Jun 27, 2019
Dr. Nathan Pennell and Dr. Jennifer Ligibel discuss weight management and physical activity programs for patients with cancer.
TRANSCRIPT:
Hello, and welcome to the ASCO Journal of Oncology Practice
podcast. This is Dr. Nate Pennell, medical oncologist at the
Cleveland Clinic and consultant editor for the JOP. I'm sure
everyone who listens to this podcast is aware that obesity and lack
of physical activity are major health problems in the USA, and they
contribute to multiple medical conditions such as heart disease,
diabetes. But how much do patients and oncologists know about how
obesity and lack of physical activity impact cancer incidence or
treatment or outcomes? And how do physicians manage these issues in
their practice?
With me today to discuss this issue is Dr. Jennifer Ligibel,
associate professor at Harvard Medical School and medical
oncologist at the Dana-Farber Cancer Institute, where she also
serves as director of the Leonard P. Zakim Center for Integrative
Therapies and Healthy Living. We'll be discussing her paper,
"Oncologists' Attitudes and Practice of Addressing Diet, Physical
Activity and Weight Management with Cancer Patients, Findings of an
American Society of Clinical Oncology Survey of the Oncology
Workforce." Welcome, Dr. Ligibel, and thanks for joining me
today.
Thank you so much for having me.
So just to set the stage for our listeners, how big of a problem is
obesity and physical inactivity among cancer patients? Is this
something that is generally mirroring the larger problem we see in
America, or is there anything different about our cancer
patients?
Well, we know that obesity and inactivity are risk factors for
developing a number of different malignancies. The International
Agency for Research in Cancer and the World Cancer Research Fund
have both analyzed observational data linking obesity, inactivity,
poor dietary quality to the risk of developing malignancy, and have
demonstrated really consistent evidence that there is at least 13
different malignancies where obesity, in particular, increases the
risk of developing the malignancy. So if you think about the fact
that obesity and inactivity are pretty prevalent in the United
States, in general, and that these factors also increase the risk
of developing malignancy, we find that an even higher proportion of
cancer survivors are obese and inactive as compared to the general
US population. We also know that treatment that patients get for
some malignancies can contribute to weight gain, and also can
contribute to inactivity. So you put all of these factors together,
and a very large proportion of cancer survivors are at risk for
obesity, inactivity, poor dietary quality, or all of those factors
together.
I mean, the number that you and your co-authors mention is that
almost 1/3 of cancer survivors are obese. That seems like a huge
number. So clearly a major problem.
Yes, that's true. And that number has increased significantly over
the last decade.
So I know that obesity contributes to cancer risk. But is there
data that even treatment of cancer can be impacted by these
issues?
Yes. So we know that obesity has an impact on treatment-related
outcomes and, likely, on the risk of recurrence and mortality in
many different diseases. Breast cancer has been the best studied,
where we know that women who are obese when they're diagnosed with
breast cancer actually have a 35% higher risk of dying from breast
cancer compared to women who are of normal weight when they were
diagnosed with breast cancer.
Similar data are emerging in other malignancies. Colorectal cancer,
there has been a strong link with obesity and cancer outcomes.
Prostate cancer, gynecologic cancers, there's emerging data as
well. So we know that these factors can impact the risk of
recurrence and mortality. But there's also evidence that suggests
that people who have excess adiposity, have metabolic complications
of obesity, are at higher risk of complications like poor wound
healing after surgery. They're at higher risk of lymphedema and
some malignancies. They may be at higher risk of things like
peripheral neuropathy related to chemotherapy. So there are a lot
of poor outcomes associated with body weight in cancer
patients.
Now, I know even dosing of chemotherapy, I believe, obese patients
are at risk for under-dosing because people are afraid to give them
proper weight-based dosing. So lots of reasons to pay attention to
this issue. Is there data, though, that changing that-- intervening
with helping patients lose weight or patients at risk losing
weight, or increasing their physical activity-- mitigates these
risks?
That is a great question, and one that will hopefully be answered
within the next few years through a number of large-scale, ongoing
phase III trials that are looking at the impact of weight loss,
increased physical activity, better dietary quality on cancer
recurrence and mortality. We don't have data from randomized
trials, at this point, looking at the impact of lifestyle change
after diagnosis on outcomes. But we do have a lot of observational
data that suggest that individuals who are physically active are at
lower risk of recurrence in malignancies like breast cancer, colon,
and prostate cancer. And we do also have a lot of information from
randomized trials that are smaller in scale that demonstrate that
losing weight, exercising more has an impact on shorter-term
outcomes, like quality of life, cancer-related and
treatment-related side effects like fatigue, neuropathy, joint
pain. So we know there are benefits of lifestyle change after
cancer diagnosis, but we're still awaiting these large-scale trials
that will show us whether changing these behaviors actually reduces
the risk of recurrence and mortality.
