I'm Dr. Ben Weinberg. I'm a gastrointestinal medical oncologist at
MedStar Georgetown University Hospital. I specialize in the treatment of patients
with colon and pancreatic cancers. We administer a variety of different
treatments. The treatment we're probably most well known for his chemotherapy. but
we also administer targeted therapy and immunotherapy. So we sort of form
the quarterback of the team that takes care of patients with cancer. So we
work closely with radiation oncologists, surgeons, gastroenterologists, pathologists,
and a variety of other support staff to help our cancer patients. We used to tell
people you know wait one month, two months, three months, a year and a new
treatment will become available, and it used to take much longer than that. Now
the field is moving so quickly, it's almost hard to stay on top of all the
advances that we're having. And those advances have basically come in one of
two forms. One is immunotherapy, and immunotherapy works by training your
body's immune system to take care of the cancer itself. And the other is targeted
therapy. If we can figure out the mechanisms by which the cancer cell
divides and grows, we could be able to stop the cancer cell in its tracks if we
can find drugs that target those mechanisms. We have a couple benefits at
MedStar Georgetown University Hospital. One is our team. So we have excellent
surgeons, excellent radiation oncologists, excellent gastroenterologists, who are
really leaders in the field, and we work together as a team to come up with
treatment plans that are best for patients. The other thing is we're on the
cutting edge of different research strategies, so immunotherapy, clinical
trials, and targeted therapy clinical trials. So treatments that we think are
promising but are not yet FDA-approved to treat cancer, we have access to those
drugs here, and if appropriate, we can get patients on those trials. Being at
MedStar Georgetown University Hospital, we definitely operate in the pursuit of
cura personalis, so treatment care of the whole person, so not just focused on
their cancer but what affects the cancer is having on their body, what effect the
treatment is having on their body, other psychosocial issues that we tend to not
spend as much time talking about but trying to focus on those when it's
critically important for our patients. There's nothing better than to feel like
you've really benefited a patient's life and especially if that
results in something like a cure. We often don't know for quite some time
whether a cure is truly a cure, so a lot of what we do is monitor patients very
closely after they finish whatever treatment, not only to make sure that
they're truly cured but to see what side effects of the treatments can crop up
later on in life. So there's a lot of aspects to survivorship that are
critically important to manage. But that feeling, that sensation is is truly
rewarding.
We offer a whole panoply of different treatments. I mean, the old standard
is different forms of chemotherapy. Those are drugs either an IV or pill form
which work on rapidly dividing cells, the theory being that the most rapidly
dividing cells in the body are cancer cells. So those drugs are typically not
smart bombs, they're sort of dumb bombs, but they work by killing rapidly
dividing cells. And we still use them even though some of them have been
around for decades because they're effective, and we know their side effect
profiles and they're pretty manageable. We also have newer therapies like
immunotherapy. And how immunotherapy works is basically by retraining your
body's own immune system to go and attack the cancer. A lot of times we have
immune cells in our body that are ready, willing, and able to go kill cancer cells,
but for whatever reason the cancer has turned themselves off to the immune
system, put the immune cells to sleep. And we now have drugs that can reenergize
or reinvigorate tumor's immune cells to go after and kill the tumor cells. And
then the other treatment we have are different forms of targeted therapy. So
through better knowledge of how tumor cells grow, we know certain pathways,
certain mechanisms by which tumor cells can grow and divide, and we now have
drugs that can exploit those pathways by shutting them down. So if we can identify
certain pathways that we can target with a novel drug, we may be able to stop a
cancer cell in its tracks. And oftentimes what we're doing is combining those
therapies together, so chemotherapy, immunotherapy, and targeted therapy. We
also work closely with a number of our colleagues throughout the hospital to
offer local therapy. So what I've mentioned so far are systemic therapies,
they go everywhere throughout the body. We also have local therapies that can go
in and treat cancer cells where they are. One is surgery, so cut out that the
cancer if it's available to do so. One is radiation, so deliver some focused
radiation to kill the cancer cell where it lies. And then we also work with
interventional radiologists who can do local procedures to inject tumors, oblate
tumors, even biopsy tumors to get us more information. There's a variety of also
therapies we work a lot with to inject drugs including chemotherapy, radiation,
directly into the liver to kill tumors that are trying to grow in the liver.
