Hypofractionation in Breast Cancer - A Retrospective Study in a Tribal Population Based Medical College in West Bengal, India

Introduction: In a tribal population based area in West Bengal, India though carcinoma cervix is the commonest malignancy in female patients, yet apart from that carcinoma breast is also increasing in number in the recent years. Breast cancer accounts for approximately 26.6% of female malignancy in the radiation oncology out-patient-department of our teaching hospital.

Aims and Objectives: To compare conventional RT regimen (50 Gy in 25 fractions over 5 weeks) with one hypofractionated regimen (40Gy in 15 fractions over 3 weeks) in stage II & stage III breast cancer patients as adjuvant radiation therapy in terms of local control, survival and adverse reactions.

Materials and Methods: It is a retrospective study which has been conducted in the department of Radiotherapy in BSMC (Bankura Sammilani Medical College) spanning from May 2012 to April 2017. A total number of patients included in this study was 302, out of which thirty six patients failed to follow up. So total of 266 patients included in the study were all histologically proved carcinoma breast treated surgically (97.74% by MRM & rest by BCS) with curative intent following which RT was used as adjuvant therapy. In one group (consisting of 133 patients) conventional regimen (50Gy in 25 fractions) was used. In another group (consisting the other 133 patients) dose-schedule used was a hypofractionated one i.e. 40Gy in 15 fractions. Dose per fraction in the 1st group was 2 Gy whereas in 2nd group it was 2.66 Gy. In all patients, RT was given in 5 days a week. Systemic therapy was administered as and when indicated.

Results: 4-year disease-free-survival (DFS) in conventional group was 78.94% and in hypofractionated group was 82.70%, (p value >0.05). 4-year overall survival (OS) in conventional group was 81.20% & in hypofractionated group was 85.70%, (p value >0.05). While adverse reactions in terms of both acute & chronic radiation toxicities were considered, there was no significant difference in between the two groups.

Conclusion: There is no significant difference between the conventional regimen and this hypofractionated regimen in terms of OS DFS & adverse reactions in this tribal-based Indian population. Hence, in our institution, we usually prefer Hypofractionated radiotherapy (40Gy/15 fractions) in adjuvant settings for breast cancer patients.