09. Indications for Colostomy in Adults - Colorectal Cancer

In this class we're going to discuss indications for colostomy and adults with a very specific focus on colorectal cancer. We'll talk about the etiology of colorectal cancer and when a permanent or fecal diversion might be indicated. We will talk about risk factors in screening guidelines, staging guidelines and treatment options. So as you already know colorectal cancers of very common malignancy and a very common cause of cancer related death. What most people don't realize is that early diagnosis is associated with a much higher curate and we're going to keep coming back to that because we really want to sell people on the value of routine colonoscopy. We also want people to realize that occasionally colorectal cancer results in temporary or permanent diversion but most of the time there is no ostomy required for people with colorectal cancer. It's actually uncommon. So let's talk first about etiology. First of all there are many different types of cancer that can involve the colon and the rectum but adenocarcinoma is by far the most common so that's typically what you see. They think based on current research that adenocarcinoma begins with one single cell that transforms into a malignant cell and undergoes mutation and then it begins an abnormal growth pattern that eventually results in polyp formation. And polyps are also known as adenomas. Now you need to realize the vast majority of polyps, the vast majority of adenomas are benign that there's a small percentage of adenomas polyps that do progress to malignancy to cancer and that is known as the adenoma carcinoma sequence. And it involves actually a whole series of genetic mutations that in the end result of those mutations is they either activate proto-oncogenes, malignant genes or they inactivate tumor suppression genes. So they either turn off protective mechanisms or activate processes that result in malignancy. Before polyp to undergo malignant deterioration you see a whole series of genetic mutations are required. So out of all of the polyps that occur only a very small percentage progress to malignancy, progress to cancer. Now as we said there are other cancers that affect the colon and the rectum. So occasionally you'll have a carcinoid, you might have a melanoma, you might have gastrointestinal stroma tumors are called G-I-S-T tumors, occasionally sore comas or lymphomas but vast majority adenocarcinomas. Who's at risk? Well as you probably know age is a risk factor for everything. So age over 50 is a risk factor for development of colorectal cancer. As a result the current recommendations are that routine screening begin at age 45-50. Any family history and we know that's true for heart disease, it's true for all kinds of things and it's definitely true for colorectal cancer. If you have a parent, a sibling, an aunt or an uncle who has a history of colorectal cancer, or higher risk and you should start screening at an earlier point. And then there are some very specific genetic conditions that tremendously increase the risk of colorectal cancer. One is familial adenomitus polyposis, it's a condition that results in the production of literally thousands of colorectal polyps and when you have that many polyps some of them are going to become elignant. But that is a relatively rare condition. The other genetic condition is the lymph syndrome, it's also known as hereditary non polyposis colorectal cancer. So those two conditions are associated with very high incidence of colorectal cancer, and they're very uncommon. Inflamatory bowel disease is also a risk factor for colorectal cancer, probably because of the chronic inflammation and the fact that mucosal cells are turning over at a much faster rate. So that increases the risk that one of those cells is going to follow a malignant pathway. So you take all of the non-modifiable risk factors and the one that affects the most individuals' age, modifiable risk factors include diet, activity, and obesity. So specifically, what's a high risk diet and what's thought to be a protective diet? Well, from all the data that we have so far, high fat, low fiber diets are a risk factor. High fiber, low fat diets seem to be protective. So the more veggies you eat, the fewer fridge fries you eat, the better. Also activity helps and weight control helps. So obesity is a risk factor and a sedentary lifestyle is a risk factor. We're going to talk about screening. Now screening for colorectal cancer is designed to look at everyone who's asymptomatic, but potentially at risk. So all the people who think, no, I'm fine. I don't have it. I don't have any symptoms. There's nothing wrong with me. And if we screen all of those people, we will find early malignancies in a significant percentage. And that's the whole goal. Very early diagnosis before symptoms occur and when cure is very, very likely. So we want to do early diagnosis, we want high cure rates. So we're going to target people who think they're fine. What do screening involve? So ideally colonoscopy, that is the best screening tool, because literally you're inspecting the bowel lining. You're looking for any