1078 Background: Androgen receptor (AR) expressing triple negative breast cancer (TNBC) is a sub-set of TNBC with an evolving prognostic and predictive behaviour. AR immunohistochemical threshold for positivity has not been standardized and a wide range of cut-offs have been used across studies ( > 0% to 75%). In this study we explored AR immunohistochemistry thresholds in relation to disease free survival (DFS) and clinical outcomes in non-metastatic TNBC using the Allred and H-Score systems. Increasing interest in AR as a therapeutic target for TNBC and the use of digital tissue image analysis makes it important to standardize AR immunohistochemistry reporting. Methods: 100 FFPE (formalin-fixed paraffin-embedded) tumour blocks were retrieved for non-metastatic TNBCs diagnosed between January 2015 and May 2017 and immunostained using AR441 (IgG1) mouse monoclonal antibody. Clinical follow-up ranged from 59 to 31 months and DFS was calculated. Cut-off scores were explored using Evaluate Cutpoints ( R maxstat package) and X-tile software. The score with maximum split in DFS (based on log-rank statistics and lowest p-value) was chosen as the cut-off. Descriptive and survival statistics was performed. Results: The median age was 51 (SD 11.262; range 28 to 82) years. Using Evaluate Cutpoints ≥3 was found as the threshold for AR by Allred Score. 36% cases were AR positive using Allred score (HR 0.508; CI 0.234 - 1.11; p-value 0.08). Using Evaluate Cutpoints ≥30 was found as the threshold for AR by H-Score (HR 0.624, CI 0.306 - 1.27; p-value 0.19). 35% cases were AR positive using H-Score. X-tile analysis also found the cut-offs as ≥3 and ≥30 for Allred and H-Score respectively (p < 0.05). A significant correlation was seen between the two scoring systems (Pearson Correlation 0.935; p < 0.01). A significantly higher number of grade III TNBCs were AR negative (n = 55/76) compared to grade II (n = 9/24) (p = 0.002). Cut-off for Ki67 was 75 (HR 1.61, CI 0.85-3.04, p-value 0.141) with a significantly higher number of AR negatives in the Ki67≥75 group (21/26; p < 0.05). The overall median DFS was 51.9 months. There was no significant difference in DFS for the AR negative (median: 47.4 months; mean: 39.39 months) and AR positive (Median survival not reached; mean: 41.3 months) groups(p = 0.23). Conclusions: AR immunohistochemistry cut-offs using the Allred (≥3) and H-Score (≥30) are close to the ones used for ER/PR immunohistochemistry as per ASCO/CAP guidelines, making a strong case for universal application of these systems for harmonization of AR data.

e12570 Background: Gene expression profiling for breast cancer has classified ER positive subtype into luminal A and luminal B. Luminal B breast cancer (LBBC) have a higher proliferation and poorer prognosis than luminal A tumors. Ki-67 index is the commonly used proliferation marker in breast cancer; however Ki67 expression can also be used to identify a subset of patients among LB with a favorable prognosis. This study attempts to verify this subset of LBBC patients based on DFS and PFS in non-metastatic and metastatic patients respectively. Methods: We retrospectively analyzed 80 IDC breast cancer patients diagnosed in 2013-2016 with complete follow-up till January-2021. We defined LBBC as ER+, PR+ or PR- , HER2+ or HER2- with a Ki67 index >20%. PFS was considered as the endpoint in patients presenting with metastatic disease whereas DFS was used in non-metastatic disease. The cut-off for ki67 was calculated using an X-tile plot (version 3.6.1, Yale University) by dividing Ki67 data into two populations: low and high, with randomized 1:1 “training” and “validation” cohorts. Results: Median age was 51.5 years. 18.7% (n=15) presented with metastasis at the time of diagnosis and their overall median PFS was found to be 25.8 months. The incidence of HER2 positive LBBC was found to be 15% (n=12) and none of them were found to be presented with metastasis. Survival and frequency of various sub groups in our study are enlisted in the given table. We estimated a Ki67 cut-off of 30% in patients with upfront metastatic disease and PFS was found to be higher in <30% compared to a Ki67 index >30% (38.9 months vs 19.7 months, p-0.002). Overall median DFS was not achieved in non-metastatic group (Mean DFS: 64.7 months) where as a statistically significant difference was observed in the survival of HER2 positive (median DFS: 53.5 months, mean DFS: 50.9) than HER2 negative patients (median DFS not achieved, mean: 66.97 months) ( p-0.021). We obtained a Ki67 cut-off of 32% in non- metastatic group and mean DFS was found to be higher in Ki67<32% (69 months) compared to Ki67>32% (61.4 months), however it failed to exhibit a statistically significant relationship ( p-0.373). Conclusions: Our study indicates that a subset of patients exists within metastatic and non-metastatic LBBC with differing prognosis based on Ki67. Larger studies are further required to confirm the findings and therapeutic implications.[Table: see text]

