Introduction: Cancer aggravates COVID-19 prognosis. Nosocomial transmission of SARS-CoV-2 is particularly frequent in cancer patients, who need to attend hospitals regularly. Since March 2020, all cancer patients having access to the Oncology Unit at the “Andrea Tortora” Hospital (Pagani, Salerno – referred to as “the Hospital”) as inpatients or outpatients receiving intravenous therapy have been screened for SARS-CoV-2 using RT-PCR nasal swab. The ongoing COICA (COVID-19 infection in cancer patients) study is an ambispective, multicenter, observational study designed to assess the prognosis of SARS-CoV-2 infection in cancer patients. The aim of the study presented here was to explore potential differences in COVID-19-related outcomes among screening-detected versus nonscreening-detected SARS-CoV-2-infected patients. Methods: The COICA study enrolled cancer patients who had received any anticancer systemic therapy within 3 months since the day they tested positive for SARS-CoV-2 on RT-PCR. The target accrual is 128 patients, and the study was approved by the competent Ethics Committee. Only the subgroup of patients enrolled at the Hospital was considered in this unplanned interim analysis. Logistic regression analysis was used to evaluate the association of screening-based versus nonscreening-based diagnosis. Results: Since March 15, 2020, until August 15, 2021, a total of 931 outpatients and 230 inpatients were repeatedly screened for SARS-CoV-2 using RT-PCR nasal swab at the Hospital. Among these, 71 asymptomatic patients were positive on routine screening and 5 patients were positive for SARS-CoV-2 outside the institutional screening. Seven patients died because of COVID-19. At univariate analysis, nonscreening- versus screening-detected SARS-CoV-2 infection was associated with significantly higher odds of O<sub>2</sub> therapy (OR = 16.2; 95% CI = 2.2–117.1; p = 0.006), hospital admission (OR = 31.5; 95% CI = 3.1–317.8; p = 0.003), admission to ICU (OR = 23.0; 95% CI = 2.4–223.8; p = 0.007), and death (OR = 8.8; 95% CI = 1.2–65.5; p = 0.034). Conclusion: Routine screening with RT-PCR may represent a feasible and effective strategy in reducing viral circulation and possibly COVID-19 mortality in patients with active cancer having repeated access to hospital facilities.