Background We compared the new outpatient clinic referrals during the first 10 months of the COVID-19 pandemic with the year before. Methods We compared baseline characteristics of the 2208 new referrals in 2020 (n=922) and 2019 (n=1286) with X-2 and Mann-Whitney U tests and calculated ORs with binary logistic regression. To evaluate the expected changes in the cancer survival secondary to stage migration, we used the 5-year survival data of Survival, Epidemiology and End Results (SEER) Program 2010-2016. Results The percentage of patients with inoperable or metastatic disease was significantly increased during the pandemic (49.8% vs 39%, OR: 1.553, 95% CI: 1.309 to 1.843, p<0.001). We observed a significant decrease in the percentage of patients diagnosed via the screening methods (18.8% vs 28.7%, OR: 1.698, 95% CI: 1.240 to 2.325, p=0.001). The 90-day mortality after the cancer diagnosis was significantly higher during the pandemic (10.5% vs 6.6%, OR: 1.661, 95% CI: 1.225 to 2.252, p=0.001). Due to the increased advanced-stage disease rate at first referral, significant decreases in 5-year survival rates were expected for breast cancer (-8.9%), colorectal cancer (-11.1%), cervix cancer (-10.3%) and melanoma (-7%). Conclusion We think that collaborative efforts are paramount to prevent the pandemic of late cancer diagnoses and ensure patient safety during the pandemic.