Vital Signs – October Teleconference Transcript: Obesity and Cancer

Press Briefing Transcript

Tuesday, October 3, 2017

Please Note: This transcript is not edited and may contain errors.

OPERATOR: Good afternoon and thank you for standing by. As a reminder, today’s conference call is being recorded. If you have any objections, please disconnect at this time. Your lines have been placed in listen only mode until the Q&A session of today’s conference. At that time, you may press star followed by the number one to ask a question. I would now like to turn the conference over to your moderator, Kathy Harben. Thank you, you may begin.

KATHY HARBEN: Thank you, Michelle. Thank you, everyone, for joining us today for the release of a new CDC Vital Signs. We are joined today by CDC’s deputy director, Dr. Anne Schuchat, as well as, Dr. Lisa Richardson, who is director of CDC’s Division of Cancer Prevention and Control.

ANNE SCHUCHAT: Good afternoon, everyone, and thanks for joining us today. CDC provides for the common defense of the country against health threats. Each month in our vital signs report, we focus on a disease from the front lines and give you information to help stop it. Today’s report contains new information about national cancer trends and focuses in on trends in those cancers associated with obesity and overweight. Let’s start with the good news. We have made great strides in overall cancer since the 1990s. As a nation, we’re now better at preventing and treating some cancers. Improvements in early detection through screening have helped drive down cancer rates. Between 2005 and 2014, the incidence of cancers not associated with overweight or obesity decreased 13%. But today’s report shows in some types of cancers, we are going in the wrong direction. As we’ve highlighted before, we are seeing the effects of obesity and overweight on many chronic conditions. Today’s vital signs report highlights how the growing prevalence of obesity and overweight is affecting cancers as well. This may be surprising to many Americans, since awareness of some cancers being associated with obesity and overweight is not yet widespread. Research shows that being overweight or having obesity is associated with at least 13 types of cancer. Today’s report looked carefully at trends in the rates of specific cancers, comparing the ones that are associated with obesity and overweight with the ones that are not, and looking closely at colorectal cancer, which is associated with obesity but also has a very effective screening intervention that can address precancers. Our study shows that cancers not associated with obesity and overweight are going down. Colorectal cancer is going down, but the rates of most of the cancers associated with obesity or overweight has increased over the past decades. They’re up 7%. We’ve noticed these cancers are increasing particularly among middle-aged adults, people between the ages of 50 and 74. These are important results, and may be harbingers of even greater challenges in the years to come. Tackling obesity is difficult. Many of us struggle with our weight. We’ve heard for a long time that people who are obese or overweight are more likely to suffer from heart disease, strokes, and diabetes. But more than half of Americans are not aware that excess weight can increase the risk of many cancers. And unfortunately, two out of three Americans are either overweight or obese. It’s easier to prevent overweight and obesity than it is to reverse it and the science is still catching up on whether and how much losing weight can lower a person’s risk of some cancers. We do know that even modest weight loss can help when it comes to lowering the risk of other chronic diseases like diabetes and heart disease. The trends we’re reporting today are concerning. The first step to addressing a risk is to be aware of it. There are many good reasons to strive for healthy weight. Now you can add reducing your risk for cancer to the list. The obesity epidemic is a complex and major public health challenge that requires comprehensive efforts. People can eat healthy, be physically active, and get recommended cancer screening. I’m going to turn things over now to Dr. Lisa Richardson, who will share the detailed findings from the report.

LISA RICHARDSON: Thank you, Dr. Schuchat. For this Vital Signs report, we analyzed data from the United States Cancer Statistics database to calculate cancer rates associated with being overweight and having obesity in 2014 and trends from 2005 to 2014. We looked at the 13 types of cancer classified by the International Agency for Research on Cancer as having enough evidence to support being associated with excess body fat. These include cancers of the thyroid, gallbladder, upper stomach, liver, pancreas, kidneys, ovaries, uterus, colon and rectum, breast in post-menopausal women, myeloma, a cancer of blood cells, meningioma, cancer in the brain and spinal cord, and a type of cancer of the esophagus. In 2014, 13 cancers associated with overweight and obesity made up 40% of all cancers diagnosed. Around 55% of cancers in men and 24% of — sorry, in more men, and 24% of cancers in men were associated with overweight and obesity. The fact that endometrial, ovarian, and post-menopausal breast cancers accounted for 42% new cases in 2014 reflects the fact that these cancers occur among females. However, among cancers that affect both males and females, incidence rates were higher among males. For the time period studied, new cancer rates for all cancers associated with overweight and obesity are down, but the decrease varied widely by age group. Colorectal cancer had the second largest decrease in rate of new cases during the study period. Increased colorectal cancer screening, which prevents colon cancer, most likely accounts for this decline. It’s important to note, though, that when we took colorectal cancer out of the equation, we found cancers associated with overweight and obesity went up in all age groups except people age 75 or older. These findings are concerning and it will take the cooperation and coordination of many more organizations to help more people nationwide get to or maintain a healthy weight. On a federal level, CDC supports comprehensive cancer control programs in all 50 states, the District of Columbia, 8 tribes and 7 territories. Our programs focus on cancer prevention, education, screening, quality of cancer care, and survivorship. Our programs work with partners in the community that are already doing some of the following activities. Schools are providing healthy food options and quality physical education. Health care providers can screen for and educate patients about the dangers of overweight and obesity. Workplaces are encouraging physical activity and offering healthy food options in vending machines. Planners are building parks, gardens, and roads that are safe for all types of transportation to share including walking. Planners are being — sorry, encouraging families to be physically active is part of the equation as well. Maintaining a healthy weight and reducing overweight and obesity in adults and children can help reduce the risk and burden of cancer. We’re still learning how losing weight can decrease the risk of some cancers in people who weigh more than recommended. Losing weight also lowers the risk for high blood pressure, diabetes, heart disease, stroke, and other chronic conditions. The bottom line is it will take everyone working together to reduce cancer associated with overweight and obesity. Thank you. I will now turn it back to the moderator.