lesions. And if you find a lesion, you're going to biopsy it and hopefully excise it. So one of the great things about endoscopy, not only is it diagnostic, it's also therapeutic, because if you find anything that could progress to malignancy, you're going to remove it before it has the chance. Well what about fecal occult blood testing? What about sigmoidoscopy? So on the one hand, your gold standard is colonoscopy. You inspect the entire colon. You identify any abnormal lesions, you biopsy or remove those lesions. On the other hand, we have fecal occult blood testing and sigmoidoscopy. Now fecal occult blood testing sigmoidoscopy, not as thorough, not as effective as colonoscopy, because sigmoidoscopy only involves assessment of the lower portion of the colon, just the recto-sigmoid. Now on the plus side, that's where most colorectal cancers occur. On the negative side, look at all the colon that's not being assessed. And you can get malignancies in the ascending colon. You can get malignancies in the descending colon. So I want to talk briefly about fecal occult blood testing. So the advantage is it's very inexpensive and it's not invasive. People don't like to do it, but it's cheap and it's not invasive. You don't have to do a bowel prep, you don't have to do anything except scoop a little poop, put it on the card, and send it in for assessment. The negative, very high incidence of false positives and false negatives. So you think, well, is it worth it? I don't really want to do that, and it sounds like it's not even very accurate. And even with all the false positives and all the false negatives, studies have shown that even 50% compliance among the at risk population, if even 50% of them did fecal occult blood testing, there would be a significant reduction in advance malignancy. actually identifies this. significant percentage of early malignancies because we know malignant tumors cause bleeding. And that's what fecal localt blood testing picks up on. So we want to encourage fecal localt blood testing and sigmoidoscopy anytime colonoscopy is not an option. Now, we've already talked about the advantages of colonoscopy. We know it's expensive, we know it's invasive, we know it involves a bowel prep, but because it's both diagnostic and therapeutic, it is the gold standard. Any polyp that you see, you remove it. And it never has the chance to develop into a malignancy. On the negative side, in addition to the cost, there is the potential for perforation, but out of thousands and thousands of colonoscopies that are done every day, perforation occurs in a very, very small percentage. So overall colonoscopy, very safe, very effective and prevents colorectal cancer before it can start. So current recommendations, screening should begin at 45 to 54, the average individual. If you're high risk because of family history, if you're high risk because of inflammatory bowel disease, then screening should begin even earlier. What are the symptoms of colorectal cancer? Well, I think you all know this. We'll go through this very quickly. First of all, blood in or on the stool because malignant tumors bleed. They erode blood vessels, they bleed. Right-sided tumors tend to bleed more than left-sided tumors. The negative is that they bleed intermittently. And that's one of the things that compromises the effectiveness of fecal occult blood testing is that intermittent pattern to bleeding. But definitely anyone who sees blood in or on the stool, they should never just explain it away. They should never just say, oh, I think I'm pretty sure I have hemorrhoids. You should always, always be evaluated if there's blood in or on the stool that is never normal and it is a very common sign of cancer. Ribbon-like stools, we talked earlier about the fact that tumors and the left side of the colon tend to narrow the lumen of the bowel. They create that apple core effect. So as a result, stool is getting squeezed through that very narrow section of the colon and you get those ribbon-like stools. So that's not normal, that should be evaluated. Generalized abdominal pain, never normal, unexplained weight loss, never normal, and fatigue and anemia. We know that when patients come in with unexplained anemia, the first place they look is the GI tract to see is that where bleeding is occurring. Any patient who has any symptom of colorectal cancer, any patient with a positive finding on fecal occult blood testing, positive finding on sigmoidoscopy should undergo a complete workup. Complete workup always requires colonoscopy. So you see any red flag, you've got bleeding, you've got ribbon-like stools, you've got a positive finding on fecal occult blood testing, you're gonna be scheduled for colonoscopy and biopsy. If they find a malignancy, then you're gonna do a metastatic workup because you need to know, okay? Where, how far has this tumor spread? Is it confined to the bowel? Has it spread outside of the bowel? Does it involve lymph nodes? Has it spread to distant organs? You know those are the three pathways of spread, direct invasion through the lymph nodes, through the vascular treat. So with a rental cancer, you're gonna do an MRI or an