Selected Podcast

Colon Cancer

Colon cancer is the third most common cause of cancer deaths in the United States. Recommended screenings can help reduce cancer risk and hasten treatment.

Gastroenterologist Dr. Peter Brennan shares what you need to know about colon cancer.
Colon Cancer
Peter Brennan, MD
Peter Brennan, MD graduated from Williams College Magna Cum Laude with a degree in chemistry. He then graduated second in his class form SUNY Upstate Medical College Magna Cum Laude. He completed residency in internal medicine and fellowship in gastroenterology at the University of Virginia and Medical College of Virginia respectively.

Dr. Brennan states that he gets the greatest professional satisfaction from getting to know his patients personally so he can apply the continually expanding science in gastroenterology for their benefit.

In his off hours Dr. Brennan enjoys the outdoors in all seasons and serves on the board of The Nature Conservancy of Central and Western New York.

Learn more about Peter Brennan, MD

Melanie Cole (Host): Colorectal cancer is the second leading cause of cancer related deaths among men and women combined; however, there are tests that can actually prevent or detect colon cancer at its earlier stages. My guest today is Dr. Peter Brennan. He’s a gastroenterologist at Cayuga Medical Center. Dr. Brennan, what are some of the risk factors for colon cancer?

Dr. Peter Brennan (Guest): Well the primary risk factor is age. It doesn’t differentiate between any of the sexes or races to any significant degree. The traditional cut off for being concerned about it is age 50, but we are seeing an increase in ages under that. Age is the biggest risk factor. Meat consumption raises your risk a little bit but vegetarians really don’t get a free pass. They might have a decreased risk of 20% to 30% but that’s not enough to stop you from properly addressing that risk. So those are the two main things. Then there’s family history that can be important. In some cases we can track through multiple generations, but even if you don’t have a family history the rate of sort of sporadic out of the blue colon cancers is high enough to warrant screening.

Melanie: So then let’s talk about screening. There’s colonoscopy which we hear is the gold standard for actual prevention of colon cancer. Speak about who should be screened and what age?

Dr. Brennan: Well right now we begin screening at 50. There has been some thought about moving that up but that’s a complicated topic. If we could get everybody to come in at 50, that would be a major accomplishment. So you come in and the idea is to find the precursor lesions to cancer which are called polyps and remove them before they get a chance to get big. I often use the analogy as removing the little seedlings before they turn into saplings before they turn into mature trees. The mature tree being the full fledged cancer. So colonoscopy, somewhat uniquely, albeit with some inconvenience I will admit, colonoscopy addresses the first stages and prevents the cancer from forming. Most of the other screening techniques are designed to pick up cancers already formed, which can be picked up early and is quite useful but it is targeted for the later stage of the disease process.

Melanie: Doctor, colonoscopy is easy but people are scared of the prep but the test is so quick that sometimes people might wake up and say when are you going to do this? Just speak a bit about colonoscopy and how simple this procedure is.

Dr. Brennan: Well it’s a major investment in time but it is simply you have to set your mind to adjusting your diet for a few days of not eating a lot of heavy roughage like granola or items with big seeds like grapes with grape seeds and then there’s a day or two thirds of a day of restricting to just liquids. The amount of fluid you have to drink has been diminished and we now do what’s called split dosing, which means you take some of the prep in the evening and then the rest in the morning. So you get a rest off in between. It turns out that that rest actually allows the prep to work better, the second part of it. So there have been advances. I still respect it. I’m not looking forward to my next one. It’s still an effort but it’s better than the alternative. So there’s been – I think there’s been major advances.

Melanie: So if we’re talking about signs and symptoms that would send somebody to you for a colonoscopy in the first place or to check, what are some of the signs and symptoms someone might notice or red flags that might indicate something’s going on there, and if you talk about bleeding, how does someone know it’s not just a hemorrhoid?

Dr. Brennan: Well I don’t know that you can’t tell that it’s not just a hemorrhoid because polyps can occur from the upper most part of the colon, five, six, eight in all the way down to the end. Clearly there are people that have had a familiar pattern of bleeding for many years and that’s familiar to them, but they were taking a risk when they didn’t get it evaluated to begin with. So I think any bleeding should be discussed with your primary care doctor and investigated. Sometimes we will decide that hemorrhoids are the explanation and it’s acceptable to have it rarely and sporadically. That’s a dangerous game to play without doing an initial workup. So the primary care doctor is really in charge of determining the significance of preliminary symptoms.

Melanie: Then speak about if you do diagnose colon cancer in someone, how is that staged? What’s the next step?

Dr. Brennan: Well the pathologist looks at the specimen we develop and generally you’ll get a CAT scan, and hopefully picked up early enough in a person who’s healthy. You go to surgery and the real staging comes from a surgical specimen. I have to say we’re doing a whole lot less surgery now than we used to because at least, in our area, colonoscopy has been pretty well accepted and has made a big impact.

Melanie: So tell us about – and I’m not going to ask you about prognosis for patients with colorectal cancer as it depends certainly on the diagnosis and staging but tell us a little bit about colon cancer and what you’re seeing today.

Dr. Brennan: Well we’re seeing earlier staged disease because even those that don’t get the screening early and prevent it, do tend to present earlier so that’s generally good. What we are seeing is the cases are often people under 50 or over 80. Those are the people that are beyond the commonly determined range that we should be screening. Now the upper limit of when we should be asking people to come in, that’s fairly controversial and it somewhat depends again on your primary care doctor assessing your overall health, which I know is a very difficult thing to be completely honest about, but there are some people who have enough medical problems that they probably shouldn’t be burdening themselves with tests looking for trouble, but many people these days are hail and hardy and doing great at 78 and 79 and it’s my philosophy that they should continue to be screened. They’re probably going to make it well into their 90s, not always but I think you should take a positive attitude towards that. The other end of the age range, any symptoms deserves evaluation. You shouldn’t just assume that you have a hemorrhoid when bleeding occurs at age 41, 38, it should be presented to a primary care doctor.

Melanie: Then wrap it up for us with your best advice about preventing colon cancer in the first place, what you would like listeners to know about a healthy lifestyle, and good nutrition, and getting their colonoscopies when they’re recommended.

Dr. Brennan: One of my apparitions is eat what’s good for your heart, so I don’t know that you have to be a vegetarian but you shouldn’t overdo it with the red meat and try to watch your weight. Weight’s a definite risk factor. I could’ve mentioned that right at the beginning with your first question, but watch your weight, eat a heart healthy diet, and follow your primary care doctor’s instructions which will probably involve a colonoscopy. One of the practical reasons for that is you get it done and you get a massive amount of information from that first test as opposed to the alternatives often involve turning in stool specimens on an annual basis or every third year or every fifth year and I know I see patient anecdotes constantly where it just never gets done and it gets delayed and gets delayed and your primary care doctor sleeps better at night knowing you’ve been fully screened. In practical terms, if it’s available and your primary care doctor, trusted person looking in on you, that’s a colonoscopy.

Melanie: That’s great advice and so important for listeners to hear, Dr. Brennan. Thank you so much for sharing your expertise as a gastroenterologist and explaining colonoscopy and prevention of colon cancer for us today, so thank you again for joining us. This is To Your Health with Cayuga Medical Center. For more information, please visit, that’s This is Melanie Cole, thanks so much for listening.