KATHY HARBEN: Thank you, Dr. Richardson. Michelle, we’re now ready for questions.

OPERATOR: Thank you. At this time if you would like to ask a question, you may press star one. To withdraw your question, you may press star two. Again, star one if you do have any questions. Jessica Glenza, from The Guardian, you may go ahead.

JESSICA GLENZA: Hello. Thank you so much for holding this call. My question is whether rates of obesity linked cancer now rival that of tobacco linked cancer since the CDC has said that tobacco-linked cancers account for 40% of overall cancer diagnoses in the United States.

ANNE SCHUCHAT: Thank you for that question. We could actually get you more information subsequently, but one thing I would like to clarify, when we say obesity associated cancers, some of those cancers are also actually associated with tobacco. It’s different to say something is associated with obesity and overweight than to say that that is the cause. We know that there are different levels of causation, and of course, tobacco has been pretty clearly shown to be the cause of several types of cancer. So, I think the specific numbers involved of adding up all the tobacco-associated cancers and whether those tally greater numbers than all of the current obesity-associated cancers is something that folks can do after the call. I do want to caution that our finding is looking at the 13 types of cancers that are considered associated to obesity and overweight, not that are necessarily all causally related to obesity and overweight. Next question.

OPERATOR: Thank you. Our next question comes from Laurie McGinley from The Washington Post. You may go ahead.

LAURIE MCGINLEY: Yes, thanks very much for taking my question. I’m interested in what you think the mechanisms are of the link here, whether it has to do with inflammation or if there is some explanation or if people don’t really know what the explanation is. And also, you mentioned that not losing weight, it’s not clear whether it would reduce the risk. Why would that be, that not losing weight would not necessarily reduce your risk? Thank you.

ANNE SCHUCHAT: Let me start — this is Dr. Schuchat, then I’ll let Dr. Richardson fill in more details. There are multiple mechanisms considered to be likely biological underpinnings for a link between overweight and obesity and cancer, including the endocrine changes that occur, as well as inflammatory mechanisms that can sometimes be turned on by some of those endocrinological changes that occur with overweight and obesity. In terms of the reversal, we know that it’s possible for some things. You know if you quit smoking for several years, your risk can reduce. The question is really whether the mechanisms that are turned on in the presence of overweight and obesity can be reversed, or whether the cancer process is already far enough along. That’s the high level answer. But let me let Dr. Richardson go into more details about the specific mechanisms.

LISA RICHARDSON: This is Dr. Richardson. Dr. Schuchat is exactly right. For some cancers, the endocrine mechanism, especially estrogen, is very prominent for blood cancer and endometrial cancer. As you stated, inflammation is extremely important in causing carcinogenesis or generating cancer in the first place. Regarding losing weight, the current evidence is the biomarkers, the inflammatory marker that we look for, are decreased when we lose weight about the evidence is still not there about whether it would reduce the risk for developing cancer completely. There is promising research that was published this year in the Journal of Clinical Oncology from the women’s health initiative looking at intention weight loss. In that study, women who lost weight of ten pounds or more did lower their risk of developing endometrial cancer. The evidence is early but promising.

ANNE SCHUCHAT: Thanks. Next question, please.

OPERATOR: Thank you. Mike Stobbe, from the Associated Press. You may go ahead.

MIKE STOBBE: Thank you for taking my call. Just a variation of the earliest one. Could you say in the clearest possible way, does obesity cause cancer, yes or no? Or what’s the most plainspoken statement you can make to answer that question?

ANNE SCHUCHAT: Obesity and overweight are associated with a higher risk of many types of cancers. Our report found an increase in a number of types of cancers associated with obesity and overweight at a period where the prevalence of obesity and overweight has increased substantially in the middle ages. So our report has indirect evidence that this greater evidence of obesity is starting potentially to show up in our cancer statistics. The evidence for a link between obesity and overweight and cancer is considered strong by the international association of research on cancer. And that consortium group has essentially identified 13 types of cancers that are associated with overweight and obesity. So it’s not exactly the same as what we say about tobacco and cancer. But the mounting evidence points to this association and the trends that we’re seeing are an indirect emphasis that there are important general changes going on. Next question?

