Colorectal cancer

Scientist has identified 40 new genetic variants associated with the predisposition to develop colorectal cancer, which are added to other 60 discovered in previous work and improve the design of the genetic architecture of this neoplasm, the most frequent its possible application in preventive screening in the general population.

These are alterations in the germline DNA presented by all human cells at the time of birth, which have been identified thanks to the complete sequencing of the genome and genetic association studies, in which data of 125,478 people have been compared. part of 21 cohorts of patients with colorectal cancer and subjects who acted as control of the study, from different countries Germany, Austria, Canada, Spain, United States, Holland, United Kingdom, Sweden and others from the European Union.

The findings can help calculate the individual risk associated with colorectal cancer and identify people for whom a colonoscopy would be indicated Calculate the individual risk of colorectal cancer In the study, which has been published in Nature Genetics, and is one of the largest that have been made so far to advance the knowledge of these tumors, the first rare genetic variant has been identified (with a frequency in the population less than 5%) of germinal predisposition to this cancer near the CHD1 gene.

In addition, the variants found include new genes and signaling pathways that are involved in the development of this disease, such as long non-coding RNAs, Krüppel-like transcription factors, Hedgehog and Hippo-YAP signaling pathways, and the immune system.

There was a person who participated in the study, it was reported that they could be allowed to calculate an individual risk value associated with the appearance of colorectal cancer, by writing these variants and determining which people are most at risk. To develop these tumors and in which, therefore, it would be indicated to perform a colonoscopy.

What are the colon and rectum?

The colon and rectum (large intestine) are located in the abdomen and are part of the digestive system. They have a fundamental role in the formation of feces. The first 150-180 centimeters of the large intestine correspond to the colon and the last 15 centimeters to the rectum. The large intestine is divided into six parts: blind, ascending colon, colon transverse, descending colon, sigma and rectum. Its function is absorption of water from ingested and digested food in the small intestine and serve as a container for the waste material. This material is going advancing to the rectum, the last part of the large intestine, until it is expelled to the outside through the anus.

What is colon and rectal cancer?

Normally, the cells that make up the different organs of our body are divided in an orderly manner in order to replace the cells old This division is strictly regulated by mechanisms of control that tells the cell when to do it. Malignant tumors they are characterized by being formed by cells whose regulatory mechanisms of division have been altered. Therefore, they can invade and destroy the tissue that is around him. When this process affects the large intestine, it is called colorectal cancer or also colon cancer. If malignant cells enter the bloodstream or lymphatic system, they can spread to any part of the body and cause damage to others. organs. This cancer extension process is called metastasis.

Is colon cancer very common?

Colorectal cancer is one of the most frequent in Western countries. In Spain, it is the second cause of cancer death in men after lung cancer and the second in women after breast cancer. It is estimated that in our country each year approximately 26,000 new cases of colon cancer are diagnosed and almost half of the patients die from the disease.

What are the causes of colorectal cancer?

Most colon cancers begin in a staggered fashion, starting with a growth of the cells of the intestinal mucosa, until they become a benign and visible bulge protrusion that projects on the surface of the inner layer of the intestine. There are different types of polyps, but only adenomatous polyps adenomas are involved in the process of colon cancer formation. We must bear in mind that adenomas are benign processes and not dangerous to life. Without However, with the passage of time, if they are not removed and remain in the intestine, some of them may become malignant and become cancer. For this reason, one way to prevent colon cancer is to detect and remove these polyps before they turn into cancer.

Who can develop colon cancer?

Colon cancer can affect both men and women and more than 90% of cases develop in people over 50 years. The risk of colon cancer increases with age. Various factors are involved in the development of colon cancer. from the genetic predisposition of each individual to environmental factors such as chemical carcinogens and substances present in the diet that can favor or inhibit their appearance. Although there are different types of inherited diseases that are associated with an increased risk of colon cancer, approximately 90% of cases The diagnoses are sporadic, that is, they are mainly influenced by environmental factors.

intestinal cancer or colon cancer

Colorectal cancer CCR, also known as intestinal cancer and colon cancer, is the development of cancer in the colon or rectum of the large intestine. It can be said that cancer is the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The signs and symptoms may include blood in the stool, changes in bowel movements, weight loss and fatigue all the time.

Most colorectal cancers are due to factors of advanced age and lifestyle, and only a small number of cases are due to underlying genetic disorders. Some risk factors include diet, obesity, smoking and the first lack of physical activity. Dietary factors that increase risk include red meat, processed meats and alcohol.

Factor de riesgo del cancer

In other risk factors is inflammatory bowel disease, which also includes Crohn's disease and ulcerative colitis. Some of the hereditary genetic disorders that can cause colorectal cancer include familial adenomatous polyposis and hereditary non-polyposis colon cancer; however, they represent less than 5% of cases.

It usually begins as a benign tumor, often in the form of a polyp, which eventually becomes cancerous.


A significant percentage of patients are treated for the first time with acute symptoms that indicate obstruction or perforation of the large intestine. Unfortunately, it is possible that the first signs of colon cancer depend on a metastatic disease. Massive liver metastases can cause pruritus and jaundice. The presence of ascites, enlarged ovaries and deposits scattered in the lungs on chest radiograph may be due to colon cancer that may be asymptomatic. The main

Colorectal cancer with acute obstruction

Colon occlusion strongly suggests cancer, especially in the elderly. In less than 10% it is complete. Patients with complete obstruction report abdominal distension, colicky abdominal pain suggesting that the cancer is on the left side that is narrower and complaining of the inability to remove gas or stool. It requires diagnosis and immediate treatment.

If the obstruction is not relieved and the colon remains distended, the pressure in the intestinal wall may exceed that of the capillaries and oxygenated blood may not reach the wall of the intestine, resulting in ischemia and necrosis. If not treated immediately, the necrosis will progress to perforation with fecal peritonitis and sepsis. The low intestinal obstruction occurs mainly in the carcinoma of the left colon (due to the smaller caliber of its light.

The typical symptomatology of low intestinal obstruction is that of colic pain, vomiting, abdominal distension and absence of gas and stool emission. Therefore we should always include colon cancer in the differential diagnosis of low acute intestinal obstructions.

Can you have colorectal cancer without symptoms?

Most adenomatous polyps and colon cancer in their early stages do not produce symptoms. For this reason, it is very important to perform early detection tests on a regular basis when not There are symptoms, because you can have a polyp, or even a cancer, without knowing it.

What symptoms should you see your doctor?

The symptoms produced by colon cancer are very nonspecific and are not different from those caused by other benign pathologies very common in our society. Since colon cancer has a progressive growth, when it produces symptoms these are of recent appearance (3-6 months), persistent and with tendency to worsening. The signs and symptoms more frequent are: Presence of blood in the stool.

 Changes in the usual way to make depositions. These changes include: Appearance of constipation or worsening of habitual constipation of more than three weeks of evolution. (Diarrhea.)  (Diarrhea alternating with constipation.) (Stools with stool thinner than usual (taped stools).