A total of 10 oncologists and 10 PCPs were interviewed for this study. Overall, PCPs had a mean of 21.8 (SD 11.3) years and oncologists had a mean of 15.4 (SD 10.4) years of experience in practice. PCPs reported that 5–20% of their patients had active cancer. Oncologists estimated that up to 40% of their current cancer patients had pre-existing type 2 diabetes. Specific characteristics of the providers and the types of cancers that the oncologists treated are presented in Table I. Interview duration ranged from 15 to 30 minutes.
From our data analysis, we identified a total of six themes that are presented in Table II and Figure I. Two major themes emerged from our interviews with PCPs: (1) cancer patients pausing primary care during cancer treatments, and (2) patients with poorer prognoses and advanced cancer. The following theme emerged from our interviews with oncologists: (3) challenges in caring for cancer patients with uncontrolled diabetes. We identified three common themes across both oncologists and PCPs: (4) providers’ discomfort with providing care outside of their specialty, (5) the need to individualize care plans according to patient-specific responses to cancer regimens, and (6) lack of effective communication between oncology and PCPs.
Theme 1: Cancer Patients Pausing Primary Care During Cancer Treatments
PCPs mentioned that once patients were diagnosed with cancer, patients struggled to prioritize primary care until their cancer treatments concluded. The lack of engagement with primary care during cancer treatments made it difficult for PCPs to continuously manage diabetes during patients’ cancer care.
“Sometimes, patients don't come to us and they'll sort of disappear for six months or a year.” (PCP)
PCPs revealed that many cancer patients with pre-existing diabetes experience significant weight loss due to their cancer treatments. However, PCPs are unable to intervene and manage diabetes during these weight fluctuations because patients do not make appointments to see them.
“One thing that comes up a lot is depending on how much weight they lose as a result of either their cancer or their treatment, their diabetes requirements tend to go down. That happens a lot. I personally in 17 years am usually not seeing that in real time because the patient just doesn't come back; doesn't want to come back; is fully immersed in their cancer care. Unless they actively seek me out, I tend to see them at some point where they've already lost a lot of weight.” (PCP)
Theme 2: Patients with Poor Prognoses and Advanced Cancer
PCPs also described overall well-being as an important factor in diabetes management for their cancer patients. Generally, patients with poor prognoses created dilemmas about how aggressive to be with diabetes management. PCPs shared how challenging it was to address these difficulties.
“Oftentimes the questions of control are ones of prognosis. In other words, if someone has an incredibly poor prognosis and they're being aggressive with palliative care or other interventions, is taking control of the diabetes the goal or is losing control of the diabetes the goal?” (PCP)
Theme 3: Challenges in Caring for Cancer Patients with Uncontrolled Diabetes
Oncologists emphasized that some of their patients’ lack of awareness of their diabetes created barriers to cancer and diabetes care management. They highlighted that patients who struggled to access adequate care due to factors, such as lower health literacy, often struggled with the competing demands from co-managing cancer and diabetes.
“Some of my patients don’t even know that they have diabetes when they come to see us. That is a significant difficulty because then I need to involve a new provider.” (Oncologist)
Theme 4: Discomfort with Providing Care Outside of Specialty
Oncologists and PCPs reported lack of sufficient knowledge in providing care outside of their respective specialties. Oncologists reported unfamiliarity with specific diabetes treatment regimens and medications:
“I have never done diabetes management, so I definitely do not feel comfortable prescribing [diabetes] medications.” (Oncologist)
Although oncologists acknowledged the need to modify patients’ use of insulin and steroids during chemotherapy, they felt that diabetes control was out of their area of clinical expertise:
“I know a lot of times with chemotherapy, part of the pre-medications are steroids, which make it harder to control blood glucose. I wouldn't feel comfortable managing any of the oral or injectables. It's sort of out of my wheelhouse.” (Oncologist)
Due to oncologists’ discomfort with diabetes management, they relied on patients to communicate health-related information pertaining to their diabetes treatment regimens. For example, providers expected their patients to explain why they are taking certain diabetes medications:
“It gets difficult because I haven't done diabetes, so I feel I’m underqualified, and you rely on the patients to communicate that.” (Oncologist)
PCPs reported that they lacked sufficient knowledge of rapidly evolving and complex cancer treatments (e.g., chemotherapy, radiation, and hormone regimens) and how they may specifically impact glucose levels during cancer treatments. With the rapidly evolving landscape of cancer treatments, PCPs believed that cancer care for diabetic patients was out of their clinical expertise.
