8 min

Meanwhile, having seen the basics about cancer in the previous article let’s take a look at some of the most common types of cancer, their occurrence, the disease process, preventive measures, and treatment in the upcoming articles. To begin with, let’s have a look at colorectal and pancreatic cancer. In addition, there are lots of types of cancers that can occur in humans. Further, some of the most common types of cancer are,

  • Cancer of the bladder
  • Breast cancer
  • Colon and rectal cancer
  • Endometrial cancers
  • Cancers of the kidney, liver, and lungs
  • Leukemia
  • Melanoma (skin)
  • Pancreatic cancer
  • Prostate cancer
  • Thyroid cancers
  • Non – Hodgkin’s lymphoma


In todays world the second most common cancers are the cancers of the colon and rectum.


Meanwhile, more than 1.9 million new cases reported ( according to WHO). Number of deaths reported : 935,000 .

It is one of the most prevalent and preventable forms of cancer. Most importantly, colorectal cancer has a tendency to occur more in males than in females.

Age seems to play a major role in the occurrence of colon cancer. It’s is pretty uncommon in younger age groups. The incidence of colon cancer is more around 50 years of age.


The digestive tract of our body span, around 10 meters (33 feet) on average. However, the last 1.5 meters (4.9 feet) of this tract is what we call the colon. The cells of this part constantly renew themselves. This is a normal physiological process. Sometimes, the genes that are responsible for the moderation of this process. If they go awry they lead to an abnormal and excess growth of the new cells. Therefore, this results in small growth or abnormal clumps of cells termed polyps.

The polyps are generally harmless. But some of these polyps might turn cancerous when their cells begin to grow and divide rapidly which in turn project into the colon transforming into colon cancer.


Subsequently, the above-explained mechanism is a very slow process and it may take about 10 years on average for a small polyp to grow and develop into a cancerous one.

Apart from this, the exact mechanism for the development of colon cancer in a person with existent polyps is still unknown. But, colon cancer, in general, involves the activation of certain oncogenes (cancer-causing genes) in the polyp and the loss of tumor-suppressor genes that are usually responsible for keeping the cancer cells in check. Most importantly, cells have proto-oncogene that helps them grow. When a proto-oncogene mutates, or there are two or more copies of it, there is a high probability that these cells might grow out of control.

This is one of the mechanisms of how colon cancer develops from a state of small polyp to full-grown cancer.

In certain scenarios, the lining of the colon tends to rupture and these cancerous cells are carried away through the blood vessels and the lymph. Seeding of the growth of new and multiple tumors occurs due to these cancerous cells. This is the metastasis of colon cancer.


There are no known causes for colon cancer. A lot of factors tend to play important roles in the development of cancer in these patients. Some of these factors include,

  • A combination of both environmental and inherited genetic factors
  • People with a family history of colon cancer and certain inflammatory condition like Crohn’s disease, ulcerative colitis, etc.
  • Racially, the African-Americans.
  • Patients, who are above the age of 50
  • People with certain inherited genetic syndromes


Colon cancer usually doesn’t show up during the initial stages. Clinical presentations and the symptoms explained by the patient play an important role in diagnosing cancers of the colon.

  • Most patients with colon cancer present with gastrointestinal bleeding. (could be rectal)
  • They might present with potentially dark tarry stools which are termed melena. (fecal occult bleeding)
  • Anemia is a common manifestation. (koilonychia- spoon-like, brittle nail bed with furrowed longitudinal lines)
  • Abdominal pain is quite common in these patients.
  • CAT (Computerized Axial Tomography) scanning of the abdomen help us to detect masses in the colon
  • It is important to understand that this is not a confirmatory test. To confirm the presence of the tumor one should always get a biopsy of the polyp or the outgrowth. The pathologists can confirm the malignancy of the tumor. Evaluation and diagnosing preceeds staging.
  • CAT scans of abdomen, pelvic region, chest


The most common and mainstay of treatment include removal of the polyps through colonoscopy.

The offending polyps are detected and removed using this method . A colonoscopy involves a long, thin, flexible tube that’s fitted with a video camera and light source at the end of the tube, which is placed internally to examine the colon for polyps.

Moreover, polypectomy is performed on the lining of the colon if polyps are present. Meanwhile it involves the removal of the polyps from the colonic wall and this procedure serves both purposes of testing and removal of the polyps.

If the polyps are too large to remove through routine colonoscopy then the next line of option is performing surgery to remove the polyps from the colon.

If cancer has breached the lining of the colon and has spread to distant organs chemotherapy or treatment through anti-cancerous drugs is the next line of treatment and therefore, chemotherapy avoids further spread of cancer.


Leading a healthy lifestyle is a very important step in preventing cancer. Some of them include

  • Reducing junk food and fast food
  • Avoiding the habit of smoking cigarettes
  • Secondly, following a healthy diet
  • Being physically active and maintaining a healthy weight
  • Likewise, access to healthcare and regular screenings at crucial times of life are some of the best ways to prevent colon cancer.

Let’s take a look at the second type of cancer, ‘the pancreatic cancer’.


