Q. I have cancer and I am being treated with chemotherapy. Do I have an increased risk of developing Covid-19 and dying?
ON. People with cancer, and people with leukemia in particular, appear to have a higher death rate from Covid-19 than the general population, although chemotherapy with cancer does not appear to increase the risk of dying from Covid any further. However, the studies have been limited and the results are sometimes difficult to interpret.
Many types of chemotherapy work by disrupting the machinery of the cancer cell that allows it to divide and grow so quickly. Unfortunately, chemotherapy can also disrupt healthy cells that grow rapidly in the body, including the bone marrow cells that make up our immune system. As a result, people receiving chemotherapy are at risk of becoming immunocompromised. The immune system, our body’s primary line of defense against microbes, can also be directly corrupted by blood and bone marrow cancers such as leukemia. This can prevent the immune system from maturing and make it incompetent to fight infection.
It’s a logical assumption that people with compromised immune systems are more prone to catching and developing the novel coronavirus. In a recent study, patients with blood and bone marrow cancer had higher coronavirus viral loads, which was associated with higher mortality. However, there are few population-based studies of the rate of coronavirus infection in cancer patients, so we don’t know for sure.
Some studies have looked at the severity of Covid-19 infections in people with cancer. A UK study of more than 1,000 cancer patients followed over a seven week period during the pandemic found a two-fold higher mortality rate in patients with leukemia but not in patients with other cancers compared to a similar group of cancer patients three or more Years earlier, before Covid.
In another study of more than 900 patients with ongoing or previous cancers and Covid-19 infections from the United States, Canada, and Spain, 13 percent and 26 percent died or had a disease so severe that intensive care was required. These rates are much higher than for the general population; Among those with Covid-19, the estimated US death rate is around 3 percent. Cancer patients receiving chemotherapy did not appear to have higher mortality rates or more severe illness than other cancer patients, although 14 percent died and 35 percent developed serious illness in patients with blood or bone marrow cancers such as leukemia and lymphoma.
Another international study of nearly 200 chronic leukemia patients found even higher death rates from Covid-19, 33 percent, although again the rates were no higher for those who received chemotherapy. Interestingly, patients receiving palliative cancer treatment focused on improving quality of life and relieving symptoms rather than active cancer treatment were more likely to die outside of an intensive care unit, likely because they refused aggressive therapy based on their cancer prognosis.
In an ongoing Covid-19 registry from the American Society of Hematology, the death rate was high at 20 percent in nearly 600 blood and bone marrow cancer patients. More than half of the patients were hospitalized, and 23 percent were sick enough to require an ICU stay. More than 50 patients refrained from being admitted to the intensive care unit and opted for a palliative treatment approach. This shows how difficult it is to interpret the severity and death rate of Covid-19 in patients with other serious diseases such as cancer.