How Does COVID-19 Affect Cancer Survivors?
Around 20% of individuals who contract COVID-19 develop severe illness that requires hospitalization. Cancer patients going through active treatment are at higher risk for COVID-19 complications, but what about cancer survivors?
Studies among women with breast cancer have found chemotherapy to be associated with changes in immune parameters that did not return to pre-treatment levels a year or more after the end of treatment. Cancer survivors are also known to have an increased risk of heart disease, which is a risk factor for COVID-19.
Little data is available to date on how COVID-19 affects cancer survivors, so researchers in England wanted to investigate whether cancer survivors are at a higher risk for severe COVID-19 outcomes. They took a deep dive into medical records to compare the prevalence of risk factors currently used to guide COVID-19 policy between cancer survivors and those with no cancer history. They also compared the risk of influenza hospitalization or death between the two groups as a way of exploring susceptibility to severe outcomes from epidemic respiratory viruses.
The study included more than 108,000 survivors of the 20 most common cancers who were at least one year post-treatment. Of those, almost 10,000 had prior hematological malignancies. The group was compared to more than 523,000 individuals with no history of cancer. Comorbidities—or additional medical conditions that can occur during or after a primary condition, such as cancer—were identified as asthma, chronic respiratory disease, chronic heart disease, chronic liver disease, chronic neurological disease, chronic kidney disease, diabetes, obesity, sickle cell disease and splenectomy. These comorbidities are also risk factors for COVID-19.
For all cancers combined, the study found a higher prevalence of all risk factors for severe COVID-19 except for obesity and sickle cell disease/splenectomy in one-year cancer survivors compared to the cancer-free group. At five years after diagnosis, cancer survivors overall had a slightly higher prevalence of all risk factors except heart disease and neurological conditions. Overall, 62.7% of the cancer survivors had at least one of the comorbidities five years after diagnosis, while 37.3% had two or more.
When it came to the flu, the risk of influenza hospitalization or death was 2.7 times higher in cancer survivors compared to those with no history of cancer. Hematological cancer survivors had a 15 times higher risk of a severe influenza outcomes compared to people without cancer.
More research is still needed on the effect of COVID-19 on cancer patients and survivors. Another UK study found substantially raised risks of COVID-19 mortality amongst individuals with prior hematological cancer persisting for at least five years and smaller raised risks for those with a history of solid tumors up to five years from diagnosis. A study reported by the COVID-19 and Cancer Consortium reported a high 30-day mortality among individuals with an active or previous malignancy, although active disease was a strong predictor of mortality. Another study found a non-statistically significant increased risk of mortality in patients exposed to chemotherapy four weeks prior to infection compared to cancer patients that did not receive chemotherapy.
“Because cancer survivors have a higher risk for COVID-19-related morbidity and mortality, we need to prioritize and emphasize the importance of vaccination in this population,” said Dr. Smitha Pabbathi, medical director of the Survivorship Clinic at Moffitt Cancer Center.
Vaccine acceptance is a challenge across the board for the flu shot, especially in the cancer survivor population. This could mean those who do not get a flu shot would also not want the COVID-19 vaccine.
“This is worrisome and should be a public health concern given the number of survivors that are projected to grow in the coming years,” said Pabbathi. “We know very little about the underlying reasons for the lack of vaccine acceptance and what kind of interventions we need to overcome these barriers. As providers, we need to take the time to learn more about the concerns and beliefs that cause this hesitancy and find better ways to advise our patients.”
Discussions about immunization are an important part of the comprehensive care the Survivorship Clinic offers, and will become even more important once a COVID-19 vaccine is available.
