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E1308: Reduced-dose IMRT in human papilloma virus (HPV)-associated resectable oropharyngeal squamous carcinomas (OPSCC) after clinical complete response (cCR) to induction chemotherapy (IC).
Abstracts that were granted an exception in accordance with ASCO's Conflict of Interest Policy are designated with a caret symbol (^).
Background: HPV+ patients (pts) in E2399 obtained a 2-yr 95% survival and 86% PFS after IC and 70Gy chemoradiation. We hypothesized reduced-dose IMRT (54Gy, 23% reduction) in HPV+ OPSCC pts could maintain high LR control and 85% 2-yr PFS in pts with cCR to IC. Methods: Pts with resectable stage III/IVa,b HPV+ OPSCC received IC q3 weeks x 3 with paclitaxel 90mg/m2 days (D) 1,8,15, cisplatin 75mg/m2 D1, and standard cetuximab (Cetux) weekly schedule. IC response determined IMRT dose independently at primary and involved nodes: IMRT 54Gy/27 if cCR vs. 69.3Gy/33 if <cCR. Cetux was continued during IMRT. Primary endpoint was 2-yr PFS. Results: 90 pts were enrolled (80 analyzable). Med FU is 23.3 months (mo). Tumor and Nodal stage: T4-10%, T3-17%, T2-50%, and T1-23%; N0,1-16%, N2a,b-54%, N2c-31%. Med age 57yrs. 46% never smoked and 84% not current smokers. IC and C-IMRT was well tolerated: 96% received all 3-cycles of IC. 71% had cCR. 62 pts (78%) received reduced-dose Cetux-IMRT. For all reduced IMRT pts, 23mo PFS is 84%, primary site LC 94%, nodal control 95%, and distant 92%. Post-treatment neck dissection was positive for tumor in 4/8 reduced dose IMRT pts compared to 1/3 pts treated with std dose. One late grade 3 toxicity occurred in 1 reduced-dose pt: hypomagnesemia at 30mo. Conclusions: IC + reduced-dose Cetux-IMRT produced high tumor control rates. Late toxicities were minimal. Low dose pts achieved 84% PFS at 23mo and 95% 2-yr survival. Pts with <10yrs smoking, T1-3 and N0-2b disease achieved 96% PFS. Further studies of reduced-dose IMRT in chemoresponsive HPV+ pts are warranted. Clinical trial information: NCT01084083.
|Variable (n)||23mo PFS (90% CI)||24mo OS (90% CI)|
|All reduced-dose pts ( 62)||0.84 (0.74, 0.90)||0.95 (0.87, 0.98)|
|T4A (7)||0.69 (0.29,0.89)||0.86 (0.45, 0.97)|
|T1-T3(55)||0.86 (0.75, 0.92)||0.96 (0.88, 0.99)|
|N2C (19)||0.77 (0.56, 0.89)||0.95 (0.76, 0.99)|
|N0-N2b(43)||0.87 (0.75, 0.94)||0.95 (0.85, 0.98)|
|Smoker > 10 pkyr (21)||0.71 (0.48, 0.85)||0.90 (0.71, 0.97)|
|Smoker <= 10 pkyr (40)||0.92 (0.81, 0.97)||0.97 (0.87, 0.995)|
<T4, <N2c (n=27)
|0.96 (0.82, 0.99)||0.96 (0.82, 0.99)|
|All standard-dose pts (15)||0.64 (0.39, 0.81)||0.87 (0.63, 0.96)|
Abstracts by Anthony Cmelak:
Sequential boost versus integrated boost intensity-modulated radiation therapy with concurrent chemotherapy for locally-advanced head and neck cancer (LAHNC).Meeting: 2016 ASCO Annual Meeting | Abstract No: 6070Category: Head and Neck Cancer - Local-Regional
Establishing quality indicators for neck dissection: Correlating the number of lymph nodes with oncologic outcomes, NRG Oncology/RTOG 9501-0234.Meeting: 2015 ASCO Annual Meeting | Abstract No: 6011
Symptom reduction from IMRT dose deintensification: Results from ECOG 1308 using the Vanderbilt Head and Neck Symptom Survey version 2 (VHNSS V2).Meeting: 2015 ASCO Annual Meeting | Abstract No: 6021