Mosquitoes as a model for understanding the neural basis of natural behaviors

Mosquito behaviors have been the subject of extensive research for over a century due to their role in the spread of human disease. However, these behaviors are also beginning to be appreciated as excellent models for neurobiological research in their own right. Many of the same behaviors and sensory abilities that help mosquitoes survive and reproduce alongside humans represent striking examples of generalizable phenomena of longstanding neurobiological interest. In this review, we highlight four prominent examples that promise new insight into (1) precise circadian tuning of sensory systems, (2) processing of complex natural odors, (3) multisensory integration, and (4) modulation of behavior by internal states.

The olfactory network of larval Xenopus laevis regenerates accurately after olfactory nerve transection

Across vertebrate species, the olfactory epithelium (OE) exhibits the uncommon feature of lifelong neuronal turnover. Epithelial stem cells give rise to new neurons that can adequately replace dying olfactory receptor neurons (ORNs) during developmental and adult phases and after lesions. To relay olfactory information from the environment to the brain, the axons of the renewed ORNs must reconnect with the olfactory bulb (OB). In Xenopus laevis larvae, we have previously shown that this process occurs between 3 and 7 weeks after olfactory nerve (ON) transection. In the present study, we show that after 7 weeks of recovery from ON transection, two functionally and spatially distinct glomerular clusters are reformed in the OB, akin to those found in non-transected larvae. We also show that the same odourant response tuning profiles observed in the OB of non-transected larvae are again present after 7 weeks of recovery. Next, we show that characteristic odour-guided behaviour disappears after ON transection but recovers after 7-9 weeks of recovery. Together, our findings demonstrate that the olfactory system of larval X. laevis regenerates with high accuracy after ON transection, leading to the recovery of odour-guided behaviour.

Immune checkpoint inhibitors for POLE or POLD1 proofreading-deficient metastatic colorectal cancer

BACKGROUND

POLE and POLD1 proofreading deficiency (POLE/D1pd) define a rare subtype of ultramutated metastatic colorectal cancer (mCRC; over 100 mut/Mb). Disease-specific data about the activity and efficacy of immune checkpoint inhibitors (ICIs) in POLE/D1pd mCRC are lacking and it is unknown whether outcomes may be different from mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) mCRCs treated with ICIs.

PATIENTS AND METHODS

In this global study, we collected 27 patients with mCRC harboring POLE/D1 mutations leading to proofreading deficiency and treated with anti-programmed cell death-ligand 1 alone +/- anti-cytotoxic T-lymphocyte antigen-4 agents. We collected clinicopathological and genomic characteristics, response, and survival outcomes after ICIs of POLE/D1pd mCRC and compared them with a cohort of 610 dMMR/MSI-H mCRC patients treated with ICIs. Further genomic analyses were carried out in an independent cohort of 7241 CRCs to define POLE and POLD1pd molecular profiles and mutational signatures.

RESULTS

POLE/D1pd was associated with younger age, male sex, fewer RAS/BRAF driver mutations, and predominance of right-sided colon cancers. Patients with POLE/D1pd mCRC showed a significantly higher overall response rate (ORR) compared to dMMR/MSI-H mCRC (89% versus 54%; P = 0.01). After a median follow-up of 24.9 months (interquartile range: 11.3-43.0 months), patients with POLE/D1pd showed a significantly superior progression-free survival (PFS) compared to dMMR/MSI-H mCRC [hazard ratio (HR) = 0.24, 95% confidence interval (CI) 0.08-0.74, P = 0.01] and superior overall survival (OS) (HR = 0.38, 95% CI 0.12-1.18, P = 0.09). In multivariable analyses including the type of DNA repair defect, POLE/D1pd was associated with significantly improved PFS (HR = 0.17, 95% CI 0.04-0.69, P = 0.013) and OS (HR = 0.24, 95% CI 0.06-0.98, P = 0.047). Molecular profiling showed that POLE/D1pd tumors have higher tumor mutational burden (TMB). Responses were observed in both subtypes and were associated with the intensity of POLE/D1pd signature.

CONCLUSIONS

Patients with POLE/D1pd mCRC showed more favorable outcomes compared to dMMR/MSI-H mCRC to treatment with ICIs in terms of tumor response and survival.

Prediction of survival after neoadjuvant therapy in locally advanced rectal cancer - a retrospective analysis

Purpose

The aim of this retrospective analysis was to determine if the response to preoperative radio(chemo)therapy is predictive for survival among patients with locally advanced rectal cancer and may act as a potential surrogate endpoint for disease free survival and overall survival.

