HOPA Past President: Research Assessing the Microbiome in Colorectal Cancer Is Emerging Daily, May Have Significant Impact to the Field

Pharmacy Times interviewed David DeRemer, PharmD, BCOP, FCCP, FHOPA, a past-president on the board of the Hematology/Oncology Pharmacy Association (HOPA), assistant director of Experimental Therapeutics at the University of Florida Health Cancer Center, and clinical associate professor at the University of Florida College of Pharmacy, on insights from the HOPA 2022 annual conference.

Alana Hippensteele: Hi, I’m Alana Hippensteele with Pharmacy Times. Joining me is David DeRemer, PharmD, BCOP, FCCP, FHOPA, a past-president on the board of the Hematology/Oncology Pharmacy Association, or HOPA, assistant director of Experimental Therapeutics at the University of Florida Health Cancer Center, and clinical associate professor at the University of Florida College of Pharmacy. David is here to discuss insights from the HOPA 2022 annual conference.

So the annual conference was held during the month of March, and I noticed there was a greater focus on colorectal screening and its importance considering March being colorectal cancer screening Awareness Month. Could you tell me a bit more about why greater focus on colorectal screening is important to highlight?

David DeRemer: Yeah, so this is a major, important topic in our nation, as well as throughout the world as it relates to colorectal cancer screening. This just sort of set this discussion up—about 3 or 4 years ago, there was a paper published in the Journal of the National Cancer Institute, in which they found that people born in 1990, who would be 30 to 32 years old this year, have doubled the risk of colon cancer and quadrupled the risk of rectal cancer compared to those born in 1950.

So there's been this shift of individuals who are being earlier diagnosed for colon cancer, which has got a lot of scrutiny from the medical community on why this is occurring. So both the United States Preventive Services Task Force and others have provided preventive guidelines for years, most oftentimes, recommending colorectal cancer screening be initiated at age of 50 [years]. But they have since changed those guidelines and recommend now that patients be screened at the age of 45 [years]. This, of course, will be 5 years earlier than previously recommended.

So there has been this greater focus on identifying colon cancer earlier. To date, there have been several investigations looking at why this is occurring in younger folk. But to date, we still don't have a definitive reason of why younger patients are getting colon cancer at these alarming rates.

Alana Hippensteele:Right. What are some of the ways that potentially social determinants of health may also be impacting colon cancer risk at this time?

David DeRemer: Yeah, so I think if you look at the death of Chadwick Boseman, [who is the actor] from Black Panther, and he died at the age of 43. So it really put a spotlight on a young African American male and the diagnosis and, unfortunately, the death in such a young person. So this has been looked at for several years now, looking at how colorectal cancer disproportionately affects the Black community. From a rates perspective, they are the highest racial-ethnic group in the United States, as it relates to having about 20% more individuals who are likely to have colon cancer, and about 40% of those are more likely to die. So there has been significant interest in looking at social determinants of health in this population.

Clearly, [issues] such as poverty, lack of education, lack of social support, social isolation, of course, healthy diets, or sedentary lifestyles, those things have all been looked at. From a broader perspective, we're all aware of this—as we look at national screening from other cancers, such as breast, prostate, lung cancers, and additional colon cancers—all these have been delayed due to COVID-19 over the past several years because many institutions shut down their ability to provide elective procedures during our shutdowns.

If you look still to this day, in 2022, if you talk to your institutions, many institutions around the country are still having about 2- to 3-month delays for colorectal cancer screening if you're trying to pursue a colonoscopy at your local hospital. So delays are still occurring.

As you just mentioned, there has been a significant rise in the interest of having a marketing campaign for everyone, including African Americans specifically because of some of the data we're seeing, to get their colonoscopies earlier and start at the age of 45.

Alana Hippensteele: Right. So you mentioned the marketing campaigns targeting increased awareness around colon cancer or colorectal cancer screening among younger populations, but specifically among Black Americans, would you say the guidelines currently align with the population who are more at risk or do the guidelines not yet align with this?

David DeRemer: Yes, to the guideline question, guidelines such as American Cancer Society as well as United States Preventative Task Force and NCCN, they don't necessarily recommend earlier screening modalities, less than the age of 45 years old for African Americans, but they are discussed in those guidelines as having a potential increased risk.

