Age the biggest risk factor for COVID-19 mortality in haematological cancer patients

A study conducted in England has shown that in patients with haematological malignancy, the risk of COVID-19–related mortality is greatly influenced by age.

“Age is the main risk factor for death regardless of diagnosis or treatment,” said study investigator Dr Jamie Maddox from the South Tees Hospitals NHS Foundation Trust, Middlesborough, UK, at EHA 2022.

Maddox used data from the South Tees NHS Trust to identify 444 patients (median age 69 years) who had been diagnosed with haematological malignancies or received curative treatment within the past 3 years and who had been diagnosed with COVID-19 since the beginning of the pandemic to April 2022. Patients with pre-malignant conditions were excluded.

Timeline of COVID-19 diagnosis was categorized based on waves 1, 2, and 3 (March–June 2020, September 2020–March 2021, and May 2021–present, respectively). Testing for COVID-19 was categorized as pillar 1 (began in March 2020 and involved testing of healthcare workers and those with clinical need [hospital data]) and pillar 2 (involved the wider population and began in mid-April 2020 but had limited capacity until July–September 2020). The COVID-19 vaccination programme commenced in the UK in December 2020 and most people had received their second dose by September 2021.

Overall, COVID-19–related mortality rates were 13 and 17 percent at 4 and 8 weeks after COVID-19 diagnosis, respectively. [EHA 2022, abstract S284]

When pillar 1 and 2 testing were taken into account, mortality rates were greatest during wave 1 and reduced during waves 2 and 3, both for 4-week mortality (46, 26, and 5.6 percent, respectively) and 8-week mortality (63, 31, and 8.8 percent, respectively).

When looking at pillar 1 data only, both 4- and 8-week mortality during wave 1 remained unchanged. However, 4- and 8-week mortality increased to 39 and 45 percent, respectively, during wave 2, and 16 and 24 percent, respectively, during wave 3, with an overall mortality rate of 28 and 37 percent at 4 and 8 weeks post–COVID-19 diagnosis.

During the first wave, almost all COVID-19 cases were diagnosed during hospital testing which could have influenced the findings. “It should be noted that widespread community testing was not available early in the pandemic so the recorded cases in wave 1 were sicker patients needing hospital care,” said Maddox.

Increased familiarity with treating COVID-19 may have led to reduced mortality rates during wave 2, a time when many patients were still unvaccinated, Maddox added. By wave 3, there was greater experience in treating the disease, more treatments available, and a larger vaccinated population.

He noted that official mortality rates from COVID-19 only include deaths occurring within 4 weeks of COVID-19 diagnosis. “[However,] mortality doesn’t settle until about 8 weeks after diagnosis,” said Maddox, highlighting that limiting the findings to 4 weeks may exclude about one-quarter of COVID-19 mortality cases.

Mortality at 4 and 8 weeks post-diagnosis was greatest in those aged ≥90 years (31 and 54 percent, respectively) followed by those aged 80–89 years (29 and 34 percent, respectively) compared with those aged <60 years (0 and 0.8 percent, respectively). There were no deaths among patients aged <50 years.

“If you have COVID-19 and haematological cancer, it doesn’t matter about your diagnosis, comorbidities, … [or] treatment, your biggest risk factor for death is your age,” remarked Maddox.

Sixty-two percent of COVID-19 cases were diagnosed in men. However, 4- and 8-week mortality rates did not differ according to sex. Presence of hypogammaglobulinaemia and receipt of active chemotherapy also did not affect the mortality outcomes. There was a twofold increased risk of mortality in patients with neutropenia.

Patients with chronic lymphocytic leukaemia (CLL) and myelodysplastic syndrome (MDS) demonstrated the worst mortality outcomes (24 and 39 percent, respectively).

According to Maddox, these findings were surprising as the MDS patients tended to have mild disease and CLL patients were in early stage of disease. However, the highest median ages in these two subgroups may have played a role, he said.