So already enough evidence that it's important that we address it,
but hopefully, we'll have more convincing evidence soon. Can you
take us through the ASCO survey? What was the background to doing
the survey, and what did it try to assess?
So in 2014, ASCO launched an obesity initiative that really sought
to educate the oncology workforce about the connections between
obesity and related factors in both cancer risk and outcomes, and
to provide tools and resources to help oncologists talk to their
patients about physical activity, weight management during and
after cancer treatment. There was also a part of the initiative
that focused on research and advocacy.
We were interested, given that 2014 was a number of years ago, to
look at what were the current attitudes of oncology providers
toward these topics? What was their practice? Were they talking
about weight? Were they talking about physical activity and diet
with their patients?
And what did they perceive as barriers to really implementing
behavior change after cancer diagnosis? And so we designed a survey
that would be delivered to individuals that were currently seeing
oncology patients. And they could be physicians, they could be
nurse practitioners, they could be dietitians or anyone that was
currently working with oncology patients and was an ASCO member.
And then we asked them questions about their practice, about the
attention that they paid to these topics, about what they felt got
in the way. And then thinking more broadly about how important did
oncology providers think that these topics were in the scope of
their practice.
Why don't we just jump right into the results? So what were the
results from the survey?
So first of all, we found that the people that filled out our
survey were pretty typical for the general ASCO membership. So
about 2/3 of the people that filled out the survey were based in
the US. The other 1/3 were international. We did have a higher
proportion of medical oncologists, partly because this was limited
to people that were actively seeing patients. We had a nice balance
of private practice and academic centers, and we had individuals
that were treating all different kinds of cancer. So we were happy
with the population that filled the survey out as being fairly
representative of oncology providers in the US and more
broadly.
We found, when we asked the providers what were their perspectives
on issues related to obesity and cancer, that there was a very
strong agreement that obesity impacts treatment outcomes in cancer
patients. And in fact, more than 90% of the survey respondents
strongly agreed or agreed with that statement, which we were very
excited to see. There was also high agreement with addressing a
patient's weight should be a standard part of cancer care. And most
of their respondents felt that it was the responsibility of the
treating physician to recommend healthy diet, regular activity,
weight management for patients in whom that was relevant.
But there was much less agreement that the oncology workforce felt
that they were prepared to be either delivering those interventions
or that they had enough information or enough training to really
feel comfortable in their skills to help patients start to make
these changes. So I thought that was very important that there was
high agreement that these things were important, but also a feeling
of there needed to be other parts of the health care team that
could help patients once these issues were identified in really
helping them to make the changes that needed to after
diagnosis.
We then asked providers about what they were doing now, and we
found that the vast majority of providers that completed the survey
indicated that they were asking patients about their physical
activity patterns, about their diets. They were assessing patients'
weights. And this was both during and after cancer treatment. There
was a much lower proportion of survey respondents that were
actually making referrals to dietitians, to weight management
services for their patients. So although there was a lot of
discussion and there was an assessment, there wasn't necessarily
the next step, which was helping patients actually incorporate
these changes through a referral to a skilled provider.
And then, the last piece was looking at barriers. And I think that
this was something that we were actually a little bit surprised
about some of the responses. The last part of the survey focused on
looking at the respondents' perceptions of barriers. What did
oncology providers feel like was getting in the way of patients
changing their diets, exercising more, losing weight when it was
relevant?
We found that, not surprisingly, lack of time for counseling was
something that many providers noted, lack of available resources.
So even if you identified that a patient wanted to lose weight or
meet with a dietitian, there wasn't necessarily someone that was
available. Lack of training or expertise on the part of the
oncology provider was also noted. We also found that the majority
of participants felt that patients' resistance to behavioral
interventions was also a large barrier to helping people make these
changes. And this really led us to think start thinking about,
well, what is the patient's perception?
And I think that's something that we did not cover in this survey,
but that is really critical. Because if we find that oncologists
are talking about these topics and are trying to reinforce the
importance, but patients aren't hearing that or aren't making these
changes, then we're really not accomplishing what we want to. So I
think from this survey, we now can see what oncologists feel is
important and what they're doing in their practices. And we need to
figure out, what are the patients hearing and what is the result of
the advice that the providers are giving to patients?
Yeah, that really is an interesting and kind of a surprising piece.