Now, to talk about some of that, there's registry data that suggests that there's an increased incidence of colorectal cancer for patients who are African American, prior to the age of 50. But if you look at the mortality data from colorectal cancer from African Americans compared to Whites, since the 1990s, it's been decreasing.

So, given mortality is complex and is related to numerous host factors, including tumor biology and diet, and some of these other things—really a lot of the efforts have been [around] African Americans having their screenings, still with that 45-year-old sort of guidance as it relates to getting your first colonoscopy.

From a marketing standpoint to the first part of your question, there have been numerous interventions that are ways to increase screening uptakes. Specifically, looking at either community demand or access. From community demand, looking at having patient reminders, patient incentives, either small media campaigns at your local cancer center or mass media at a larger level. From an access issue, this is where a lot of challenges as well as a lot of efforts have been occurring. Trying to reduce structural barriers, I think all of us in clinical practice, understand, particularly as it relates to help with transportation, if patients are trying to get to a cancer center for treatments, the same thing with preventative strategy—various centers are looking at having flexible office hours to potentially provide those type of services after traditional 5 pm [closing] hours.

Then, of course, cost is always an issue. So there's been efforts to try to reduce the out-of-pocket expenditures with either vouchers for reimbursements, even as something as simple as bowel prep reimbursement. We don't traditionally think about the bowel prep, of course, which is such an issue before the colonoscopy, but even looking at reimbursement or patient assistance for the financial aspects of that as well have been looked at by a variety of groups to try to improve the ability for patients to be able to get screened effectively.

Alana Hippensteele: Right. Could you tell me a bit more about some of the research currently underway assessing the role of microbiome in colon cancer?

David DeRemer: Yeah, so there's a lot of research in this field, and this continues to emerge daily. I was keeping up last week when they had the [American Association for Cancer Research (AACR)] meeting in New Orleans, and there were several discussions about how the microbiome is involved in the prevention of cancer as well as how the microbiome might affect cancer therapies.

I think all of us are aware of some of the older data currently, where patients that have had chronic exposure to antibiotic therapy, which would affect the gut microbiome, those individuals are less likely to have an immune response to immune checkpoint inhibitors. So we've seen that data over the past several years and the data continues to emerge.

One bug that comes to mind is Bacteroides fragilis, which is a particularly bad bug as it relates to producing a toxin which damages intestinal cells. This leads to chronic inflammatory states, which is known to generate cancers. So this area just continues to emerge.

I'm curious where we go in the near future as it relates to this field of science. Specifically, for colon cancer, are there foods or other ways which could generate a stronger CdA or a CD4 T cell response, which would sort of improve our traditional responses to therapies. Numerous foods—are there other ways, including fecal transplantation—we've talked about fecal transplantation in the setting of C diff, but there is sort of this emergence of microbiome research into impacting drug therapies. I'm just curious where that goes as we go in the future.

Alana Hippensteele: To date are there any treatments that are being currently investigated that seem promising in terms of the relationship between microbiome and colon cancer?

David DeRemer: Not necessarily for treatments, but I will say that it is being evaluated. When I say that, I will say that I work in early phase clinical trials. I'm going to say with any industry-sponsored study, now in the setting of any colorectal cancer, as well as any of our investigator-initiated trials that involve an immune checkpoint inhibitor that we collect stool, and we do associated microbiome analysis, we have a microbiome group here on our campus.

So, as this becomes more well established, I think we'll be able to [have a] better understanding of how certain drugs affect the microbiome, I think over the next 5 to 10 years, we'll continue to see more data emerge in this. But clearly, in all our clinical studies, we're collecting stool samples for microbiome analysis, and I think we're going to have more data soon.

Alana Hippensteele: What are some areas you'll be looking to follow in terms of future developments in the field?

David DeRemer: Yes, that's a great question. I think as pharmacists, as other health care professionals also looking at this, I think most of us have had interests looking at drug response, particularly through the lens of either germline or somatic mutations and how that affects drug response and a variety of malignancies.

Clearly with the emergence of microbiome data and how that integrates itself with either mutational status, as well as microbiome and how that integrates itself into potential drug response, I think that is something that all of us have an interest of looking at in terms of current or future research in this field.