Spss v 25.0 statistical package

Numerical and categorical variables were presented as mean and standard deviations and counts and relative frequencies, respectively. Categorical and numerical variables were compared between the two cohorts using the Chi square and student t-test, respectively, with significance considered for p-values <0.05. Progressive disease was plotted using the Kaplan Meier curve to calculate median time-to-progression, defined as the time from initial diagnosis to disease progression date or the end of follow-up (censored observations for subjects who did not reach the progression event). The backward conditional multivariate regression analysis was run to identify factors affecting vitamin C plasma levels. The following variables were assessed at the univariate level: Age, gender, Body Mass Index (BMI), smoking status, cancer diagnosis (control vs. case), and physical activity level. Variables with a p-value <0.10 at the univariate level were considered significant and incorporated in the multivariate model. A value of p < 0.05 was considered significant for the rest of the analyses. All statistical analyses were performed using the SPSS v.25.0 statistical package (IBM, Armonk, New York, United States).

The IBM SPSS v25.0 statistical package (International Business Machines Corporation, Armonk, NY, USA) was used. Data are expressed as mean values ± standard deviation of the mean (SD). The statistical analysis was based on the Student’s t-test. The limit of statistical significance was set at p < 0,05. Graphics were prepared by using the GraphPad Prism v9.0 software (GraphPad software, San Diego, CA, USA).