Neoadjuvant chemoradiotherapy (nCRT) is the standard for locally advanced rectal cancer (LARC). However, distant metastasis remains the primary cause of treatment failure. Early identification of high-risk individuals for personalized treatment may offer a solution. Circulating tumour DNA (ctDNA) could assist in this process. From September 2017 to June 2019, the study prospectively recruited 113 patients with LARC (cT3-4N0M0 or cTanyN + M0) who underwent nCRT followed by radical surgery across 8 tertiary centers. ctDNA was analysed using large-panel targeted sequencing at baseline, during nCRT, pre-surgery, post-surgery, post-adjuvant chemotherapy (ACT), and during annual follow-ups for 3 years. We analysed 103 tissue and 669 plasma samples from 103 patients. With a median 53-month follow-up, significantly worse progression-free survival (PFS) and overall survival (OS) were observed if median variant allele frequency (mVAF) of baseline ctDNA per patient was ≥0.5% (PFS, HR 4.39, p < 0.001; OS, HR 5.61, p = 0.004) or ctDNA was still detectable two weeks into nCRT (PFS, HR 7.63, p < 0.001; OS, HR 5.08, p < 0.001). Furthermore, when compared to the low-risk (C1) group (characterized by "ctDNA undetected during nCRT with baseline mVAF <0.5%" or "ctDNA undetected during nCRT with TMB (tumour mutational burden) ≥20/Mb"), the high-risk (C2) group (characterized by "ctDNA detected during nCRT" or "baseline mVAF ≥0.5% with TMB <20/Mb") showed significantly worse long-term outcomes (3 y-PFS, 55.9% vs. 94.2%; 3 y-OS, 79.4% vs. 100%). The ctDNA clearance during nCRT, baseline mVAF, and TMB may be effective prognostic indicators. Our findings reaffirm the clinical monitoring value of ctDNA and demonstrate the strong prognostic value of baseline ctDNA and its early clearance status in patients with LARC undergoing nCRT. This highlights the potential of dynamic ctDNA monitoring as actionable stratified indicators to guide personalized neoadjuvant treatment strategies. This work was supported by the Major Grants Program of Beijing Science and Technology Commission (No. D171100002617003) and the National High Level Hospital Clinical Research Funding (2022-PUMCH-C-005).

Iron is among the most abundant elements in the soil of paddy fields, and its valence state and partitioning can be transformed by flooding and drainage alternations. However, little is known about the function of soil microbes that interact with Fe(II). In this study, sandy and loamy soils originating from rice fields were treated with Fe(II) at low and high concentrations. The findings demonstrate that additional Fe(II) has various effects on the soil’s microbial community structure and metabolic pathways. We conclude that Fe(II) at high concentrations reduced bacterial abundance and diversity in two textured paddy soils, yet the abundance in loamy soils was higher than it was in sandy soil. Additionally, in environments with high Fe(II) levels, the relative abundance of both anaerobic and chemoautotrophic bacteria increased. The Fe(II) concentration was positively correlated with total reduced substances but negatively correlated with redox potential and pH. Co-occurrence networks revealed that Fe(II) significantly promoted interactions with the most anaerobic and chemoautotrophic bacteria. In addition, adding Fe(II) greatly increased the number of more complex bacterial networks, and an increase in the number of mutually beneficial taxa occurred. We found that Fe(II) promoted the methane pathway, the Calvin cycle, and nitrate reduction to small but significant extents. These pathways involve the growth and interrelation of autotrophic and anaerobic bacteria. These results suggest that changes in the bacterial community structure occur in many dry–wet alternating environments.

Background: Atezolizumab plus bevacizumab has shown promising efficacy in advanced mucosal melanoma in the multi‐centre phase II study. This report updates 3‐year survival outcomes and multi‐omics analysis to identify potential response biomarkers.Methods: Forty‐three intention‐to‐treat (ITT) patients received intravenous administration of atezolizumab and bevacizumab every 3 weeks. Available samples underwent whole exome sequencing, transcriptome sequencing and targeted bisulphite sequencing to assess correlations with clinical outcomes.Results: With a median follow‐up of 40.3 months, the median overall survival (mOS) was 23.7 months (95% confidence interval [CI], 15.1–34), and the 3‐year OS rate was 28.7% (95% CI, 17.6%–46.8%). Patients with upper site melanoma exhibited longer progression‐free survival (PFS), higher tumour neoantigen burden (TNB) and greater copy number variations (CNVs) burden compared to those with lower site melanoma. NRAS mutations were associated with enhanced angiogenesis, with five of six patients achieving partial response. Inflammatory cell infiltration, angiogenic status and activation of the SMAD2 and p38 MAPK pathways may be prognostic indicators.Conclusions: This 3‐year updated analysis confirms the sustained efficacy of atezolizumab in combination of bevacizumab in patients with advanced mucosal melanoma. Inflammatory cell infiltration and angiogenic status were associated with therapeutic response. Furthermore, mucosal melanoma of upper site and NRAS mutation appear to be good predictors of response to immune checkpoint inhibitor and anti‐angiogenic combination treatment. Targeting SMAD2 and p38 MAPK pathways may further improve the outcome of mucosal melanoma.Key points: 3‐year follow‐up study confirmed the therapeutic efficacy of atezolizumab combined with bevacizumab Tumors in the upper site and NRAS mutations are more sensitive to treatment Inflammatory cell infiltration, angiogenic status, and activation of the SMAD2 and p38 MAPK pathways may be prognostic indicators

