Specialty Registrar and ECAT Clinical Lecturer in Medical Oncology Dr Karin Purshouse outlines the early evidence around the risk posed by COVID19 to patients with cancer
Cancer centres across the UK have radically changed their approach to managing patients with cancer in response to the COVID19 pandemic. In line with NICE guidelines, this has included patient shielding advice, reducing face-to-face consultations and modifying anti-cancer treatment approaches. This advice was based on early data from China and Italy, small cohort analyses (the largest of which can be found here), and modelling studies. In addition, evidence from previous SARS and influenza outbreaks suggested cancer patients were at higher risk of severe infection.
There was significant concern that patients with cancer, and/or patients undergoing chemotherapy, would have an impaired immune response, therefore rendering them more at risk from COVID19. Cancer care requires a great deal of face-to-face contact with healthcare sevices, which might also increase cancer patients’ risk of exposure. Finally, cancer services must sit in the context of the wider needs of the health service. There was an awareness that cancer healthcare staff may need to be redeployed to other areas of the healthcare service. Cancer treatment inherently has an impact on acute care services due to the staff required to plan and deliver treatment, and manage the complications of anti-cancer therapy, such as neutropenic sepsis. Rationalising cancer treatment during COVID19 thereby also aimed to reduce the burden of cancer treatment complications on acute and intensive care services.
Our early experience suggested, however, that further nuance was required. Our centre, like many, rapidly evolved its services to maintain cancer treatment where possible, whilst evolving its acute service to keep suspected and confirmed cases of COVID19 separate from other clinical areas. We looked at the first 10 patients with confirmed COVID19 in our region. We noted that the two patients who died harboured a high metastatic burden of disease. However, three patients who survived were profoundly neutropenic (neutrophils <0.5) from recent chemotherapy, and yet had recovered without requiring intensive care. Whilst this was an insufficient number to draw decisive conclusions, our ten patients didn’t fit with the published data, and our team became increasingly concerned about the assumptions being made about patients with cancer. We wrote a rapid response to the BMJ expressing these concerns (our pre-print with further details can be downloaded at the bottom of this page).
Other evidence is emerging which also suggests we need to take a closer look. The largest cohort of patients with cancer and COVID19 has come from New York, and while details about cancer treatment, comorbidities and cancer stage are missing, it’s notable that they saw no overall difference in mortality rate between cancer and non-cancer patients. Similarly, a study from China comparing COVID19 inpatients with and without cancer showed mortality rates were no worse for patients with stage I-III disease. Notably, although they concluded that patients with cancer were overall at higher risk of severe COVID19 infection than patients without cancer, the cancer cohort were older and had more cardiovascular disease, both known risk factors for severe disease.
Finally, the emerging evidence from the UK Coronavirus Cancer Monitoring Project (UKCCMP), to which Edinburgh Cancer Centre (ECC) is contributing, also suggest a closer look is needed. When comparing patients who had had chemotherapy in the last 4 weeks with those who had not, a greater proportion of patients survived in the cohort who had had chemotherapy. It is likely that patients who had not had chemotherapy represent a cohort of greater frailty or comorbidities, and more granularity is needed, but it challenges the assumption that chemotherapy leads to worse outcomes. Noting that the UKCCMP comprises a symptomatic COVID19-tested cancer population, it also highlights that 56% have COVID19 infection of mild severity (and 44% have a severe or critical presentation). It will be important to learn more from this large data set as it emerges.
We have now looked at the first 25 cases of COVID19 in patients from our cancer network collated for the UKCCMP, and our data reflects that of the national registry. Where the outcome has been reached, all of our patients who had chemotherapy in the four weeks preceding their COVID19 diagnosis have survived. Collating all systemic anti-cancer therapy (chemotherapy, targeted therapy, hormonal therapy) together, only one patient has died. While numbers remain too small to make conclusions around subtypes of treatment, including radiotherapy, our experience suggests great care must be taken in presuming anti-cancer therapy itself increases the risk posed by COVID19.
There is increasing concern around the possibility that the mortality from undiagnosed and undertreated cancer will exceed that from COVID19, with an estimated 2,300 cancers going undiagnosed every week. Of course, further evidence is required for cancer teams to plan COVID19-driven cancer treatment recommendations, and the impact on wider healthcare structures and NHS capacity must be considered.
The Cancer Research UK Edinburgh Centre and the Edinburgh Cancer Centre, based at the Western General Hospital, are leading research efforts to rapidly answer these questions using a data science approach. Utilising a now-active real-time surveillance strategy, researchers and clinicians will work closely to help NHS staff make rapid adjustment to patients treatment strategies. This is in addition to many other projects and initiatives which all aim to moderate the profound impact COVID19 is having on patients with cancer – you can read about this elsewhere on our website.
Dr Karin Purshouse is an ECAT Clinical Lecturer at the University of Edinburgh and Honorary Specialty Registrar in Medical Oncology at Edinburgh Cancer Centre.
Dr Peter Hall is a Reader at the University of Edinburgh, he is a Consultant Oncologist and leads the Edinburgh Cancer Informatics Programme at the Edinburgh Cancer Centre.