672 The effect of chemoradiotherapy and tumor histology on the immune contexture of tumor-draining lymph nodes in NSCLC

BackgroundRecently, the concept of locally delivered immune modulatory agents (re-)invigorating sub-optimally primed tumor-specific T cells and lifting suppression in the tumor microenvironment (TME) and tumor-draining lymph nodes (TDLN) has gained attention. TDLN play an important role in the induction of tumor-specific effector T cells. It is here that specialized dendritic cell (DC) subsets present tumor-derived antigens to naïve T cells and start effective adaptive immune responses to cancer. Unfortunately, TDLN are also rapidly targeted by tumors for immune suppression, which may impair the efficacy of immunotherapy. Currently, there is limited knowledge on the immune contexture of TDLN in non-small cell lung cancer (NSCLC), differences between types of tumor histology, and the influence of standard treatment.MethodsIn an exploratory study, we collected and analyzed viable cells from TDLN from patients with NSCLC, scheduled for surgical resection. To date, we have analyzed 43 TDLN from a total of 10 patients with multiparameter flowcytometry panels, either untreated or after neoadjuvant chemoradiotherapy (nCRT).ResultsOur analyses reveal differences between squamous cell carcinoma (SCC) and adenocarcinoma (AC), discernable even within this small cohort. In AC, higher levels of PD-L1 on CD11c+CD1c- LN-resident macrophages and CD1a+ migratory DC were accompanied by a lower activation state of CD8+ T cells by PD-1, CTLA-4 and CD69 expression levels. Furthermore, we found decreased activation of LN-resident DCs (by PD-L1 and CD83 levels) and a striking decrease in PD-1 and CD69 on CD8+ T cells, a decrease in effector and central memory CD8+ T cells, and an increase in naïve CD8+ T cells and Treg subsets after nCRT treatment, the current standard treatment of stage III NSCLC patients.ConclusionsThese AC/SCC –related differences and nCRT-induced alterations in the immune status of hold clues for future patient stratification and combinatorial design of CRT with immunotherapy.Ethics ApprovalThis study was approved by the Medical Ethics Committee; 2017.545

Choroid Plexus Carcinoma with Rhabdoid Features: A Case Report

The case of a patient under 2 years of age with acute vomiting, fever and seizures. MR imaging of the brain revealed a right lateral intraventricular mass and mild hydrocephalus. Surgery achieved gross total tumor resection, but tumor histology revealed choroid plexus carcinoma with heavy stratification and atypical “rhabdoid” cells.

Tumor Histology is an Independent Prognostic Factor in Locally Advanced Cervical Carcinoma. A Retrospective Study

Background: Even with different histologic origins, squamous cell carcinoma (SCC) and adenocarcinoma (AC) are considered a single entity, and the first-line treatment is the same. Locally advanced disease at the diagnosis of cervical cancer is the most important prognostic factor, the recurrence rate is high, making it necessary to evaluate prognostic factors other than clinical or radiological staging; histology could be one of them but continues to be controversial. The aim of this study was to evaluate tumor histology as a prognostic factor in terms of treatment outcomes, disease-free survival (DFS) and overall survival (OS) in a retrospective cohort of patients with Locally Advanced Cervical Carcinoma (LACC). Methods: The records of 1291patients with LACC were reviewed, all of them were treated with 45-50 Gy of external bean radiotherapy with concurrent chemotherapy and brachytherapy. A descriptive and comparative analysis was conducted. Treatment response was analyzed by the chi-square test; DFS and OS were calculated for each histology with the Kaplan-Meier method and compared with the log-rank test; and the Cox model was applied for the multivariate analysis. Results: We included 1291 patients with LACC treated from 2005 to 2014, of which 1154 (89·4%) had SCC and 137 (10·6%) had AC. Complete response to treatment was achieved in 933 (80·8%) patients with SCC and 113 (82·5%) patients with AC. Recurrence of the disease was reported in 29·9% of SCC patients and 31·9% of AC patients. Five-year DFS was 70% for SCC and 62·2% for AC. The five-year OS rates were 74·3% and 60% for SCC and AC, respectively. The mean DFS was 48·8 months for SCC vs 46·10 for AC (p=0·043), the mean OS was 50·8 for SCC and 47·0 for AC (p=0·002).Conclusion: Our findings support the hypothesis that SCC and AC are different clinical entities. Trial Registration: NCT04537273

