A Retrospective Analysis of Concurrent CRT in HNSCC Cases using Low Doses of CDDP: Efficacy of Combination with Hybrid Type AHF only Indicated during Chemotherapy

Abstract

To evaluate long term results on survival, locoregional control and larynx preservation in the patients with operable Stage III–IV laryngopharyngeal Ca mainly, who had been treated with low-dose of CDDP regimen. To evaluate an altered fractionated RT regimen in which AHF was indicated only during 2 cycles of chemotherapy, which was introduced in order to intensify RT more than conventional schedule. Since April 1992 to March 2007, 102 cases with loco- regional advanced but operable laryngopharyngeal SCC has been consecutively treated with 2 cycles of chemotherapy, Chemotherapy regimen was 20mg/m2 4 times a week of CDDP or CDGP. CDGP was administered in patients with low renal function (CCr24<70ml/min) or adverse effects after first course of CDDP. Since April 1999, 71 patients has been consecutively enrolled to the hybrid type AHF regimen which was indicated in only chemotherapy weeks. 1.5 Gy/F b.i.d. 4 days a week was administered in first and 5th week of total 6.5 weeks RT schedule. They were compared with another group of 31 cases treated in 7.5 weeks conventional schedule before the altered fractionation regimen started. Prescribed doses of hybrid type AHF and conventional schedule were 68 Gy/36F/6.5 weeks and 68.2 Gy/31F/7.5 weeks, respectively. The BED at α/β=10 for each them were 56.5 and 58.7, respectively, and at α/β=3 they were 104.6 and 118.2, respectively. As primary site distribution was unbalanced between two groups, we also analyzed for primary adjusted 73 cases with oropharynx T4 limited, hypopharynx, and larynx. Finally the distribution became 1: 22: 8 in the former and 2: 30: 10 in the latter. The Stage distribution on Stage II: III: IVA was 5: 14: 12 in the former and 6: 14: 22 in the latter, respectively, in the 73 cases. Median observation time was 92 months in the conventional group and 35 months in the hybrid AHF group. Eighteen cases of all had experienced double cancer and 2 cases triple. Five-year CSS was 80.6% in the former, 90.2% in the latter. Definitive RT were done in 94 cases of all. In primary adjustment study 5-year CSS was 80.6% in the conventional group, and 89.2% in the hybrid type AHF (p = 0.235), 5-year locoregional RFS was 86.3% and 86.7%, respectively. And 5-year larynx preservation rate was 73.3% and 92.7%, respectively. There was significant difference between two groups (p = 0.028) only in the larynx preservation rate. We have experienced CRT using low dose CDDP/CDGP for 102 cases with locally advanced but operable HNSCC for 15 years. From this historical control analysis we estimate that CRT combination with hybrid type AHF would make functional preservation easier than CRT in conventional schedule in operable HNSCC. We should make a plan for the RCS on this issue as soon as we can.