevant to pancreatic cancer , it is essential to highlight the meaning (as well as related aspects) of pancreas- the hub of pancreatic cancer. Pancreas is a part of the digestive system and produces insulin (which is secreted into the bloodstream where it regulates the body’s glucose or sugar level. Problems related to pancreatic  function leads to diabetes and pancreatic cancer) and other important enzymes and hormones that help break down foods. Pancreas is a gland organ (about 6 inches long  and is shaped like a thin pear. The wider end of the pancreas is called ‘head’ and the narrow end is called ‘tail’. The pancreas lies between the stomach and the spine) .

• The pancreas has endocrine function (it releases juices directly into blood vessel)
• And  exocrine function (it releases juices directly into the ducts)

2. What is Pancreatic Cancer?

Pancreatic cancer occurs when the uncontrolled cancer cell growth begins in a part of the pancreas. Tumors develop which interfere with the normal function of the pancreas. Pancreatic cancer typically spreads in the nearby organs and is seldom detected in the early stage.

3. Symptoms, signs and diagnosis of pancreatic cancer

Symptoms are subjective phenomena observed or experienced by the patient, while signs are  mostly objective phenomena detected by the doctor through suitable test results. On the other hand diagnosis is  identifying and confirming the root problem through applying various tests, detecting symptoms found and experienced by the patient as well as interrogating the patient about his feelings ,genetic history, personal history pertaining to previous diseases including the treatments and more importantly, the life style followed.

3.1) Symptoms of pancreatic cancer:

Most of the symptoms of pancreatic cancer are detected in the later stage. The following are the major symptoms that stand as evidence of the presence of pancreatic cancer in a patient.

• Jaundice (the yellowing of eye and skin)
• Belly or back pain
• Weight loss and poor appetite
• Nausea and vomiting
• Enlargement  of gallbladder
• Blood clots
• Fatty tissue abnormalities
• Diabetes
• Dark urine
• Light colored stool

3.2) Signs of pancreatic cancer

The signs of pancreatic cancer are detected by the doctor through performing various  tests and procedures.

Physical examination with history: 

An exam of overall health is administered to check general health conditions that include the signs of various possible diseases (such as lumps or anything else that seems unusual). Additionally, the patient's lifestyle including health habits and past illnesses preceding treatments  will also be recorded.

Blood chemistry studies:

Blood samples of the patient will be tested to measure the amount of bilirubin (released into the blood by the organs and tissues in the body). An unusual amount lying outside the range and safe limits may indicate the sign of the disease.

Tumor marker test for pancreatic cancer:

It is a testing procedure in which  a sample of blood, urine or tissue is checked to measure the amount of certain substance, such as CA 19- 9 ( It is used to differentiate between cancer of the pancreas and other conditions) and CEA (Carcino-embryonic antigen- a blood test that detects the level of CEA protein. A high level of CEA protein  indicates that cancer has spread to other parts of the body) produced by the organs, tissues, and tumor cells in the body. Such  substances (when found at high levels) are linked to specific types of cancer. These are called tumor markers.

Imaging tests for pancreatic cancer:

• CT scans: Computed tomography scan-  used in detecting cancer. The test creates  a 3 dimensional image of the inside of the body with the help of an X- ray machine.
• MRI: Magnetic resonance  imaging-  an image test in detecting cancer.
• Ultrasound: It is a safe and painless test that produces the picture of the inside of the body using sound waves.
• PET scans: During the test, the patient is first injected with a glucose solution that contains a very small amount of radiation materials. The test is very helpful to detect cancerous tissues) are all used to help the doctor see the cancer inside the body. Some of these tests involve first  receiving an injection I V (intravenous) so as to see more of what is going on inside the body.

Endoscopic ultrasound test:

With this procedure the doctor will pass a thin tube down the esophagus and into the stomach to take images of the pancreas.

Biopsy:

Sometimes the doctor may take a small piece of tissue from the pancreas to examine under a microscope .A biopsy can be performed through a needle or administering an endoscopic ultrasound.

3.3) Diagnosis of pancreatic cancer:

Pancreatic cancer is often diagnosed when the disease has advanced too far. Because, initially, it does not reveal  the symptoms which are detected mostly when it has spread outside the pancreas. After performing all the necessary tests and interrogating the patient so as to record  the patient’s past history pertaining to his food and other habits, past illness and treatments , the doctor can only confirm whether the patient is fit for surgery or not. Still after all the tests, the doctor cannot be sure about the spread of the cancer until the surface of the body is opened up to look inside the body.