Results

Eight hundred seventy-eight patients from five centers were analyzed. There were 304 women and 574 men; the median age was 64.7 years. 77.6% and 22.4% of patients received neoadjuvant radiochemotherapy or short-course radiotherapy, resulting in a pathological complete response in 7.3%. T-downstaging and N-downstaging occurred in 50.5% and 37% of patients after neoadjuvant therapy. In patients with T-downstaging, the 10-year DFS and 10-year OS were 64.8% and 66.8% compared to 37.1% and 45.9% in patients without T-downstaging. N-downstaging resulted in 10-year DFS and 10-year OS in 56.2% and 62.5% compared to 47.3% and 52.3% without N-downstaging. Based on routinely evaluated clinical parameters, an absolute risk prediction calculator was generated for 5-year disease-free survival, and 5-year overall survival.

Conclusion

T-downstaging and N-downstaging after neoadjuvant radiochemotherapy or short-course radiotherapy resulted in better DFS and OS compared to patients without response. Based on clinical parameters, 5-year DFS, and 5-year OS can be predicted using a prediction calculator.

Consistency of convolutional neural networks in dermoscopic melanoma recognition: A prospective real-world study about the pitfalls of augmented intelligence

BACKGROUND

Deep-learning convolutional neural networks (CNNs) have outperformed even experienced dermatologists in dermoscopic melanoma detection under controlled conditions. It remains unexplored how real-world dermoscopic image transformations affect CNN robustness.

OBJECTIVES

To investigate the consistency of melanoma risk assessment by two commercially available CNNs to help formulate recommendations for current clinical use.

METHODS

A comparative cohort study was conducted from January to July 2022 at the Department of Dermatology, University Hospital Basel. Five dermoscopic images of 116 different lesions on the torso of 66 patients were captured consecutively by the same operator without deliberate rotation. Classification was performed by two CNNs (CNN-1/CNN-2). Lesions were divided into four subgroups based on their initial risk scoring and clinical dignity assessment. Reliability was assessed by variation and intraclass correlation coefficients. Excisions were performed for melanoma suspicion or two consecutively elevated CNN risk scores, and benign lesions were confirmed by expert consensus (n = 3).

RESULTS

117 repeated image series of 116 melanocytic lesions (2 melanomas, 16 dysplastic naevi, 29 naevi, 1 solar lentigo, 1 suspicious and 67 benign) were classified. CNN-1 demonstrated superior measurement repeatability for clinically benign lesions with an initial malignant risk score (mean variation coefficient (mvc): CNN-1: 49.5(±34.3)%; CNN-2: 71.4(±22.5)%; p = 0.03), while CNN-2 outperformed for clinically benign lesions with benign scoring (mvc: CNN-1: 49.7(±22.7)%; CNN-2: 23.8(±29.3)%; p = 0.002). Both systems exhibited lowest score consistency for lesions with an initial malignant risk score and benign assessment. In this context, averaging three initial risk scores achieved highest sensitivity of dignity assessment (CNN-1: 94%; CNN-2: 89%). Intraclass correlation coefficients indicated 'moderate'-to-'good' reliability for both systems (CNN-1: 0.80, 95% CI:0.71-0.87, p < 0.001; CNN-2: 0.67, 95% CI:0.55-0.77, p < 0.001).

CONCLUSIONS

Potential user-induced image changes can significantly influence CNN classification. For clinical application, we recommend using the average of three initial risk scores. Furthermore, we advocate for CNN robustness optimization by cross-validation with repeated image sets.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04605822).

Image-based consensus molecular subtyping in rectal cancer biopsies and response to neoadjuvant chemoradiotherapy

