Pancreatic Cancer: Abnormal cell growth in Pancreas
Pancreatic cancer is a condition caused due to abnormal growth and division of mutated pancreatic cells. The pancreatic cells start functioning abnormally. This causes the mutated cells to build up and form a mass known as a tumor. A tumor that has cancerous cells becomes malignant.
Pancreatic ductal adenocarcinoma is the most common type of pancreatic cancer. It begins in the cells that line the ducts that carry the digestive enzymes out of the pancreas. It is challenging to detect pancreatic cancer in the early stages as there are no symptoms manifested in this stage. By the time the symptoms appear, cancer must have reached its advanced stages.
In India, the incidence of pancreatic cancer is low. Studies have revealed that the incidence of pancreatic cancer in Indian men is around 0.5 to 2.4 per 100,000 males, while that of Indian women is around 0.2 to 1.8 per 100,000 females. Within the country, the urban male population residing in India’s Western and northern parts is more prone to developing this cancer than the others.
Pancreatic Cancer Types:
The types mainly depend on their site of origin of pancreatic cancer. It mostly describes whether cancer began in the endocrine part; or the pancreas’ exocrine part. Rarely do other pancreatic cancer types originate in the pancreas, like sarcoma or lymphoma. Pancreatic cancer is broadly divided into :
- Exocrine tumor – It is the most common type of pancreatic cancer. It can be either malignant or benign. Most of these are either cysts or benign tumors, known as cystadenomas. Adenocarcinoma is the most common type of exocrine tumor of the pancreas that begins in the gland cells in the pancreatic ducts. The other most common type would be acinar cell carcinoma in the pancreatic enzyme cells. Ampullary cancer starts where the bile duct and pancreatic duct meet the duodenum. Adenosquamous carcinoma, squamous cell carcinoma, and giant cell carcinomas are also exocrine tumors of the pancreas.
- Endocrine tumor – An endocrine tumor is found in about 7-8% of people having pancreatic cancer. It is also known as a pancreatic neuroendocrine tumor and affects the pancreas’ endocrine functions. It usually originates in the hormone-producing cells of the pancreas and is subdivided into :
- Insulinomas – These begin in the insulin-producing beta cells of the pancreas.
- Glucagonomas – This is due to the overproduction of glucagon by the pancreatic alpha cells and is often accompanied by a rash.
- Gastrinoma is a tumor that originates from the G cells of the duodenum, pancreas, and stomach. This tumor causes hypersecretion of hydrochloric acid by the G cells and induces ulcers.
- Somatostatinoma – It increases the level of somatostatin secreted by the pancreas’ delta cells, which in turn inhibits the pancreatic and gastrointestinal hormones.
- VIPoma – It originates from the non-beta islet cells of the pancreas. It causes the overproduction of Vasoactive Intestinal Peptide or VIP.
Stages of Pancreatic Cancer
The different stages of pancreatic cancer are :
- Stage 0 – This is also known as cancer in situ and refers to the stage in which cancer has not yet grown outside the duct it had originated.
- Stage I – The tumor is localized to the pancreas and has not spread to the nearby lymph nodes or distant organs.
- Stage II – The tumor is around 4 cm in size, localized to the pancreas or just beyond it but has not yet spread outside the pancreas.
- Stage III – The tumor has spread to 4 or more regional lymph nodes and nearby arteries and veins but not the other parts of the body.
- Stage IV- The tumor has metastasized to other parts of the body.
The other most common way to classify pancreatic tumor is based on its extent of spread and treatment by surgery as follows :
- Resectable – This type of cancer can be removed by surgery immediately after diagnosis.
- Borderline resectable – Surgery cannot be done immediately after diagnosis in this category. It is still feasible if the tumor is shrunk using chemotherapy and radiation therapy beforehand.
- Locally advanced – In this category, cancer has spread to the nearby organs and lymph nodes. Hence, surgery is unconventional for treating it.
- Metastatic – Cancer has spread to distant organs like the liver, lungs, and other abdomen parts.
Pancreatic Cancer Symptoms:
The symptoms are most evident in the advanced stage when the tumor has grown very large and spread outside the pancreas. The symptoms are as follows :
- Pain in the upper quadrant of the abdomen that radiates towards the back
- Loss of appetite
- Unexplained loss of weight
- Blood clots
- Jaundice or icterus if there is blockage of the bile duct
- Due to pressure on the abdomen, there is persistent nausea and vomiting.
