Colorectal cancer: what are the symptoms?

In the early stages the symptoms can often be very nuanced. Those at risk should therefore undergo screening examinations.

The entire intestinal tract may be affected by a neoplasm. In the vast majority of cases, however, it is the large intestine that is affected. In this case we generally speak of colorectal cancer, a malignant tumor caused by the uncontrolled proliferation of cells of the mucosa that covers this organ.

Symptoms often faded

The symptoms of colorectal cancers are quite varied, generally non-specific. It can be very nuanced or, in the initial phases, even absent; For this reason, if it is true that the presence of certain symptoms, even if localized to the intestine, is not necessarily a sign of a tumor, it is also true that the lack of the same symptoms does not allow to exclude the suspicion of the disease.

Within certain limits, the symptomatology of colorectal cancer may depend on the size of the tumor mass and its location in the different tracts of the intestine, which have different shape, orientation and functions.

The most frequent localization of this type of cancer is in the final tract of the intestine (located in the right part of the pelvis), ie at the level of the rectum or sigmoid (up to 70% of cases), while the other segments, namely the ascending colon (located vertically at the left side), the transverse colon (located horizontally in the upper part of the abdomen) and the descending colon (located vertically at the right side), They are more rarely affected.

Beware of blood in the stool

An ever-present symptom in case of colorectal cancer, regardless of the site of onset, is bleeding, due to damage to the blood vessels of the intestinal wall due to infiltration of the neoplastic mass.

However, blood loss is more easily recognizable in tumors located in the terminal part of the intestine, as the blood is generally visible on the outer surface of the stool and bright red, while it can go unnoticed in tumors located further upstream because, mixing gradually with the faeces, if present in modest quantities it may not be visible. If, on the other hand, it is a large amount, it can give the stool a very dark color. In the latter case, the blood is detectable only with a laboratory analysis, known as a search for occult blood in the stool.

Internal bleeding, however small, over time leads to the appearance of anemia and related disorders: exhaustion, fatigue, difficulty breathing.

Intestinal symptoms

Another rather common symptom, typical of tumors localized in the last stretch, is the alteration of the cadence of defecation episodes, as well as the shape and consistency of the stool:

• alternation, even at short intervals, of constipation and diarrhea
• feeling of incomplete emptying
• so-called ribbon-like feces, i.e. they take on a thin shape similar to that of a pencil.

In localization to the descending colon, sigmoid and rectum the presence of the tumor mass, if of significant size, can also partially or completely obstruct the progression of the stool towards the anus, causing intestinal obstruction, which represents a serious complication of the advanced stages of the disease. This occurrence is less frequent in the forms of the first tract, as at this level the intestinal lumen has a larger diameter.

Finally, it is possible that in some cases there is also a painful symptomatology, characterized by cramps, often associated with meteorism, or persistent pain at the site of the tumor and possibly at the level of the anus in the localizations to the rectum.

The development of colorectal cancer can be preceded by the appearance of polyps along the inner wall of the intestine, generally benign neoformations that can sometimes evolve into cancerous forms over time. Polyps are generally asymptomatic, except for a possible minor bleeding that, if detected, allows to intervene by removing the polyps with a minimally invasive intervention (endoscopically).

The importance of screening

In consideration of the fact that the symptoms related to the presence of colorectal cancer is so little indicative, it is recommended to age groups at risk (over 50 years), in predisposed subjects (with familiarity for this type of neoplasia) or in the presence of a suspicion to evaluate with their doctor the need to perform some instrumental examinations that can allow early diagnosis: First of all, the search for occult blood in the stool and, secondly, colonoscopy.