Impact of p16 status on the QOL effects of chemoradiation for locally advanced oropharynx cancer: Results of TROG 02.02.

Abstract

5571 Background: We report the impact of p16 status on quality of life (QOL) for patients with stage III or IV (excluding T1-2N1 and M1) squamous cell carcinoma of the oropharynx (OPC) treated with concurrent chemoradiotherapy in a large international phase III trial (TROG 02.02/HeadSTART). Methods: The 861 patients accrued received definitive radiotherapy (RT) (70 Gy/7 weeks) concurrently with 3 cycles of either cisplatin (100mg/m2) or cisplatin (75 mg/m2) plus tirapazamine (290 mg/m2/day) by random assignment, as previously described. QOL was measured with the FACT-H&N at baseline, 2,6,12, 23 and 38 months. No significant difference in overall or subscale QOL score change from baseline was observed between arms at any subsequent time point; results for the oropharynx subgroup by p16 status are reported for both treatment arms combined. Results: Of 853 eligible participants, 465 had OPC, for whom p16 status could be determined in 206. Of 179 who received adequate RT (≥ 60 Gy, no major deviations) and completed baseline QOL, 104 were p16+ and 79 were p16-. p16+ patients had better baseline ECOG PS, lower T-category, higher N-category, were younger and were less likely to be current smokers. Baseline mean FACT-H&N score was statistically and clinically significantly better in p16+ patients (111 vs. 102, p=0.001). The drop in QOL from baseline to 2 months was more severe in p16+ cases (-20.4 vs -9.1, p=0.001), resulting in an equalization of 2 month scores (p16+: 90.6, p16-: 93.6, p=0.16). At 6 and 12 months post-treatment, no difference in score changes from baseline by p16 status was seen (6 mo, p16+: -6.2, p16 -:-1.2, p=0.22; 12 mo, p16 +: -0.3, p16 -: +2.0, p=0.82). Conclusions: p16 associated oropharyngeal cancer has been shown to be a distinct entity with different demographic features. In our study, such patients exhibited better baseline QOL and a more severe drop immediately after treatment, but did not differ in long-term QOL response to the effects of aggressive concurrent chemoradiation. Given the favorable prognosis of p16-associated oropharyngeal cancer, efforts to reduce the QOL burden of treatment are warranted.