endoscopic ultrasound that will give you a lot of information about local invasion and also about local lymph nodes. You're gonna do cat scans of the chest, of the abdomen, of the pelvis, and you're looking for spread to distant organs, most commonly the liver and the lungs. Now what about carcinotembryonic antigen? That's a blood test, it picks up on a tumor marker. It would be wonderful if all colorectal cancers produced carcinotembryonic antigen, but they don't. There's a subset of tumors that produces CEA. So typically when a patient is diagnosed with colorectal cancer, they will do a CEA. If that CEA is elevated, then we know that this patient has a CEA producing tumor and then we can use CEA levels to monitor for tumor progression or regression. If the initial CEA is negative, then we know this tumor does not produce CEA and that test is of no value. Now we're gonna talk a little bit about staging of colorectal cancer. I don't want you to get too lost in this. I'm going to, at the end of the discussion, highlight what you really need to know. But big picture, there are two very commonly used staging systems for colorectal cancer. The first is the T in M system, T stands for tumor, N stands for nodes, M stands for metastases. And then following each of those letters, you'll get numbers. And in general, the lower the number, the better the prognosis. So you'd rather have T zero, which means it's very, very localized to the mucosal layer than T four, which means it's extended outside the colon, outside the rectum. And stands for nodes. You'd like to see N zero. N zero obviously means no positive nodes. And one and two, yes, as the numbers go up, the number of positive nodes goes up. And M, you'd like to see zero, you'd like to have no metastatic disease. If you see M one, you've got metastatic disease. And again, as the numbers increase, the number of involved organs increases as well. So T in M, pretty straightforward in understanding what they're trying to tell you. The other system is AJCC, American Joint Committee on Cancer, and they use a numeric system, and also alphabetical, so a zero to four B. And there's a lot of overlap between T and M and AJCC, and that's what we're going to show you. Now, accurate staging is critical, because it pretty much dictates prognosis, a guide's treatment, and also, people who are doing research across the globe, I need to be able to compare what the researcher in the UK found, what the researcher in Australia found, what the researcher in Israel found. And if they're using narrative terms to describe the tumor and the extent of spread, it's going to be very difficult. But if we're all using the same staging system, I can say, oh look, all three of these studies addressed node positive disease. That's what I'm looking for. Okay, so let's go through the stages again. I see you're looking at that, and you're probably like going, oh my God, don't get lost in this. We're just going to walk through, and then I'm going to give you some re-information. So you would prefer to have stage zero cancer if you have to have it at all. Stage zero is the same as tumor and situ, and it means that the tumor is confined to the mucosal layer of the bowel. It does not yet have access to large blood vessels or lymph nodes. Okay, if you can't get a zero, let's go for a one. A stage one tumor is confined to the bowel wall and nodes are negative. If it's a T1N0, it means that the tumor has extended to the submucosal layer, but no further, not to the muscle just to the submucosal layer and nodes remain negative. If you have a T2N0, now the tumors extended to the muscle layer, but the nodes remain negative. If you have a stage two, it means you have greater local spread. Okay, so the tumor has extended. farther in the bowel wall, but nodes remain negative. Across the board, stage two disease is node negative. So if you have stage two A, then the tumor involves the subcerosal layer. So now it's out of the muscle, through the muscle, into the subcerosal tissue, or it's through the rectum into the peri-rectal tissue. But again, your nodes are OK. If it's to B, the tumor has invaded the visceral peritoneum. So now it's through the subcerosal layer. It's into the visceral peritoneum, node still OK. And then to C, it's out of the colon, into adjacent structures, out of the rectum, into adjacent structures. But again, nodes are negative. Stage three disease, now your nodes are involved. Across the board. So you see how this is going. Stage two confine to the bowel wall and the adjacent tissue. And you have to look at the specifics to see exactly how much local spread you have. But your nodes are negative across the board. Stage three nodes are positive across the board. So three A, it could be a T12N1M0. That means the tumor involves the submucose in the muscle. And you have limited positive nodes, one to three. If you have T12N2A, now you have four to six positive nodes. If you move into 3B, so you've got T3 to 4N1, OK. Again, you've got greater local spread, but only one to three positive nodes. If you go into A, now you've got four to six positive nodes. And if you go into B, as you can see, you've got seven