The development of deep learning (DL) models to predict the consensus molecular subtypes (CMS) from histopathology images (imCMS) is a promising and cost-effective strategy to support patient stratification. Here, we investigate whether imCMS calls generated from whole slide histopathology images (WSIs) of rectal cancer (RC) pre-treatment biopsies are associated with pathological complete response (pCR) to neoadjuvant long course chemoradiotherapy (LCRT) with single agent fluoropyrimidine. DL models were trained to classify WSIs of colorectal cancers stained with hematoxylin and eosin into one of the four CMS classes using a multi-centric dataset of resection and biopsy specimens (n = 1057 WSIs) with paired transcriptional data. Classifiers were tested on a held out RC biopsy cohort (ARISTOTLE) and correlated with pCR to LCRT in an independent dataset merging two RC cohorts (ARISTOTLE, n = 114 and SALZBURG, n = 55 patients). DL models predicted CMS with high classification performance in multiple comparative analyses. In the independent cohorts (ARISTOTLE, SALZBURG), cases with WSIs classified as imCMS1 had a significantly higher likelihood of achieving pCR (OR = 2.69, 95% CI 1.01-7.17, p = 0.048). Conversely, imCMS4 was associated with lack of pCR (OR = 0.25, 95% CI 0.07-0.88, p = 0.031). Classification maps demonstrated pathologist-interpretable associations with high stromal content in imCMS4 cases, associated with poor outcome. No significant association was found in imCMS2 or imCMS3. imCMS classification of pre-treatment biopsies is a fast and inexpensive solution to identify patient groups that could benefit from neoadjuvant LCRT. The significant associations between imCMS1/imCMS4 with pCR suggest the existence of predictive morphological features that could enhance standard pathological assessment.

S100Z is expressed in a lateral subpopulation of olfactory receptor neurons in the main olfactory system of Xenopus laevis

In contrast to other S100 protein members, the function of S100 calcium-binding protein Z (S100Z) remains largely uncharacterized. It is expressed in the olfactory epithelium of fish, and it is closely associated with the vomeronasal organ (VNO) in mammals. In this study, we analyzed the expression pattern of S100Z in the olfactory system of the anuran amphibian Xenopus laevis. Using immunohistochemistry in whole mount and slice preparations of the larval olfactory system, we found exclusive S100Z expression in a subpopulation of olfactory receptor neurons (ORNs) of the main olfactory epithelium (MOE). S100Z expression was not co-localized with TP63 and cytokeratin type II, ruling out basal cell and supporting cell identity. The distribution of S100Z-expressing ORNs was laterally biased, and their average number was significantly increased in the lateral half of the olfactory epithelium. The axons of S100Z-positive neurons projected exclusively into the lateral and intermediate glomerular clusters of the main olfactory bulb (OB). Even after metamorphic restructuring of the olfactory system, S100Z expression was restricted to a neuronal subpopulation of the MOE, which was then located in the newly formed middle cavity. An axonal projection into the ventro-lateral OB persisted also in postmetamorphic frogs. In summary, S100Z is exclusively associated with the main olfactory system in the amphibian Xenopus and not with the VNO as in mammals, despite the presence of a separate accessory olfactory system in both classes.

Changes over time in the course of advanced pancreatic cancer treatment with systemic chemotherapy: a pooled analysis of five clinical trials from two decades of the German AIO study group

BACKGROUND

Over the past two decades, our group has conducted five multicenter trials focusing on first-line systemic therapy for patients with advanced pancreatic cancer. The current pooled analysis was designed to evaluate prognosis over time and the impact of clinical characteristics on survival.

PATIENTS AND METHODS

Individual patient data were derived from five prospective, controlled, multicenter trials conducted by the 'Arbeitsgemeinschaft Internistische Onkologie' (AIO): 'Gem/Cis', 'Ro96', 'RC57', 'ACCEPT' and 'RASH', which recruited patients between December 1997 and January 2017.

RESULTS

Overall, 912 patients were included. The median overall survival (OS) for all assessable patients was 7.1 months. OS significantly improved over time, with a median OS of 8.6 months for patients treated from 2012 to 2017 compared with 7.0 months from 1997 to 2006 [hazard ratio (HR) 1.06; P < 0.004]. Eastern Cooperative Oncology Group performance status (HR 1.48; P < 0.001), use of second-line treatment (HR 1.51; P < 0.001), and Union for International Cancer Control (UICC) stage (III versus IV) (HR 1.34, P = 0.002) had a significant impact on OS. By contrast, no influence of age and gender on OS was detectable. Comparing combination therapy with single-agent chemotherapy did not demonstrate a survival benefit, nor did regimens containing epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) such as afatinib or erlotinib, compared with chemotherapy-only arms. Patients with early-onset pancreatic cancer (age at study entry of ≤50 years, n = 102) had a similar OS compared with those >50 years (7.1 versus 7.0 months; HR 1.13; P = 0.273). The use of a platinum-containing regimen was not associated with better outcomes in patients with early-onset pancreatic cancer.

CONCLUSIONS

Within this selected group of patients treated within prospective clinical trials, survival has shown improvement over two decades. This effect is likely attributable to the availability of more effective combination therapies and treatment lines, rather than to any specific regimen, such as those containing EGFR-TKIs. In addition, concerning age and sex subgroups, the dataset did not provide evidence for distinct clinical behavior.

