MCM7 (Minichromosome maintenance 7, DNA replication licensing factor 7) thanks to its close relationship with DNA replication is a good marker of proliferation. That's why, we can assume there is a correlation between the degree of MCM7 expression and cancer aggressiveness. The aim of the study is to investigate how expression of MCM7 protein is associated with a prognosis in oral cancer patients using different methods of the measurement. The study included 129 patients, suffering from squamous cell carcinoma of mouth floor (C04) or malignant neoplasm of other and unspecified parts of tongue (C02), treated in the Lower Silesian Oncology Center in the years 1996-2011. 39 (30%) patients were diagnosed in stage II, 37 (29%) in stage III and 53 (41%) in stage IVa. All patients underwent microscopically radical resection of the primary tumor with simultaneous resection of regional lymph nodes and adjuvant radiotherapy. MCM7 protein expression was evaluated using a immunoreactivity Remmele scale (IRS), the percentage of stained cells (MCM7%) and the intensity of the color reaction (INT). In all 129 patients MCM7 protein expression was observed. The parameters of MCM7 protein expression (Table 1): INT, MCM7% and IRS in univariate analysis, significantly affected the patient outcome. However, the best correlating expression parameter with the chance of cure turned out to be INT. INT was the only parameter that had a statistically significant impact on OS. Another advantage was easier method of INT evaluation in comparison to MCM7% and IRS scoring.Abstract 2922; Table 1The percentage of 5-year locoregional recurrence-free survival (LRFS), disease-free survival (DFS), disease specific survival (DSS) and overall survival (OS) of patients based on the expression of MCM7 protein in cells of squamous cell carcinoma5-year LRFS5-year DFS5-year DSS5-year OSMCM7%≤25%88%85%85%65%>25%71%64%65%50%p-value0,0260,0120,0160,062MCM7 INT186%80%83%61%277%70%70%57%359%54%54%37%p-value0,0050,0050,0060,041MCM7 IRS<486%81%83%63%≥469%62%62%48%p-value0,0170,0090,00540,052 Open table in a new tab The level of MCM7 expression in the cells of squamous cell carcinoma of mouth floor or body of the tongue is a prognostic factor. All parameters – MCM7%, MCM7 INT and MCM7 IRS – had a significant influence on the survival of cancer patients. However, the most advantageous method was assessment of the MCM7 INT expression.