@article{VLAD_ACHIMAŞ-CADARIU_IRIMIE_CAZACU_2012, title={Prognostic Significance of Perineural Invasion in Patients with Rectal Cancer using R Environment for Statistical Computing and Graphics}, volume={31}, url={https://ami.info.umfcluj.ro/index.php/AMI/article/view/395}, abstractNote={<span style="font-family: Times New Roman; font-size: small;"> </span><p class="MsoNormal" style="margin: 0in 0in 0pt; line-height: 150%;"><em>Purpose</em>: In recent studies perineural invasion (PNI) is associated with poor survival rates in rectal cancer, but the impact of PNI it’s still controversial. We assessed PNI as a potential prognostic factor in rectal cancer. <em>Patients and Methods</em>:<em> </em>We analyzed 317 patients with rectal cancer resected at The Oncology Institute”Prof. Dr. Ion Chiricuţă” Cluj-Napoca, between January 2000 and December 2008. Tumors were reviewed for PNI by a pathologist. Patients data were reviewed and entered into a comprehensive database. The statistical analysis in our study was carried out in R environment for statistical computing and graphics, version 1.15.1. Overall and disease-free survivals were determined using the Kaplan-Meier method, and multivariate analysis using the Cox multiple hazards model. Results were compared using the log-rank test. <em>Results</em>:<em> </em>In our study PNI was identified in 19% of tumors. The 5-year disease-free survival rate was higher for patients with PNI-negative tumors versus those with PNI-positive tumors (57.31% vs. 36.99%, p=0.009). The 5-year overall survival rate was 59.15% for PNI-negative tumors versus 39.19% for PNI-positive tumors (p=0.014). On multivariate analysis, PNI was an independent prognostic factor for overall survival (Hazard Ratio = 0.6; 95% CI = 0.41 to 0.87; p = 0.0082). <em>Conclusions:</em> PNI can be considered an independent prognostic factor of outcomes in patients with rectal cancer. PNI should be taken into account when selecting patients for adjuvant treatment. R environment for statistical computing and graphics is complex yet easy to use software that has proven to be efficient in our clinical study.</p><span style="font-family: Times New Roman; font-size: small;"> </span>}, number={4}, journal={Applied Medical Informatics}, author={VLAD, Ioan Catalin and ACHIMAŞ-CADARIU, Patriciu and IRIMIE, Alexandru and CAZACU, Mircea}, year={2012}, month={Nov.}, pages={13–20} }