Cancer Topics - ASCO Guidelines: Antimicrobial Prophylaxis for Adult Patients with Cancer-Related Immunosuppression Guideline

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Hello and welcome to the ASCO Guidelines podcast series. My name is Shannon McKernin, and today I'm interviewing Dr. Randy Taplitz from UC San Diego Health, lead author on Antimicrobial Prophylaxis for Adult Patients With Cancer-Related Immunosuppression: ASCO and IDSA Clinical Practice Guideline Update.

Thank you for being here, Dr. Taplitz.

Thank you.

So first, can you give us a general overview of what this guideline covers?

Yes. I mean, I think we're all aware that infection in the setting of neutropenia associated with cancer chemotherapy is really a major cause of morbidity in these patients. And it's also important to be aware that prevention and appropriate management of febrile neutropenia and infection should thus be a critical focus in cancer care. So the focus of this particular guideline was to evaluate the risk and benefits of antimicrobial prophylaxis in these patients and really to determine evidence-based best practices for prevention of infection and how to go about doing that. So

In this guideline, what we do is we identify the groups at risk for febrile neutropenia and really recommend settings for which prophylaxis with antibacterial, antifungal, antiviral medications are indicated. And then as well make recommendations for consideration of vaccination and other measures such as respiratory etiquette, and hand hygiene, and the like that will help reduce the risk of infection in these vulnerable patients.

So since this is an update of a 2013 guideline, what are the major changes? And can you tell us a little bit about the research that informed this update?

Yes. Really, when you update a guideline, one is informed by review of articles that encompass, in this setting, randomized clinical trials as well as meta analysis of interventions to prevent microbial infections in patients with neutropenia or other types of immunosuppression.

And one example of this-- I think one of the better examples-- is we reviewed a large meta analysis of antibiotic prophylaxis in neutropenic patients after chemotherapy that showed that for fluoroquinolone prophylaxis resulted in really significant reductions in all cause mortality and febrile episodes, particularly in patients who were high risk, meaning the hematologic malignancy population and stem cell transplant population. And in that particular population, in fact, the number needed to treat to prevent one death was 29. So therefore, in that high risk population, really as with prior guidelines, the fluoroquinolone prophylaxis is recommended.

However, we also reviewed other articles that include emerging data on some of the risks of fluoroquinolone prophylaxis. So for instance, the effect of fluoroquinolone on the intestinal microbiome and its association with selection of fluoroquinolone-resistant bacteria such as Gram-negative rods, as well as selection of organisms such as Clostridium difficile and enterococcus. And then we also reviewed fluoroquinolone toxicities.

So what is added to this guideline are some qualifying statements alerting clinicians to really be aware for these concerns and to consider what the clinical spectrum of things like Clostridium difficile infection, et cetera, look like.

In terms of antifungal prevention, including pneumocystis prevention, we really haven't made any major changes to this guideline with the exception that in this new guideline, the panel has also started looking at complications associated with immunotherapy and actually makes a suggestion that people consider pneumocystis prophylaxis in the setting of prolonged steroid use when it's used to treat immune-related adverse events that we've begun to see in increasing numbers associated with agents like checkpoint inhibitors and other immunotherapies.

In terms of viral infections, the updated guidelines recommend risk assessment for hepatitis B reactivation and then treatment in accordance with other ASCO guidelines and yearly influenza vaccine, as well as really endorsing other vaccines as described in the Infectious Disease Society of America Guideline for Vaccination in Immunocompromised Hosts.

So really, those are the main new events since 2013.

And what are the key recommendations of this guideline?

So the key recommendations-- the first thing is what we call a risk assessment. So after-- what one does is carefully assess, really, what the risk of febrile neutropenia is. And that includes assessment of patient, what the cancer is, and what the treatment-related factors are. And then after they're risk adjusted and risk assessed, then we take, in turn, different forms of prophylaxis that we consider.

And so the first one that we always consider is antibiotic prophylaxis against bacterial infections. And the recommendation is still with the fluoroquinolone. And that's recommended for most patients who are at high risk for febrile neutropenia or profound, really prolonged neutropenia, such as those getting therapy for AML, or myelodysplastic syndrome, or stem cell transplant recipients, particularly with myeloablative regimens. In the lower risk groups, such as those with most solid tumors, fluoroquinolone prophylaxis is not recommend.

In terms of antifungal prophylaxis, what is recommended is an oral triazole or Micafungin-- for patients, again, at risk for profound protracted neutropenia such as that AML, MDS, stem cell transplant group during that period of neutropenia.

When the risk of invasive aspergillus is high, such as in patients with AML or MDS during the neutropenia period while getting chemotherapy, then the consideration of a mold-active triazole is recommended and in addition should be considered in the context of stem cell transplant recipients with graft versus host disease.

In terms of PCP prophylaxis, PCP preventive therapies are recommended for those at high risk for PCP, which include those on greater than what we say 20 milligrams of prednisone equivalent a day for over a month, or based on purine analog use.

Viral prophylaxis for HSV is recommended for seropositive patients undergoing allogeneic stem cell transplant or leukemia induction.

And then as I mentioned before, patients at risk for hepatitis B reactivation are recommended treatment with a nucleoside reverse transcriptase inhibitor. And this is more carefully discussed in the ASCO Provisional Clinical Opinion on Hepatitis-B Virus Screening for Patients With Cancer Before Therapy.

It's also recommended that a yearly flu vaccine is given to patients as well as given to family, household contacts, and health care workers. Other vaccination recommendations are as per the Infectious Disease Society of America Guidelines for Vaccination of Immunocompromised Hosts.

And then the other things that are recommended are really review and repeat recommendation of adherence with hand hygiene, with respiratory etiquette, which is recommended and really required for all health care workers. And that out patients with neutropenia from cancer chemotherapy should avoid high risk activities, which include really contact with environments that have high concentration of fungal spores such as construction and demolition, high intensity gardening, et cetera.

So those are really a summary of the key recommendations of this guideline.

And finally, how will these guideline recommendations affect patients?

I think it's important to remember that to ensure best practices on infection prevention, the literature needs to be reviewed frequently and guidelines need to be updated. I don't think that these current guidelines will dramatically change the preventive strategies that are used for patients, with the exception of perhaps a few extra vaccines-- some newer indications for pneumocystis prevention, hepatitis B reactivation prevention, those kinds of things.

However, I think in reviewing the literature, it becomes clear what will we will need to be thinking about in the coming years, what we will need to be assessing. And a couple of those things are the dramatic increase in the use of immune-based therapies and how that will affect infection risk in patients with or without neutropenia. We need to be considering the effects of routine antibiotic prophylaxis on the microbiome and the risks that that might incur. And we need to really understand how new vaccines can be utilized.

So yeah, I think these areas are really ripe for research and need to be followed closely to ensure optimization of these preventive strategies for our patients in the future.

Thank you for your time today, Dr. Taplitz.

You're quite welcome.

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