Combined DNA Analysis from Stool and Blood Samples Improves Tumor Tracking and Assessment of Clonal Heterogeneity in Localized Rectal Cancer Patients

Objectives: In this study, stool samples were evaluated for tumor mutation analysis via a targeted next generation sequencing (NGS) approach in a small patient cohort suffering from localized rectal cancer. Introduction: Colorectal cancer (CRC) causes the second highest cancer-related death rate worldwide. Thus, improvements in disease assessment and monitoring that may facilitate treatment allocation and allow organ-sparing "watch-and-wait" treatment strategies are highly relevant for a significant number of CRC patients. Methods: Stool-based results were compared with mutation profiles derived from liquid biopsies and the gold standard procedure of tumor biopsy from the same patients. A workflow was established that enables the detection of de-novo tumor mutations in stool samples of CRC patients via ultra-sensitive cell-free tumor DNA target enrichment. Results: Notably, only a 19% overall concordance was found in mutational profiles across the compared sample specimens of stool, tumor, and liquid biopsies. Conclusion: Based on these results, the analysis of stool and liquid biopsy samples can provide important additional information on tumor heterogeneity and potentially on the assessment of minimal residual disease and clonal tumor evolution.

Early clinical trial unit tumor board: a real-world experience in a national cancer network

PURPOSE

Early clinical trials are the first step into clinical therapies for new drugs. Within the six Bavarian university-based hospitals (Augsburg, Erlangen, Regensburg, Munich (LMU and TU), Würzburg) we have enrolled a virtual network platform for patient discussion.

METHODS

The virtual Early Clinical Trial Unit Tumor Board (ECTU Tumor Board) is a secured web-based meeting to evaluate early clinical trial options for patients, where representatives from local ECTUs participate. We retrospectively analyzed patient cases discussed between November 2021 and November 2022.

RESULTS

From November 2021 to November 2022, a total of 43 patients were discussed in the ECTU Tumor Board. Median age at diagnosis was 44.6 years (range 10-76 years). The median number of previous lines of therapies was 3.7 (range 1-9 therapies) including systemic treatment, surgery, and radiation therapy. A total of 27 different tumor entities were presented and 83.7% (36/43) patients received at least one trial recommendation. In total, 21 different active or shortly recruiting clinical trials were recommended: ten antibody trials, four BiTE (bispecific T cell engager) trials, six CAR (chimeric antigen receptor) T-cell trials, and one chemotherapy trial. Only six trials (28.6%) were recommended on the basis of the previously performed comprehensive genetic profiling (CGP).

CONCLUSION

The ECTU Tumor Board is a feasible and successful network, highlighting the force of virtual patient discussions for improving patient care as well as trial recruitment in advanced diseases. It can provide further treatment options after local MTB presentation, aiming to close the gap to access clinical trials.

Unraveling Resistance to Immunotherapy in MSI-High Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related deaths. Incidences of early CRC cases are increasing annually in high-income countries, necessitating effective treatment strategies. Immune checkpoint inhibitors (ICIs) have shown significant clinical efficacy in various cancers, including CRC. However, their effectiveness in CRC is limited to patients with mismatch-repair-deficient (dMMR)/microsatellite instability high (MSI-H) disease, which accounts for about 15% of all localized CRC cases and only 3% to 5% of metastatic CRC cases. However, the varied response among patients, with some showing resistance or primary tumor progression, highlights the need for a deeper understanding of the underlying mechanisms. Elements involved in shaping the response to ICIs, such as tumor microenvironment, immune cells, genetic changes, and the influence of gut microbiota, are not fully understood thus far. This review aims to explore potential resistance or immune-evasion mechanisms to ICIs in dMMR/MSI-H CRC and the cell types involved, as well as possible pitfalls in the diagnosis of this particular subtype.

Functional odor map heterogeneity is based on multifaceted glomerular connectivity in larval Xenopus olfactory bulb

Glomeruli are the functional units of the vertebrate olfactory bulb (OB) connecting olfactory receptor neuron (ORN) axons and mitral/tufted cell (MTC) dendrites. In amphibians, these two circuit elements regularly branch and innervate multiple, spatially distinct glomeruli. Using functional multiphoton-microscopy and single-cell tracing, we investigate the impact of this wiring on glomerular module organization and odor representations on multiple levels of the Xenopus laevis OB network. The glomerular odor map to amino acid odorants is neither stereotypic between animals nor chemotopically organized. Among the morphologically heterogeneous group of uni- and multi-glomerular MTCs, MTCs can selectively innervate glomeruli formed by axonal branches of individual ORNs. We conclude that odor map heterogeneity is caused by the coexistence of different intermingled glomerular modules. This demonstrates that organization of the amphibian main olfactory system is not strictly based on uni-glomerular connectivity.

