COVID-19 May Promote Tumor Development in Patients With Cancer

Liam Davenport for Medscape

December 23, 2021

The study  covered in this summary was published on as a preprint and has not yet been peer reviewed.

Key Takeaway

  • Cancer patients exposed to SARS-CoV-2 infection experience persistent increases in cytokines, chemokines and (angiogenic) growth factors (CCGs) over and above those seen in unexposed patients, indicates a Belgian analysis of serial blood samples.

Why This Matters

  • Cancer-related inflammation, orchestrated by CCGs, has been shown to play an important role in the progression of both solid and hematologic cancers, including the proliferation and survival of malignant cells, angiogenesis, and metastasis.

  • The current findings could help to explain the observed worse outcomes in patients with cancer infected with SARS-CoV-2, particularly in those with hematologic malignancies, and suggest the need for increased vigilance of patients as part of the ongoing follow-up of COVID-19.

Study Design

  • Ambulatory patients with cancer scheduled for routine blood testing during the COVID-19 pandemic, including 52 exposed and 54 who were unexposed to SARS-CoV-2, were studied alongside 15 exposed and 42 unexposed healthcare workers from the oncology units they attended.

  • All participants underwent serial CCG immunoassays from whole blood samples, with healthcare workers assessed at baseline and after 1, 2, and 3 months. Clinical data, including peak disease severity on the World Health Organization COVID-19 ordinal scale, was gathered.

  • Patients were divided into solid (n = 36 for exposed, n = 32 for unexposed) and hematologic (n = 16 for exposed, n = 22 for unexposed) cancers. Changes in CCG concentrations over time were determined.

Key Results

  • Unexposed patients with cancer were found to have increased levels of 35 CCGs compared with unexposed healthcare workers with no significant differences between patients with solid and hematologic cancers.

  • Among the 19 CCGs common to both cancer types were cytokines such as IL-6, TNF-alpha, IL-1Ra, IL-17A, and VEGF, and less well-described cytokines and chemokines such as Fractalkine, Tie-2, and T cell chemokine CTACK.

  • Exposed patients with cancer were found to have seven CCGs that were additionally significantly altered compared with healthcare workers. Of these, TNF-alpha, IFN-beta, TSLP, and sVCAM-1, which were elevated in patients with hematologic cancers, are known tumor-promoting factors.

  • Longitudinal analysis over 3 months revealed that CCGs such as TNF-alpha, IL-2, and MCP-3 remained elevated in exposed patients with cancer, but not in healthcare workers. In patients with hematologic malignancies, levels of IL-2 and MCP-3 were found to temporarily increase during follow-up.


  • The authors highlight several limitations of the study, including that it is a case–control study and that a prospective study of exposed patients with cancer was not possible.

  • As well as the imbalance in baseline characteristics between the patients with cancer and healthcare workers, they also note that patients with cancer who were immediately transferred to COVID-19 wards were not included.

Study Disclosures

  • The clinical study was funded by Kom Op Tegen Kanker grant, a UZA Foundation grant, and University of Antwerp grants. The laboratory reagents were funded by GOA. Authors were individually funded by COMBACTE, H2020-Orchestra, and by FWO.

  • No relevant financial relationships declared.

This is a summary of a preprint research study , "Blood cytokine analysis suggests that SARS-CoV-2 infection results in a sustained tumour promoting environment in cancer patients," led by Samir Kumar-Singh, MD, PhD, of the Laboratory of Cell Biology & Histology at the University of Antwerp, Belgium. It was published on on October 29 and provided to you by Medscape. This study has not yet been peer reviewed. The full text can be found at

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