A clinical study to assess safety profile of adjuvant hypo-fractionated radiation therapy of 1 week duration in the management of early-stage breast carcinoma

Objectives Breast cancer is the most common cancer in women both worldwide and in India. In India, it comprised 27.70% of all new cancer cases in females in 2018 and caused 12.11% of cancer deaths, amounting to 87,0901. The crude rate of projected incidence of cancer statistics in India, 2020, for breast cancer in females is 1 in 29, and the annual percentage change in age-adjusted incidence rates over the period 1982–2014 was 3.1% in Bangalore. So far there are scarce Indian studies on extreme hypofractionation. Hence, the study was taken up. Materials and Methods Thirty patients with post-operative early breast cancer who required adjuvant RT were selected for this study. 26 Gy in 5 fractions were delivered to the PTV chest wall/breast tissue with a sequential lumpectomy boost to a dose of 10 Gy in 5 fractions in post-BCS cases by the 3DCRT technique. Patients were clinically evaluated and toxicities graded as per RTOG. Acute and late toxicity criteria at baseline, at the completion of radiation therapy, 3 weeks, 3 months, and 6 months post-radiation therapy for skin and subcutaneous changes. 2D echo, CT chest were done at the baseline and also at post-treatment at 3 months and 6 months to note any cardiac or lung changes. Results The majority of the patients had no skin or subcutaneous reactions. Grade I skin reaction was seen in 3 patients at the end of RT and another 3 patients at 3 weeks post RT among those who received sequential boost in post-BCS patients. Grade I subcutaneous reaction was seen in 4 patients at 3 months and 6 patients at 6 months. Sonomammogram was done on follow-up at 3 months and 6 months post-RT showing mild inflammatory changes in 5 patients at 3 months and fibrosis in 1 patient at 3 and 6 months who had received whole breast RT with tumor bed boost (19 patients). Grade I cardiac toxicity was seen in 1 patient at 6 months post RT. The patient had received NACT followed by MRM followed by adjuvant RT to the left chest wall. 2DECHO done before the start of RT and 3 months post-RT was normal. At 6 months post-RT, it showed minimal pericardial effusion with 57% left ventricular ejection fraction (Grade I cardiac toxicity according to RTOG toxicity). However, the patient was asymptomatic. Conclusion Extreme hypofractionation of 26 Gy in 5 fractions post-MRM or post-BCS with sequential tumor bed boost in the adjuvant setting of early-stage breast cancer post-systemic therapy is well tolerated. However, a longer follow-up is required for assessment of overall survival, disease-free survival, and further late toxicity profile in a large multi-institutional setting, recruiting a larger number of patient populations to confirm the present clinical findings.