More than one in two patients with cancer may experience symptoms of long COVID for more than 6 months after initial COVID-19 infection, according to a new study published by Dagher et al in eLife. The findings were comparable to the reported incidence of long COVID in the general population, but also showed that female patients undergoing cancer treatment may be at higher risk than male patients of developing long COVID. 

Background

In the general population, long COVID’s development rate has a variable range of 10% to 87%—with symptoms persisting beyond 30 days among patients who had severe COVID-19 infections or were hospitalized.

“Although [patients with] cancer fall into a higher COVID-19 infection risk group, there is limited data on [long COVID] in [these] patients and how it affects their progression, care, and treatment,” explained lead study author Anne-Marie Chaftari, MD, Associate Professor of Infectious Diseases, Infection Control, and Employee Health in the Division of Internal Medicine at The University of Texas MD Anderson Cancer Center. “In order to provide a better understanding of post–COVID-19 [infection] management among patients [with cancer], we sought to characterize the patterns of long COVID specifically in these patients,” she added.

Study Methods and Results

In the new study, the researchers identified patients who were infected with COVID-19 between March 2020 and September 2020 and followed their progress for up to 14 months via remote symptom monitoring and their usual hospital visits. Questionnaires were sent out to the patients daily for 14 days after their initial COVID-19 diagnosis, then weekly for 3 months, and then monthly for the remainder of the 14 months. Patients were asked to record symptoms of fatigue, coughing, chest tightness, difficulty breathing, headaches, fevers, an altered sense of smell or taste, muscle aches, gastrointestinal symptoms, sleep disturbance, and any limitations in their daily activities. Long COVID was defined as COVID-19–related symptoms persisting beyond 30 days after the initial diagnosis or the emergence of new COVID-19 symptoms.

The researchers collected data for 312 patients with cancer, 60% (n = 188) of whom developed long COVID. Patients who had relapsed or treatment-resistant cancer at baseline and those who had more severe acute COVID-19 infections were found to be less likely to develop long COVID. Further, female patients with cancer had a higher rate of developing long COVID compared with male patients with cancer (63% vs 51%). There were otherwise no differences in the characteristics of patients who developed long COVID and those who did not—and risk factors such as having depleted white blood cells, requiring oxygen therapy, and being hospitalized for a COVID-19 infection or multiple organ failure were similar in both groups. The most commonly reported symptoms of long COVID among the participants were fatigue, sleep disturbances, muscle pain, and gastrointestinal symptoms.

Additionally, the researchers discovered that patients who had high blood pressure were surprisingly less likely to develop long COVID, despite the fact that high blood pressure is a known risk factor for a more severe acute COVID-19 infection. Similar findings were also seen in another study of long COVID among immunocompromised patients. The link between blood pressure and the risk of a severe acute COVID-19 infection may be the result of the binding of the COVID-19 spike protein to angiotensin-converting enzyme 2 (ACE-2)—the target of many blood pressure–lowering medications. These findings might rule out this mechanism as a causative factor in the development of long COVID.

Among the 188 patients with cancer who developed long COVID, 31% (n = 59) of them were readmitted to hospital, but only 8.5% (n = 16) were readmitted for COVID-19–related reasons—with most of these patients having symptoms that were likely manageable in outpatient care. 

Conclusions

“Our study found that long COVID occurred in the majority of our [patients with] cancer and was more prevalent [among female patients] than [male patients],” emphasized senior study author Issam Raad, MD, FACP, FIDSA, FSHEA, Professor of Infectious Diseases, Infection Control, and Employee Health and the Endowed Distinguished Chair in the Division of Internal at The University of Texas MD Anderson Cancer Center. “Even in this high-risk patient population, long COVID was not associated with a high rate of hospital admissions. We also found no underlying conditions or severity of illness during [an] acute COVID-19 [infection] that would predict [the risk of developing] long COVID,” Dr. Raad concluded.

Disclosure: For full disclosures of the study authors, visit elifesciences.org.