or more. The big picture, positive lymph nodes. So now you're outside the organ, into the adjacent tissue, and your nodes are positive. Three C, you've got more local extension. And again, you see if it's two A, four to six positive, regional nodes right in that area, to B, seven, or more positive nodes. And then you can have lymph nodes along a major blood vessel. So now you're out of the local area, and the lymph nodes distant to the tumor are involved. So now you've got another step forward. And then stage four is metastatic disease. And as you can see, you can have M1A or M1B. M1A mats to only one organ. M1B mats to two or more. Now I promised you I would bring this all down. This is what we want you to remember, staging at a glance. If you can remember this and that general rule of thumb, the lower the number, the better the prognosis, then you're going to be able to interpret your pathology reports and know what's going on with your patient. So stage one disease across the board is tumor is confined to the bowel wall. Stage two disease, now the tumor extends through the bowel wall to the bowel surface or the surrounding tissue. But nodes remain negative. Stage three disease, any degree of tumor extension, now you have positive nodes. And you have to look at the specific indicators to know how many nodes are positive. And are all the positive nodes confined to the region or do you have positive nodes along major blood vessels and moving away from the tumor? And then stage four is any degree of metastatic disease. So M1A, one organ is involved, M1B, multiple organs are involved. So if you can remember this staging system is going-- or this staging synopsis is going to be very helpful to you. OK, so now let's talk about treatment. And treatment is always based on the stage of the disease because you have to think, OK, my disease is confined to the colon, confined to the rectum. My nodes are negative, I have no metastatic disease, then I can focus on surgical excision. If I have positive nodes, if I have metastatic disease, local excision is never curative. Now I have to do systemic treatment. I have to think about chemo. I may need to think about radiation. I'll go on and mention now we do not typically do radiation for colon cancer. We do it for rectal cancer. We don't do it for colon cancer because there's significant risk of stretcher formation. So when you talk about treatment of colon cancer, you're talking about some combination of surgery and chemo. When you're talking about treatment of rectal cancer, you're talking about some combination of surgery and chemo plus radiation. OK, so let's talk first about non-metastatic disease. So stage one to three either is confined to the bowel wall. It extends to the bowel wall and to the adjacent tissue. Or you have involved lymph nodes. What about surgical resection? Yes, surgical resection is indicated here. And you're trying-- when you're doing surgical resection, your goal is to remove all of the local disease. Remember, you have three things to think about. One to three disease, you have two things to think about-- local spread and nodes. So let's talk first about local spread. You want to do a wide end block resection of the involve section of the colon, the involve section of the mesenteri. The mesenteri includes the feeding vessels, the artery supplying the tumor bed, the veins draining the tumor bed, and the lymph nodes. Now, the extent of resection is based on years and years, thousands and thousands of pathology reports. And so now there are very well-defined guidelines about how much colon has to be removed, how much mesenteri has to be removed. And the recommendation is that you remove the entire colon and mesenteri between the proximal and distal feeding vessels, the very large feeding vessels, not the little ones, the large feeding vessels. Again, based on hundreds of thousands of pathology reports. So people are frequently surprised at how much colon is removed. If you have a tumor in the transverse colon, they're going to take out the entire transverse colon. They're usually going to take out from midpoint on the ascending colon to midpoint on the descending colon. You can see in the slide on the bottom, the illustration on the bottom. If you have a tumor in the descending colon, can you see that they're removing from midpoint on the transverse colon all the way down to midpoint on the sigmoid? So they take a lot more than you would think because they know you have to take the entire colon, entire mesenteri from the proximal feeding vessel to the distal feeding vessel. Once they do a curative resection, they're going to connect the two ends of the colon. It's very rare for them to need to do anostomy. The colonic mesenteri is almost always very mobile. So you take out the involved section. You bring the two ends together and you do the anestimosis. About the only time you would need to do anostomy is if you have a large obstructing tumor, and then they would need to do a temporary diversion followed by a tumor resection, anastomosis, anostomy takedown. Now, if they have extensive local invasions, so the tumor extends to the surface of the colon