Herbert Stöger

Background: Biomarkers for predicting response to immune checkpoint inhibitors (ICI) are scarce and often lack external validation. This study provides a comprehensive investigation of pretreatment C-reactive protein (CRP) levels as well as its longitudinal trajectories as a marker of treatment response and disease outcome in patients with advanced non-small cell lung cancer (NSCLC) undergoing immunotherapy with anti PD-1 or anti PD-L1 agents. Methods: We performed a retrospective bi-center study to assess the association between baseline CRP levels and anti PD-(L)1 treatment outcomes in the discovery cohort (n = 90), confirm these findings in an external validation cohort (n = 101) and explore the longitudinal evolution of CRP during anti PD-(L)1 treatment and the potential impact of dynamic CRP changes on treatment response and disease outcome in the discovery cohort. Joint models were implemented to evaluate the association of longitudinal CRP trajectories and progression risk. Primary treatment outcomes were progression-free survival (PFS) and overall survival (OS), while the objective response rate (ORR) was a secondary outcome, respectively. Results: In the discovery cohort, elevated pretreatment CRP levels emerged as independent predictors of worse PFS (HR per doubling of baseline CRP = 1.37, 95% CI: 1.16–1.63, p < 0.0001), worse OS (HR per doubling of baseline CRP = 1.42, 95% CI: 1.18–1.71, p < 0.0001) and a lower ORR ((odds ratio (OR) of ORR per doubling of baseline CRP = 0.68, 95% CI: 0.51–0.92, p = 0.013)). In the validation cohort, pretreatment CRP could be fully confirmed as a predictor of PFS and OS, but not ORR. Elevated trajectories of CRP during anti PD-(L)1 treatment (adjusted HR per 10 mg/L increase in CRP = 1.22, 95% CI: 1.15–1.30, p < 0.0001), as well as a faster increases of CRP over time (HR per 10 mg/L/month faster increase in CRP levels = 13.26, 95% CI: 1.14–154.54, p = 0.039) were strong predictors of an elevated progression risk, whereas an early decline of CRP was significantly associated with a reduction in PFS risk (HR = 0.91, 95% CI: 0.83–0.99, p = 0.036), respectively. Conclusion: These findings support the concept that CRP should be further explored by future prospective studies as a simple non-invasive biomarker for assessing treatment benefit during anti PD-(L)1 treatment in advanced NSCLC.

Pancreatic enzymes might play a pivotal role in the pathophysiology and prognosis of pancreatic cancer. The aim of this study is to investigate the lipase/amylase ratio (LAR), representing a marker previously used in the differentiation of pancreatitis, as a potential prognostic marker in pancreatic cancer. Data from 157 surgically treated patients with ductal pancreatic adenocarcinoma and 351 patients with metastatic disease were evaluated retrospectively. Cancer-specific survival (CSS) was considered the endpoint of the study. After applying Kaplan–Meier curve analysis, uni- and multivariate Cox regression models were calculated to evaluate the prognostic relevance of LAR. An elevated LAR at diagnosis of localized pancreatic cancer was significantly associated with higher CA19-9 levels (p < 0.05). In univariate analysis, we observed an increased LAR as a significant factor for lower CSS in localized pancreatic cancer patients (HR = 1.63; 95% CI = 1.12–2.36; p = 0.01), but not in metastatic patients (HR = 1.12; 95% CI = 0.87–1.43; p = 0.363). In multivariate analysis, including age, gender, tumor stage, Karnofsky Performance Status, tumor grade, administration of chemotherapy and the LAR, an increased LAR was confirmed to represent an independent prognostic factor regarding CSS (HR = 1.81; 95% CI = 1.17–2.77; p = 0.007) in localized pancreatic cancer patients. In conclusion, our study identified the LAR as an independent prognostic factor in surgically treated pancreatic cancer patients.

Introduction: The activity of butyrylcholinesterase (BChE) in blood reflects liver function and has recently been associated with systemic inflammatory response and tumor cachexia. As these conditions have been previously linked with pancreatic cancer (PC), the purpose of the present study was to evaluate the prognostic impact of plasma BChE in PC. Methods: Data from 574 consecutive PC patients, treated between 2004 and 2018 at a single academic center, was evaluated. The primary endpoint was cancer-specific survival (CSS), analyzed by Kaplan–Meier curve, and both univariate and multivariate Cox proportional models. Results: BChE activity negatively correlated with other liver parameters (bilirubin, gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and C-reactive protein (CRP)), and positively correlated with albumin levels, respectively (p < 0.01). In univariate analysis, a low plasma BChE activity was a factor of poor CSS (hazard ratio: 1.4, 95% confidence interval: 1.129–1.754, p = 0.002). In multivariate analysis, tumor stage, tumor grade, administration of chemotherapy, bilirubin levels and a low BChE activity (hazard ratio: 1.42, 95% confidence interval: 1.10–1.82; p = 0.006) were identified as independent prognostic factors. Conclusion: Decreased activity of BChE in blood plasma predicts shorter survival time in PC patients. Therefore, BChE might be helpful in additional stratification of patients into different prognostic risk groups.

