Results of reduction of treatment intensity based on response to a novel induction therapy in stage III and IV head and neck cancer

Abstract

5561 Background: Concurrent cisplatinum based chemotherapy and qd radiotherapy (RT) to 70 Gy is standard therapy for stage III-IV head and neck (H/N) SCCA. Presented is a prospective IRB approved study tailoring the definitive therapy based on response to induction therapy. Methods: 25 patients with Stage III-IV H/N SCCA were treated with 2 cycles of induction therapy every 21 days comprised of carboplatin (AUC 6 day 1), paclitaxel (75 mg/m2 days 1, 8, and 15), and low dose RT (0.5 Gy BID days 1, 2, 8, and 15) for chemosensitization. The response rates of this mode of induction therapy have been presented previously (ASCO 2005 #3184). Patients with complete response (CR) to induction were treated with reduced dose RT at the primary site (reduced from 70 to 60–66 Gy) and 2 cycles of IV cisplatin (100 mg/m2) instead of 3. Those with partial response (PR) or stable disease (SD) were treated with surgery and adjuvant therapy or with altered fractionation regimens. The impact of dose reduction on survival (OS and DFS), failure patterns, compliance and toxicity (according to NCI CTCAE) were used as end points for the study. Results: Patients included 9 with tonsil, 5-L, 3-HP, 3-OC, and 5-BOT. There were 4-T1,9-T2,9-T3,and 3-T4 tumors. The nodal involvement was N0–5, N1–3, N2–13, N3–4. Patients presented with Stage III (28%), IVA (52%), and IVB (20%). Sixty percent had a CR, 32% had a PR, and 8% had SD after induction therapy. Two patients with CR were non-compliant after induction therapy and not further evaluated. With a median FU of 20.5 months (range 11–36 mo) the OS and DFS is 100% (13/13) in the dose reduced group (CR) and 60% (6/10) in the PR/SD treated with more aggressive regimens. The incidence of distant failure is 40% (4/10) in the PR vs 0% (0/13) in the CR. No patients in the dose reduced group required feeding tubes; however 30% (3/10) were required in patients with PR. Compliance with chemotherapy was 79% (10/13) in the CR vs 80% (8/10) in the PR. Conclusions: Our early results show that the patients showing a CR to induction chemotherapy are a favorable group of patients and they may be treated with reduced treatment intensity. This report provides strong evidence that RT dose deescalation for head and neck cancers may be feasible following assessment after induction therapy. [Table: see text]