or beyond. So you've got involvement of the serosa. You've got involvement of the visceral peritoneum. You've got involvement of the adjacent tissue. If you have any positive nodes, then you also need to do adjuvant chemotherapy. And the current regimen that's most widely used [BLANK_AUDIO] the fol fox chemotherapy graduate, which, as you can see, is five FU look-of-voron and oxaloplatin. What if you have stage four colon cancer? What if you already have METs to one or more organs? So there's three things that could happen. Again, you've got to think about local disease as well as lymph nodes and distant disease. If your primary tumor is resectable, then you're going to do a surgical resection and you're going to do adjuvant chemotherapy. So you're going to remove local disease surgically and you're going to target everything else through chemo. If you have an unresectable tumor and is causing obstruction, then you're going to do a fecal diversion to address the obstruction and you're going to do chemotherapy to address the malignancy. If you have an unresectable tumor and it's not causing obstruction, you can just do chemotherapy. The principles of surgical resection for rectal cancer are very different and they have to do with location of the tumor within the rectum. So always your goal is essentially the same. Remove the segment of rectum with the tumor. Make sure you remove enough of the adjacent tissue to get all of what they call the daughter cells. Remove all cancer cells that have moved away from the primary tumor. Remove regional lymph nodes as well because they're a point of spread. You will commonly see the term if you look at surgical reports and you read research studies, you'll see the term TME total mesorectal excision. Mesorectal excision means resect the involved rectum, tissue, proximal, distal and peripheral to the tumor so that you're getting all the daughter cells, resect any regional lymph nodes. In surgery, you take out the specimen. So if you look at the tumor on top, so you can see it's in the proximal rectum, so you know that they would remove part of the sigmoid, proximal to the tumor, part of the rectum, distal to the tumor, all of the peripheral tissue and lymph nodes and you ascend it to pathology. While the patient is still on the table, the pathologist is going to carefully inspect this specimen with a focus on proximal and distal edges. If the proximal and distal edges are free of cancer cells, the pathologist, the pathologist, the surgeon, okay, you're good to go. Looks like you have a curative resection. You can connect the proximal bowel to the distal bowel. But if the pathologist finds positive cancer cells that either the proximal or distal margin, the surgeon is alerted, further resection is required. Patients ask me this a lot when I'm doing pre-out teaching, how will they know they've gotten it all? Am I going to maybe have to go back to surgery again? No. We have a system. There's a pathologist in the operating room, in the operating suite. They will evaluate while you're still on the operating room table. If further resection is required, they'll go on and do it at that time, as very reassuring to patients. Okay. Now the specific surgical procedure is going to depend on the location of the tumor within the rectum, the size and impasiveness of the tumor, if the curative resection, if in order to remove tissue around the rectum, around the tumor, if in order to get clear margins, let me back up and say that again, I garbled it. So if curative resection extends to the level of the spinters, then they will remove the anal canal and this fincters and they'll do a permanent ostomy. So remember, they're sending it to pathology. Let's say the pathologist says there's still cancer cells along the distal margin. So the surgeon goes back to take additional tissue distal to the tumor, but that additional resection now extends past the anal rectal junction into the anal canal, past this fincters. No, they'll go ahead and take the entire rectum, anal canal, spincters and do a permanent ostomy. Also you should be aware that many of our patients with rectal cancer get chemotherapy and possibly radiation preoperatively. And the goal in giving preoperative chemo and radiation is to shrink the tumor and make it more resectable. We started doing chemo radiation preoperatively. It actually meant that a number of patients could undergo curative resection and anastomosis of the proximal and the distal bowel and they no longer require a permanent colostomy. So it actually saved a lot of patients from having to undergo ostomy surgery. So to summarize what you're trying to do, you're trying to take the tumor, you're trying to take enough tissue proximal distal and peripheral to the tumor to get clear margins all the way around and you're going to take regional lymph nodes. If you're able to do all of that and retain the spincters and the distal rectum, then almost always you can do a colo anal anastomosis and you can prevent a permanent colostomy. So there's three things that typically happen. If you have a very superficial tumor like a T1 tumor that is literally confined to the mucosal layers or