“From the internist’s perspective, there are newer and newer cancer treatments coming out, right? So, the old chemotherapy has evolved into agents that are far less toxic and there are also targeted therapies, immunotherapies, right? There’s a whole other armamentarium out there that the general internist is not as familiar with anymore.” (PCP)
Theme 5: Importance of Tailoring to Patients’ Specific Responses to Cancer Regimens
Due to the complexities associated with the management of concurrent diabetes and cancer, providers highlighted the need for individualized approaches to providing care for each patient. Providers reported that in order for an individualized approach to be successful, it was important to closely monitor how the cancer treatments were impacting patients’ diabetes care. However, close monitoring is time and resource intensive. As providers adjusted care plans in response to patients’ specific needs, a need for improved care coordination and a diverse care team was emphasized.
“There are no algorithms or protocols that we follow. It’s very individualized here in terms of how we manage the patients.” (PCP)
In order to address patients’ specific needs in co-managing diabetes and cancer, providers called for a multi-disciplinary care team. These members included an oncologist, PCP, endocrinologist, certified diabetes educator, and a nurse practitioner.
“The whole rest of the healthcare team should be part of this, including the oncologist and team of specialists who is trained in managing diabetes in the course of chemotherapy and cancer treatments. We have nurse practitioners, certified diabetes educators and nurses who help us take care of our patients. I think all of that can be incorporated really well into the co-management of a patient getting active treatment for cancer with diabetes.” (PCP)
While providers acknowledged that a multidisciplinary care team would benefit all patients, they agreed that disadvantaged patients might experience the most benefit from such an approach.
“Where possible, a physician paired with a diabetes nurse educator, paired with a nutritionist, paired with a care manager would be optimal. There are some patients who have very complicated diabetes and/or who have low health literacy that would maximally benefit from that.” (PCP)
Theme 6: Lack of Communication between Oncologists and PCPs
Lack of communication was a prominent theme that emerged as providers expressed that they do not regularly communicate with providers from other specialties. Despite having questions or concerns regarding patients’ care plans, oncologists and PCPs did not routinely communicate with each other. They rarely updated one another to inform each other of new adjustments that were made to patients’ care plans.
“I have to say, I rarely reach out to them [PCP] saying, this is what I'm doing for the patient.” (Oncologist)
“To be honest, I probably have never sent an oncologist a new message saying that I altered their metformin dose, or I altered their insulin dosing.” (PCP)
While oncologists reported that they were aware of how steroids may lead to worse glucose control, they did not communicate these concerns to the patient’s PCP. Similarly, although PCPs noticed that their cancer patients with diabetes experienced worse glucose control due to their cancer treatments, the PCP did not discuss these intricacies with the oncologists. Oncologists and PCPs highlighted the need for regular communication between providers of the patient’s cancer and diabetes care teams.
“…if the oncologist is seeing sort of more quick day-to-day change or quick changes because they're seeing the oncologist more frequently, I wouldn't mind if the oncologist took care of it [diabetes management] as long as there's some clear communication… (PCP)
While oncologists and PCPs agreed that all providers involved in the patient’s care team (e.g., the oncologist, PCP, endocrinologist, nurse practitioner, etc.) should engage in consistent communication with each other, they admitted that this did not occur. They acknowledged that by regularly reaching out to one another when modifying the patient’s care plan, providers would be able to closely monitor how these adjustments would impact the patient’s health:
“Many patients have protocols about having their diabetes tightly controlled simply because they're required to be in certain ranges for [cancer] treatments. Oftentimes, we find that they're not well controlled and they come back to us after their treatment is finished and their sugars have been uncontrolled for a long period of time. Sometimes, they also get into trouble in the opposite direction because they stop eating because of chemotherapy and nausea and the cachectic stage of cancers and they'll often get quite low. There’s not enough collaboration and communication to really help manage this well.” (PCP)
Due to this lack of consistent communication across oncology and primary care, PCPs and oncologists expressed the need for patient involvement regarding diabetes management during cancer care:
“I rely on the patients to share that information about medication changes with the oncologist.” (PCP)