ICHNO-ECHNO 2022 - Abstract Book

S108

ICHNO-ECHNO 2022

Results There were 40 males and 37 females. Sixty five patients were treated with S+RT and 12 patients were treated with RT. 38/77 patients were ≤ 60 and remaining 39/77 patients were >60 years age; this difference was significant as younger patients had better overall survival (OS) (p <0.001). In terms of T-stage, 15 patients were with T1, 25 with T2, 14 were with T3 and 23 with T4 disease. T-stage by itself was not a significant factor (p 0.117). With regards to N-stage, 47 patients were with N0, 10 with and N1, 18 with N2 and 2 patients were with N3 disease and this N-stage was not prognostic factor (p 0.294). In terms of overall stage, 13 patients were with stage I, 18 with stage II, 12 with stage III, and 34 with stage IV. Overall stage was not significant factor either (p 0.167). Eighteen patients had adenocarcinoma, 11 patients had squamous cell carcinoma (SCC) differentiation with no obvious skin primary, 10 patients had other high-grade histology and remaining 38 patients had other low-grade histology (including acinic cell, adenoid cystic, mucoepidermoid) and this difference was statistically significant as SCC had the worst OS (p 0.001).Six patients also had addition of concomitant chemotherapy to the radiotherapy and this factor was not significant (p 0.676). Intent of treatment was a significant prognostic factor. The mean OS was 104 months (95%CI: 89.3–119.0) for S+RT cohort versus 38 months (95%CI: 15.5-60.6) for the RT alone cohort, p< 0.0001. Estimated 5-year OS for S+RT group was 68.4% and for RT group was 28.1% [Figure 1]. Cox regression analysis showed that S+RT group had 0.243 times less risk of dying as compared to that of RT group (p 0.001). Even for progression free survival (PFS), S+RT group had better PFS than RT group (mean PFS 93.38 months with SE 6.34 vs 39.93 with SE 12.0, p 0.001). Females had better survival (p 0.001). Patients were treated with either 60-65Gy in 30 fractions or 50-55Gy in 20 daily fractions and this dose fractionation was not a significant factor for OS (p 0.70). 5 patients (7%) had local recurrence, 4 regional (5%) and 16 (21%) developed distant metastasis. Age (p 0.022) and N-stage (p 0.003) were significant factors for PFS whilst gender, dose fractionation, T & overall-stage and histology were not.

Conclusion Our analysis showed that patients with parotid carcinoma who had radical radiotherapy alone had worst prognosis. Male gender, age >60 at diagnosis and SCC histology were associated with worst survival.

PO-0171 Combined use IT- RT for the elderly& frail with loco-regionally advanced squamous cell skin cancer

S. appel 1 , I. Gluck 2

1 Sheba Medical Center, Radiation Oncology, Ramat Gan, Israel; 2 Seba Medical Center, Radiation Oncology, Ramat Gan, Israel Purpose or Objective LA-SCSC in elderly patients is challenging to treat. Elderly patients may not tolerate radical surgery and/or radiotherapy. Immunotherapy (i.e., anti-PD1 therapy) is effective in only 50% of patients and its prolonged administration may inflict significant adverse events. Objectives: To evaluate the outcome of elderly patients with LA-SCSC who were treated with concurrent short-term immunotherapy with hypofractionated radiotherapy (RT-IT) Materials and Methods A Retrospective chart review of consecutive patients treated with RT-IT at Sheba Medical Center. Data collected: patients' characteristics: age, performance status, hematologic comorbidities, dementia, disease extent, reason for inoperability. Treatment delivered: radiation (RT) dose and fields, type of immunotherapy, duration of IT treatment, reason for IT discontinuation. Local control was assessed clinically and if perineural invasion (PNI) existed, also radiologically. Any side effected from RT or IT were recorded and graded according to CTCAE v.5 Results Seventeen patients were included. Median age 80 (range 64-92), F/M 3/14, PS-3 in 5, dementia in 5 and immunosuppression in 5. Disease Stages: III in 3 and IV in 14 including perineural invasion (5/17), in-operable (7/17), medically in-operable (7/17) and expected mutilating surgery (9/17).