Advancing Personalized Medicine in the Treatment of Locally Advanced Rectal Cancer.

Rectal cancer presents a significant burden globally, often requiring multimodal therapy for locally advanced cases. Long-course chemoradiotherapy (LCRT) and short-course radiotherapy (SCRT) followed by surgery have been conventional neoadjuvant approaches. Recent trials favor LCRT due to improved local control. However, distant tumor recurrence remains a concern, prompting the exploration of total neoadjuvant therapy (TNT) as a comprehensive treatment strategy. Immune checkpoint inhibitors (ICIs) show promise, particularly in mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) tumors, potentially revolutionizing neoadjuvant regimens. Nonoperative management (NOM) represents a viable alternative post-neoadjuvant therapy for selected patients achieving complete clinical response (cCR). Additionally, monitoring minimal residual disease (MRD) using circulating tumor DNA (ctDNA) emerges as a non-invasive method for the assessment of treatment response. This review synthesizes current evidence on TNT, ICIs, NOM, and ctDNA, elucidating their implications for rectal cancer management and highlighting avenues for future research and clinical application.

PD-L1 Expression in Paired Samples of Rectal Cancer.

Immune checkpoint inhibitors and immune-related biomarkers are increasingly investigated in rectal cancer (RC). We retrospectively analysed PD-L1 expression in diagnostic biopsy and resection samples from RC patients treated at our centre between 2000 and 2020. PD-L1 immunostaining (22C3 clone) was evaluated according to tumour proportion (TPS), immune cell (ICS), and the combined positive score (CPS). Eighty-three patients were included. At diagnosis, PD-L1 expression ≥1%/≥5% was observed in 15.4%/0%, 80.7%/37.4%, and 69.2%/25.6% of patients based on TPS, ICS, and CPS, respectively. At surgery, the respective figures were 4.6%/1.5%, 60.2%/32.5%, and 50.7%/26.2%. Using the 1% cut-off and regardless of the scoring system, PD-L1 was less expressed in surgery than biopsy samples (p ≤ 0.04). In paired specimens, PD-L1-ICS reduction was especially observed following neoadjuvant long-course (chemo)radiotherapy (p = 0.03). PD-L1-ICS of ≥5% in surgical samples (HR: 0.17; p = 0.02), and a biopsy-to-surgery increase in PD-L1-ICS (HR: 0.19; p = 0.04) was predictive for longer disease-free survival, while the PD-L1-ICS of either ≥1% (HR 0.28; p = 0.04) or ≥5% (HR 0.19; p = 0.03) in surgical samples and the biopsy-to-surgery increase in PD-L1-ICS (HR: 0.20; p = 0.04) were associated with better overall survival. Our study suggests that PD-L1 expression in RC is largely reflective of immune cell infiltration, and its presence/increase in surgical samples predicts better outcomes.

Inflammatory indices as prognostic markers in metastatic colorectal cancer patients treated with chemotherapy plus Bevacizumab.

Background: Validated predictors of sensitivity or resistance to Bevacizumab (Bev) are not available, and Inflammatory Indexes (IIs) has been reported to be useful prognostic factors in various malignant solid tumours, including metastatic colorectal cancer (mCRC). Objectives: To explore the prognostic value of IIs in mCRC patients treated with first-line chemotherapy plus Bev. Design: One hundred and eighty-two patients diagnosed with mCRC and treated with first line chemotherapy plus Bev were considered for this prospective non-pharmacological study. Neutrophil, lymphocyte, platelet, aspartate transaminase (AST) and lactate dehydrogenase (LDH) tests were carried out at baseline and before each treatment cycle, according to clinical practice. Methods: Pre-treatment Systemic Immune-inflammation Index (SII), Colon Inflammatory Index (CII) and Aspartate aminotransferase-Lymphocyte Ratio Index (ALRI) were evaluated to assess a correlation with progression-free survival (PFS) and overall survival (OS). Results: In the overall population, PFS and OS were lower in patients with high SII (HR 1.64, p = 0.006 and HR 1.75, p = 0.004, respectively) and high ALRI (HR 2.13, p = 0.001 and HR 1.76, p = 0.02, respectively), but no difference was detected according to CII value. The multivariate analysis confirmed both SII and ALRI as independent prognostic factors for PFS (HR 1.64 and 2.82, respectively) and OS (HR 1.65 and 2.12, respectively). Conclusion: Our results demonstrate and confirm that IIs, and in particular SII and ALRI, are easy to measure prognostic markers for patient candidates to first line chemotherapy plus Bev for mCRC.

Inflammatory Indexes can predict the efficacy of bevacizumab in metastatic colorectal cancer Bevacizumab (Bev) is a humanized monoclonal antibody with antiangiogenic activity, used in combination with chemotherapy as a standard first line treatment for many metastatic colorectal cancer patients. Validated predictors of sensitivity or resistance to Bevacizumab are not available, although several studies have investigated this issue in recent years. In this study, we investigated whether some selected baseline inflammatory indexes levels, namely Systemic Immune-inflammation Index (SII) and Aspartate aminotransferase-Lymphocyte Ratio Index (ALRI) could predict the survival in patients with metastatic colorectal cancer treated with Bevacizumab plus chemotherapy. We enrolled 182 patients diagnosed with mCRC and treated with first line chemotherapy plus Bev. For each patient we tested blood neutrophils, lymphocytes, platelets, aspartate transaminase (AST) and lactate dehydrogenase (LDH) before each treatment cycle, according to clinical practice. We calculated the SII value as platelet count × neutrophil count/lymphocyte count, and ALRI as AST/lymphocyte count. We found that patients with high SII and high ALRI values had lower survival as compared to those with low values. These parameters represent reproducible, inexpensive and easy to measure biomarkers to be used in both clinical practice and clinical trials, for patient selection.