Systemic treatment of patients with locally advanced or metastatic cholangiocarcinoma - an Austrian expert consensus statement

Locally advanced or metastatic cholangiocarcinoma is an aggressive carcinoma with a dismal prognosis. For the first-line treatment of locally advanced or metastatic cholangiocarcinoma, cisplatin/gemcitabine has been the standard of care for more than 10 years. Its combination with the immune checkpoint inhibitor durvalumab resulted in an efficiency improvement in the phase III setting. Regarding the use of chemotherapy in the second line, positive phase III data could only be generated for FOLFOX. The evidence base for nanoliposomal irinotecan (Nal-IRI) plus 5-fluorouracil (5-FU) and leucovorin (LV) is contradictory. After the failure of first-line treatment, targeted therapies can be offered if the molecular targets microsatellite instability-high (MSI-H), IDH1, FGFR2, BRAF V600E, and NTRK are detected. These targeted agents are generally preferable to second-line chemotherapy. Broad molecular testing should be performed, preferably from tumor tissue, at the initiation of first-line therapy to timely identify potential molecular targets.

Comparison of gemcitabine plus oxaliplatin versus gemcitabine plus nab-paclitaxel as first-line chemotherapy for advanced pancreatic adenocarcinoma: A single-center retrospective analysis

BACKGROUND

Pancreatic cancer is mostly diagnosed in an advanced stage and treated with systemic therapy with palliative intent. Nowadays, the doublet chemotherapy of Gemcitabine and nab-paclitaxel (Gem-Nab) is one of the most frequently used regimens worldwide, but is not ubiquitarily available or reimbursed. Therefore, we compared the clinical efficacy of Gem-Nab to a historical control of patients treated with gemcitabine and oxaliplatin (Gem-Ox) at our tertiary cancer center, which was the standard treatment prior to the introduction of FOLFIRINOX.

METHODS

This single-center retrospective real world study includes 121 patients diagnosed with locally advanced or primary metastatic pancreatic adenocarcinoma who were treated with chemotherapy doublet, with either Gem-Nab or Gem-Ox in palliative first-line. Survival rates were analyzed using the Kaplan-Meier method, and comparisons were made with log-rank tests. Gem-Ox was considered as standard first line therapy at our institution for patients who were deemed fit for doublet chemotherapy between the years 2006 to 2012. These patients were compared to a cohort of patients treated with the new standard first-line therapy of Gem-Nab between 2013 and 2020.

RESULTS

A total of 554 patients with pancreatic cancer of all stages were screened, and 73 patients treated with Gem-Nab and 48 patients treated with Gem-Ox in the palliative first-line setting were identified and included in this analysis. Patients receiving Gem-Ox had a statistically significantly better performance score (ECOG PS) when compared to the Gem-Nab group (Odds ratio (OR) 0.28, 95% CI 0.12-0.65, p = 0.005), more often suffered from locally advanced than metastatic disease (OR 3.10, 95% CI 1.27-7.91, p = 0.019) and were younger in age (OR 0.95, 95% CI 0.91-0.99, p = 0.013). Median overall survival (OS) of the whole study cohort was 10.3 months (95% CI 8.5-11.6). No statistically significant difference in OS could be observed between the Gem-Nab and the Gem-Ox cohort (median OS: 8.9 months (95% CI 6.4-13.5) versus 10.9 months (95% CI 9.5-13.87, p = 0.794, HR 1.27, 95% CI 0.85-1.91)). Median progression-free survival (PFS) was 6.8 months in the entire cohort (95% CI 4.9-8.4). No statistically significant difference in PFS could be observed between the Gem-Nab and the Gem-Ox cohort (median PFS: 5.8 months (95% CI 4.3-8.2) versus 7.9 months (95% CI 5.4-9.5) p = 0.536, HR 1.11, 95% CI 0.74-1.67). Zero-truncated negative binomial regressions on OS and PFS adjusting for gender, age, performance status (ECOG PS), and CA19-9 levels yielded no significant difference between Gem-Nab or Gem-Ox.

