Neil Carleton is a postdoctoral researcher at the University of Pittsburgh. He investigates the intersection of aging and breast cancer to find clinical strategies for older populations. In this Postdoc Portrait interview, he shares how serving this underrepresented group of people can lead to meaningful results and real-world impact.
Understanding the Aged Tumor Microenvironment
Q | What motivated you to study breast cancer in older patients?
It is an exciting intersection of clinical interest and unanswered clinical questions, combined with tumor biology and the kind of work that can be done at the bench and in translational spaces. Together, those elements made breast cancer a compelling area to focus on.
As both a researcher and a physician, I stay closely connected to the clinical side of these conditions. Clinical observations were what first sparked my interest, especially between 2018 and 2020, when evidence emerged showing that some breast cancer patients did not need axillary surgery. These findings led to changes in surgical guidelines and highlighted the need to better understand how age-related breast tumors may develop and behave differently.
I also find this patient population especially rewarding to work with. Many patients think deeply about how treatment decisions fit into their lives, and discussions around de-escalation based on tumor biology are often reassuring and empowering.
Q | What scientific problem are you trying to solve?
I have become deeply passionate about understanding the relationship between aging and cancer. My primary focus is breast cancer, an age-related disease, with most women diagnosed around the age of 67–70. Treating this population can be particularly challenging, as many patients have comorbidities and other medical conditions that can influence how their breast cancer is managed.
Our approach has been to better understand the tumor biology of age-related breast cancers so that treatment intensity can be matched more precisely to the biology of the tumor. In some cases, this may mean de-escalation, or less treatment for less aggressive tumors, while in others it may require more aggressive treatment, depending on the specific tumor type.
Clinical Impact and Surgical De-Escalation
Q | What’s one thing you learned from your work that you didn’t expect?
I was surprised by the involvement of older adults in our studies for circulating tumor DNA (ctDNA), as a tool for evaluating treatment de-escalation for breast cancer. Although older adults are often underrepresented in clinical trials, largely because they are not approached or because trials are not conducted where they receive care, we found that many of these patients were eager to participate. They were not only willing, but genuinely excited to enroll and contribute to the research. Many expressed a desire to help future patients, not just themselves. This level of engagement and enthusiasm was surprising and deeply encouraging. It reinforced the importance of designing studies that include older patients and actively inviting them to participate, as they are highly motivated to contribute meaningful data that can shape future care.
Q | If your research succeeds, what could it change for science or society?
Our ongoing prospective trials aim to test different treatment paradigms for older patients with breast cancer. If successful, this work could fundamentally change how these tumors are viewed and treated. For example, one of our studies explored whether ctDNA could be used upfront as a biomarker to identify patients who may safely undergo surgical de-escalation. Other studies focus on identifying patients who require more intensive treatment based on tumor biology. Collectively, this research has the potential to shift clinical practice toward more personalized, biology-driven treatment approaches for older adults with breast cancer.
Q | What question are you most excited to answer next?
I am particularly excited about expanding our ctDNA findings to larger and more diverse patient populations. Our initial study was relatively small, so the next step is to validate these results across multicenter cohorts and generate broader enthusiasm for this approach. Another critical question is how to act on ctDNA results. Patients who are ctDNA-negative appear to do very well on endocrine therapy alone, raising the possibility of even further treatment de-escalation, potentially including discontinuation of medication. For ctDNA-positive patients, the key question becomes which escalated treatments such as surgery or alternative medication regimens are most effective. Answering these questions will be essential for translating ctDNA-guided strategies into routine clinical care.
Responses have been edited for length and clarity.
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