Evaluation of Efficacy and Tolerance of Radical Radiotherapy and Radiochemotherapy in Treatment of Locally Advanced, Unresectable Rectal Cancer.

A retrospective evaluation of tolerance and efficacy of two schemes of neoadjuvant treatment in patients (pts) with unresectable rectal cancer: radiochemotherapy (CRT) and radiotherapy (RT), including conventional and accelerated hyperfractionation. A total of 145 consecutive pts with unresectable, locally advanced rectal cancer. The schemes used are RT in 73 (50%) or CRT in 72 (50%). In CRT, 54 Gy in 1.8 Gy fractions was given with chemotherapy, In the RT group, conventional fractionation (CFRT) and hyperfractionated accelerated radiotherapy (HART). HART was introduced at first as an alternative to CFRT, after radiobiological studies suggesting a therapeutic gain of hyperfractionation in other cancers, and second to administer relatively high dose needed in unresectable cancer, which is not feasible in hypofractionation because of critical organs sensitivity to high fraction doses (fd). HART was an alternative option in pts with medical contraindications to chemotherapy and to shorten overall treatment time with greater radiobiological effectiveness than CFRT. Objective response (OR) in the RT and CRT group was 60% versus 75%. Resection rate (RR) in RT and CRT: 37% versus 65%. Tumor mobility and laparotomy-based unresectability were significant factors for OR. Performance status (PS), tumor mobility, and neoadjuvant treatment method were significant for RR.