Prevalence of COVID-19-like symptoms in Italy and Lombardy, March-April 2020, and their implications on cancer prevention, diagnosis and management.

Two population-based surveys on coronavirus disease-2019 (Covid-19)-like symptoms were conducted by BVA-Doxa on representative samples of the general population from Italy and its largest region, Lombardy, with over 10 million inhabitants and heavily struck by Covid-19, on 27-30 March and 3-7 April, on a total of 2000 individuals - 353 from Lombardy. Overall, 14.2% of Italians - and 19.6% in Lombardy - reported Covid-19-like symptoms. The estimated prevalence was higher in the young, in smokers, and in Lombardy over the period 20 March to 7 April. Although the influenza season was ended by mid-March, at least part of the symptoms may be not Covid-19 related. Even assuming that only half are, at least 7% of Italians and 10% in Lombardy had been affected by Covid-19. To these, asymptomatic or paucisymptomatic cases have to be added. These estimates are at least one or two orders of magnitude larger than official registered cases. This has major implications for cancer prevention, management and treatment.