Prognosis of Distant Metastatic Sites in Anterior Skull Base Malignancies

Objective This study aimed to provide information regarding the prognosis of patients presenting with metastatic anterior skull base malignancies based upon histology and site of distant metastasis (DM). Patients and Methods The National Cancer Database was queried for patients with anterior skull base malignant neoplasms with DM. Outcomes Prognosis was compared between site of DM and tumor histologies. A multivariable Cox proportional hazards model was used to identify prognostic factors for overall survival (OS). Results A total of 481 patients were identified. Lung was the most common site of DM (24.9%), followed by bone (22.2%), liver (5.6%), and brain (2.5%). Lung was the most common site for squamous cell carcinoma (SCCa) (28.3%), melanoma (37.7%), and adenoid cystic carcinoma (ACC; 31.4%). The median survival for patients presenting with metastatic disease regardless of tumor histology was 9.0 months (95% confidence interval [CI]: 8.2–10.3), and patients with metastasis to the liver had the best median survival at 15.5 months (95% CI: 10.5–25.6). The median survivals for the most common histologies, SCCa, melanoma, and ACC were 8.2 months (95% CI: 5.5–10.2), 10.5 months (95% CI: 8.7–14.1), and 15.0 months (95% CI: 11.1–61.1), respectively. Multivariable analysis demonstrated worse overall survival (OS) for older patients, higher Charlson-Deyo comorbidity scores, and tumors with higher grade and T stage. Compared with metastasis to bone, lung metastasis had better OS on multivariable analysis (hazard ratio [HR]: 0.70, 95% CI: 0.51–97). Adenoid cystic carcinoma had improved OS compared with SCCa (HR: 0.62, 95% CI: 0.39–99). Conclusion Tumor histology, metastatic sites, and several disease factors affected prognosis in anterior skull base malignancies with DM.

KEYNOTE-799: Phase 2 trial of pembrolizumab plus platinum chemotherapy and radiotherapy for unresectable, locally advanced, stage 3 NSCLC.

8512 Background: KEYNOTE-799 (NCT03631784) is an ongoing study of the anti‒PD-1 antibody pembrolizumab (pembro) plus concurrent chemoradiation therapy (cCRT) in patients (pts) with unresectable, locally advanced stage III NSCLC. Prior results from this study in a subset of pts (primary efficacy population) showed an ORR of 69.6% in cohort A (squamous and nonsquamous, n = 112) and 70.5% in cohort B (nonsquamous, n = 61), and grade ≥3 pneumonitis in 8.0% and 7.9% of pts, respectively. Here, we present results for all pts enrolled in KEYNOTE-799. Methods: This nonrandomized, multisite, open-label phase 2 trial enrolled pts aged ≥18 y with previously untreated, unresectable, pathologically confirmed, stage IIIA‒C NSCLC with measurable disease per RECIST v1.1. Pts in cohort A (squamous and nonsquamous) received 1 cycle of carboplatin AUC 6 and paclitaxel 200 mg/m2 and pembro 200 mg. After 3 wks, pts received carboplatin AUC 2 and paclitaxel 45 mg/m2 QW for 6 wks and 2 cycles of pembro 200 mg Q3W plus standard thoracic radiotherapy (TRT). Pts in cohort B (nonsquamous only) received 3 cycles of cisplatin 75 mg/m2, pemetrexed 500 mg/m2,and pembro 200 mg Q3W, and TRT in cycles 2 and 3. All pts received an additional 14 cycles of pembro 200 mg Q3W. Primary endpoints were ORR per RECIST v1.1 by blinded independent central review (BICR) and the incidence of grade ≥3 pneumonitis (per NCI CTCAE v4.0). Efficacy and safety were assessed in all pts as-treated. Results: Of 216 pts enrolled in KEYNOTE-799 (cohort A, n = 112; cohort B, n = 104), 112 in cohort A and 102 in cohort B received treatment. As of October 28, 2020, the median (range) time from first dose to database cutoff was 18.5 (13.6–23.8) mo in cohort A and 13.7 (2.9–23.5) mo in cohort B. ORR (95% CI) was 70.5% (61.2%‒78.8%) in cohort A and 70.6% (60.7%‒79.2%) in cohort B. Median DOR was not reached in either cohort (Table). ORR was similar regardless of PD-L1 status ([TPS <1% and TPS ≥1%]; Cohort A, 66.7% and 75.8%; Cohort B, 71.4% and 72.5%) and tumor histology (Cohort A, squamous, 71.2% and nonsquamous, 69.2%). Grade ≥3 pneumonitis occurred in 9 pts (8.0%) in cohort A and 7 (6.9%) in cohort B. Grade 3‒5 treatment-related AEs occurred in 72 pts (64.3%) in cohort A and 51 (50.0%) in cohort B. Conclusions: Pembro plus cCRT continues to demonstrate promising antitumor activity, regardless of PD-L1 TPS and tumor histology, and manageable safety in pts with previously untreated, locally advanced, stage III NSCLC with longer follow-up. Clinical trial information: NCT03631784. [Table: see text]

