Colorectal Cancer Myths and Common Questions

As of 2019, colorectal cancer is the third most common cancer diagnosed in men and women in the United States, according to the American Cancer Society — but survival after diagnosis has been gradually increasing in the past decade due to advances in treatment. However, since 1994, cases of young onset colorectal cancer have increased by 51%, according to the National Cancer Institute.

In March 2019, Dana-Farber/Brigham and Women’s Cancer Center announced the launch of the Young Onset Colorectal Cancer Center, which focuses exclusively on the care of colorectal cancer patients under age 50 in an effort to address the alarming increase in rates among young adults.

In this podcast, we talk about common myths and questions surrounding colorectal cancer with Jeffrey Meyerhardt, MD, MPH, clinical director of the Gastrointestinal Cancer Center at Dana-Farber. He answers common questions about treatment and research, family history, and ways that you can reduce your risk, whether you’re a young adult or older.

Transcript

MEGAN (INTERVIEWER): So, first of all, colorectal cancer or colon cancer or rectal cancer — is there a difference between any of these terms? Or do they all refer to the same type of cancer?

JEFFREY MEYERHARDT, MD, MPH: I mean, biologically, they’re the same type of cancer. The colon and the rectum are the end of your digestive tract. The rectum is, essentially, the last few inches, so we think of it somewhere between 12 and 15 centimeters (which, you know, is about 5 to 6 inches) at the end of the colon.

There are some differences in how we treat them because the rectum is a little bit more in a fixed structure. So, for earlier-stage disease, sometimes we’ll include radiation for rectal cancer, but we rarely include radiation when we treat an early-stage colon cancer, and surgically there are definitely differences in techniques on how to surgically treat early-stage colon and rectal cancer differently.

Because rectal cancer is kind-of right at the end of the digestive tract, sometimes when you have surgery for your rectum, it does require a colostomy, but often colostomy can be avoided eventually. Sometimes there will be a temporary colostomy, but that’s really the difference — to some degree, the treatment of it, but biologically, the risk factors and the behavior of the cells are actually very similar.

MEGAN: I talked earlier in my introduction about the colon cancer rate and how it’s rising in young adults. So, what do researchers think is the cause for this at this point?

MEYERHARDT: So, the answer is we don’t really know. You know, colon cancer is something that we know a lot about different risk factors relatively — so, family history being a big one in terms of either having one of these genetic syndromes (something like Lynch syndrome) or just having a family history (a parent or a sibling who has had either colon or rectal cancer). But then there are other risk factors. Some are environmental. Some are what we consider modifiable. Some are related to other diseases, like ulcerative colitis and Crohn’s disease.

Some of the thought on why the rise, particularly in people in their 30s and 40s, relatively… I mean, still, most people who get colorectal cancer are in their 60s, 70s, and 80s, but relatively, the risk for the people in their 30s and 40s is higher than it was several decades ago, albeit it’s still a very small risk.

And one of them is one of the environmental factors (or what we would consider an environmental factor), which is obesity, and there have actually been studies that have suggested and really started to point some of the evidence to the rising body mass index and obesity in this country as well as other countries, and that’s part of the explanation. There may also be some shifts in diet that have also been affecting. There’s a lot of research we’re doing here as well as other places looking at what’s called the microbiome, which is the bacteria that normally live in our gut, and has that been sort of shifting as, again, obesity has increased and as diets have changed, and some of those changes may be affecting the risk. But we’re really still in the early stage of trying to really understand what’s the difference and how can we intervene on that in earlier life.

MEGAN: So, people often have the misconception when they’re diagnosed with colorectal cancer that there is nothing doctors can do for them. Can you talk about this and discuss some recent advancements in colorectal cancer treatment?

MEYERHARDT: So, I mean, for the majority of people, colorectal cancer is a curable disease. The earlier you catch it, the more curable it is, which is really the importance of screening for patients who are asymptomatic — routine screening as you get older.

The treatments have definitely advanced in terms of both the people who have early-stage disease, surgery… There have been advances in surgery that have improved the cure rates. There has been some advance in what we call adjuvant chemotherapy, which is therapy given after surgery to reduce the risk of recurrence in people who have earlier-stage disease, and there have definitely been advances with people with metastatic disease.

It’s true — if we talk about two decades ago, the survival for patients with metastatic disease was more limited. There’s definitely variability in how people with metastatic disease do now, but the survival has actually increased threefold compared to two decades ago on average. And, again, there are some people who live well beyond the averages, but we still have a lot of work to do to really improve outcomes for all patients.

MEGAN: So, yeah, you mentioned screening recommendations. So, they have recently changed for colorectal cancer. What do listeners need to know? And what does screening usually look like?

MEYERHARDT: So there are various ways to potentially screen for colorectal cancer, and the honest answer is there are some pretty large studies that have looked at screening and shown a benefit for both reducing the risk of colorectal cancer as well as survival and mortality from colorectal cancer.

Those screening techniques range from checking for blood in your stool (what we call either fecal occult blood testing or a FIT test), which is looking, again, for occult blood or hidden blood in the stool, to doing a sigmoidoscopy (which some people think of it as half of a colonoscopy but just looking at part of the colon) to a full colonoscopy.

