Colon Cancer (CRC) Signs & Symptoms (& Why They Occur)

 Colon Cancer (CRC) Signs & Symptoms

learn more about the helpful science and medicine education offered within pack in this lesson we're going to talk about what colon cancer is and then we're going to get into signs and symptoms of colon cancer and we're going to teach students why these sign symptoms occur so colon cancer or colorectal carcinoma or colorectal cancer is a cancer involving the large intestine and or rectum so if we look at the gastrointestinal system here's the esophagus going into the stomach this leads into the small intestines which wind around in the abdomen eventually leading to the large intestine there is the ascending colon the transverse colon the descending colon the sigmoid colon and eventually to the rectum into the anus so any part of the large intestine or the rectum may be involved in this cancer so what happens is there may be a tumor or growth that may affect the right colon which would be this area on this side as we're looking directly on the patient the left colon may be affected or the rectum may be affected and what happens is a malignant growth arises from a previous polyp that paul may have been developing for many years.

now colon cancer is the fourth most common type of cancer most cases of colon cancer are going to be related to several risk factors are going to talk about in a moment but there is an estimated five percent of cases that are attributed to two genetic causes one of them being familial adenomatous polyposis and the other one being lynch syndrome colon cancer is also the most common cause of large bowel obstruction in adults which can also lead to some other signs and symptoms we're going to talk about later on in this lesson and there are several factors that can increase the risk for developing colon cancer one of them is older age this is going to be the most important risk factor so particularly past the age of 50 so older than 50 is going to be a risk factor for developing colon cancer but we can also see it with low fiber intake so a chronic or long history of consuming low fiber this can be an associated risk factor for having colon cancer a family history particularly if a first degree relative has had colon cancer before the age of 50 this is going to be a important risk factor to make note of and then a history of inflammatory bowel disease particularly ulcerative colitis is also another risk factor for colon cancer but the topic of this lesson is the signs and symptoms of colon cancer before we get into the signs and symptoms it's important to make note of the fact that colon cancer may be asymptomatic which means it may not present with any symptoms at all but if it does it can present with a variety of symptoms and complications we're going to talk about those in the upcoming slides so we just mentioned.

that colon cancer may be asymptomatic and oftentimes the onset of signs and symptoms of colon cancer occurs with advanced disease one of those symptoms is going to be abdominal pain so oftentimes abdominal pain is going to be the most common symptom that presents to the clinic and oftentimes that abdominal pain may be caused by a partial or complete obstruction by the tumor or the growth or the pain may be related to invasion of the tumor into the peritoneum that could also be a reason for that abdominal pain as well another very important sign of colon cancer is stool changes so the caliber of the stool can change and you can imagine that if there is a tumor within the large intestine the stool has to pass by that tumor that can change the shape of the stool so what can happen is the shape of the stool can become very thin it can be pencil-shaped stool the reason is is because again that tumor is going to be something that the stool is going to have to get around if the tumor gets larger and larger the stool is going to become very thin to go past that obstruction so the stool becomes thinner especially if the tumor is in the left colon and that leads us into our video sponsor chegg now a lot of science and medical topics can be very challenging and complex to learn and remember but with the pack you can learn even more about colon cancer including some of the basics about cancer and even more about some of the pathophysiology behind.

why colorectal cancer occurs each topic is organized in a very clear way and guides you all the way from the basics of the topic through to the more advanced information for me personally i've used chegg in the past during my pre-med undergraduate studies as an additional learning resource which was definitely helpful i have also used the to further complement my studies on a variety of science and medicine topics and have found their resources very helpful the check study pack is particularly useful because it also helps improve your writing skills and your math skills as well not only does chegg have a large library of their own educational resources they also provide a variety of significant discounts on many different textbooks which is incredibly helpful for students also has many different practice tests and millions of flash cards to help with your studies as well if you want to get access to this great resource the first month of tag steadypack and now back to the lesson some other important findings in colon cancer are bowel habit changes bowel habit changes are going to be more likely to occur with left-sided colon tumors if it is a right-sided colon tumor it's unlikely to cause bowel habit changes and what happens with bowel habit changes is there's often an alternation between constipation and diarrhea they may have had normal bowel habits throughout their entire life and then all of a sudden they start to have issues with diarrhea which then alternate to constipation it can look like irritable bowel syndrome but because the patient is oftentimes going to be older past the age of 50 this is going to be a red flag if we see these symptoms weight loss can also occur with some patients so losing weight may occur in colorectal cancer weight loss is actually going to be one of the constitutional symptoms of many types of cancers so the cancer and the cancer cells can lead to cancer-related or tumor-related anorexia that can be one reason as to the weight loss but it can also be due to the high energy demand of the cancer itself so this may be the reason why some patients will have weight loss and then another important constitutional symptom in colon cancer is fatigue fatigue is actually one of the most common symptoms of colorectal cancer and again this fatigue is going to be due to cancer-related changes and like many other types of cancer fatigue is going to be an important constitutional symptom to think about some other very important signs of colon cancer include bleeding so bleeding can either be hematopezia.

