Systemic and Tumor Immune Response during pelvic (chemo)Radiation and or brachytherapy for cervical cancer (STIRR Cervix Study)

Cervical cancer is the second most common cancer in Indian women. This cancer is mostly associated with persistence of human papillomavirus infection and hence the role of immune system is thus relevant. The pelvic bones region which houses a lot of immune cells receives a high dose of radiation as part of their treatment. Therefore we are conducting a study that will assess how immune system is affected by pelvic radiotherapy (various radiotherapy doses and volume) in cervical cancer.

A total of 110 patients will participate in the study from Tata Memorial Centre. We expect to complete the accrual in a period of 30 months from our department. All patients will receive radiation followed by brachytherapy as a standard of care. Concurrent chemotherapy will be given when indicated. Once patients gives consent to participate in the study, they will be allotted into a study group depending on their treatment plan. The study has three main cohorts. Cohort A is Pelvic RT which is further divided into 3 sub-cohorts - Radical (45Gy/25#), Palliative A (25Gy/5#), Palliative B (30Gy/3#). Cohort B is Pelvic + Paraaortic RT (45Gy/25#). Cohort C is Reirradiation cohort which is further divided into 3 sub-cohorts - Proton (40Gy/20#), Photon (25-30Gy/5-6#), SFRT (45Gy/25#). Patient will then go ahead with planned radiation treatment. According to the group in whom the patient is allotted, samples will be taken at baseline and after receiving radiation to study the immune profile.

Variation in immune response will be studied in each cohort. Furthermore, different cohorts will be studied against each other to understand how different doses, field volumes and techniques of radiotherapy impact body’s immunity. Additionally, for each of the recruited cohorts, a three-year disease-free survival will be reported based on the immune cell composition before and after radiation therapy. After completing study related procedure patients will continue follow up as per standard policy at every 3 months up to 24 months and every 6 months for next 24 months post treatment completion. They will be checked clinically at every follow up visit.

The outcome of the study would be useful in improving the quality of radiation treatment and in reducing disease recurrence and improving survival in patients with cervical cancer.