text: Blood Cytokine Analysis Suggests That SARS CoV 2 Infection Results in a Sustained Tumour Promoting Environment in Cancer Patients Cytokines chemokines and angiogenic growth factors CCGs have been shown to play an intricate role in the progression of both solid and haematological malignancies Recent studies have shown that SARS CoV 2 infection leads to a worse outcome in cancer patients especially in haematological malignancy patients Here we investigated how SARS CoV 2 infection impacts the already altered CCG levels in solid or haematological malignancies specifically whether there is a protective effect or rather a potentially higher risk for major COVID 19 complications in cancer patients due to elevated CCGs linked to cancer progression Serially analysing immune responses with 55 CCGs in cancer patients under active treatment with or without SARS CoV 2 infection we first showed that cancer patients without SARS CoV 2 infection i n i 54 demonstrate elevated levels of 35 CCGs compared to the non cancer non infected control group of health care workers i n i 42 Of the 35 CCGs 19 were common to both the solid and haematological malignancy groups and comprised previously described cytokines such as IL 6 TNF α IL 1Ra IL 17A and VEGF but also several less well described cytokines chemokines such as Fractalkine Tie 2 and T cell chemokine CTACK Importantly we show here that 7 CCGs are significantly altered in SARS CoV 2 exposed cancer patients i n i 52 Of these TNF α IFN β TSLP and sVCAM 1 identified to be elevated in haematological cancers are also known tumour promoting factors Longitudinal analysis conducted over 3 months showed persistence of several tumour promoting CCGs in SARS CoV 2 exposed cancer patients These data demonstrate a need for increased vigilance for haematological malignancy patients as a part of long COVID follow up 