- Rarely diabetes
- Depression and anxiety
- Light-colored or greasy stool
- Itchy skin
- Gallbladder or liver enlargement
- A blood clot in a large vein, especially in the leg (deep vein thrombosis)
The exact cause is unknown, but doctors assume that consuming tobacco increases the risk of developing this condition. Genetics is also found to play a significant role in inducing the pancreas’ uncontrolled cell growth. Most of the genetic changes that cause this cancer are sporadic and get developed by chance after a person is born. Only around 10 % of pancreatic cancers are inherited. The mutations that are passed on in families are called germline mutations.
which are the Risk Factors?
The following factors increase the risk of developing pancreatic cancer:
- Tobacco – Smoking tobacco increases the risk of developing pancreatic cancer by two to three times.
- Alcohol – Excessive alcohol consumption leads to health conditions like chronic pancreatitis, liver cirrhosis, and these are known to increase the risk.
- Obesity – Obese and overweight people are more prone to developing pancreatic cancer than non-obese people.
- Age – Older adults are at higher risk, which increases with age. Adults above 55 years of age are most often diagnosed with pancreatic cancer. Men are more often affected when compared to women.
- Family history – It two or more first-degree relatives of the individual being diagnosed with pancreatic cancer. The chances of developing pancreatic cancer are increased in the individual.
- Genetics – Family history of genetic disorders like Lynch syndrome, hereditary pancreatitis, hereditary breast, ovarian cancer syndrome, familial malignant melanoma, and pancreatic cancer also increase cancer risk.
- Diet and physical activity – People who do not exercise regularly and those who eat food rich in fat are more likely to develop pancreatic cancer.
- Diabetes – People who have long-standing type 2 diabetes are twice as likely to develop pancreatic cancer as non-diabetic patients.
- Race/ethnicity – African-American people at a higher risk than Asian, Hispanic, or White people.
- Other conditions – People with chronic pancreatitis, hepatitis B infection, cirrhosis, and H.pylori infections are at a higher risk.
- Exposure to certain chemicals – People who work with pesticides and chemicals like benzenes, dyes, and petrochemicals are more prone to developing pancreatic cancer.
Diagnosis: how to diagnose Pancreatic Cancer?
After checking the patient’s medical history and family history, the doctor suggests dome general tests to confirm his suspicions. These are as follows :
Physical examination – The patient is examined for any jaundice signs such as yellow eyes, skin, or tongue. This exam detects any abnormality in the abdomen, but this is rarely seen in pancreatic cancer cases. The doctor also detects any abnormal buildup of fluid in the abdomen. This is called ascites and is a sign of pancreatic cancer.
Blood tests – Abnormal bilirubin levels and other blood substances are detected by using blood tests. Since the pancreatic tumor blocks the bile duct, bilirubin levels reach higher values in people with this cancer. However, this does not confirm pancreatic cancer as non-cancerous conditions like hepatitis, gallstones, and mononucleosis are also known to elevate the bilirubin levels.
CA 19-9 test – Carbohydrate antigen 19-9 (CA 19-9) is a tumor marker produced by tumors and present in the blood. This antigen level is increased in most pancreatic cancer patients. It can be used to diagnose and not confirm the presence of pancreatic cancer as the levels of this marker are high in other conditions like liver cancer, colorectal cancer, liver cirrhosis, and non-cancerous blockage of the liver.
Computed tomography (CT) scan – This helps determine the tumor’s size and location and facilitates the visualization of the tumor by providing a 3-dimensional image of the body’s internal organs. Sometimes, a contrast medium (dye) is given intravenously before the test to detect the exact location of the tumor concerning the nearby organs and also to determine if the tumor needs to be removed by surgery or not.
Positron emission tomography (PET) scan – A small amount of radioactive sugar called a tracer accumulates at the cancer cells is injected into the patient’s body. A scanner is then used to detect and produce images of the tracer’s locations in the body.
Ultrasound – A transabdominal ultrasound device is used to get images of the pancreas and the surrounding tissues using sound waves. In an endoscopic ultrasound, a thin, lighted tube is passed through the patient’s mouth, into his stomach, and small intestine. This tube is used for taking pictures of the pancreas. This ultrasound is done while the patient is sedated.
Endoscopic retrograde cholangiopancreatography (ERCP) – An endoscope inserted into the mouth and stomach until the small intestine. A catheter is then passed to reach the bile duct and pancreatic ducts. A dye is injected via this catheter into the ducts, and x-rays are then taken to identify if the duct is compressed or narrowed. Biopsies can also be done using this method.