CONCLUSION

From our analysis, we could evidence no difference in outcome parameters in this retrospective analysis despite the worse prognostic pattern for GemOX. Therefore, we suggest Gem-Ox as potential first line treatment option for inoperable locally advanced or metastatic pancreatic cancer, especially if Gem-Nab is not available.

Management of metastatic colorectal cancer in patients ≥70 years - a single center experience

BACKGROUND

Age-standardized mortality rates for metastatic colorectal cancer (mCRC) are highest among elderly patients. In current clinical guidelines, treatment recommendations for this patient population are based on a limited number of clinical trials.

PATIENTS AND METHODS

In this monocentric, retrospective analysis we characterized patients aged ≥70 years undergoing systemic therapy for mCRC and overall survival (OS) was investigated.

RESULTS

We included 117 unselected, consecutive mCRC patients aged ≥70 years undergoing systemic therapy for mCRC between February 2009 and July 2022. Median OS was 25.6 months (95% CI: 21.8-29.4). The median age was 78 years (range: 70-90) and 21%, 48%, 26% and 5% had an ECOG performance score of 0, 1, 2, and 3, respectively. The median number of systemic therapy lines was 2 (range: 1-5). The choice of first-line chemotherapy backbone (doublet/triplet versus mono) did not impact OS (HR: 0.83, p=0.50) or the probability of receiving subsequent therapy (p=0.697). Metastasectomy and/or local ablative treatment in the liver, lung, peritoneum and/or other organs were applied in 26 patients (22%) with curative intent. First-line anti-EGFR-based therapy showed a trend towards longer OS compared to anti-VEGF-based therapy or chemotherapy alone in left-sided mCRC (anti-EGFR: 39.3 months versus anti-VEGF: 27.3 months versus chemotherapy alone: 13.8 months, p=0.105). In multivariable analysis, metastasectomy and/or local ablative treatment with curative intent (yes versus no, HR: 0.22, p<0.001), the ECOG performance score (2 versus 0, HR: 3.07, p=0.007; 3 versus 0, HR: 3.66, p=0.053) and the presence of liver metastases (yes versus no, HR: 1.79, p=0.049) were independently associated with OS.

CONCLUSIONS

Our findings corroborate front-line monochemotherapy in combination with targeted therapy as the treatment of choice for elderly mCRC patients with palliative treatment intent. Metastasectomy and/or local ablative treatment with curative intent are feasible and may improve OS in selected elderly mCRC patients.

Treatment Algorithm for Patients With Gastric Adenocarcinoma: Austrian Consensus on Systemic Therapy - An Update

Over the last decade, therapeutic options for patients with gastric cancer have improved significantly. However, despite these recent advances, mortality is still substantial. Surgery and chemotherapy represent the cornerstones of patient management. Immune checkpoint inhibitors as well as targeted treatments such as HER2-directed therapies and antiangiogenic agents contribute to improved patient prognosis. Herein, we present the updated version of an Austrian consensus on the systemic treatment of patients with gastric adenocarcinoma and adenocarcinoma of the lower gastroesophageal junction, including those with human epidermal growth receptor 2 (HER2) overexpression, microsatellite instability, programmed death-ligand 1 (PD-L1)-positive disease, and claudin 18.2 positivity. The consensus considers the curative setting as well as first-line and later-line systemic treatment options in advanced disease. For HER2-positive disease, HER2 testing is discussed in addition to a review of first-line and later-line therapies. Potential future therapies are also listed, with a focus on targeted [e.g., fibroblast growth factor receptor 2 (FGRF2)-directed] treatments that might provide a further step forward in the management of patients with gastric cancer.

Heavy rains control the floating macroplastic inputs into the sea from coastal Mediterranean rivers: A case study on the Têt River (NW Mediterranean Sea)