the submucosal layers, then a lot of times they can just go up through the anus and do a trans anal excision. We don't see that many of those. So the two most common approaches are either a low anterior resection or an abdominal perineal resection. If the tumor is located in the mid or upper rectum like you see in the illustration on top, then what they can do is they can remove the top, half of the rectum, the sigmoid colon, the peripheral tissue, double check with the pathologist, did we get clear margins? Yes. Okay, then you can do a colo anal anastomosis. So look at the illustration on the top right. So you see the area and white. That's the area that will be removed. And then you see the area in orange. Those are the two ends that will be reconnected. You'll have a colo anal anastomosis. Now when they do this low anterior resection with a colo anal anastomosis, it can be done with or without a temporary protective ostomy. It can be done with or without creation of a little colonic pouch, just proximal to the anastomosis. And we'll come back to that in a minute. Okay, so very localized superficial tumors, transcendental excision. Larger, more invasive tumors that are located in the proximal rectum, they can almost always do a low anterior resection where they remove the proximal rectum, the sigmoid, the surrounding tissue, the lymph nodes, and connect the distal colon to the anal canal. But if the tumor is located in the distal rectum, so if you look at the illustration on bottom, you can see that that tumor, which is illustrated in black, you can see that it sits just proximal to the anal rectal junction. And by the time they remove the tumor, and enough proximal and distal tissue to get clear margins, you're going to be past this finctures and out into the anal canal. So you cannot do a reconnection, in this case, you're forced to remove the tumor, the surrounding tissue, the anal canal, and the sphinters, and this patient will have a permanent colostomy, as you see in the illustration just above the bottom. out. going into a little bit more detail on low anterior resection you need to be very clear on this terminology and what it means. It will enable you to teach your patients accurately because when you're talking to a patient pre-operatively if they're scheduled for a low anterior resection you've got to know what that means. So remember that a low anterior resection is done when you can remove the tumor, remove enough of the surrounding tissue to provide a curative resection. You're still above the sphinters. You can do an asthmosis between the distal colon and the anal canal while maintaining sphinters and sphinter function. Now sometimes it's very easy to mobilize the colon and bring it down to the anal canal. You can't mobilize the anal canal. Let's go anywhere. So the colon has to be mobilized and brought down into the pelvis to the anal canal. If you're able, if the surgeon is able to mobilize the colon, bring it down to the anal canal, doing an asthmosis without tension, then typically no further surgeries required. Typically they do not need to do a temporary ostomy. But what if I'm able to bring the colon down? I get it there. I'm able to do my staple to asthmosis, but it's definitely under tension. Well what I know about an asthmosis under tension is this going to take longer to heal and it's much higher risk for an asthmotic breakdown. Do I want form stool passing through that anastomotic line before it's well healed? No, I do not. I've already got an anastomosis at risk as under tension. It's going to take longer to heal. It's higher risk for breakdown. So if my anastomosis is under tension or if I have any other reasons to be concerned about delayed healing, I'm going to do a temporary diversion, a temporary ostomy, like a temporary eleostomy to protect that an asthmotic line. The other thing that the surgeon has to think about is we have great data that says when you take out the rectum, you've eliminated the reservoir for stool storage. And now you've got the colon connected directly to the anal canal. And what happens is that you get intense fecal urgency and frequency, typically after a meal. So people will tell you I wouldn't dare leave a restaurant before I go to the bathroom two or three times because otherwise I'm going to be in trouble in the car. Now over the first three to six months post-operatively, the section of colon just proximal to the anastomosis will gradually descend to form what is sometimes referred to as a neorectum. But for those first three to six months, stool frequency stool urgency can be a major issue for the patient. So some surgeons will create a reservoir just proximal to the anastomotic line. If you look at the bottom illustration, you can see where the surgeon has basically flipped the colon back on itself. It's called a coloanol J-pouch because it looks like the letter J. And that gives a temporary reservoir. Or sometimes they will create. You can see if you look at the far right where they've done this colopexy where they've essentially pulled the colon out and sutured it differently so that it's created a little pouch. So many surgeons are doing either