MIKE STOBBE: Thank you.

ANNE SCHUCHAT: I’m sorry, did you have a follow-up, mike?

MIKE STOBBE: I was just wondering, are there other possible explanations for some of the trends that were noted in some of these cancers besides the fact that these categories of cancer are associated with obesity?

ANNE SCHUCHAT: Yes, and in particular, I think one of the simplest ones to think about is the trend in liver cancer. We saw an important increase in liver cancer between 2005 and 2014. But we know of a number of factors that are associated with liver cancer besides obesity and overweight. Of course, we’re talking a lot about Hepatitis C here as something that’s become quite a bit more common. So I think with liver cancer, there are a number of factors. Hepatitis C and Hepatitis B are both associated with liver cancer, as is fatty liver, which can result from alcohol problems and can also result from overweight and obesity. So I think that gives you an example of the complexity of each of these cancer statistics. I think the importance of today’s report is when we step back and we lump together all of the types of cancers that are associated with overweight and obesity, we saw a direction upwards. And when we looked at all of the other cancers except for colorectal cancer, we saw a direction downwards. That’s not a smoking gun. But that is a note of caution for us. And that’s one of the reasons that we’re trying to bring broader attention to awareness that at this point, obesity and overweight have been associated with a number of types of cancers. Most of us hadn’t heard of that, and that’s one of the things we’re trying to alert the public about. Next question.

OPERATOR: Thank you. Leigh Ann Winick from CBS News. You may go ahead.

LEIGH ANN WINICK: Thank you. I’m wondering and you mentioned in your introduction that about half of Americans are not aware of this association. What does that point to as far as a directive to primary care physicians and other public health officials? What might you be suggesting?

ANNE SCHUCHAT: You know, awareness is the beginning. And certainly we know that people hearing from their doctors or nurses take information differently than when they hear it from the general public or the media. So we do think it’s important for us to get the word out and for clinicians to get the word out with their patients about the potential health effects of overweight and obesity. We know that there’s lots of challenges with maintaining a healthy weight, but that it’s an important thing each of us can do. We know that there can be challenges with having enough physical activity in our daily schedules. But it’s an important thing to do. We do urge clinicians to talk with their patients about how to maintain a healthy weight. And if they are overweight or obese, what kinds of steps they might take to work on that. Next question.

OPERATOR: Thank you. Once again, as a reminder, you may press star one if you would like to ask a question. Our next question comes from Tom Corwin with Augusta Chronicles. You may go ahead.

TOM CORWIN: Thanks for taking my question. I see you have the 13 cancers listed here. One that’s not on the list is prostate cancer. I’m curious whether that was looked at in this report or not.

ANNE SCHUCHAT: Dr. Richardson can answer that one.

LISA RICHARDSON: No, prostate cancer was not reviewed in the most recent report, no. The report, it was not looked at.

TOM CORWIN: Okay. Thank you.

ANNE SCHUCHAT: Okay. Next question.

OPERATOR: Our next question comes from Rachel Bergman with the American Public Health Association. You may go ahead.

RACHEL BERGMAN: Yes, hi, thanks.

ANNE SCHUCHAT: It’s hard for us to hear you, could you try to speak closer to the microphone, please.

RACHEL BERGMAN: Is this any better?

ANNE SCHUCHAT: Just a little bit.

RACHEL BERGMAN: I apologize. I’ll try to speak up. You spoke a little bit about the disparate incidence between males and females with these cancers. Can you talk about other disparities you saw in other population groups?

ANNE SCHUCHAT: Right. Thank you. We did see that the increases were more pronounced in the middle-aged adults than in adults over 75 — or 75 and over. So that was — the trends were, you know, increasing in that middle-aged population. That was an important factor. You know, in terms of the direction that things were going rather than the individual risk. When we look at age in general, of course, cancer rates are higher in the oldest of age groups. But when we looked at the trend in the obesity and overweight associated cancers, we saw it was increasing in those younger age groups and not in the group that was 75 and over. There of course have been some racial and ethnic differences in the incidence of cancers in general, and there are as well in the incidence of obesity and overweight-related cancers, some geographic differences. But I think the important — most important of the differences that we found was that this age group of middle-aged adults, who probably are the cohort that has really experienced this increase in the prevalence of obesity and overweight in America, that that’s the group where obesity and overweight-related cancers, associated cancers, have been increasing, rather than in the oldest age group.

ANNE SCHUCHAT: Next question.

OPERATOR: Once again, if you do have any questions or comments, you may press star one. Again, that is star one if you would like to ask a question.

KATHY HARBEN: Michelle, this is Kathy Harben, the operator. If anyone else has questions, they’re welcome to call us at 404-639-3286. Or they can e-mail us at I would like to thank Dr.’s Schuchat and Richardson for joining us today. We will post a transcript of this call later. And again, if you have other questions, please contact us by phone or e-mail. Thank you very much.

OPERATOR: And thank you. This concludes today’s conference call. You may go ahead and disconnect at this time.


Page last reviewed: October 3, 2017