Percutaneous transhepatic cholangiography is an x-ray procedure in which a thin needle is inserted through the skin to reach the liver. A dye is injected via this needle, which helps identify if the bile duct is blocked or in the x-ray.
Biopsy – A small amount of the pancreatic tissue is taken by either fine-needle aspiration or core needle biopsy. This is then sent to a pathologist who examines these cells under a microscope to confirm pancreatic cancer. If cancer has metastasized, then biopsies are done at more than one location, such as the liver.
Molecular testing of the tumor – Mutations of the BRCA gene, specific genetic alterations like NTRK fusion, high microsatellite instability, and defective mismatch repair are detected by this method. This is done to determine treatment options by the doctors.
Pancreatic Cancer Treatment :
The following treatment options are most often used in patients with pancreatic cancer :
Surgery is not done in all patients as the disease is often diagnosed after it has metastasized in most cases. It is combined with systemic therapy and radiation therapy. It involves removing the pancreas and a part of the healthy tissue. The common surgical procedures used are :
Laparoscopy – Several small incisions are made in the abdomen. A tiny camera is placed to detect the tumor’s spread in the body. It is usually not recommended if cancer has spread to distant organs.
Surgery to remove the tumor – It is done to remove the tumor that is localized to the pancreas. Whipple procedure, distal pancreatectomy, and total pancreatectomy are the commonly adopted surgical treatment options for removing tumors located at the head, tail, or throughout the pancreas. READ MORE Types of Cancer Surgery
Radiation therapy – High energy x-ray or other particles like protons are used to destroy the cancer cells. The most commonly recommended procedure is external radiation therapy that achieves this by using a machine. It is usually given over 5 to 6 weeks in total.
Chemotherapy – Medications like oxaliplatin, capecitabine, erlotinib, gemcitabine, and irinotecan are given for some cycles over a set period. This is then followed by a rest period in between, which comprises the chemotherapy regimen or schedule. It helps to destroy the cancer cells and keep them from growing.
Targeted therapy – Specific cancer genes, proteins, and receptors are targeted in this therapy. It involves the use of drugs like erlotinib, larotrectinib, and olaparib. These target the epidermal growth factor receptors, the BRCA mutation, and the NTRK fusion, respectively, to facilitate cancer cells’ destruction. They are effective in treating metastatic and advanced pancreatic cancer.
Immunotherapy – This therapy aims at boosting the body’s natural defense against cancer cells. Commonly used drugs include pembrolizumab, an anti-PD-1 antibody. This is an immune checkpoint inhibitor and is often used for treating pancreatic cancer.
- Obstruction of bowels.
- Loss of weight
- Metastasis of cancer.
- Pain in the abdomen
- Jaundice due to obstruction of the bile duct.
Lifestyle changes for prevention
- Avoid smoking cigarettes.
- Avoid tobacco products
- Avoid excessive consumption of alcohol.
- Eat healthy food.
- Avoid fatty and oily food.
- Exercise regularly.
1. Is it curable?
Pancreatic cancer is curable if diagnosed in the early stages, but this is very difficult as no symptoms manifest during this stage. Suppose cancer has spread to the other parts of the body, as in stage IV cancer. In that case, complete recovery chances are greatly reduced, but cancer can be managed using palliative care.
2. What are the survival chances of pancreatic cancer?
The 5- year survival rate for pancreatic cancer is 37 % when the cancer is detected in the early stages. At the same time, it is confined to the pancreas. However, when it has spread to the surrounding tissues and organs, the survival rates drop to 12 %.
3. What is the cost of treatment for pancreatic cancer in India?
The average cost of pancreatic cancer surgery is around 7.5 to 12 lakhs, while radiation therapy costs around 1.5 to 3 lakhs. The cost of chemotherapy per cycle ranges from Rs.50,000 to 2 lakhs.
4. What hospitals to get treatment in India?
Read more about hospitals treating cancer- Cancer Hospitals from India
5. Is pancreatic cancer hereditary?
Less than 10 % of the world’s pancreatic cancer cases are hereditary. Lynch syndrome and hereditary breast and ovarian cancer syndrome are two inherited syndromes known to increase pancreatic cancer risk. These syndromes are due to genetic mutations and are passed on in the family.
Other cancer-related articles:
- Cancer: all you need to know about the Malady
- Types of Pancreatic Cancer
- Cancer Patients and Emotional Health
- Cancer Hospitals from India
- Pancreatic Cancer key points
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