6081 Background: Treatment selection based on actionable alterations (AAs) is an appealing strategy for pts with R/M SGT. The GEMS-001 study (NCT02069730) at Princess Margaret Cancer Centre (PM) and the Vall D´Hebron Institute of Oncology (VHIO) pre-screening program facilitate the identification of AAs for R/M SGT pts and treatment selection. Methods: We analyzed R/M SGT treated at PM and VHIO from 2015 to 2020. Clinicopathological features, molecular alterations and treatment modalities were correlated with outcomes. The primary endpoint was overall response rate (ORR) by RECIST 1.1. Clinical benefit rate (CBR) was defined by pts with partial response or stable disease ≥4 months. Clinical actionability of multigene panel testing (NGS) and immunohistochemistry (IHC) were assessed as per institutional molecular tumor boards or investigators. Pts were opportunistically matched to available therapies from each center. Results: In total 206 pts were enrolled. On IHC, HER2 overexpression was present in 9%, Androgen Receptor (AR) 33%, Estrogen/Progesterone Receptor (ER/PR) 11% and ALK overexpression 0%. On NGS, PIK3CA mutation (mut) was in 9%, NTRK fusion 6%, NOTCH1-3 mut 5%, HRAS mut 6%, ERBB2/3 alterations (alt) 4% and FGFR1-4 alt 3%. Up to 92 pts (45%) displayed at least 1 AA and 36 pts (18%) had ≥2 AAs. A total of 60 pts (29%) were matched to AAs. Of those matched, median age was 60 years (range 33-84), M:F 21:39, 95% ECOG≤1 with a median number of prior treatment lines 0 (range 0-3), and their AAs included 26 AR, 9 HER2 or ERBB2 overexpression, 9 PIK3CA mut, 3 NTRK fusion, 3 FGFR1-3 alt and 10 other AAs (2 ER/PR overexpression, 2 EGFR mut, 1 c-kit mut, 1 BAP1 mut, 1 Non-V600 BRAF mut, 1 CDKN2A mut, 1 CHEK2 mut and 1 PTCH1 mut). Overall, ORR was 27% for the matched population. See table for outcomes. Conclusions: In our cohort, almost one third of the population received therapies matched to AAs. Our results suggest that targeted therapies have promising activity in pts with R/M SGT supporting comprehensive molecular and IHC profiling in treatment determination.[Table: see text]

CheckMate 743 trial demonstrated survival benefit of immunotherapy in first line in MPM with some differences in the efficacy of chemotherapy according to histology. The objective of this study is to characterize the impact of chemotherapy according to histology in patients diagnosed with MPM at our institution. Clinical records of all MPM patients diagnosed at Vall d’Hebron University Hospital between November 2002 and April 2020 were reviewed. Associations between clinical variables and outcomes were assessed with Cox regression models. Survival data were calculated by the Kaplan–Meier method. 189 patients were included with 76% of tumors classified as epithelioid subtype. First line chemotherapy was offered to 85% of patients. Median survival in overall population was 21.3 months (95% CI 17.2–24.3). We found that patients with epithelioid tumors had better overall survival (OS) and progression free survival (PFS). Median OS of epithelioid patients treated with first line chemotherapy was 26.7 months versus 15.0 months in non-epithelioid patients (HR 2.25 CI 95% 1.4–3.4; p < 0.001). Median PFS for patients with epithelioid tumors treated with chemotherapy was 4.8 months versus 3.6 months in non-epithelioid (HR 1.5 CI 95% 1.0–2.3; p = 0.03). The improvement of outcomes in patients with epithelioid histology was detected in patients treated with cisplatin or carboplatin. Histology was not a predictive factor for the platinum agent sensitivity (p of interaction PFS = 0.09, p of interaction OS = 0.65). In our series, patients with non-epithelioid tumors presented worse prognosis. Although epithelioid tumors exposed to cisplatin had higher PFS, histology was not a clear predictor of chemotherapy efficacy.

PurposeCheckMate 743 trial demonstrated survival benefit of immunotherapy in first line in MPM with some differences in the efficacy of chemotherapy according to histology. The objective of this study is to characterize the impact of chemotherapy according to histology in patients diagnosed with MPM at our institution. MethodsClinical records of all MPM patients diagnosed at Vall d´Hebron University Hospital between November 2002 and April 2020 were reviewed. Associations between clinical variables and outcomes were assessed with Cox regression models. Survival data were calculated by the Kaplan-Meier method. Results189 patients were included with 76% of tumors classified as epithelioid subtype. First line chemotherapy was offered to 85% of patients. Median survival in overall population was 21.3 months (95%CI17.2-24.3). We found that patients with epithelioid tumors had better overall survival (OS) and progression free survival (PFS). Median OS of epithelioid patients treated with first line chemotherapy was 26.7 months versus 15.0 months in nonepithelioid patients (HR2.25 CI95% 1.4-3.4; p<0.001). Median PFS for patients with epithelioid tumors treated with chemotherapy was 4.8 months versus 3.6 months in nonepithelioid (HR1.5 CI95% 1.0-2.3; p=0.03). The improvement of outcomes in patients with epithelioid histology was detected in patients treated with cisplatin or carboplatin. Histology was not a predictive factor for the platinum agent sensitivity (p of interaction PFS=0.09, p of interaction OS=0.65). Conclusions In our series, patients with nonepithelioid tumors presented worse prognosis. Although epithelioid tumors exposed to cisplatin had higher PFS, histology was not a clear predictor of chemotherapy efficacy.

Background: Breast reconstruction (BR) has psychosocial and sexual well-being benefits in breast cancer (BC) patients that undergo mastectomy. However, this practice remains infrequent in many low-and middle-income countries as it is not usually covered by public health insurance schemes. This study aims to determine the prevalence and main predictors of BR among BC patients treated in a public center in Mexico.Methods: Medical records of women diagnosed with primary BC from 2009 to 2020 at a center in Monterrey, Mexico were reviewed. Patients who underwent a mastectomy and had at least a 2-year follow-up were included. Fisher's exact and logistic regression tests were employed to determine variable associations.Results: A total of 586 patients with a median age of 50 years (range 20-88) were included. The majority of patients were in a relationship (67%), postmenopausal (58%), and had a BMI 25 kg/m 2 (80%). Most common stages at diagnosis were II (44%) and III (41%). Overall, 54 (9%) received BR (41% immediate and 59% delayed). Predictors for undergoing BR were stages 0-I at diagnosis (OR 2.13, 95%CI 1.10-4.10; p¼0.024), age <40 years (OR 2.15, 95%CI 1.10-4.22; p¼0.026), premenopausal status (OR 2.62, 95%CI 1.45-4.73; p¼0.001), not receiving adjuvant radiotherapy (RT) (OR 2.34, 95%CI 1.30-4.21; p¼0.005), BMI <25 kg/m 2 (OR 2.62, 95%CI 1.44-4.74; p¼0.002), negative lymph node (LN) status (OR 2.47, p¼0.004), and bilateral mastectomy (OR 4.08, p<0.001). In a multivariate analysis, menopausal status, BMI, not receiving adjuvant RT, and bilateral mastectomy remained independent predictors for BR. Of note, no significant association was found between BR and type of LN surgery (axillary dissection v sentinel biopsy, p¼0.123).Conclusions: BR is one of the foremost strategies to improve BC survivors' quality of life. However, its uptake remains low in resource-constrained settings, possibly due to its high economic cost and information gaps among patients. Further studies are needed to identify other potential factors that influence BR uptake. The development of interventions that tackle the barriers limiting patients' adequate and equitable access to this procedure is urgently needed.Legal entity responsible for the study: The authors.

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