BackgroundSars Cov-2-related disruptions to health services might have impaired the initial clinical presentation of new solid tumor patients. The aim of this systematic review was to compare the initial tumor stage of solid cancer diagnoses before and after the Sars Cov-2 outbreak.MethodsFollowing PRISMA and MOOSE guidelines, we systematically reviewed articles in MEDLINE and EMBASE on the tumor stage of new solid cancer diagnoses before and after the initial Sars Cov-2 pandemic waves. A random-effects meta-analysis was conducted to compare the rate of metastatic tumors at initial presentation. Subgroup analyses were performed per primary tumor site, and per study country. Interstudy heterogeneity and subgroup differences were assessed with I2 and X2 tests, respectively.ResultsFrom 2,013 studies published between January 2020 and April 2022, we included 58 studies including 109,996 patients. The rate of metastatic tumors was higher after than before the pandemic (OR: 1.29 (95% confidence interval (95%CI), 1.06-1.57) with a I2 of 89% (95%CI, 86%-91%). OR (95%CI) were 1,51 (1.07-2,12) for breast cancers, 1.51 (1.04-2.18) for gynecologic cancers, 0.79 (0.18-3.52) for lung cancers, 1.15 (0.89-1.49) for colorectal cancers, 1.45 (0.62-3.42) for other digestive cancer, 2.26 (0.51-10,05) for prostate cancer, 12.07 (0.57-253,68) for genitourinary cancers and 1.01 (0.59-1.75) for other types of cancer (X2 = 24,60, p<0.01). Only 2 countries out of 17 studied showed a significantly higher rate of metastasis after the pandemic: Italy (OR (95%CI) = 1.55 (1.01-2.39)) and Spain (1.14 (1.02-1.29)) Conversely, Taiwan and Canada showed a significantly lower rate of metastasis after the pandemic: OR (95%CI): 0,51 (0,28-0,93) and 0,14 (0,07-0,29).ConclusionsDespite inter-study heterogeneity, our meta-analysis showed a higher rate of metastatic tumors at initial presentation after the Sars Cov2 outbreak. The burden of social distancing policies might explain those results, as patients may have delayed seeking care.