EGFR-TKIs were used in NSCLC patients with actionable EGFR mutations and pro-long prognosis. However, most patients treated with EGFR-TKIs developed resis-tance within around one year. This suggests that residual EGFR-TKIs resistant cells may eventually lead to relapse. Predicting resistance risk in patients will facilitate individualized management. Herein, we built an EGFR-TKIs resistance prediction (R-index) model and validate in cell line, mice, and cohort. We found significantly higher R-index value in resistant cell lines, mice models and relapsed patients. Patients with an elevated R-index had significantly shorter relapse time. We also found that the glycolysis pathway and the KRAS upregulation pathway were related to EGFR-TKIs resistance. MDSC is a significant immunosuppression factor in the resistant microenvironment. Our model provides an executable method for assessing patient resistance status based on transcriptional reprog-ramming and may contribute to the clinical translation of patient individual man-agement and the study of unclear resistance mechanisms.

Mucosal melanoma is an aggressive malignancy with limited neoadjuvant options. We conducted a single arm, phase II study of neoadjuvant pembrolizumab plus lenvatinib followed by surgery and adjuvant pembrolizumab in resectable mucosal melanoma (NCT04622566) along with exploratory biomarker analysis. Primary objective was pathological complete response (pCR) rate; secondary endpoints included relapse-free survival (RFS), overall survival (OS), clinical response, surgical outcomes, and safety. Among 21 surgical patients, the pCR rate was 9.5%, major pathologic response (MPR) rate was 19.0%, and the pathologic response rate was 38.1%. Median RFS was 14.8 months (1-year rate: 61.9%); median OS was not reached. No grade 4–5 treatment-related toxicities or additional perioperative complications occcurred. Spatial profiling revealed a more immune-inflamed baseline microenvironment in responders, with activated CD4⁺/CD8⁺ T cell signatures associated with favorable outcomes. Treatment induced vascular normalization and increased T cell infiltration in non-responders, partially narrowing the immune gap. Responders exhibited higher prevalence of persistent TCR clonotypes and tighter spatial proximity between activated CD4⁺ and CD8⁺ T cells. Although the pre-specified primary endpoint was not met, our findings identify activated CD4 ⁺ /CD8 ⁺ T cell states and TCR persistence as key outcome-associated features, supporting immune-informed optimization of peri-operative therapy in mucosal melanoma.

EGFR-TKIs were used in NSCLC patients with actionable EGFR mutations and prolonged the overall survival. However, most patients treated with EGFR-TKIs developed resistance within around one year. This suggests that TKIs cannot eliminate 100% of cancer cells, and residual drug-resistant cells eventually lead to drug resistance in patients. Predicting drug resistance risk in patients on medication will facilitate individualized management and prolong patient relapse. Herein, we built an EGFR-TKIs resistance prediction (R-index) model trained by single-cell RNA (scRNA) data with the OCLR algorithm. The performance of our model is validated on cell line, mouse, and cohort datasets. We found significantly higher R-index value in resistant cell lines, mouse models and relapsed patients. In addition, patients with an elevated R-index had significantly shorter time to relapse than those with a low R-index when stratified by the median post-treatment R-index value. We also found that the glycolysis pathway and the KRAS up-regulation pathway were related to EGFR-TKIs resistance. MDSC is a significant factor of immunosuppression in the resistant microenvironment. Our model provides an executable method for assessing patient resistance status based on transcriptional reprogramming and may contribute to the clinical translation of patient drug management and the study of resistance mechanisms. Funding Information: Thanks for the support from the following funding. Declaration of Interests: ZL, XG, XX, LC, LL, and XY are employees of Beijing GenePlus Technology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.