Currently, patients with extremity soft tissue sarcoma (eSTS) who have undergone curative resection are followed up by a heuristic approach, not covering individual patient risks. The aim of this study was to develop two flexible parametric competing risk regression models (FPCRRMs) for local recurrence (LR) and distant metastasis (DM), aiming at providing guidance on how to individually follow-up patients. Three thousand sixteen patients (1931 test, 1085 validation cohort) with high-grade eSTS were included in this retrospective, multicenter study. Histology (9 categories), grading (time-varying covariate), gender, age, tumor size, margins, (neo)adjuvant radiotherapy (RTX), and neoadjuvant chemotherapy (CTX) were used in the FPCRRMs and performance tested with Harrell-C-index. Median follow-up was 50 months (interquartile range: 23.3–95 months). Two hundred forty-two (12.5%) and 603 (31.2%) of test cohort patients developed LR and DM. Factors significantly associated with LR were gender, size, histology, neo- and adjuvant RTX, and margins. Parameters associated with DM were margins, grading, gender, size, histology, and neoadjuvant RTX. C-statistics was computed for internal (C-index for LR: 0.705, for DM: 0.723) and external cohort (C-index for LR: 0.683, for DM: 0.772). Depending on clinical, pathological, and patient-related parameters, LR- and DM-risks vary. With the present model, implemented in the updated Personalised Sarcoma Care (PERSARC)-app, more individualized prediction of LR/DM-risks is made possible.

The role of mean platelet volume (MPV) as a predictor of outcomes in various cancer entities including colorectal cancer (CRC) has already been analyzed. However, data on the prognostic and predictive value of MPV in CRC over multiple lines of systemic therapy are missing.

Venous thromoboembolism (VTE) is a frequent and burdensome complication of metastatic colorectal cancer (CRC). However, the epidemiology of VTE in patients with localized CRC after surgery in curative intent is incompletely understood. In this single-center observational cohort study, we investigate patterns of VTE risk in localized CRC, and define its relationship with baseline risk factors, adjuvant chemotherapy and CRC recurrence. Five-hundred-sixteen patients with stage II/III CRC were included retrospectively at the time of surgery, and followed until the occurrence of VTE, CRC recurrence, or death (median age = 65.1 years, stage II and III: n = 151 (29.5%), n = 361 (70.5%); adjCTX: n = 339 (65.7%)). During a median follow-up of 2.7 years, 15 VTEs (2.7%) and 116 recurrences (22.5%) occurred, and 46 patients (8.9%) died. Six-month, 1-year, and 5-year VTE risks were 1.6%, 2.0% and 3.2%, respectively. In competing risk time-to-VTE regression, adjCTX was not associated with an increased risk of VTE (Subdistribution hazard ratio = 0.98, 95% CI:0.33–2.88, p = 0.97). The occurrence of disease recurrence strongly increased the risk of VTE (Multi-state model: Transition hazard ratio (THR) = 13.03, 95% CI:4.39–38.74, p < 0.0001)). Conversely, the onset of VTE did not predict for recurrence (THR = 1.95, 95% CI: 0.62–6.16, p = 0.25). VTE risk is very low in localized CRC and does not appear to be increased by adjuvant chemotherapy. Thus, primary thromboprophylaxis is unlikely to result in clinical benefit in this population. The strongest determinant of VTE risk appears to be disease recurrence.

E16038 Background: Febrile neutropenia (FN) is a serious complication of chemotherapy (CTX). Here, we aim to characterize the clinical course of FN in patients (pts) with testicular germ cell tumors (TGCT). Methods: 413 TGCT patients who underwent at least one cycle of CTX in adjuvant or curative intent were studied within this single-center observational cohort study. Baseline characteristics of the subpopulation with FN are reported in Table 1. Results: During a total number of 1,196 CTX cycles in 413 patients, we observed 70 episodes of febrile neutropenia (16.9%). 55 (79%) of these episodes occurred during the 1^stcycle of CTX. The median time between CTX start and FN onset was 14 days [IQR: 12-15, range: 7-18]. One (1%) FN episode was fatal, and 56 patients (80%) had to be hospitalized. Median time in hospital was 7 days [IQR: 6-8, range: 3-12], and the median number of days with an absolute neutrophil count below 0.5G/L was 2 [IQR: 2-3, range: 1-7]. Twelve (20%) FN episodes occurred in the 60 pts who received primary G-CSF support. There was very little treatment delay due to FN (median: 0 days [IQR: 0-0, range: 0-7]. 3 patients (4%) developed a second FN episodes. Conclusions: This study supports prior reports that FN is a relatively frequent complication of CTX in TGCT. However, the case-fatality-rate of FN in TGCT appears to be very low. [Table: see text]

