ESTRO 2023 - Abstract Book

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ESTRO 2023

RTx, high risk CRTx post-surgery). Follow-up was comparable (56-57 months median per Tx group). Tumor samples were stained/quantitated for 20 biomarkers (5 tumor cell, 15 tumor microenvironment); 2 ratios; 14 combinations were prospectively defined, including low/high thresholds for each biomarker, ratio; combinations defined as +ve or -ve. Defined prospective interactions models (all subjects) allowed three-way interactions assessment for risk groups, biomarker level to analyze Tx efficacy for OS, PFS, LRC hazard ratio (HR) outcomes using proportional hazard models. Results The HPP (n=453) and the LR HPP (n=210) were representative of the overall population (n=923). LR efficacy was favorable for LI+CIZ+SOC vs SOC as shown below

LR HPP (n=210) Overall Survival Prog-Free Survival Local Regional Control

HR (95% CI)

0.64 (0.41 - 1.01) 0.67 (0.44 - 1.02)

0.62 (0.35 - 1.09)

Cox p-value

0.0569

0.0632

0.0961

5-year success 63.9% vs 44.4%

56.9% vs 41.1%

73.1% vs 63.6%

Efficacy for the 36 marker sets analysis favored LI+CIZ+SOC vs SOC (FLI) significantly more often than favoring SOC (FSOC) (conditional binomial; p<0.0001); see below

Proportion Statistically Significant, one-sided p<0.025

Overall (n=453)

LR (n=210)

Overall Survival

26/93 (FLI) vs 1/93 (FSOC) 21/93 (FLI)

Prog-Free Survival 17/93 (FLI) vs 2/93 (FSOC) 16/93 (FLI)

Local Reg Control 18/93 (FLI) vs 2/93 (FSOC) 17/93 (FLI)

Totals 61/279 (21.9%>>2.5%) vs 5/279 (1.9%) 54/279 (19.4%>>2.5%)

All LR advantages favored LI+CIZ+SOC vs SOC (FLI)

Conclusion LI neoadjuvant Tx followed by surgery and NCCN-directed RTx confirmed efficacy (OS, PFS, LRC) in the HPP subset. Multiple biomarkers (tumor: p16, PDL1, TME: CD4, CD8, CD3, FOXP3, CD20, CD68, CD163, CD1A, immune cells: PD1, CTLA4, PDL1, and CD25), ratios (CD4/CD8, CD8/FOXP3), and combinations proved to be predictive. LI + Surgery + RTx prolongs OS in SCCHN patients with no new Tx options in decades.

PO-1232 The impact of weight loss in head and neck cancer patients treated with chemo-radiotherapy

C.L. deantoni 1 , L. Giannini 1 , M. Midulla 1 , A. Chiara 1 , A. Fodor 1 , F. Zerbetto 1 , A. Mirabile 2 , S. Cardellini 3 , I. Dell'Oca 1 , N.G. Di Muzio 4 1 IRCCS San Raffaele Scientific Institute, Radiation Oncology, Milano, Italy; 2 IRCCS San Raffaele Scientific Institute, Unit of Oncology, Medical Oncology Department, Milano, Italy; 3 IRCCS San Raffaele Scientific Institute, Nutritional Biology, Milano, Italy; 4 Vita-Salute San Raffaele University, Medicine and Surgery, Milano, Italy Purpose or Objective The weight loss is one of the most common consequences in head and neck cancer treatments and plays an important role on worsening short-term quality of life and patient compliance. Its impact on long-term survival is already uncertain. Materials and Methods In order to standardize the study population, we considered only one-hundred head and neck cancer patients, with locally advanced (stage III-IVA/B) nasopharyngeal or oropharyngeal disease treated in our center with radical intent from 2005 and 2021 with the following schedule: -Helical TomoTherapy (HT), delivered with a Simultaneous Integrated Boost (SIB) technique: 54 Gy (1.8 Gy/day) to the clinically negative neck region and 66 Gy (2.2 Gy/day) or 69 Gy (2.3 Gy/day) to the tumor and positive nodal regions based on 18FDG CT/PET imaging. -concomitant platinum-based CT (at least 200 mg/m2). This population was divided in two subgroups, based on the weight difference between the beginning and the end of radiotherapy: less or equal to 5% (subgroup 1=33 pts) versus more than 5% (subgroup 2=67 pts). Results All patients concluded the treatment, without significant interruption. The median weight loss during CT-RT was 7% (range 0-23%). The median overall survival was 52 months (range 3-209). Using Kaplan Meier method the OS was significantly higher in the subgroup with the lower weight loss (fig 1, p-value 0.04)