Types of Colon Cancer
Colorectal carcinoma is one of the most common neoplasms in older adults, which can appear in any segment of the large intestine. This pathology has multiple forms of presentation, which is why there are different types of colon cancer. Colonic tumors have their own characteristics, which allow them to be differentiated from one another.
Intestinal neoplasms are one of the most frequent cancers today, being the third cause of cancer worldwide according to some studies. Most of these tumors present as adenocarcinomas, however, they can vary depending on the cell from which they originate.
Histological types of colon cancer
Different colorectal tumors differ from each other according to the cells that make them up and the histological patterns observed in the microscope study. In this regard, it’s possible to find any of the following tumors in patients affected by the disease.
Adenocarcinoma
Adenocarcinomas are malignant neoplasms that derive from epithelial cells, they originate in the columnar cells of the mucous layer of the colon and rectum. The American Society Against Cancer establishes that they’re found in up to 96% of cases, being the most common tumors.
Most colon adenocarcinomas develop from a pre-existing intestinal polyp, which becomes malignant over time. The appearance of these tumors occurs sporadically, being related to various risk factors such as age and gastrointestinal diseases such as ulcerative colitis.
In general terms, the prognosis for this type of colon cancer is good as long as it’s diagnosed in the early stages. However, adenocarcinomas can have multiple forms of histologic presentation, some of which have a poor prognosis. In this regard, colon adenocarcinomas can be divided as follows:
- Signet ring cell carcinoma
- Small cell carcinoma
- Mucinous adenocarcinoma
- Medullary carcinoma
- Undifferentiated carcinoma
The most aggressive carcinomas on the list mentioned are signet ring cell and undifferentiated. Fortunately, colon cancer treatment is the same in most cases. In this way, it’s possible to use surgical procedures, chemotherapy, and radiation therapy.
Carcinoid tumors
Carcinoid tumors or neuroendocrine tumors are one of the less common types of colon cancer. They originate from a special type of cell called neuroendocrine cells. This group of cells is responsible for the secretion of hormones and the control of the gastrointestinal muscles.
Multiple studies show that these neoplasms are more common in the rectum, although they can also appear in other portions of the intestine such as the cecum, sigmoid, and ascending colon. At the same time, carcinoid tumors can be divided into 3 different grades, which will determine the aggressiveness of the tumor and its ability to metastasize.
Grade 1 and 2 neuroendocrine tumors are slow growing, while grade 3 are fast-growing and can metastasize. Unfortunately, the symptoms of this colon cancer are very subtle, predominantly abdominal pain and weight loss without apparent cause.
Gastrointestinal stromal tumors
Gastrointestinal stromal tumor is a rare type of cancer, which originates from a group of cells called interstitial cells of Cajal. These lumps can be found anywhere in the intestine and are very rare in the colon.
The frequency of these tumors is very low and they represent less than 3% of all gastrointestinal tumors according to multiple studies. They differ from other neoplasms due to their ability to produce special receptors for the enzyme tyrosine kinase.
In general terms, these tumors are usually benign, although some can become malignant, especially when they’re larger than 5 centimeters. Cancers originating from these tumors are very aggressive, grow rapidly, and metastasize to the liver and peritoneum with great ease.
Lymphomas
Lymphomas are neoplasms that originate in the body’s lymphatic system, and most often appear in the lymph nodes. On some occasions, they have an extranodal location at the level of the lungs, the skeleton, or the gastrointestinal system, where non-Hodgkin’s lymphoma is the most frequently observed type.
Gastrointestinal lymphomas are very rare tumors and represent between 1% and 3% of all gastrointestinal tumors, according to research. They’re located in the stomach more frequently, although they can also appear in the colon or small intestine.
The appearance of these types of colon cancer is related to other gastrointestinal diseases such as celiac disease and Epstein-Barr virus infection. Fortunately, these tumors have a slow evolution and present symptoms similar to those presented in cases of adenocarcinomas.
Sarcomas
Sarcomas are tumors that originate in the soft tissue of the organs, so they can appear from blood vessels or muscle cells. They can be located in any area of the body, although their location in the gastrointestinal system is rare.
Some retrospective studies show that only 433 cases of colon sarcomas were detected between 1998 and 2012, making it the rarest of all. They appear more frequently in young people and are usually larger when compared to adenocarcinomas.
Unfortunately, the disease is usually detected in advanced stages in most cases. Also, people with these tumors have a much shorter 5-year life expectancy than other types of colon cancer.
Multiple forms of presentation for the same disease
Colon cancer can manifest itself in different ways depending on the cells that give rise to the tumor. The most common form of presentation of all is adenocarcinoma, which can have multiple cell patterns that confer specific characteristics.
Other tumors such as sarcomas, carcinoid tumors, and stromal tumors are much rarer, accounting for less than 10% of all cancers. The prognosis of people with the disease improves considerably when it’s detected in the early stages, so a doctor should be consulted in the presence of abnormal symptoms.
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