Colon Cancer: Risk Factors, Diagnosis & Treatment

00:01 Our topic now is colon cancer.

00:03 It's the fourth most common cause of cancer in the United States.

00:06 And the second most common cause of cancer death.

00:09 Dr. Raj, I thought this was a number three.

00:12 Yeah, it is.

00:13 What do you mean? How could we both? Listen, if you were to separate the genders and the sexes, males and females.

00:22 Mortality.

00:23 Males: Number one, lung cancer; number two, prostate; number three, colorectal cancer.

00:31 Females. Mortality. Number one, lung cancer.

00:37 Number two, breast cancer. Number three colorectal cancer.

00:42 So, you just don't use third, correct? But if you combine your genders... Oh...

00:50 When combined for both genders, it becomes the second most common cause of cancer death.

00:54 That's up there.

00:56 Age: greater than 40.

01:01 Low fiber, high fat diet.

01:05 Personal history of colonic adenoma or cancer.

01:10 History is big.

01:11 Long-standing.

01:15 Such as inflammatory bowel disease, especially ulcerative colitis.

01:20 No joke.

01:22 Family history: Sporadic colon cancer, and HNPCC.

01:27 Hereditary nonpolyposis colorectal cancer Nonpolyposis.

01:34 Now, pause here for a second.

01:37 I want to bring two things to light here so that we're clear moving forward.

01:43 HNPCC. Remember that colorectal cancer What do you want to do? You want to divide this into really two types.

01:49 Just like we did for primary gastric adenocarcinoma.

01:52 We talked about two types there.

01:55 You have two types here.

01:56 But two types here.

01:58 literally, anatomically, location wise.

02:01 You have left sided, right sided.

02:04 Left sided, descending colon; right sided, ascending colon.

02:10 Genetically, amazingly, pay attention.

02:14 HNPCC. Hereditary Nonpolyposis Colorectal Cancer.

02:19 Remember biochemistry, microsatellite instability.

02:22 You've heard of MLH and MSH and such.

02:26 That will give rise to much more, so, right side of colorectal cancer.

02:30 Memorize that.

02:32 Whereas, if it's Familial adenomatous polyposis then it'll be left side of colorectal cancer.

02:38 What do you know about FAP? 100% of going on to colorectal cancer.

02:42 No joke. No, the genetics here big time.

02:48 Diagnosis: Slow growing tumor may present as iron deficiency, especially if it's right sided.

02:56 Could you find blood with left sided? Remember, you've heard a napkin ring or circumferential? So you have a ring around a napkin squeezing the napkin, "the napkin is the colon." Left sided, the descending colon.

03:11 You're squeezing strangulating it. Is that clear? That's left sided.

03:14 So the circumferential pattern, and napkin ring is the left side, apple core.

03:20 Once again. Could you find beating there? Sure, but that's more altered bowel habit.

03:26 On the right side, we'll talk about the description it's called polypoid.

03:31 And with the polypoid, much more so involved with bleeding and iron deficiency.

03:38 Abdominal pain, change in bowel habits much more so with left sided.

03:43 Perforation is a complication we're worried about, and rectal bleeding obviously will be taking place with both.

03:49 But much more so with right, and therefore iron deficiency.

03:55 Your tests for diagnosis include colonoscopy is the test of choice here.

04:00 Remember the colonoscopy, you want to use prudently.

04:03 And a patient that made them present with diverticular disease acutely.

04:07 But in colorectal cancer, my goodness, it is detested choice.

04:11 And your tumor marker, not sensitive, but prognostic evaluation is important known as CEA.

04:18 Carcinoembryonic antigen.

04:21 And of course, some of the new things that you want to pay attention colorectal cancer include your KRAS.

04:28 And with management, remember, not only would you have drugs such as your Leucovorin and company, but then you have a drug cost cetuximab which is then addressing your receptor tyrosine kinase.

04:39 Those are molecular pharmacology that you want to be familiar with.

04:44 Let's talk about colonoscopy in colon cancer, test of choice.

04:49 With the colonoscopy very rarely would ever ask you anything about sigmoidoscopy? Because if you were to only do and examine or investigate the sigmoid, what if you had a cancer on the right side? What if you had a polyp on the right side? You would miss it completely.

05:03 And hat makes no sense.

05:04 We know for a fact that a second leading killer overall third, leading killer individually engenders.

05:13 So, therefore, never choose sigmoidoscopy, when you're dealing with a colonoscopy.

05:16 You do a full colonoscopy to make sure that you catch anything on the right side.

05:22 This particular lower colonoscopy is showing you decreased caliber of the lumen of your colon.

05:31 And you see a little bit of blood as well.

05:33 You notice here, but this colonoscopy that you would have altered bowel habits as you're coming down the descending limb.

05:42 The left side we show you what's known as circumferential.

05:45 The left side oftentimes referred to as being, apple core.

05:49 And you might have heard this being used as napkin ring.

05:55 Colon cancer prognosis, it's important that you pay attention to staging.

05:59 On a boards, nowadays, whatever board that you're taking, I understand the staging becomes important because it tells you, well, prognosis goes from relatively maybe decent, to absolutely poor.

06:12 The staging system for colon cancer is known as the SEER system.

06:15 And it's based on three categories.

06:18 Localized: where there's no sign of spread outside the colon or rectum.

06:21 Regional: where the cancer has spread to nearby tissues or structures.

06:25 Or distant: Where the cancer spread to distant parts of the body such as the liver or lungs.

06:30 And their survival rates are 91%, 72%, and 14%.

06:36 Once you get the D, you're gone.

06:38 What that means is that metastasis taking place, and with colorectal cancer, you can either choose hematogenous or lymphatic spread.

06:47 And if it chooses hematogenous spread therefore, the number one place that metastasized to colon to the liver.

06:55 Alright? Colon to the liver.

06:58 From the liver, then maybe perhaps up into the lungs.

07:02 Management: surgery with wide resection, adjuvant chemotherapy, radiation therapy, especially when you start getting into Duke staging...

07:10 B B B as in boy.

07:14 Prevention: screening, screening, screening.

07:17 Age 50 years of age, a general population.

07:19 Keep in mind because of low fiber, high fat diet type of issue.

07:23 Age 40 years, 10 years, prior to diagnosis, if you're thinking about a patient, and the relative is in fact affected 10 years younger.

07:32 So, kind of behaves like you're mammography and a female with breast cancer, doesn't it? Beginning eight years if you're thinking about a patient with the inflammatory bowel disease of the ulcerative colitis type Prevention: Test for screening, colonoscopy.

07:51 A cold blood testing, and virtual colonoscopy.

07:54 Nowadays, of course, is playing a major role.