4. Causes and risk factors:

In fact, the causes are the agents directly responsible for the occurrence of the disease. In most cases it is not clear what causes pancreatic cancer. On the other hand, a risk factor is not necessarily a cause. A risk factor may be anything that increases the likelihood of for a patient to develop the disease  (for instance, age is a  great risk factor for most of the malignancies including pancreatic cancer, but it is not a cause.

4.1) Causes of pancreatic cancer:

Veritably, medical experts and scientists don’t know what are the specific reasons behind most pancreatic cancers. One of the possible reasons is affecting DNA ( Deoxyribo-nucleic acid -  the hereditary substance in humans and other  organisms) of cells in the pancreas, which can result in abnormal cell growth causing tumors to form.

4.2) Risk factors of pancreatic cancer:

Risk factors that increase the chances of occurrence  of pancreatic cancer include:

Pancreatitis

Chronic inflammation of pancreas

Diabetes

Diabetes is both a symptom as well as a risk factor. An uncontrolled diabetes invites a lot of malignancies, such as heart disease, kidney disorder as well as cancer of various types including pancreatic cancer.

Family history

Family history of genetic syndromes which can increase cancer risk) that include:

• BRCA- 2 gene -mutation: BRCA-2 are human genes that produce human suppressor proteins. These proteins help repair damaged DNA and therefore, play a key role in ensuring the stability  of each cell’s genetic material .When  these genes are  mutated (or altered) , such that the  protein product is not made or does not function correctly, then cells are more likely to develop additional genetic alterations  that can lead to cancer of various types including pancreatic cancer.
• Lynch syndrome: It is an autosomal dominant genetic condition that stands as a risk for most of the cancers including pancreatic cancer.
• FAMMM: Familial atypical mole malignant melanoma syndrome. It is an inherited genodermatosis characterized by the presence of multiple melanocytic  ’nevi’ and a family history of melanoma having  increased  risk of developing pancreatic cancer and other malignancies.

Smoking

Smoking is an expensive bad habit having no social recognition that exchanges longer life  for earlier death.

Obesity

(It leads to a lot of fatal diseases: high blood pressure, heart disease, diabetes as well as cancers of various types including pancreatic cancer)

Old age

As one ages, risk of developing various malignancies including pancreatic cancer also goes higher.

Recent study: Recent study reveals the fact that the conglomerated effects of smoking, long standing diabetes, poor diet and more importantly, apathy towards physical activity increases the risk of pancreatic cancer beyond the extent of risks invited by any other factor.

5. Endometriosis pain

Endometriosis is one cause of severe menstrual pain. But the pain can also occur due to the non-cancerous growth of muscle tissues of the uterus. Endometriosis pain can also flare up due to other reasons. Pancreatic endometriosis is very rare. The imaging features  are nonspecific  and the definitive diagnosis is  usually established only after surgery. Endometriosis is a fairly uncommon condition (affecting only  5%- 10% women in the reproductive age group). However, extra genital manifestations of endometriosis  occur up to 40%  among the patients with pelvic endometriosis.

6. Types of pancreatic cancer:

There are mainly 2 different types of pancreatic cancers depending on where it affects, causes, risk factors,  symptoms, diagnostic tests and treatments

6.1) Endocrine pancreatic cancer:

Pancreatic NETs (Neuro-endocrine tumors) may be benign (non-cancerous) or malignant (cancerous). When pancreatic NET is   malignant , it is called endocrine pancreatic cancer. It is less common (as compared to exocrine pancreatic cancer).

6.2) Exocrine  pancreatic cancer:

The cancer starts in the ducts of the pancreas. Less often it develops from the cells (which make the pancreatic enzymes). The cancer is usually adeno-carcinomas (which implies a malignant tumor formed from the glandular structures in the epithelial tissue)

Again based on the criteria of spread  as well as malignancy, pancreatic cancer may be divided into following 3 categories:

Resectable:

Resectable pancreatic cancer is  that which is removable by surgery. On imaging tests, the pancreatic cancer appears to have  spread not far off, and the surgeon feels it might be removed.