e16507 Background: Oesophageal cancer is the twelfth most common cancer worldwide and seventh leading cause of cancer related death. Neoadjuvant treatment in addition to surgery has shown improved overall survival compared to surgery alone in resectable oesophageal cancer. We aimed to analyse the survival outcome among locally advanced oesophageal carcinoma patients in neoadjuvant setting. Methods: We analysed 37 patients with locally advanced carcinoma of oesophagus from 2015 to 2019 who underwent neoadjuvant chemoradiotherapy followed by surgical excision of tumour. Descriptive analysis was used for demographic data. overall survival and disease free survival was analysed using Kaplan-Meier survival analysis. Results: Our study includes 20 males (54%) and 17 females (45%). Over all consumption of Tobacco and alcohol consumption was found to be 64% and 18% respectively. The most common tumour site in this study was middle oesophagus (56%) followed by lower (37%) and upper (5%). Histopathologically, moderately differentiated squamous cell carcinoma constituted the highest (62%), followed by well differentiated squamous cell carcinoma (21%) and poorly differentiated carcinoma (16%). The pathological stage post chemoradiotherapy was 80%, 50% and 57% for stage I, II and III respectively. Median over all survival is 60 months and no statistical difference in stage I and stage II. Median over all survival for poorly differentiated squamous cell carcinoma is 16 months and lower one third of squamous cell carcinoma is 37 months. Complete pathological response is 42 %. Conclusions: Our study concluded that patients with tobacco and alcohol consumption have poorer survival. Prognosis was worst for patients with lower end oesophagus and poorly differentiated type. Disease free survival was better for patients who achieved complete pathological response when compared to partial responders.

e15020 Background: Neutrophil-Lymphocyte Ratio (NLR) and Lymphocyte-Monocyte Ratio (LMR) have been under scrutiny for their potential as a prognostic tool in various cancers. While there have been conflicting opinions on their reliability, NLR has shown rather near accurate predictions in previous studies. Targeted tyrosine kinase inhibitors have shown good results in improving OS and PFS of patients with EGFR-mutated NSCLC but the prognostic indicators are limited. This study aims to decipher if baseline NLR and LMR ratios are valid tools to predict prognosis of patients with EGFR-mutated NSCLC. Methods: We analyzed 78 advanced NSCLC patients harboring Exon 19 Deletion and Exon 21 L858R mutation undergoing EGFR-TKI therapy. Baseline NLR and LMR were measured in peripheral blood within two weeks prior to the initiation of TKIs. Overall survival was used as an outcome measure for TKI therapy and it is defined as from the initiation of TKIs to death by any cause. The cut-off for NLR and LMR was calculated using an X-tile plot (version 3.6.1, Yale University, New Haven, CT, USA) by dividing marker data into three populations: low, middle, and high (i.e., two divisions), with randomized 1:1 “training” and “validation” cohorts. Results: Overall median survival of the study group was 31.5 months and median age was found to be 60 years. Gefitinib (35.9%) and afatinib (34.6%) were the most commonly prescribed followed by erlotinib (21.8%) and osimertinib (7.7%). With cut-points of 1.8 and 4.9 we analyzed three populations for baseline NLR as ≤1.8, 1.9-4.9 and > 4.9. Similarly, for LMR cut-points of 3.49 and 5 were found and we analyzed patients with LMR of ≤3.49, 3.5-5 and >5. There was a statistically significant overall median survival observed as per the obtained NLR as well as LMR cut-off as given in the table. Conclusions: A statistically significant co-relation was observed with baseline NLR and LMR ratio in predicting response to EGFR TKIs in NSCLC. Our study further strengthens the concept of using NLR and LMR as peripheral blood biomarkers for prognostic assessment in cancer patients undergoing treatment.[Table: see text]