Systemic and Tumor Immune Response During Pelvic (Chemo)Radiation and/or Brachytherapy for Cervical Cancer (STIRR Cervix Study)

This study will be performed using blood and tumor material at different time points and available information from blood tests that have been performed prior to initiating chemoradiation in the institution. The proposed sample size is 110 is a convenience based sampling that is based on estimate of people participating in the study during their radiotherapy course. Participants will be allotted in the cohort as per their radiation treatment plan. Collection of blood and tumor tissue material from participants will happen at different time points. These time points will be decided as per the cohort in whom the patient is. The study intends to investigate immunohistochemical (IHC) expression of PD-L1 on baseline and post-treatment tumor biopsy. Furthermore, the study will also investigate expression of immune cells through flow cytometry - fluorescence-activated cell sorter (FACS) at baseline and after RT on blood and tumor tissue sample. The study also intends to capture radiotherapy information - PTV Dose, HRCTV, Mean liver, spleen, Ileocecal junction dose, TRAK values. Using Analysis of Variance (ANOVA) test, all these parameters will be analyzed against their time points in the individual cohorts and also with other cohorts to provide us a better understanding of how pelvic radiotherapy affects our immune system. Furthermore, the investigators will also use Bonferroni correction test to account for multiple statistical comparison. Most of the research studies in cervical cancer that have been published till date do not utilize various aspects of radiotherapy like dose, dose per fraction, field volumes and techniques. This study will represent the first large cohort focusing on all the above mentioned aspects in cervical cancer patients.