I often see patients after they've already been diagnosed with colon or
pancreatic cancer, and I think it's important a lot of times patients want a
second opinion. So they often see an oncologist in the community who gives
them sort of standard of care options. I think it's important you know for them
to come to see us so we can review their scans, their pathology, their treatment
course, recommend certain standard of care options, but also see if we have
clinical trials available for that patient. And so we work closely with our
fellow community physicians to figure out you know what patients are best
treated in the community, what patients should come here. Often it's you know the
patient preference, but a lot of times we try to get patients back to the
community so they can get the treatment closer to home.
The good news is overall rates of colorectal cancer incidence are actually
on the decline. And that's largely due to the advent of colonoscopy screening and
the older patient population started in the late 80s. The sad part is we're
actually seeing a rise in young onset colorectal cancer, so this is the
population that's under 45 that's too young to get a routine surveillance
colonoscopy if they're at average risk for developing colorectal cancer. And
this is a relatively recent phenomenon. The incidence really started increasing
in the 90s, and the the rate of death from colorectal cancer and younger
patients has started increasing since the year 2000. And we don't really know
why this is occurring. There's a lot of theories that it has to do with rises
in rates of obesity, diabetes, something we eat in our diet. But to be honest, we
really don't know the answer. So this is a field of very active research to try
to figure out why young patients are getting colon cancer.
There's a variety of theories out there. One is obesity. One is diabetes. But I
will tell you, our clinic is filled with young patients with colon and rectal
cancer who are neither obese nor diabetic. So something is clearly going
on. One of our theories is it has to do with microbiome. So you have about a
trillion cells in your body. You have a trillion, probably trillion and a half,
cells in your guts, which are bacteria, most of which we don't really know
exactly what they do. We know some are good. They help us digest foods. We know
some are bad. They can cause disease, cause infections. And we actually now
know that some can actually cause colon and rectal cancers. And so one of our
research interests is to try to see is the microbiome both in the gut but also
in the tumor itself different in patients with young onset colorectal
cancer in older onset colorectal cancer. So we have a grant from the Colorectal
Cancer Alliance looking at young versus older onset colorectal cancer
specifically looking at the intra-tumoral microbiome. meaning the bacterial DNA
that are present in the tumor tissue as opposed to what's found throughout the
gut. And we're hoping to demonstrate some sort of difference that would one shed
light on what's causing these cancers to develop, may actually allow us to develop
novel therapies including antibiotics and vaccine therapy to target those
bacteria, and then also might inform us to help to best screen these patients.
Should everybody get colonoscopies at 45, 40, 35? What if we could do it in a
smarter way where we can identify patients with a high risk stool for
example via a stool sample and then say that patient should get a colonoscopy
much earlier or they could get routine colonoscopy at 45 or older. So those are
the types of things we're trying to unlock through this research.
I have a specific research interest in young onset colorectal cancer. So I have
a trial I'm looking at the microbiome or the bacteria within the tumor itself
in patients who were diagnosed before age 45 and those who were diagnosed
after age 65. So I'm trying to capture as many patients as possible to try to
answer this question: is the bacteria within the tumor different in young
versus older onset colorectal cancer? So I encourage all young onset colorectal
cancer patients to come here so that we can do those types of testing. The other
reason to come here is for a second opinion to figure out am I getting the
right treatment, should we switch to something else, is there a clinical trial
available.
You have a trillion cells in your body. You have a trillion to probably trillion
and a half cells in your gut and that's what we refer to as the gut microbiome.
And those are mostly bacterial cells, many of which we don't know exactly what
they do. We know some are good. They help us digest foods. We know some are bad, can
can cause disease like infections. And we now know that some can actually cause cancer
specifically colorectal cancer. And we think of the microbiome as an interplay
between the immune system, the environment like your diet, and genetics
so what you've inherited from your parents. And this is important not only
for risk of disease and things but they've actually shown for immunotherapy
a drug we use a lot of, different bacteria in your gut can actually change
how well your cancer responds to immunotherapy. So that's a sort of
separate interest from my interest which is mainly looking at what bacteria are
within the tumor. But a lot of oncologists are interested in bacteria
throughout the gut because it may actually impact how patients respond to
therapy. And if patients aren't responding to immunotherapy, maybe we
should be giving things like antibiotics, probiotics, even stool transplants to
maybe alter the microbiome. A lot of that research is still ongoing right now.