E15621 Background: Second-line chemotherapy (2LCTX) is increasingly applied in patients (pts) with advanced biliary tract cancer (aBTC), although no randomized trial has so far demonstrated the benefit of this intervention over best supportive care (BSC) alone. In the absence of randomized data, we thus conducted a comparative effectiveness analysis of survival outcomes in aBTC pts treated with BSC±2LCTX. Methods: In this single-center cohort study, we retrospectively included 80 pts with metastatic, recurrent, or inoperable aBTC who completed 1^st-line CTX at our department between 2003 and 2016. Thirty-eight of these pts (48%) received 2LCTX+BSC (Fluoropyrimidine (FP) mono: n = 26 (68%), FP-based combination CTX: n = 9 (24%), Others: n = 3 (8%)). Primary endpoint was 18-month overall survival (OS). An inverse-probability-of-treatment-weighted analysis (IPTW) was implemented to rigorously account for imbalances in prognostic variables between the two study groups. Results: During a median follow-up of 14.8 months, we observed 49 deaths. Six-month, 12-month, and 18-month OS estimates were 77%, 53% and 23% in the BSC+2LCTX group, and 29%, 21%, and 14% in patients in the BSC group, for a univariable hazard ratio (HR) for OS of 0.36 (95%CI: 0.20-0.64, p = 0.001). However, pts receiving 2LCTX+BSC had a significantly higher prevalence of favorable prognostic variables, such as a higher Karnofsky Index (p = 0.0001), lower serum bilirubin (p = 0.03), higher hemoglobin (p = 0.002), and higher serum albumin (p = 0.0007). After careful adjustment for these imbalances using IPTW, 2LCTX+BSC was not associated with an OS benefit over BSC alone (Adjusted HR = 0.62, 95%CI: 0.30-1.29, p = 0.201). In IPTW analysis, 6-, 12-, and 18-month OS were 51%, 33% and 14% in the BSC+2LCTX group, and 35%, 29%, and 19% in patients in the BSC group. The beneficial association of 2LCTX with OS was highly time-dependent, with IPTW HRs of 0.07 (p = 0.002), 0.42 (p = 0.05), and 0.53 (p = 0.11) after 3, 6, and 12 months, respectively. Conclusions: Within the limitations of a non-randomized study, our data support the concept that 2LCTX is associated with a short-term OS benefit in pts with aBTC.

E16520 Background: The introduction of Abiraterone (Abi) and Enzalutamide (Enza) into treatment of mCRPC has led to a survival benefit. However, in a subset of patients treated with Enza/Abi, rapidly progressive disease with atpical metastatic spread develops. According to Eric Small et al. (ASCO 2015 Abstract 5003), 39% of metastases in mCRPC-patients treated with Enza/Abi have small cell neuroendocrine or mixed type histologies. Based on these findings we aimed at characterising NCD in a case series of 8 patients using 1) clinical, laboratory, radiological parameters, 2) molecular features generated by liquid biopsy and 3) to present outcome variables after treatment of these patients with combination chemotherapy carboplatin/etoposide (CE). Methods: Clinical, radiological, laboratory parameters, whole-genome sequencing of cfDNA (PlasmaSeq) and ctDNA taken at different time points during treatment were ascertained from 8 mCRPC-patients with NCD. Results: All patients presented with rapid tumour progression and atpical metastatic spread (3x liver, 3x lungs, 1x skin, 1x adrenal glands) during treatment with Enza/Abi. Laboratory findings revealed marked increase in CRP, AP and LDH levels and elevation of NSE ( > 5x times upper normal limit), whilst PSA levels were low or declining. All patients received Carboplatin AUC5 day 1 and Etoposid 100 mg/m3 day 1-3 q3w. In 7 out of 8 patients, initially high levels of CRP, LDH, AP and NSE decreased under CE therapy. Very good partial response on radiological examination was observed after 3-6 cycles of CE in these patients. One patient had progressive disease. Copy number profiles of ctDNA taken peri-interventionally revealed loss of androgen receptor and a clonal shift in comparison to profiles taken during endocrine treatment phase. Conclusions: Rapid clinical and radiologic progression, atypical metastases and sharp rise in LDH, CRP, AP and NSE levels combined with low PSA are indicative of NCD. For these patients, CE-based chemotherapy is a promising treatment option. In order to identify clonal shift from adenocarcinoma to neuroendocrine cancer, genetic profiling using ctDNA may be of use.