The pancreas is one of the most important digestive organs. They are located right behind the stomach. This organ produces a mixture of water, sodium bicarbonate, and certain special digestive enzymes to absorb nutrients from the food we eat and neutralize the stomach’s acidity and hence this organ is very essential to keep us in a good shape and save us from malnutrition. The pancreas is divided into a head, body, and tail based on its appearance. This organ is made up of two main cell types

  • The exocrine cells, and the
  • The endocrine cells (clustered into small groups which are termed as the ‘islets of Langerhans)

The exocrine cells of the pancreas mainly produce enzymes into a small tube-like structure called the duct. These enzymes travel through the duct and empty into the small intestine and help in the digestion of the food we consume.

The endocrine cells, on the other hand, produce the two most important hormones the ‘insulin’ and ‘glucagon’ which are released periodically into our bloodstream meanwhile these hormones, help us control the blood sugar level physiologically.

How pancreatic cancer occurs?

Pancreatic cancer starts as mutations (a variation from the normal cell structure) of pancreatic cells causing them to grow rapidly and in an uncontrolled way. The mutated cells tend to clump together to form tumors, which then interferes with normal pancreatic function. Most pancreatic tumors form in the duct and they are termed as ‘adenocarcinoma’ or ‘ductal adenocarcinoma’ (Exocrine tumors)- almost 90% of pancreatic cancers. Adeno – cells lining the inside of organs mostly secretory or glandular, carcinoma – cancerous. 

Exocrine tumours are less common compared to endocrine type.

Certain types of tumors that are rare include,

Lymphomas (in the lymph nodes)


Acinar cancer (tumor growth within the acinar cells)

Solid and pseudocapillary cancer

Diagnosing pancreatic cancer……

Pancreatic cancer also tends to show up during the later stages of cancer. Some physical manifestations are common but they are often mistaken for other conditions.

The patient might complaint of,

  • Decreased appetite, weight loss, back pain and sometimes jaundice.

Apart from these to diagnose pancreatic cancer properly, the doctor might order some of these tests

An abdominal ultrasound scan:

This test is done mainly to check for dilations in the blood vessels. In addition, to check for the head of the pancreas which may appear massive in cases of pancreatic cancer. Gastric accumulation in the bowels and oftentimes all these are accompanied by jaundice.

Contrast enhanced Computed Tomography scans:

A contrast CT is ordered to visualize the pancreas and in case of the presence of a tumor, the relationship or proximity of the tumor to the blood vessels is checked and also to find out whether the tumor is operable or not. Screening for metastatic diseases is also done as usual. The underlying abdominal cavity and the lungs are also visualized

Endoscopic ultrasound :

This method of diagnosis uses a probe to visualize the tissues and also to procure some tissue for biopsy.

Treating pancreatic tumors……

The treatment basically depends upon the following, namely

  • The type of pancreatic cell
  • Location of the cancer
  • Stage of the cancer

The most common modalities of treating pancreatic cancer includes,

  • Surgery
  • Radiation
  • Chemotherapy
  • Targeted therapy
  • A combination of the above said procedures

Surgery includes three main options namely,

A whipple procedure aka pancreatoduodenectomy.

In this procedure, the surgeon might remove the head of the pancreas, the gallbladder, and portions of the common bile duct, small intestine, and stomach. Though this procedure involves the removal of larger portions of the digestive system the remaining healthy parts are re-arranged in such a way as to aid in normal digestion.

Total pancreatectomy

In this procedure, the surgeon removes the entire pancreas, gallbladder, the common bile duct, spleen, and surrounding lymph nodes. A small portion of the stomach and the small intestine are also removed if required.

Distal pancreatectomy

This procedure involves the removal of the body and tail of the pancreas as well as the spleen.


Radiation as we already saw, uses high-energy X-ray waves to kill cancer cells. Again, there are two types of radiation therapy,

External beam radiation therapy:

The source of radiation is present outside the body and this source treats the cancer.

Brachytherapy (Internal radiation therapy):

On the other hand, in brachytherapy, the radiation originates from within the body and the Radioactive pellets implanted treat the cancer.


As we already saw in the previous article, chemotherapy is nothing but the use of certain anti-cancerous drugs to treat cancer. These drugs work by killing away the cancerous cells. or preventing further growth. Therefore, the types of chemotherapy include,


Meanwhile in this method, the chemotherapeutic drugs are delivered through intravenous lines which travel through the bloodstream and reach the cancerous cells and destroy them.


This involves injecting the drug around the arteries that surround the tumor thus allowing direct delivery to the cancerous cells.


Meanwhile, targeted therapy focuses on specific abnormalities of the cancer cells. For example, certain forms of targeted therapy involve blocking the path of chemical signals that initiate cell growth and division. Thus, this avoids further complications by blocking the growth of the tumor.


Having seen about colorectal and pancreatic tumor, consequently, we could totally get is diagnosis or catching up the tumor in the early stages is not quite a simple task. Hence to avoid all the agony of the aftermath, it is wise to do regular screenings and be mindful of your symptoms. It is equally essential to treat your guts in a good manner but avoiding bad food and taking healthy ones in a regular manner.  

Like it? Share with your friends!

Dr Kavitha M

I am an undergraduate degree holder in dentistry. I have a great interest in music and reading. I am a linguaphile. My areas of interest lie in psychology, medical imaging, diagnostics, and oncology. I am a person who focuses more on the emerging areas of forensics.


Your email address will not be published. Required fields are marked *