In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 35, No. 15_suppl ( 2017-05-20), p. 6066-6066
Abstract:
6066 Background: In this prospective phase II de-escalation study, we used induction chemotherapy to identify favorable HPV+ oropharyngeal cancer (OPC) pts, including those with high-risk tumors, and applied significantly lower radiation or chemoradiation doses than previously reported. Methods: Pts with HPV+ OPC were classified as low-risk (≤T3, ≤N2B, ≤10 PYH) or high-risk (T4 or ≥N2C or 〉 10 PYH). Pts received 3 cycles of carboplatin (AUC 6, D1) and nab-paclitaxel (100 mg/m2, D1/8/15). 1) Low-risk pts with ≥50% response received low-dose radiotherapy alone to 50Gy (RT50). 2) Low-risk pts with 30-50% response OR high-risk pts with ≥50% response received low-dose chemoradiotherapy to 45Gy (CRT45). 3) All other ( = poor response) pts received regular-dose CRT (CRT75). All pts also received de-escalated RT volumes limited to the first echelon of uninvolved nodes. CRT consisted of paclitaxel, 5-FU, hydroxyurea, and 1.5Gy twice daily RT every other week. Primary site biopsy and neck dissection were performed only after de-escalated treatment (RT50, CRT45) for pathologic confirmation. The primary endpoint was 2-year PFS. Secondary endpoints included pathologic complete response (pCR) rate and toxicity. Results: 62 pts were enrolled. 28 pts (45.2%) were low-risk and 34 pts (54.8%) were high-risk. 71.4% of low-risk pts received RT50 and 21.4% received CRT45. 70.6% of high-risk pts received CRT45. The pCR rate was 94.4% after RT50 and 92.3% after CRT45. Median follow-up is 1 year. The 2-year PFS and OS were both 100% for low-risk pts, and 91.6% and 97.0% for high-risk pts. Significant decrease in the rates of grade ≥3 mucositis (15.8% RT50, 46.4% CRT45, 60.0% CRT75, p = .033) and grade ≥3 dermatitis (0% RT50, 21.4% CRT45, 30.0% CRT75, p = .056) were observed. PEG-tube dependency was improved at 3 months (0% RT50, 14.8% CRT45, 70.0% CRT75, p 〈 .001) and 6 months (0% RT50, 3.7% CRT45, 20.0% CRT75, p = .066) post-treatment. Conclusions: Favorable response to induction chemotherapy appears to be a powerful biomarker for dose and volume de-escalation with 50Gy RT or 45Gy CRT. Outstanding survival and high pCR rates suggest that completion neck dissection may not be necessary. Toxicity and functional outcomes are significantly improved. Clinical trial information: NCT02258659.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2017.35.15_suppl.6066
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2017
detail.hit.zdb_id:
2005181-5
detail.hit.zdb_id:
604914-X