Unresectable:

In case of unresectable pancreatic cancer, the cancer cells have gone far into major blood vessels on imaging tests, so that tumors can’t be safely removed by surgery.

Metastatic:

‘Metastatic’ is a medical term for cancer in which case the cancer cells have spread to new areas and other organs of the body, so that in such cases also, surgery fails as a cure.

7. Stages of pancreatic cancer:

The stage of any malignant disease including pancreatic cancer, indicates the growth and spread of abnormal cells. In addition, the stage indicates how far the cells have travelled from the place of origin. Hence the treatment of pancreatic cancer  is  largely  influenced  by the  stage it has reached, the spread of the cancer and other factors. On the other hand, the stages are determined by the key  information : tumor size, proximity to lymph nodes and spread to other organs. 

Pancreatic cancers are staged on a scale  0—4 as stated below.

Stage 0 pancreatic cancer

No spread. Pancreatic cancer is confined to top layers of  cells  in the ducts of the  pancreas. The pancreatic cancer is visible neither to the naked eye, nor even on imaging tests.

Stage 1 pancreatic cancer

Local growth. Pancreatic cancer is limited to pancreas and has grown to less  than 2 cm. It is 2 cm (for stage 1-A) and   greater than 2cm (for stage 1- B)

Stage 2 pancreatic cancer

Local spread. Pancreatic cancer has grown over 4 cm and travelled outside the pancreas or spread to nearby lymph nodes. But the cancer has not spread to nearby distant sites.

Stage 3 pancreatic cancer

Wider spread. The cancer cells might have expanded  into the nearby major blood vessels or nerves, but the cancer has not metastasized  to distant sites.

Stage 4 pancreatic cancer

Confirmed spread. Pancreatic cancer has spread to distant organs.

For pancreatic cancer, doctors choose the treatment methods based on imaging studies, surgical findings, specific health problems and general health conditions. Additionally, the stages of pancreatic cancer are an important guide for treatment and classification of patients for clinical trials (clinical trials are research investigations in which people volunteer in new tests, interventions needed to detect, prevent, treat or manage various diseases. Some investigations look at how people respond to a new test or interventions and the side effects that might crop up)

8. Treatment options of pancreatic cancer

8.1) Option one:

After an imaging test , when the doctor feels that the cancer can be removed by surgery (as in case of resectable cancer), then surgery is applied.

8.2) Option two

When cancer has spread to other organs (metastatic), and as such  surgery fails, then the following treatment methods are applied.

Chemotherapy:

Chemotherapy uses special medications to kill cancer cells. It can be delivered as an injection or as an oral pill. In people with inoperable pancreatic cancer , chemo is usually  used to halt the growth of cancer and improve survival.

Radiotherapy:

It applies high energy beams to all cancer cells. It is sometimes given along with chemo. Some medical centers offer newer forms of radiation therapy that target tumors more precisely (such as Cyber knife radiation therapy which is a non-invasive option for cancer patients.  Nano knife radiation therapy is another option which is minimally invasive for patients)

Targeted therapy:

The therapy  targets only cancer cells leaving healthy cells alive. Some targeted therapies (such as Tastuzumab and Cetuximab) may treat the patients with advanced pancreatic cancer. Sometimes they can be combined with chemo. 

Biological therapy:

These treatments are given to prompt the immune system to fight the cancer in the body. They can be used alone or in combination with chemo.

Novel treatments with clinical trials:

Clinical trials are available to test novel treatments for inoperable pancreatic cancer. Being involved in a new clinical trial,  it  could give the patient access to new therapies  (which , otherwise, could not be available).  

Other procedures:

Some procedures can help control specific symptoms (for example,  the doctor may insert a small  stent in the body to relieve symptoms of a blocked bile duct causing nausea and vomiting).

9. Survival rates of pancreatic cancer

Survival rate tells what percentage of people  (with the same type and stage of cancer) are still alive  after diagnosis  for a certain period of time (usually 5 years). Survival rate cannot specifically  predict  in case of a particular pancreatic cancer patient as to how long he will live after diagnosis. But survival rate can give an idea in general,  about how likely  the treatment will be successful for a particular stage.

For a particular stage of Instance, a 5 year survival rate of 70% means that an estimated 70 (out of 100 pancreatic cancer patients) will still remain alive (at least for 5 years after diagnosis). In this connection it needs to be mentioned that survival rates are simply estimates based on samples.