This study focuses on the relevance of small watersheds in the macroplastic pollution of coastal environments. It aims to identify and quantify in terms of composition, number and mass, current riverine flows of floating macroplastics (>2.5 cm). Estimates are based on 66 visual monitoring of total litter over a 4-year-period (2016-2019) in a small coastal Mediterranean river, the Têt River (NW Mediterranean Sea). The plastic fraction represented 97 % of the observed litter, mainly cigarette butts (20.5 %), polystyrene fragments (18.8 %) and light packaging (16.3 %). The Tet River is characterized by frequent flash-flood events caused by heavy rain, that can induce a sudden rise of the water discharge. Such hydroclimatic forcing greatly influence macroplastic flows, both in terms of their average compositions and loads. We have estimated that 354,000 macroplastic items, corresponding to 0.65 tons, are discharged annually from the Tet River into the sea, and that 73 % of them are released during rain events (∼6 % of the year). The short observation distance from the water surface allowed to exhibit the great abundance of small litter (80 % of them were < 10 cm) and to evaluate to 1.8 g the average mass of floating plastics. Our results suggest that remediation actions must be taken on rainy days and target small litter in order to significantly limit macroplastic inputs from rivers to the sea. Moreover, the large share of cigarette butts in macrolitter inputs demonstrates that reducing ocean pollution cannot be achieved solely by improving waste management, but that changes in social behavior are also needed to stem waste production at the source.

Prognostic value of [18F]FDG PET/CT on treatment response and progression-free survival of gastroesophageal cancer patients undergoing perioperative FLOT chemotherapy

PURPOSE

To evaluate the prognostic role of [¹⁸F]FDG PET/CT metabolic parameters in gastric cancer (GC) and gastroesophageal adenocarcinoma (GEJAC) patients receiving neoadjuvant chemotherapy.

METHOD

In this retrospective study, 31 patients with biopsy-proven GC or GEJAC were included between August 2016 and March 2020. [¹⁸F]FDG PET/CT was performed before the neoadjuvant chemotherapy. Primary tumours' semi-quantitative metabolic parameters were extracted. All patients received a perioperative FLOT regimen thereafter. Post-chemotherapy [¹⁸F]FDG PET/CT was performed in most patients (17/31). All patients underwent surgical resection. Histopathology response to treatment and progression-free survival (PFS) were evaluated. Two-sided p-values < 0.05 were considered statistically significant.

RESULTS

Thirty-one patients (mean age = 62 ± 8), including 21 GC and 10 GEJAC patients, were evaluated. 20/31(65%) patients were histopathology responders to neoadjuvant chemotherapy, including twelve complete and eight partial responders. During the median follow-up of 42.0 months, nine patients experienced recurrence. The median PFS was 60(95% CI:32.9-87.1) months. Pre-neoadjuvant chemotherapy SULpeak was significantly correlated with pathological response to treatment (p-value = 0.03;odds ratio = 16.75). In survival analysis, SUVmax (p-value = 0.01;hazard ratio[HR] = 1.55), SUVmean (p-value = 0.04;HR = 2.73), SULpeak (p-value < 0.001;HR = 1.91) and SULmean (p-value = 0.04;HR = 4.22) in the post-neoadjuvant chemotherapy pre-operative [¹⁸F]FDG PET/CT showed significant correlation with PFS. Additionally, aspects of staging were significantly correlated with PFS (p-value = 0.01;HR = 2.21).

CONCLUSIONS

Pre-neoadjuvant chemotherapy [¹⁸F]FDG PET/CT parameters, especially SULpeak, could predict the pathological response to treatment in GC and GEJAC patients. Additionally, in survival analysis, post-chemotherapy metabolic parameters significantly correlated with PFS. Thus, performing [¹⁸F]FDG PET/CT before chemotherapy may help to identify patients at risk for inadequate response to perioperative FLOT and, after chemotherapy, may predict clinical outcomes.

Cancer of unknown primary (CUP) through the lens of precision oncology: a single institution perspective

PURPOSE

For patients with cancer of unknown primary (CUP), treatment options are limited. Precision oncology, the interplay of comprehensive genomic profiling (CGP) and targeted therapies, aims to offer additional treatment options to patients with advanced and hard-to-treat cancers. We aimed to highlight the use of a molecular tumor board (MTB) in the therapeutic management of CUP patients.

METHODS

In this single-center observational study, CUP patients, presented to the MTB of the Comprehensive Cancer Center Munich LMU, a tertiary care center, were analyzed retrospectively. Descriptive statistics were applied to describe relevant findings.

RESULTS

Between June 2016 and February 2022, 61 patients with unfavorable CUP were presented to the MTB, detected clinically relevant variants in 74% (45/61) of patients, of which 64% (29/45) led to therapeutic recommendation. In four out of 29 patients (14%), the treatment recommendations were implemented, unfortunately without resulting in clinical benefit. Reasons for not following the therapeutic recommendation were mainly caused by the physicians' choice of another therapy (9/25, 36%), especially in the context of worsening of general condition, lost to follow-up (7/25, 28%) and death (6/25, 24%).