There is general agreement that a colonoscopy is still the most sensitive test. It’s the most complex test, but it’s the most sensitive test, but, again, the randomized studies show, even if you don’t do a colonoscopy, doing fecal occult blood testing or FIT testing now can detect blood, and then you follow up with a colonoscopy in those patients.

So, there are a lot of different ways to screen. In fact, the multiple societies that make recommendations, both the American Cancer Society and the gastroenterology societies and the U.S. Task Force, have all sort of agreed upon that there are different techniques that people can do, and the importance is just to do some type of screening. The recommendations until recently were just to start at age 50 because, again, that’s where the incidence really starts increasing — at the rate of every 5 years starts increasing.

The American Cancer Society recently suggested to lower that starting screening — and this is for an average-risk patient — to 45. That hasn’t been fully adopted by all the different other societies yet, so I think, right now, we’re in a little bit of a transition in terms of knowing what’s the best time to start screening and what insurances will cover in terms of starting screening. And again, I think the importance is that’s screening for someone who doesn’t have significant risk factors.

If you have a family history, like if you had a father who had colon cancer at age 50, all societies would say to start your screening at least 10 years prior to that. If you are someone who has one of the diseases that we associate with colorectal cancer, like ulcerative colitis, there’s a whole screening program for that. And if you are a family member who has a familial syndrome, like Lynch syndrome, again, there are different screening guidelines. The 50 (and maybe soon 45 or younger) is for patients who are sort of average risk, as we call them.

MEGAN: And what about those commercials for at-home DNA screening tests?

MEYERHARDT: It’s basically the concept of looking at fragments of DNA that are associated with, potentially, cancer cells. So, these are the fecal DNA tests of which there are various commercial products out there, which, again, have some sensitivity. The reimbursement is a little less clear, so for some patients that are not reimbursed… And again, it’s all… They still would have to be followed up with a colonoscopy. So, if you had found something abnormal, you would follow up with a colonoscopy, and, again, they’re not 100% sensitive, too, so they will miss some patients, including missing some polyps.

MEGAN: So, you touched on this, but another common misconception is that people don’t need to be screened for colon cancer if they don’t have a family history of the disease, so can you just talk about that and reiterate the important points?

MEYERHARDT: Yeah. So, I think, absolutely, if you have family history, you should get screened, but only about 15% to 20% of patients who are diagnosed with colorectal cancer will have had a family history of a first-degree relative. So, the vast majority of people who develop colorectal cancer and diagnose with colorectal cancer don’t have a family history, so all those people, again, would have benefited from screening.

The other important part of screening is, and the reason screening can be helpful is most colorectal cancers start as polyps, little growths in the colon or rectum that, over time, as they continue to grow, some of them will become a cancer, and one of the other purposes of screening is to try to detect those early, remove them, and then you actually never develop a cancer from that polyp.

MEGAN: Are there any signs and symptoms of polyps that come up for people regularly?

DR. MEYERHARDT: Yeah. So, polyps can bleed, so you will have patients who will have a positive fecal occult blood test or actually see blood in their stool, and they’ll actually get a scope, and they’ll have a polyp that, fortunately, hasn’t turned malignant yet or hasn’t become cancerous.

Polyps, if they become large enough, can also lead to what we call obstructive symptoms. Your colon, your rectum, and most of your G.I. tract is a big piece of plumbing, and, if inside you block the plumbing, things can back up, and you can get symptoms from that, whether that be abdominal cramping or constipation or change in the caliber of the stool. So, some polyps can become large and lead to similar symptoms that you would see with someone where it truly became malignant.

MEGAN: So, what advice, too, would you give to anyone who really dreads a colonoscopy?

DR. MEYERHARDT: As I said, colonoscopies are the most complex of the screening techniques. For most people, what they dread the most is the prep, actually, because you have to clean out your stool. It’s the best way for the gastroenterologist or the surgeon to be able to look inside the colon, really see particularly small polyps or other lesions there. So, the prep is the toughest part.

For most people, that means not eating the day prior and then, sometime in the afternoon, starting a clean-out. I think there are a lot of different ways to, potentially, clean out, and there has been some evolution in the formulas that are used — you know, different gastroenterologists and surgeons will prefer different formulas in terms of cleaning out. The most important thing is to stay hydrated.

The day of the procedure is, for most people, a little easier. In general, most people get some level of anesthesia to make sure they’re comfortable. They do pump air into the colon, so there are some gassy symptoms that you’ll have after. But again, if you get a colonoscopy and it looks clean, the guidelines then would say you can go 8 to 10 years if you’re an average-risk patient. So, you know, I think the compromise of some discomfort and some inconvenience of it to sort of feel that things are clear for a period of time is really important.

Now, if they do find something, then you may need your next colonoscopy a little sooner, and that all depends on if they find some polyps, the number of polyps, the size of the polyps, so there are various recommendations in terms of follow-up based on what they find.

MEGAN: Is there anything else you think people should kind of just generally know about colorectal cancer that we haven’t covered yet?

MEYERHARDT: Yeah, I mean, again, I would reiterate this is a curable disease for most patients, so the earlier we catch it — and certainly, if we catch it before it even became a cancer, in the polyp state, but even if it has developed into cancer, the earlier we catch it, the higher chance of curing a patient is. So, I think that’s really an important take-home point.