Intensity-modulated radiation therapy combined with concurrent and adjuvant chemotherapy in anaplastic thyroid carcinoma: A single-institution study.

Abstract

5591 Background: Only 10% of patients with anaplastic thyroid cancer (ATC) historically survive one year despite surgery and conventional radiotherapy. In response, we modified our approach to ATC, combining intensity modulated radiation therapy (IMRT) with aggressive chemotherapy in patients with stages IVA and IVB disease. Methods: From 2003 to 2007 twenty four ATC patients were seen at our institution. Ten presenting with metastatic (IVC) disease underwent palliative treatment, while four presenting with locoregional disease (IVA or IVB) underwent treatment at other institutions. Of the remaining 10 patients with regionally confined ATC, all elected to pursue an aggressive approach under our direction. Surgical intervention included complete resection (3), incomplete resection (positive margins in 3, gross residual disease in 3), and biopsy only in 1 patient - leaving only 3 of 10 patients pathologically free of disease following surgery. Pathology, centrally reviewed by a single expert pathologist (R.V.L.), demonstrated ATC alone in six - and ATC arising in a background of differentiated thyroid carcinoma in four. In all cases of mixed histology, ATC was dominant. Therapy following surgery consisted of IMRT combined with radiosensitizing and adjuvant chemotherapy, intending four cycles of docetaxel 60 mg/m2 and doxorubicin 60 mg/m2 IV with pegylated Filgrastim support - unless toxicities dictated otherwise. Results: No deaths resulted from therapy, and morbidity was modest. Median follow-up (including patients who died) was 30 months, with 6 patients (60%) still alive 25-82 months after diagnosis. Five patients (50%) were alive and cancer free >2 years following diagnosis. Overall survival in this consecutive series at one and two years respectively was 70% and 60% - compared to 10% historical survival at one year in analogous patients previously treated at our institution with conventional radiation therapy alone following surgery. Conclusions: Although preliminary, these findings suggest that an aggressive approach combining IMRT and chemotherapy has potential to improve outcomes in ATC patients with regionally confined disease at diagnosis. No significant financial relationships to disclose.