 The study aimed to model the change in tumor size over time for outpatients with cervical cancer using a linear mixed effect model. The results showed that a one-month increase in visit time led to a 0.009 square centimeters reduction in tumor size, while every kilogram more in weight decreased the tumor size change by 0.0098 square centimeters. Additionally, HIV-positive patients had a greater tumor size change than HIV-negative outpatients. The study found a significant association between longitudinal changes in tumor size and predictor variables such as visit time, therapy, patient weight, cancer stage, HIV, oral contraceptive use, history of abortion, and smoking status. This article was authored by Chalachu Gashu and Aragore Eshiti Aguade.