Differential outcome of concurrent radiotherapy plus epidermal growth factor receptor inhibitors versus radiotherapy plus cisplatin in patients with human papillomavirus-related head and neck cancer.

BACKGROUND: Human papillomavirus (HPV)-related head and neck cancer has been associated with an improved prognosis in patients treated with radiotherapy (RT) +/- chemotherapy (CT); however, RT combined with epidermal growth factor receptor (EGFR) inhibitors has not been fully studied in this group of patients. METHODS: Immunohistochemical expression of p16 and PCR of HPV16 DNA were retrospectively analyzed in tumor blocks from 108 stage III/IV head and neck cancer patients treated with RT+CT (56) or RT+EGFR inhibitors (52). Disease-free survival (DFS) and overall survival (OS) were analyzed by the Kaplan-Meier method. RESULTS: DNA of HPV16 was found in 12 of 108 tumors (11%) and p16 positivity in 18 tumors (17%), with similar rates in both arms of treatment. After a median follow-up time of 35 months (range 6-135), p16-positive patients treated with RT+EGFR inhibitors showed improved survival compared with those treated with RT+CT (2-year OS 88% vs. 60%, HR 0.18; 95% CI 0.04 to 0.88; p = 0.01; and 2-year DFS 75% vs. 47%, HR 0.17; 95% CI 0.03 to 0.8; p = 0.01). However, no differences were observed in p16-negative patients (2-year OS 56% vs. 53%, HR 0.97; 95% CI 0.55 to 1.7; p = 0.9; and 2-year DFS 43% vs. 45%, HR 0.99; 95% CI 0.57 to 1.7; p = 0.9). CONCLUSIONS: This is the first study to show that p16-positive patients may benefit more from RT+EGFR inhibitors than conventional RT+CT. These results are hypothesis-generating and should be confirmed in prospective trials.

Importance of dose in palliative treatment for incurable head and neck cancer with radiotherapy.

PURPOSE: To identify predictors of palliation for head and neck cancer treated with the "Hypo Trial" hypofractionated radiation therapy regimen in a clinical setting. DESIGN/METHOD: We retrospectively assessed 106 consecutive patients with incurable cancer, treated between January 2008 and December 2018. Regimen used was 30-36Gy in 5-6 biweekly fractions of 6Gy. RESULTS: The prescription dose was 30Gy in 57 (53.8%) patients and 36Gy in 49 (46.2%) patients. 89.6% patients completed the prescribed treatment. With a median follow-up of 6.92 months, 79.2% of the patients experienced clinical palliation. Palliation was correlated with the radiation therapy dose (P = 0.05). Median overall and progression-free survival (OS, PFS) were 7 and 4.63 months, respectively. Achieving palliation was associated to OS (P = 0.01). CONCLUSIONS: This short palliative hypofractionated scheme resulted in a high rate of palliation, with excellent compliance and acceptable toxicity. Our results show that radiation dose is a predictive factor for palliation.