Colon Cancer

What is Colon Cancer?

Colon cancer, also known as bowel cancer or colorectal cancer or cancer of the bowel, is the cancer of considerable intestine (lower part of the digestive system). Majority of colon cancer cases start as small and non-cancerous cluster of the cells known as adenomatous. After a certain course of time, these polyps become colon cancers.

Types of Colon Cancer

Adenocarcinoma is treated as the most common type of colon cancer. This type of colon cancer begins in the inner layer that advance deep into the other layers. Adenocarcinoma can be further classify into two subtypes that include –

Signet Ring Cell Adenocarcinoma

Mucinous Adenocarcinoma

Other Types of Colon Cancer

Gastrointestinal Stromal Tumors: This is treated as a rare type of colon cancer that begins in a cell found in the gastrointestinal tract covering known as interstitial cells of Cajal (ICCs). These type of tumors are classified as sarcomas that comprise cartilage, fat, bones, blood vessels, deep skin tissues, muscle and nerves.

Squamous Cell Carcinomas: Certain portions of the gastrointestinal expanse such as the end of the anus and the upper part of the esophagus are lined with squamous cells. Squamous cell carcinomas are those cancers that begin in these cells.

Leiomyosarcomas: This type of cancer typically means- cancer of smooth muscle. This is treated as a rare type that account for only 0.1% of all colon cancer cases.

Gastrointestinal Carcinoid Tumors: This type of colon cancer is treated as a slow-growing cancer that advances in the neuroendocrine cell in the GI tract lining.

Melanomas: This type is primarily associated with skin but can also appear anywhere that introduce recturm or colon.

Primary Colorectal Lymphomas: The cancers that advance in the lymphatic system of cells (lymphocytes) are known as lymphomas. Primary colorectal lymphomas establish in the later stages of life and are more generally seen in men as compared to women.

Causes of Colon Cancer

The irresistible success of cells that do not die motivation cancer. There is a normal cycle of growth, distribution and death in case of ordinary cells but colon cancer do not maturity this type of normal cycle and progress to grow and divide. There are no as such known causes of colon cancer.

Symptoms of Colon Cancer

The early symptoms of colon cancer include –

Unexplained weight loss

Bleeding from the rectum or blood in the stools

Abdominal pain

Change in normal bowel habits that continue for more than 3 weeks including passing of stools more frequently, diarrhea or constipation

Sometimes bleeding happens when the colon cancer improvement. Gradually, there will be not enough red blood cells in the body that is called as anemia. Following are some of the symptoms of anemia –

Breathlessness

Fatigue

Also obstruction is caused by the colon cancer that include following symptoms –

Vomiting

A feeling of bloating, especially near the belly button

Constipation

Abdominal pain

Stages of Colon Cancer

Stage 1: In the first stage, cancer has not spread further than the original tumor.

Stage 2: The second stage is marked by the growth of tumors through the bowel wall that are close to the tissues. However, this growth has not spread to any part of the body.

Stage 3: In the third stage, there are tumor cells close to the lymph nodes.

Stage 4: The last stage is marked by the spread of the tumor to other parts of the body.

Diagnosis of Colon Cancer

A number of tests are performed for diagnosing colon cancer that include –

Carcinoembryonic Antigen (CEA) Assay: CEA levels in the blood are consistent in this test. The normal as well as cancer cells release CEA in the bloodstream. When these CEA is found in large amounts then it demonstrates colon cancer.

Proctoscopy: A proctoscope (a thin and tube-like instrument having light and lens for viewing) is inserted into the rectum in this rectum test. Sometimes removal of the tissue is also done by using a tool in order to analysis the existence of a cancer by examining under a microscope.

Physical Examination and History: This is done for examining the general signs of health and also for seeing any expression of disease that may include lumps. Proper appraisal of the history of a patient is done that include past illnesses and treatments taken.

Colonoscopy: This test is executed for viewing the colon and rectum from within in order to see the existence of cancer, polyps or abnormal areas.

Digital Rectal Exam (DRE): This is treated as a test of the rectum. The injection of the gloved and grease finger is done into the lower part of the rectum for viewing the existence of lumps. Vagina is examined in case of women.

Biopsy: The signs of cancer are checked by removing tissues or cells that are then examined under a microscope. The removal of tissue at the time of surgery is helpful in checking the gene alteration in a patient that is answerable for causing HNPCC. The other two tests include –

Immunohistochemistry Study: Certain antigens are checked by using some material such as radioisotope, dye or an antibody and they are then added to a tissue sample.

Reverse-Transcription Polymerase Chain Reaction (RT-PCR) Test: Function of genes or the changes in the organization in a tissue sample are examined by using certain types of chemicals.

Certain other tests are also appropriate for finding the cancer cells that have advance inside the rectum and colon or conceivably to other body parts that include –

Carcinoembryonic Antigen (CEA) Assay

Chest x-ray

Positron Emission Tomography Scan (PET)

CT scan

Endoscopic Ultrasound (EUS)

Magnetic Resonance Imaging (MRI)

Treatment of Colon Cancer

There are six treatment options for colon cancer that include –
Targeted Therapy: Certain substances and drugs are used by the conduct therapy in order to target particular cancer cells without causing any harm to nearby normal cells. The two types of targeted therapy include –

Angiogenesis Inhibitors: This helps in stopping the growth of new blood vessels which tumors need to grow.

Monoclonal Antibodies: These antibodies are prepared in the laboratory with the help of a single type of immune system. Certain substances can be identified by these antibodies that are on the cancer cells or it also indentifies certain normal material that is helping in the expansion of cancer cells. These antibodies then attach themselves with the object for destroying cancer cells and also avoid them from growing.

Chemotherapy: Certain types of drugs are used for stopping the advance of cancer cells or for destroying the cancer cells. The needle of this medicine is done into a vein from where they enter the bloodstream and they then tour through the integrated body.

Radiation Therapy: High-energy beams are used for destroying cancer cells. intramural radiation and extraneous emission are the two types of emission analysis. A radioactive material that is sealed in catheters, needles wires or seeds is placed close to the cancer in the case of constitutional radiation. On the other hand, linear accelerators outside the body are used for sending radiation to the cancer in the case of extraneous radiation. The type of radiation depends on the moment and type of the cancer.

Surgery: The surgical method associate the elimination of afflicted segment with acceptable margins, neighboring lymph nodes and tissue. Following are some of the types of surgeries performed –

Pelvic Exenteration: The expulsion of lower rectum, bladder and colon are done when the cancer has increase to disparate organs nearby the rectum. In the case of women, nearby lymph nodes, vagina, ovaries and cervix are removed. The prostate is removed in the case of men. For flowing the urine and stool out of the body, artificial openings are made in order to assemble them in a bag.

Polypectomy: During a colonoscopy, a polyp is detached if the cancer is found indoors a polyp.

Resection: The removal of nearby healthful tissue and a category of the rectum having cancer is done when the cancer has advance to the wall of the rectum.

Local Excision: A small amount of nearby healthy tissue and the cancer is removed when the cancer has spread to the inside surface of the rectum and also has not escalation into the rectum wall.

Sometimes chemotherapy or radiation therapy is administer after surgery in order to shrink the tumor. This makes the removal of the tumor easy while together lessening the problems combine with bowel control after surgery. Neoadjuvant therapy is the name given to the treatment that is given before the surgery.