ESMO calls for cancer patients to be prioritized for COVID-19 vaccination
“Patients with cancer [ie, haematological malignancy requiring chemotherapy or active, advanced solid tumour or history of solid tumour <5 years ago] are at an increased risk of severe COVID-19. They should be vaccinated against SARS-CoV-2 regardless of any other indications [ie, age] and positioned at high prioritization,” the ESMO representatives stated. “Healthcare workers caring for patients with cancer with increased risk should be prioritized in receiving vaccination to minimize nosocomial transmission.” [https://www.esmo.org/covid-19-and-cancer/covid-19-vaccination]
Rates of severe disease and mortality from COVID-19 in cancer patients ranged from 5 percent to 61 percent (unadjusted for comorbidities, performance status [PS] and other confounding factors) in the COVID-19 and Cancer Consortium registry and other cohorts, compared with 2–3 percent in the overall population. [Lancet 2020;395:1907-1918]
SARS-CoV-2 infection per se may also lead to delays in screening, diagnosis and management of cancer, resulting in increased risk of cancer-related morbidity and mortality.
To date, 52 of 214 research projects worldwide for SARS-CoV-2 vaccine development are at clinical stage. [https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines] Different strategies for prioritizing SARS-CoV-2 vaccine administration to various population groups have been published worldwide. [Lancet 2020;395:1907-1918] The WHO, for instance, considers healthcare workers and the elderly as the first-priority groups in phased SARS-CoV-2 vaccine distribution (phases 1a and 1b, respectively), followed by cancer patients (phase 2). [https://apps.who.int/iris/handle/10665/334299; https://apps.who.int/iris/bitstream/handle/10665/337569/WHO-2019-nCoV-SAGE_Framework-Evidence-2020.1-eng.pdf]
While acknowledging the need to generate further data on the efficacy and safety of SARS-CoV-2 vaccines in patients with cancer, the ESMO representatives proposed a
four-step prioritization process to refine the risk/benefit profile and prioritize subgroups of patients with cancer for vaccination:
1) Step 1: Consider the phase of malignant disease and therapy (ie, active cancer on treatment, chronic disease after treatment, or survivorship).
2) Step 2: Consider patients’ age, fitness or performance status, and medical comorbidities as general risk factors (ie, specifically, obesity, diabetes mellitus, hypertension, and respiratory, cardiac and renal disorders).
3) Step 3: Consider vaccine-related interactions on the tumour and on treatment efficacy.
4) Step 4: Secure informed consent and improve shared decision-making.
Compared with patients with active cancer where the efficacy of SARS-CoV-2 vaccines maybe reduced due to interaction with anticancer therapy, vaccination seems essential in protecting cancer survivors and those in the chronic phase of cancer without active treatment, the ESMO representatives stated.
Patients with cancer are often fragile with compromised immune status. Although former evidence from influenza vaccination showed an ability of cancer patients to mount an immune response, the level of response from SARS-CoV-2 vaccines may vary depending on the type of malignancy, anticancer therapies, timing of vaccine administration, pre-existing immune dysfunction and fitness of patients. [CA Cancer J Clin 2017;67:398-410; Clin Infect Dis 2014;58:309-318; Cochrane Database Syst Rev 2018;2:CD008983; Br J Cancer 1999;80:219-220; Support Care Cancer 2001;9:65-68; Med Oncol 2002;19:71-78; Br J Cancer 2011;104:1670-1674; Ann Oncol 2020;31:959-961; Ann Oncol 2012;23:450-457]
“There are no published data on the immunogenicity and interaction of mRNA-based antiviral vaccines with antineoplastic therapies in cancer patients. Some of these vaccines are encapsulated in liposomes. An increased uptake of these liposomes is theoretically possible in tumour tissues, which may potentially impact the immunogenicity of such vaccines,” the ESMO representatives noted. [Br J Cancer 2020; doi: 10.1038/s41416-020-01219-3]
Informed consent and shared decision-making should be the guiding principles in discussing the benefits and risks of COVID-19 vaccination to prevent patients from the double jeopardy of cancer and SARS-CoV-2 infection, the ESMO representatives stated.