CONCLUSION

CGP and subsequent presentation to a molecular tumor board led to a high rate of therapeutic recommendations in patients with CUP. Recommendations were only implemented at a low rate; however, late GCP diagnostic and, respectively, MTB referral were found more frequent for the patients with implemented treatment. This contrast underscores the need for early implementation of CGP into the management of CUP patients.

Real-world Data of Palliative First-line Checkpoint Inhibitor Therapy for Head and Neck Cancer

BACKGROUND/AIM

Pembrolizumab alone or combined with chemotherapy is now approved in PD-L1-positive patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). Since real-world data are pending, our goal was to evaluate the efficacy and safety of immune checkpoint inhibitor (CPI) therapy in an unselected cohort of patients with SCCHN.

PATIENTS AND METHODS

We analyzed 78 patients with recurrent or metastatic SCCHN from three Austrian cancer centers that received CPI therapy alone or with chemotherapy as palliative first-line systemic treatment for this retrospective study. Patient characteristics, details on treatment, and survival were analyzed by a chart-based review.

RESULTS

Of the 78 patients analyzed, 55 patients were treated with CPI alone (45 with Pembrolizumab, 10 with Nivolumab) and 23 patients received chemotherapy with a platinum and 5-FU in addition to CPI. With a median follow-up of twelve months, the median PFS of all patients was 4 months [95% confidence interval (CI)=2.2-5.8] and the median OS was 11 months (95% CI=7.1-14.9). The overall response and disease control rates were 20.5% and 46.1%, respectively. There was no statistically significant difference in clinical outcome between patient groups with a different combined positive score (CPS). The rate of reported immune related adverse events was comparable to existing data.

CONCLUSION

Our findings confirm the results of the KEYNOTE-048 trial that CPI therapy alone or together with chemotherapy is an effective treatment for patients with recurrent or metastatic CPS-positive SCCHN.

GCaMP Imaging in Mosquitoes: Central Nervous System

Mosquitoes spread dengue, Zika, malaria, and other pathogens to hundreds of millions of people every year. A better understanding of mosquito behavior and its underlying neural mechanisms may lead to new control strategies, but such an understanding requires the development of tools and approaches for exploring the nervous system of key vector species. For example, we can now image neural activity in mosquito brains using genetically encoded calcium sensors like GCaMP. Compared with other types of neural recording, GCaMP imaging has the advantage of allowing one to record from many neurons simultaneously and/or to record from specific neuronal types. Successful implementation requires careful consideration of many factors, including the choice of microscope and how to make the brains of experimental animals visible and stable while minimizing damage. Here, we elaborate on these points and provide a concise introduction to GCaMP imaging in the mosquito central nervous system.

Two-Photon Calcium Imaging in the Brain of Aedes aegypti Mosquitoes

Understanding the neural basis of mosquito behavior is critical for designing effective vector control strategies and can potentially shed new light on basic nervous system function. Because mosquitoes are a non-model species, however, functional studies of mosquito nervous systems have long been restricted to electrophysiological recording from peripheral sensory organs such as the antenna. This is now changing with the advent of CRISPR-Cas9 gene editing and the development of other powerful new genetic tools. Transgenic mosquitoes that carry genetically encoded calcium sensors, for example, open the door to optical recording of neural activity with two-photon calcium imaging. Compared with electrophysiology, calcium imaging permits continuous monitoring of neural activity from large populations of neurons, even deep in the brain. When combined with selective neural drivers, it also allows targeted recording from specific neuronal types. Here, we describe a calcium imaging protocol we use in our laboratory to study neural activity in the brain of Aedes aegypti mosquitoes.

How We Treat Localized Rectal Cancer-An Institutional Paradigm for Total Neoadjuvant Therapy

Total neoadjuvant therapy (TNT)-the neoadjuvant employment of radiotherapy (RT) or chemoradiation (CRT) as well as chemotherapy (CHT) before surgery-may lead to increased pathological complete response (pCR) rates as well as a reduction in the risk of distant metastases in locally advanced rectal cancer. Furthermore, increased response rates may allow organ-sparing strategies in a growing number of patients with low rectal cancer and upfront immunotherapy has shown very promising early results in patients with microsatellite instability (MSI)-high/mismatch-repair-deficient (dMMR) tumors. Despite the lack of a generally accepted treatment standard, we strongly believe that existing data is sufficient to adopt the concept of TNT and immunotherapy in clinical practice. The treatment algorithm presented in the following is based on our interpretation of the current data and should serve as a practical guide for treating physicians-without any claim to general validity.