Conclusively, the higher the  stage of pancreatic cancer , the less is the chance to survive (after treatment). On the other hand,  as quality of treatment  improves and the general access to health care services widens , so do survival  rates.

Stage-wise survival rates for pancreatic cancer at least for 5 years after diagnosis

10. Recurrence

Cancers that come back during or after treatment‘ are known as Recurring cancer’ which can’t be operated on as it spreads to other organs of the body. Even after potentially curative surgery, pancreatic cancer can come back months or years after. It may return in the areas  of the pancreas or spread to other parts via the blood or lymph system. When pancreatic cancer recurs, it mostly affects the liver first.

Treatments of recurrence mainly include the following options:

• Palliative surgery or stent placement:  The treatment procedure is applied to bypass  the blocked areas in the duct or small intestine.
• Palliative radiation therapy: It is applied to shrink the tumor.
• Other palliative medical care: The treatment reduces symptoms to relieve pain
• Chemotherapy

11. Prognosis for pancreatic cancer

Prognosis is a guess or forecast regarding the outcome of the treatment. Prognosis of  pancreatic cancer depends to a great extent  on the stage it has reached at the time of diagnosis. Certain other factors (such as chances of recurrence, survival rates and treatment options) also affect prognosis. As compared to earlier stages,  pancreatic cancer (of advanced stage having wider spread) is more fatal and has poorer prognosis.

12. Follow-up care:

Often questions arise to the survivors after treatment of pancreatic cancer about what to do in the next steps so as to live long and stay healthy. For some patients having pancreatic cancer, treatments can remove or destroy the cancer (Exocrine type). Again for some other patients (having pancreatic cancer of neuro-endocrine type) the cancer might come back in other parts of the body. Such patients need to be under constant watch of the doctor with regular treatments (with chemotherapy, radiotherapy or other therapies) to keep the cancer under control or not to deteriorate further at least for the period as long as possible. 

So, learning to live with cancer under the umbrella of defense provided by due care and caution, is quite important. Hence for malignancy like pancreatic cancer, although treatment in some stages may be discontinued, care and nursing must continue and should not end till the end of life. It is therefore essential  to stick to all follow up appointments with the doctor who may ask the patient about any problems felt after the treatment and may apply lab or imaging tests to look for signs of cancer or after- treatment side effects. Some side effects might last for a long time. Again in some other cases, the side effects may not occur immediately after treatment. Therefore, to be on the safe side,  regular visits to the doctor following  the treatment is indispensable. The follow-up care plan prepared by the doctor must convey the following advice:

• A suggested schedule for follow-up exams and tests
• A list of possible long term side effects following the treatment (in addition to: what to watch for/what to do/ when to contact  the doctor)
• A schedule of other tests that might be needed depending on the health effects following treatments of pancreatic cancer.
• Suggestions concerning post treatment diets and physical activity.

13. Key global messages

• Globally, most patients of pancreatic cancer are diagnosed after age 65.
• Only about 10% of pancreatic cancers are considered removable by surgery.
• To a large  extent, pancreatic cancer is considered incurable, although survival rates have been found increasing  globally over the last few decades.
• On average for all stages of pancreatic cancer combined, the survival rate is found 20% (at least for 1 year after diagnosis) and 7% (at least for 5 years after diagnosis)
• Pancreatic cancer is the 4th leading cancer in the western world in the USA.
• Around 3% cancers in USA are pancreatic cancer (source: American Cancer Society)

14. Concluding remark:

In most of the cases, pancreatic cancer can’t be detected until it has spread and travelled to other parts of the body. That is why it is so important to get regular check-ups and discuss with the doctors about the risks and concerns relating to the disease.

In case of most malignancies including pancreatic cancer, age and smoking  are the 2 major risk factors. But  unlike age, smoking is avoidable and in addition, smoking is a greater risk factor (as compared to aging)  and is branded as the “Gateway inviting all malignancies “. Globally, only due to smoking related diseases, in every 10 seconds,1 person dies on average (source: World Health Organization, 2015). Moreover, smoking which has no social recognition anywhere in the world, spoils both money and health (not only of the smoker, but also of  the non-smokers among the family members, friends as well as the office colleagues staying around him who  fall a victim to unhygienic smoke and offensive smell).