ABSTRACT
Background: Inadequate knowledge about extent of coronavirus disease 2019 (COVID19) epidemic challenges health response and planning. COVID19 mortality among cancer patients (pts) is higher than in general population. The identification of asymptomatic COVID19 cancer pts is important from both a personal and a health system point of view as immunosuppression increases COVID19 disease severity. Screening for asymptomatic carriers is being tested in some categories. The best method for screening and monitoring is yet unknown. Material and methods: Azienda Usl Toscana Centro Oncology department tested pts receiving chemo-or radio-therapy. Aims were checking the prevalence of asymptomatic COVID19 cancer pts and evaluating the need and the best method for subsequent monitoring. Pts were offered both a quantitative serologic IgM and IgG test (Qt-ST) and a RT-PCR test for SARS-CoV-2 in nasopharyngeal and oropharyngeal swabs (NOS). As the Qt-ST is costly and requires hours for response, in S.M. Annunziata Hospital (SMA), pts were also tested with a qualitative serologic IgM and IgG method (Ql-ST) to collect information on different serologic assays. Results: Between May 11th and 17th, 1148 pts receiving an active antineoplastic treatment signed a written informed consent and were screened with RT-PCR for SARS-CoV-2 in NOS and Qt-ST. 317 pts in SMA were also tested with Ql-ST. 16 pts refused RT-PCR, 3 Qt-ST and none Ql-ST. 89 pts with haematological malignancy didn't receive ST. Only 0.44% (5/1132) of asymptomatic cancer pts had a positive RT-PCR. 1 of them had COVID19 disease and was declared healed 14 days before screening. All pts with a positive RT-PCR in NOS had a positive Qt-ST for IgM. 1/5 had also IgG positivity. Qt-ST was positive in 26/1145 pts (2.3%): 3 were IgM+/ IgG+, 10 IgM+/IgG-and 13 IgM-/IgG+. 19.2% of pts with a positive Qt-ST (5/26) were asymptomatic carriers of COVID19 disease. In SMA, 6/317 (1.9%) had a positive Qt-ST, 21 (6.6%) a positive Ql-ST and all were negative for RT-PCR in NOS. Conclusions: With a positivity of 0.44%, RT-PCR for SARS-CoV-2 in NOS may not be cost-effective for screening in asymptomatic cancer pts under antineoplastic treatment from a patient point of view. However, RT-PCR may improve both the compliance and the safety's sense of pts and operators in hospital and is mandatory in case of ST positivity. Qt-ST is more accurate than Ql-ST. Both Qt-ST and Ql-ST were safe and may be a proper option for monitoring cancer pts based on local organization.