We used to refer to colorectal cancer as one entity. And once a cancer spread
outside the colon or rectum, we treated them as the same cancer. It's a colon
cancer that spread to the liver, a rectal cancer that spread to the liver. There
are once and you know cohesive entity. But we now know through doing a lot of
studies of tumor DNA profiling, so taking tumor tissue, sequencing out the DNA to
find the mutations that cause that cancer to grow, we now though there
actually are significant differences in tumors that come from what we call the
right side of the colon which is closer to the liver, the left side of the colon
which is closer to the rectum, and the rectum itself are all sort of discrete
different pockets of cancer. And those mutational patterns kind of change
throughout the colon and also change as patients age. So we know that younger
patients for example tend to get colon cancers more in the rectum or near the
rectum, whereas older patients tend to get cancers in the colon that are closer
to the liver. And this is actually important because it impacts response to
certain treatments for patients with advanced disease.
Immunotherapy is designed to retrain your body's own immune cells to go after
and attack the cancer. There are some cancers that have basically put up a
force field to the immune system. They've developed ways to escape our immune
cells which normally go and kill bacteria or other bad things the body
finds. So there are certain handshakes that some cancers have where they can
shake the hands of the immune cell and say you don't need to attack me you can
just go to sleep and that immune so will go to sleep.
We now have drugs that can disrupt that handshake and can say no the tumor cell
can't turn the immune cell off anymore now the immune cell is awakened and can
actually go out and find and kill the cancer.
Immunotherapy is more or less effective in different types of cancers and even
in the cancers where it's effective it doesn't seem to work for all patients.
And why that is, we're still trying to figure out. What we do know is that the
more mutations or the more irregular your tumor is, the more susceptible it is
to immunotherapy. And the best examples of that are melanoma skin cancer which
often is developed from ultraviolet light radiation. That radiation doesn't
cause some changes to the tumor cell, it causes lots of changes. It disrupts the
DNA of the tumor cell. And more DNA disruption leads to more mutations and
more mutations can actually lead to the development of cancer. The more mutations
your cancer cell has, the more irregular it looks to your immune system. So the
immune system is trained not to go attack normal body cells, otherwise we'd
have bad autoimmune diseases in all of our bodies. But if the more irregular the
cancer cell looks, the better able the immune cell is than to say oh I have a
receptor on an immune cell that can recognize that cancer cell. And if that
interaction exists, then the immune cell can go and kill the cancer cell.
We have a variety of clinical trials available. And because they open and
close all the time and even if a trial is open, slots may or may not be
available and sometimes this changes on a day to day basis, I highly encourage
patients to reach out to our nurse navigators and to us as physicians to
find out what's available at any given moment in time. That said, a lot of our
trials use different approaches. Some are immunotherapy trials where we're trying
to combine immunotherapy with some other agents to work in tumors where
immunotherapy by itself has not been effective. So some of those are trials
where we take traditional chemotherapy and add chemotherapy plus immunotherapy.
Some are trials where we take a targeted agent that we think can help unleash the
immune system. Sometimes that's a pill blocking the cancer-causing pathway.
Sometimes that's a vaccine, like a flu vaccine type of vaccine, that's then
given with the immunotherapy and those are designed to try to retrain the
immune system to tak those attack those cancers.
Cancer is, unfortunately, pretty smart. We're getting smarter, but the cancer
cell usually still outsmarts us at some point. So even if we have a therapy
that's working, the classic example is chemotherapy, often times we can't keep
giving the chemotherapy indefinitely because of side effects. But sometimes, we
can. And when we can, usually the cancer cell eventually finds a way to grow with
that chemotherapy. The idea is if you can kill 99% of the cancer cells with
chemotherapy, that's great, but that 1% of cells eventually sometimes only order of
months two years later will eventually grow big enough to be a visible on a
scan, for example. And then, we really need to switch therapies often to come up
with something to target that resistance cell. And sometimes, it's like playing a
game of whack-a-mole where you again you've killed the vast majority of cells
but that one so that lingers pops up somewhere else. And so we have to keep
thinking and recycling treatments to see what's best for the patient.
At MedStar Georgetown University Hospital, we offer treatment for the
whole patient in our pursuit of cura personalis. So, it's not just treating the
patient and their cancer, but it's treating their symptoms, their symptoms of their
cancer, their side effects from their treatment, but also working with a
cohesive group of docs to find what's best for the patient and their family.