the coloanol J-pouch or that colopexy procedure to create temporary stories. So you may see that done. You might not see that done. Again, a review on abdominal perineal resection. That's what's done when the tumor is in the distal rectum. And you've got a couple of illustrations there. You can see on the top right the tumor sitting right at the rectoanol junction. And so there's no way to get a curative resection without removing the sphincters. In this case, you'll end up with both an abdominal and a perineal incision to remove the rectum and the anal canal and the sphincters. You'll always end up with a permanent colostomy. Now there is some potential for urinary retention and some potential for sexual dysfunction when they do an abdominal perineal resection because the autonomic nerves that elevate the bladder, the autonomic nerves controlling the erection and ejaculation pass right around the rectum, pass through the perine rectal tissue on their way to the erectile tissue to the bladder. Fortunately, surgeons have learned so much more about nerve pathways. Plus, many times these procedures are now done laparoscopically which minimizes tissue trauma. So we're seeing many fewer problems with urinary retention, many fewer problems with sexual dysfunction, even among patients who require abdominal perineal resection. Now chemo radiation. This is adjuvant therapy for the patient with rectal cancer that is either locally invasive, it goes through the rectal wall into the serenity tissue or they have positive notes. Also indicated for a patient who has locally resectable disease but disappears because in that case, you have to treat both locally and systemically. Chemo radiation is primary therapy if you have a tumor that is unreceptible at the time of diagnosis. Now there are some very well-defined adverse effects of pelvic radiation. One is radio dermatitis, so skin damage. You know that radiation effects are rapidly dividing cells and skin cells are rapidly dividing. So where any patient who's getting pelvic radiation is at risk for both perineal skin breakdown, we see that and we also see peristomal skin breakdown in a patient who undergoes abdominal perineal resection with colostomy. So we want to do everything we can to protect the peristomal skin and to minimize the risk of trauma. We want to use silicon based adhesive releases so that we don't cause trauma when we remove the pouch. We want to teach the patient very gentle peristomal skin care, no scrubbing. Frequently helpful to collaborate with the radiation oncologist to determine does the pouch need to be removed for radiation? Can the pouch be left in place for radiation? Diarrhea is another very common side effect because the mucosal cells are also a group of cells that turn over very rapidly. You constantly shed mucosal cells and produce more mucosal cells. So things that we need to be alert to, we usually tell patients stay on a low fiber diet so that you're not increasing peristalsis talk to your radiation oncologist about anti-diarrhea reagents and do not do any kind of colostomy irrigation, no enemas through the stoma. Occasionally we'll see stomatitis. So you know patients who get chemotherapy frequently have oral stomatitis. They have ulcers within the mouth that are very painful. Patients who receive abdominal pelvic radiation can get ulcers on the stoma. We just have to be very aware of any evidence of stomal damage if the stoma is abnormally edimitis abnormally inflamed if we start to see mucosal ulcers. We want to notify the radiation oncologist and again alert the patient to be very gentle in their care. So in summary, add no carcinoma by far the most common type of colorectal cancer, the most effective screening is colonoscopy. If for any reason the patient can't get colonoscopy done, then you want them to undergo fecal occult blood testing and sigmoidoscopy. Diagnostic workup, this is for any patient with positive fecal occult blood test, any patient with a positive symptom. They have to undergo colonoscopy with biopsy. They're also going to undergo scanning to look for any metastatic disease, so CTs, MRIs of the abdomen and the pelvis and the lungs. Management of colon cancer. Columns cancer is typically managed with wide surgical resection, so they're going to take the segment of colon and the segment of mesentery. They're going to resect from one feeding vessel to the other feeding vessel, proximal and distal. They're going to do adjuvant chemotherapy if there's a locally invasive disease, if there's no positive disease or if there's metastatic disease. Rectal cancer is going to depend on location, so if the tumors located in the med or upper rectum and they can do curative resection without damaging the sphincters, they'll do a low anterior resection with coloeonal anaesthmosis. They may or may not do a protective iliostomy until the anaesthmosis heals. If the tumor is distal and curative resection involves the sphincters, they're going to do an abdominal perennial resection. Chemo radiation is indicated if you have locally invasive disease, if you have positive nodes or if you have metastatic disease. That's it for this one. Thank you.