Pancreatic Cancer Overview
The pancreas is a crucial organ in human life. It is found in the abdominal cavity, lying horizontally behind the stomach. Apart from releasing digestive enzymes and hormones, it regulates blood sugar through making and releasing hormones such as insulin and glucagon. Pancreatic cancer is a kind of cancer that occurs within the tissues of the pancreas.
Pancreatic cancers are classified into two main types, and these are:
- Exocrine tumors.
- Neuroendocrine tumors, also known as islet cell carcinoma.
The tumor marker for pancreatic cancer is known as carbohydrate antigen (CA) 19-9. This type of protein is released by pancreatic cancer cells and higher than normal levels suggest presence of a tumor.
Methods of Staging / Staging Techniques
Tumor Staging
- This refers to the anatomical extent to which a tumor has spread.
- It is the strongest predictive and prognosticating measure of a malignancy.
- There are two main methods for tumor staging. These are TNM and AJCC.
- TNM staging is utilized for staging of pancreatic cancer. It uses three parameters, which are:
- Tumour size (T)
- Regional nodal metastasis (N)
- Distant metastasis (M)
- AJCC is an acronym for American Joint Committee on Cancer.
Pancreatic Cancer Stages
- Cancer stage gives a description of the extent of the cancer in the human body.
- 5 stages are used for pancreatic cancer, they are:
- Stage 0 (carcinoma in situ).
- Stage I (also known as stage 1) pancreatic cancer.
- Stage II (also known as stage 2) pancreatic cancer.
- Stage III (also known as stage 3) pancreatic cancer.
- Stage IV (also known as stage 4) pancreatic cancer.
Stage 0 (carcinoma in situ)
The lining of the pancreas has abnormal cells, which may become cancerous and spread into surrounding normal tissues.
Stage I (also known as stage 1) pancreatic cancer
- Cancer is found in the pancreas only.
- Subdivisions for stage I are IA and IB. In stage IA, the tumor is less than or equal to 2 centimeters whereas in stage IB the length of the tumor is anywhere between 2 and 4 centimeters.
Stage II (also known as stage 2) pancreatic cancer
Based on the size of the tumor and the location into which the cancer has spread, stage II can be divided into stage IIA (tumor is greater than 4 centimeters) and stage IIB (sizeable tumor- any size- that has spread to one, two or three nearby lymph nodes).
Stage III (also known as stage 3) pancreatic cancer
- The pancreatic tumor is any size.
- It has spread to:
- 4 or more surrounding lymph nodes.
- Major blood vessels around the pancreas.
Stage IV (also known as stage 4) pancreatic cancer
- It is also called metastatic pancreatic cancer.
- The tumor is any size.
- It has spread (or metastasized) to other body parts such as the liver and the lung.
- Metastasis happens when the pancreatic tumor cells travel from the pancreas through blood vessels or lymph vessels to distant parts or organs.
- When this occurs, the metastatic tumor is the same kind of tumor as the primary tumor. For example, if metastasis occurs to the lung, it will be metastatic pancreatic cancer and not lung cancer.
Resectable Versus Unresectable Tumors
Clinicians have ranked pancreatic tumors into 4 different classes. These are:
Resectable pancreatic tumor
- The tumor is only found in the pancreas.
- There is no involvement of blood vessels located nearby or other close organs.
Borderline resectable pancreatic tumor
- The tumor is in the pancreas.
- Nearby blood vessels are involved. However, it can be removed surgically but there is a high chance that all of the cancer cells will not be gotten rid of.
Locally advanced pancreatic tumor
- The tumor is in the pancreas.
- Closely surrounding blood vessels are significantly involved.
- It is not safe to surgically remove the tumor.
Metastatic pancreatic tumor
- The tumor spreads to anatomically distant areas like the liver and lungs.
- It might as well have spread to organs, tissues and lymph nodes around the pancreas.
- Such tumors cannot be completely removed through surgery.