eP173 - Exploring the Contribution of Deprivation, Body Composition and Systemic Inflammation to Outcomes in Anal Squamous Cell Cancer

Purpose/Background: Anal squamous cell cancer (ASCC) is rare, but incidence rates are rising globally. Deprivation disparities have been reported both in incidence and outcomes. We hypothesise that this may relate to higher rates of adverse host factors including sarcopenia and systemic inflammation.Methods/Interventions: Consecutive patients diagnosed with stage 1-3 ASCC treated with primary chemoradiotherapy (CRT) between 2008-2018 were identified from a prospectively maintained database. Clinicopathological data was extracted from medical records. Socioeconomic status was assessed by Scottish Index of Multiple Deprivation 2016 (SIMD) ranging 1-10, with 1 most deprived. Sarcopenia was assessed on CT images at the L3 level using ImageJ. Systemic inflammation was assessed using the modified Glasgow Prognostic Score (mGPS) and neutrophil-lymphocyte ratio (NLR). Associations between clinicopathological characteristics were assessed using X2. Survival was assessed using Cox regression. Statistical analyses were performed using SPSS version 28.Results/Outcomes: Of 207 cases of ASCC observed, 120 patients had primary CRT. Most were female (n=83, 69%), under 65 (n=90, 75%) and AJCC Stage 1-2 (n=75, 63%). Prevalence of HIV (n=2, 3%) and immunosuppression (n=4, 3%) was low. Patients were predominantly from deprived areas (SIMD 1-4, n=75, 63%). No difference in age, gender or T Stage was seen when comparing deprived and non-deprived groups (p>0.05). Deprivation was associated with a NLR >5 (p=0.019), but not mGPS (p=0.309).A total of 110 patients were eligible for sarcopenia analysis. Sarcopenia was observed in 42 patients (38%) but was not associated with T/N Stage, mGPS or NLR. No association between deprivation and sarcopenia was noted.Complete response to CRT occured in 102 patients (85%). An incomplete response was associated with higher T/N Stage, mGPS, NLR and immunosuppression (P < 0.05). No association was seen with deprivation or sarcopenia. At 5-years, overall survival (5yOS) was 66%. Poorer 5yOS was associated with deprivation, increased T/N Stage and mGPS (p < 0.05). There was no association with sarcopenia (p=0.986). On multivariate analysis, deprivation was associated with 5yOS (HR 2.574 p=0.019), independent of T Stage (2.383, p=0.014) and mGPS (HR 2.319, p=0.015). Recurrence developed in 26 patients (22%), primarily local (n=16, 62%). Mean time to recurrence was 26 months. Univariate analysis showed association between female gender and higher BMI (p < 0.05), with deprivation trending towards significance (p=0.052). NLR, mGPS and sarcopenia was not associated. Salvage surgery, performed in 8 patients (4 persistent disease and 4 recurrence) was not associated with deprivation, sarcopenia, NLR or mGPS.Cancer-specific survival at 5 years (5yCSS) was 74%. Lower 5yCSS was associated with higher T/N Stage and mGPS, alongside NLR>5 and immunosuppression (p < 0.05). Sarcopenia was not associated (p=0.833). On multivariate analysis, increased T Stage (HR 2.978, p=0.011) and mGPS (HR 2.656, p=0.017) remained prognostic factors.Conclusion/

Discussion: Deprivation is associated with lower 5yOS in patients with ASCC and may be associated with developing recurrence. While deprivation was associated with systemic inflammation as represented by NLR>5, it was not associated with sarcopenia. Future work is required in a larger and independent cohort to validate these findings and identify other host and tumour factors contributing to inferior survival outcomes in ASCC.