Studies seeking to gain insight into patients’ perspectives on the burden of CIM are important, as hematologic side effects can have a substantial negative impact on patients’ quality of life and may contribute to suboptimal treatment outcomes [1, 4, 6, 19]. Many studies have sought to understand patients’ perceptions of the symptoms associated with CIM, but few studies have been designed to better understand patients’ perspectives on the overall impact of CIM and how it is managed in daily practice.
In the current survey, anemia and neutropenia were reported most commonly (61% and 59% of participants, respectively), whereas thrombocytopenia and lymphopenia were relatively less common (34–37% of participants). The actual rates of myelosuppression reported in the survey are higher than would be expected in an all-comer population, given that we focused only on participants with a diagnosis of myelosuppression and/or treatment for myelosuppression. In a study of electronic medical records from 339 evaluable patients diagnosed with SCLC, for example, real-world rates of chemotherapy-induced neutropenia, anemia, and thrombocytopenia were 45%, 41%, and 25%, respectively [27]. The finding that anemia and neutropenia were more common than thrombocytopenia is consistent with the prescribing information for a range of myelosuppressive chemotherapy treatments, although many report neutropenia as being more common than anemia [3]. It is possible that the relatively broad inclusion criteria in this online survey may have led to overestimation of the incidence of CIA, since participants with anemia resulting from the cancer itself or other underlying causes would also have been included.
In line with the finding that most participants were diagnosed with anemia or neutropenia, G(M)-CSF, ESAs, and RBC transfusions were described as the most common supportive care interventions, each being reported in approximately one-third of participants. Retrospective studies of supportive care use among US patients with solid tumors or lymphoma have shown that 35–55% of patients receive prophylaxis with myeloid growth factors [28, 29]; however, far fewer patients receive ESAs [27, 30]. The low utilization of ESAs in the USA may partly reflect the US Food and Drug Administration’s decision in 2007 to restrict ESA use to patients with a hemoglobin (Hb) level of less than 10 g/dL owing to concerns over rapid tumor progression and shortened overall survival with ESAs at Hb greater than 12 g/dL [31]. Similarly, there has been a shift toward a more restrictive policy on transfusions for CIA in recent years, with guidelines supporting a Hb threshold of less than 7 g/dL for most patients [32]. Despite these recommendations, the findings of the current study, along with previous reports on patterns of supportive care use in patients on chemotherapy, suggest that, in general, interventions such as growth factors and transfusions are commonly used. Indeed, only 21% of survey participants in the current study reported receiving no treatment. This finding is notable, as the supportive care interventions themselves can present additional risks, such as bone pain with G(M)-CSF; thrombotic events with ESAs; and transfusion reactions and infections with RBC and platelet transfusions; as well as being a burden to patients [7, 8, 24,25,26, 33].
Approximately two-thirds of survey participants experienced an issue with continuing on their current chemotherapy regimen due to myelosuppression, reflecting the substantial impact of hematologic side effects on standard-of-care treatment schedules and doses. This is in line with findings from studies in patients with advanced non-small cell lung cancer and breast cancer. In these studies, chemotherapy was delayed by at least 1 week in approximately one-third of patients, and approximately 40% of patients had a relative dose intensity of less than 85% [9, 34]. Such dose modifications are clinically relevant, as maintaining appropriate dose intensity is important in both the curative setting and in treatment with palliative intent [3]. For this reason, the development of equally effective chemotherapy regimens that carry less long-term risks has been an important focus of research. The frequent, uninterrupted administration of low-dose (metronomic) chemotherapy, for example, is thought to result in sustained, low blood levels of chemotherapy, with fewer side effects, and a reduced need for supportive therapies [35]. However, although alternative dosing strategies may be useful to reduce CIM, they should be limited to situations where dose reductions are not expected to compromise long-term outcomes.
Participants reported that myelosuppression was most frequently managed by an oncologist, as opposed to a nurse, physician assistant, or other HCP. This differs to other areas of supportive care, such as the management of nausea and vomiting, where oncology nurses are often better placed to manage side effects, as they have more frequent contact with individual patients and offer a holistic approach to care [36, 37]. Nevertheless, most participants had confidence in their oncologist to be aware of and treat side effects, although some perceived that their oncologists did not understand the impact that side effects had on their lives. A previous study examining patients’ perceptions of the physician–patient relationship and communication about AEs also found that most patients reported having a good relationship with their physician, and that they had extensive discussions about what side effects might occur. However, those discussions did not always provide patients with sufficient understanding or adequately equip patients to cope with the AEs [38]. Overall, the results are encouraging, but suggest that there is a need for improved communication between patients and their treating physician, both in terms of improving patients’ understanding of potential side effects and in listening to their perspectives on how these events affect everyday life. Indeed, improved patient–physician communication would help foster shared decision-making, especially when critical decisions regarding treatment discontinuation or treatment changes must be made.
It is notable that most participants, particularly younger participants, felt that myelosuppression side effects had a moderate-to-major life impact, despite the fact that most perceived their symptoms to be expected and treated quickly. In particular, in their verbatim responses, many participants described a substantial negative impact on their ability to carry out daily tasks, due to fatigue and concerns about infection. This is especially pertinent in light of the COVID-19 pandemic that occurred following the completion of this survey, which is likely to further exacerbate the impact of myelosuppression on patients’ lives by creating an additional burden to health care systems and by heightening fears that a weakened immune system will put oncology patients at risk of severe complications from the virus [39, 40].
One limitation of this study is that the use of an online patient database to engage participants may have created bias in favor of reflecting the preferences of participants with more familiarity with online technologies, or who were healthier than the average oncology patient. In principle, patients with worse disease characteristics, requiring aggressive treatment for cancer and/or CIM may not have been interested or able to participate in the survey. The study is also based solely on patient self-report, and the extent to which patients can accurately recall this type of information is not known. Thus, these findings should be considered alongside findings from other patient populations and using other methods, such as prospective observation, patient diaries, and/or interviews within clinical settings, to confirm and extend the findings. On the other hand, a key strength of using an online platform is that participants may be more willing to share information than in a face-to-face interview, and may be less likely to be directed toward a socially desirable response. Additionally, the use of verbatim responses provides important information on aspects of the patient burden of CIM that would not otherwise be captured in a closed response questionnaire.