which is going to be a bright red blood in the stool this is more likely going to occur with left-sided colonic tumor so if there's a tumor growing in the left colon you can imagine that it may be disrupting a lot of the mucosal surfaces in the colon leading to bleeding so there will be bright red blood in the stool molina can also occur with colorectal cancer as well moline is going to be a black tari and smelly stool this is more likely to occur in right-sided colonic tumors if it does occur so the reason is because it gives colonic bacteria more time to digest that blood so if the tumor is on the right side of the colon that bleeding may be a slow bleed it allows bacteria to digest that blood and then the blood will come out as a black and tarry smelly stool so molina and then with the bleeding comes anemia so because of those blood losses from hematochesie and the molina and occult bleeding it's important to note that bleeding may be occurring in the patient doesn't even know it so a cold bleeding you can think of it as hidden bleeding you don't see it so blood losses from those sources can lead to anemia a low red blood cell count and the ultimate reason that this happens is because of iron deficiency because of that blood loss the patient is also losing iron and eventually that iron is not going to be replaced enough and it's going to lead to an iron deficiency anemia it's also important to rule out other causes that may be leading to this iron deficiency anemia but if you see iron deficiency anemia in an older patient it's very important to look out for colon cancer along with this iron deficiency anemia we see signs and symptoms of iron deficiency anemia including fatigue power shortness of breath and some other interesting findings like pica if you want more information please check out my full lesson on that topic patients with colon cancer can also experience weakness this may be related to anemia a palpable or a mass that you can feel may also be found in some patients with colon cancer so an abdominal mass may become palpable especially with right lower quadrant masses so if you look here the abdomen is split into four quadrants using the belly button of the umbilicus as the midpoint so right upper quadrant left upper quadrant right lower quadrant and left lower quadrant oftentimes if there's a tumor in the right colon and it's in the right lower quadrant it may be palpable so there may be a right lower quadrant mass in some patients there are signs and symptoms of a large bowel obstruction that can occur as well we talked about colon cancer being the most common cause of large bowel obstruction in adults so there can be signs and symptoms of a large bowel obstruction and this large bowel obstruction is going to be more likely to occur with a left-sided colon tumor so what can be noted is the following constipation and obstupation so constipation is going to be decreased frequency or an increased consistency of stool we talked about that being part of the altered bowel habits that can occur with colon cancer but you can imagine that if the tumor has grown so large that it completely blocks the lumen of the large intestine nothing can pass it so either very little stool or no stool at all may pass that obstruction if it is completely obstructed then no stool will pass there will be a cessation of bowel movements and then there may even be obstupation or no passing of fledus again that very large tumor may be in the way causing a complete obstruction allowing no stool or flatus to pass it so this can occur in some patients nausea and vomiting can then ensue with these patients this is going to be due to decreased gastrointestinal motility.

you can imagine that if there's a big blockage in your gas intestinal tract eventually everything's going to back up and it's going to cause nausea and vomiting for the patient some other signs and symptoms of a large bowel obstruction include abdominal distension this is due to increasing volume of air and gas within the gastrointestinal system from the obstruction again this is going to be a complete obstruction if no flatus can pass the obstruction the air is going to build within the gastrointestinal tract causing this abdominal distension and the severity depends on the location of the obstruction some patients may also experience a fever so an increase in body temperature this may occur if there is bowel strangulation or if a perforation occurs if there is a complete obstruction and air and gas and stool contents begin to build up within the gastrointestinal system the bowels may begin to dilate and perforation may occur and this is going to lead to gastrointestinal or colonic bacteria escaping and getting into the surrounding areas into the peritoneum this is going to cause an infection and a fever in some patients and then there can be some signs and symptoms of rectal cancer these include tenesmus so tenismus is a feeling or sensation of urge to defecate and then there can also be a sensation of incomplete evacuation so you can imagine that if there's a large tumor in the rectum the patient can sense this and they may feel that there is something there that there's an incomplete evacuation so this can be very important to recognize as well and then there is signs and symptoms of metastatic disease cancer from the colon can spread to other parts of the body some of these include the liver so there may be issues with liver disease if there's enough spread of the cancer the spread of colon cancer to the liver is through hematogenous spread via the portal vein so again it can cause signs and symptoms of liver disease lungs can also be impacted as well this is going to be caused by hematogenous spread via the inferior vena cava so this may lead to issues with breathing although in some cases there may be no symptoms and then the lymph nodes can also be impacted as well so there can be supraclavicular lymphadenopathy so above the clavicles there's lymph node if that is swollen and palpable.

this can be a sign of metastatic disease from colon cancer this is going to be due to the fact that the colon cancer is spreading through the lymphatic system so these are some of the more common sites of metastatic spread and with each of these there may be other particular signs and symptoms so it's important to think about those as well i hope you found this lesson helpful if you did.