COMPARATIVE EVALUATION OF SEQUENCIAL CHEMORADIATION VERSUS SANDWICH CHEMORADIATION IN LOCOREGIONALLY ADVANCED CARCINOMA BREAST POST MASTECTOMY
Sunder Singh, Abhishek Soni*, Ashok Chauhan, Yashpal Verma, Vivek Kaushal and Monica Verma
ABSTRACT
BACKGROUND: Combination of chemotherapy and radiotherapy are well established in the treatment of carcinoma breast. Chemotherapy is generally recommended prior to radiotherapy but decisive data on the optimal sequence of these two modalities are sparse. This retrospective analysis aimed to assess the role of sequencing of chemoradiation in patients after mastectomy because of advanced locoregional breast cancer. METHOD: A total of 579 histopathologically proven eligible patients included in the study in the period of 2012 to 2017 and had locoregionally advanced breast cancer and received adjuvant chemotherapy and radiotherapy after modified radical mastectomy and axillary dissection. Out of these patients, 394 patients were treated sequentially i.e. chemotherapy followed by radiotherapy (SQ group), and 185 patients had a sandwich treatment i.e. radiotherapy sandwiched between chemotherapy (SW group). Radiotherapy was administered with dose of 50 Gy to thoracic wall and regional lymph nodes. Anthracycline and taxanes based chemotherapy were given to all patients. RESULT: The baseline parameters like age, grading, stage and hormonal receptor status were distributed homogeneously among the two groups. The parameter significantly imbalanced was nodal involvement among the two treatment groups. The 5 year overall survival (OS) and disease free survival (DFS) were 65.3% vs 52.8% (p=0.02, significant), and 58.3% vs 46.6% (p=0.08, NS), respectively for the SQ and SW group. There was no significant difference seen with respect to the 5 year locoregional or distant recurrence free survival among the two groups. On multivariate analyses, the sequence of chemoradiation had no significant impact on overall survival or disease free survival. Also, the acute and late toxicities showed no significant differences among the two groups. The grade III acute side effects were seen in 3.8% and 6.5% for the SQ and SW group, respectively with no significant difference. CONCLUSION: To conclude, no significant advantage can be stated for chemotherapy and radiation sequence in breast cancer treatment. This was confirmed in our retrospective study also in high risk breast cancer patients after modified radical mastectomy. However, the sequential chemoradiation approach is better and recommended according to the current treatment guidelines considering a lower toxicity.
Keywords: Chemotherapy, radiotherapy, sequential, sandwich, breast, mastectomy.
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