So the first part resonates with me. So I certainly address, you
know, in my patients that are in follow-up and survivorship,
exercise and trying to maintain a healthy weight. And I also feel
that I'm not super comfortable with trying to intervene in that
myself, but rather try to suggest that they look for SilverSneakers
or some sort of local exercise gym or other opportunities or,
perhaps, refer them to a dietitian.
But I don't know that I have a perception that the patients
wouldn't welcome that advice or that they might be resistant. Is
there any plan to try to get an assessment of cancer patients'
attitudes on this?
So this is something that we are planning at this time. We are
trying to develop a survey and partner with some patient advocacy
groups to really better understand what the patients' perceptions
of these topics are. There is not much currently in the literature,
but there have been some assessments. There was a large study that
was done in the UK that looked at patients with colorectal cancer
and the attention that was paid on the part of their provider to
exercise. And if patients remembered hearing about exercise, they
were much more likely to do it.
So I think that something that we really need to better tease out
is, what is the patients' receptivity to this type of information?
And are the suggestions that oncologists are making enough to get
patients, on their own, to seek out a program? Or do we really need
to try to educate providers about effective ways of making
referrals?
I think the reality is that we also need more programs that
patients can be referred to. And something that I think is a real
need within the oncology space is programs that help people lose
weight that are able to help people become more active, and
recognizing some of the limitations that many patients have as a
result of their therapy. Things like lymphedema, things like
neuropathy, that can be barriers. How can we manage those in
oncology patients to help them successfully achieve these behavior
changes?
And this is, I think, such a great topic because patients really
care about interventions that they can do themselves to help their
cancer care and their health. And there's so much out there, in
terms of complementary therapies and whatnot. But we have real data
on things like diet and exercise, and I think more attention being
paid to this within cancer centers would really be welcomed by
patients.
I think so too. You know, we, right now here at Dana-Farber, are
leading a trial called the Breast Cancer Weight Loss Trial that's a
phase III study looking at the impact of a weight loss intervention
on recurrence in women who are overweight or obese when they're
diagnosed with breast cancer. And when we started this study, we
weren't sure what the uptake would be. It's a very different type
of model. But we've enrolled now more than 2,000 patients in less
than three years. So there's definitely a very, very significant
interest in this topic amongst patients.
There's a similar trial going on in ovarian cancer that just
enrolled 1,000 patients with a disease that's much less common than
breast cancer over just a few years. So I think that the interest
on the part of patients in this topic is large and we want to be
able to provide them with evidence-based recommendations. There's a
lot of stuff out there that's not so evidence-based, especially
about diet, and I think that, as oncology providers, we really owe
it to our patients to get them the best information that we have
about things that they can do to help improve their outcomes and to
make themselves feel better during and after their cancer
treatment.
And we're very lucky to work at institutions like the Dana-Farber
Cancer Institute or here at the Cleveland Clinic, where we've
actually got a lot of resources devoted to these efforts. But what
can people who work at smaller institutions, or really don't have a
lot of infrastructure for this, where can they access data or
suggestions on how they can counsel patients or help their patients
address problems with obesity and lack of physical activity? Is
this something that ASCO can help with?
So as part of the ASCO Obesity Initiative, we developed toolkits
for oncology providers and for patients about the role of weight
management and physical activity in cancer. And so those are
available at cancer.net. They can be downloaded. You can give them
to your patients to start a conversation about the importance of
these topics in oncology care.
The American Cancer Society also has diet and exercise guidelines
for cancer survivors that oncologists can use as a guideline. The
American College of Sports Medicine also has a website where they
have oncology-trained exercise professionals in different
communities. So if a patient wants to work with a trainer that has
an understanding of the complications of cancer treatment and the
side effects that patients have, that's another good resource.
The other thing that is available in many communities is the
Livestrong at the YMCA program, which is a free exercise program
that's offered for cancer survivors. This is offered now in more
than 700 YMCAs across the country. It's a 12-week program that
includes both aerobic exercise and strength training. And this is a
resource that I send a lot of patients to, and that is available to
people not everywhere, but increasingly more places. So that's
another good resource for oncologists and for patients across the
US.
Well, that's fantastic. So good, I'm glad we got to plug that on
the podcast. And Dr. Ligibel, thanks so much for talking to me
today.
Thank you.
And I also want to thank all of our listeners out there who joined
us for this podcast. The full text of the paper will be available
online at ASCOpubs.org/journal/JOP in June 2019. This is Dr. Nate
Pennell, for the Journal of Oncology Practice, signing off.