Patterns of survival in NSCLC with de novo brain metastasis: SRS, WBRT, and no radiotherapy cohorts.

9122 Background: Prognostic determinants in metastatic non-small cell lung cancer (mNSCLC) include numerous sociodemographic and clinical characteristics. We provide granular, real-world survival data in different cohorts of this heterogeneous population, stratifying by: age, Charlson/Deyo scoring (CDS) of comorbidity, tumor histology, and use of immunotherapy. Methods: This retrospective analysis uses the National Cancer Database (NCDB) to explore patterns of survival in patients diagnosed between 2010-2016 with mNSCLC involving the brain. Kaplan-Meier (KM) modeling was used to evaluate for differences in overall survival (OS) between 3 cohorts of patients: those undergoing 1) stereotactic radiosurgery (SRS), 2) whole-brain radiotherapy (WBRT), and 3) those not undergoing brain radiotherapy (NR) as part of the first course of treatment. As per Table, we ran 8 KM models to generate median OS (mOS) data across stratifications for age (<70 vs. ≥70), CDS (0-1 vs. 2-3), tumor histology (adenocarcinoma vs. squamous), and use of immunotherapy (yes vs. no). We provide a ranked order of these 3 cohorts by mOS (‘survival sequence’, or ‘SS’), as well as differences in mOS (‘ΔmOS’) between NR and WBRT – the two cohorts most comparable in life expectancy. Results: A total of n=38,119 patients were included in this study. Most received WBRT (n=18,052, 47.4%), n=6,562 (17.2%) received SRS, while n=13,505 (35.4%) did not receive brain radiation as part of their first course of treatment. In all subgroups, patients treated with SRS for brain metastasis had the highest mOS. Survival for those receiving WBRT was better or comparable (difference in mOS <0.5 months) to those that did not receive radiotherapy, except in patients aged ≥70 (SS: NR > WBRT; KM p-value <0.05; ΔmOS of 1.6 months), those with Charlson-Deyo comorbidity scores of 2-3 (SS: NR > WBRT; KM p-value <0.05; ΔmOS: 0.6 months), those with squamous carcinoma (SS: NR > WBRT; KM p-value <0.05; ΔmOS: 0.7 months), and those already receiving immunotherapy (SS: NR > WBRT; KM p-value <0.05; ΔmOS: 0.6 months). Conclusions: SRS for de novo brain metastases is associated with improved OS in mNSCLC. In contrast, the burden of WBRT may outweigh the survival benefit it affords in patients ≥70, and those with comorbidities. Squamous cell carcinomas may be associated with more radio-resistance than adenocarcinomas to WBRT. Finally, as previously described in melanoma, the survival benefit afforded by brain radiotherapy may be lower in patients on immunotherapy.[Table: see text]