College of American Pathologists Tumor Regression Grading System for Long-Term Outcome in Patients with Locally Advanced Rectal Cancer.

BACKGROUND: The National Comprehensive Cancer Network's Rectal Cancer Guideline Panel recommends American Joint Committee of Cancer and College of American Pathologists (AJCC/CAP) tumor regression grading (TRG) system to evaluate pathologic response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer (LARC). Yet, the clinical significance of the AJCC/CAP TRG system has not been fully defined. MATERIALS AND METHODS: This was a multicenter, retrospectively recruited, and prospectively maintained cohort study. Patients with LARC from one institution formed the discovery set, and cases from external independent institutions formed a validation set to verify the findings from discovery set. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were assessed by Kaplan-Meier analysis, log-rank test, and Cox regression model. RESULTS: The discovery set (940 cases) found, and the validation set (2,156 cases) further confirmed, that inferior AJCC/CAP TRG categories were closely /ccorrelated with unfavorable survival (OS, DFS, LRFS, and DMFS) and higher risk of disease progression (death, accumulative relapse, local recurrence, and distant metastasis) (all p < .05). Significantly, pairwise comparison revealed that any two of four TRG categories had the distinguished survival and risk of disease progression. After propensity score matching, AJCC/CAP TRG0 category (pathological complete response) patients treated with or without adjuvant chemotherapy displayed similar survival of OS, DFS, LRFS, and DMFS (all p > .05). For AJCC/CAP TRG1-3 cases, adjuvant chemotherapy treatment significantly improved 3-year OS (90.2% vs. 84.6%, p < .001). Multivariate analysis demonstrated the AJCC/CAP TRG system was an independent prognostic surrogate. CONCLUSION: AJCC/CAP TRG system, an accurate prognostic surrogate, appears ideal for further strategizing adjuvant chemotherapy for LARC. IMPLICATIONS FOR PRACTICE: The National Comprehensive Cancer Network recommends the American Joint Committee of Cancer and College of American Pathologists (AJCC/CAP) tumor regression grading (TRG) four-category system to evaluate the pathologic response to neoadjuvant treatment for patients with locally advanced rectal cancer; however, the clinical significance of the AJCC/CAP TRG system has not yet been clearly addressed. This study found, for the first time, that any two of four AJCC/CAP TRG categories had the distinguished long-term survival outcome. Importantly, adjuvant chemotherapy may improve the 3-year overall survival for AJCC/CAP TRG1-3 category patients but not for AJCC/CAP TRG0 category patients. Thus, AJCC/CAP TRG system, an accurate surrogate of long-term survival outcome, is useful in guiding adjuvant chemotherapy management for rectal cancer.

Effects of neoadjuvant chemotherapy with or without intensity-modulated radiotherapy for patients with rectal cancer.

Neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision and adjuvant chemotherapy is the standard regimen for patients with locally advanced rectal cancer (LARC). However, whether and to which extent neoadjuvant radiotherapy could be removed from nCRT for patients with LARC is still unclear. This was a multicenter, retrospectively recruited, prospectively maintained cohort study. A propensity score matching model was employed to minimize potential confounding factors between subgroup patients treated with neoadjuvant chemotherapy (nCT) or nCRT. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were assessed between subgroup patients by Kaplan-Meier analysis, log-rank test, and Cox regression model. In total, 3233 consecutive patients, consist of 571 nCT and 2662 nCRT-treated cases, were included. After propensity score matching (1:4), 565 nCT-treated patients were matched to 1852 nCRT-treated patients. Compared with nCT, nCRT treatment indeed decreased 3-y local recurrence (10.0% vs 6.6%, P = .026), but had no impact on OS, DFS and DMFS (all P > .05) for LARC. Stratified analysis further confirmed that nCRT treatment was associated with higher 3-y LRFS and 3-y DFS than nCT treatment for baseline high-risk subgroup (cT4, cN+, and cIII stage) patients (all P < .05). Conversely, for the baseline low-risk subgroup patients (cT3, cN0, and cII stage), nCRT and nCT treatment had similar 3-y OS, LRFS, DFS, and DMFS (all P > .05). The administration of neoadjuvant radiotherapy for LARC patients might be determined by baseline risk classification, the high-risk individuals could be delivered while low-risk patients might be omitted.

MRNIP condensates promote DNA double-strand break sensing and end resection.

The rapid recognition of DNA double-strand breaks (DSBs) by the MRE11/RAD50/NBS1 (MRN) complex is critical for the initiation of DNA damage response and DSB end resection. Here, we show that MRN complex interacting protein (MRNIP) forms liquid-like condensates to promote homologous recombination-mediated DSB repair. The intrinsically disordered region is essential for MRNIP condensate formation. Mechanically, the MRN complex is compartmentalized and concentrated into MRNIP condensates in the nucleus. After DSB formation, MRNIP condensates move to the damaged DNA rapidly to accelerate the binding of DSB by the concentrated MRN complex, therefore inducing the autophosphorylation of ATM and subsequent activation of DNA damage response signaling. Meanwhile, MRNIP condensates-enhanced MRN complex loading further promotes DSB end resection. In addition, data from xenograft models and clinical samples confirm a correlation between MRNIP and radioresistance. Together, these results reveal an important role of MRNIP phase separation in DSB response and the MRN complex-mediated DSB end resection.

Pathologic-Based Nomograms for Predicting Overall Survival and Disease-Free Survival Among Patients with Locally Advanced Rectal Cancer.

PURPOSE: Preoperative neoadjuvant therapy is standard before surgery for locally advanced rectal cancer in current clinical treatment. However, patients with the same clinical TNM stage before treatment vary in clinical outcomes. More and more studies noted that pathological findings after preoperative neoadjuvant therapy are better prognostic factors to determine prognosis than clinical TNM stage in patients with locally advanced rectal cancer. The purpose of this study is to develop and validate models based on pathological findings to predict overall survival (OS) and disease-free survival (DFS). PATIENTS AND METHODS: A total of 3026 patients from two hospitals were included. The endpoint was OS and DFS. Significant predictors of OS on multivariate analysis were used to establish the nomogram. RESULTS: The Harrell's C index for OS prediction was 0.72 (95% confidence interval [CI], 0.68 to 0.77) in the training cohort, 0.66 (95% CI, 0.60 to 0.72) and 0.68 (95% CI, 0.64 to 0.73) in the internal and external validation cohorts. Using this nomogram, high- and low-risk groups for OS were defined in the training cohort. The 3-year OS was 78.1% (95% CI: 72.4-84.2%) for the high-risk group and 95% (95% CI: 93.6-96.5%) in the low-risk group (HR: 4.42, 95% CI: 3.22-6.05; P<0.001). This finding was also applied in the two external cohorts. Similarly, a nomogram that contained the same indices was developed and validated to predict for DFS. CONCLUSION: Nomograms based on pathological findings are a reliable tool to predict 3-year OS and DFS rate in patients with locally advanced rectal cancer.

A Genotype Signature for Predicting Pathologic Complete Response in Locally Advanced Rectal Cancer.

PURPOSE: To construct and validate a predicting genotype signature for pathologic complete response (pCR) in locally advanced rectal cancer (PGS-LARC) after neoadjuvant chemoradiation. METHODS AND MATERIALS: Whole exome sequencing was performed in 15 LARC tissues. Mutation sites were selected according to the whole exome sequencing data and literature. Target sequencing was performed in a training cohort (n = 202) to build the PGS-LARC model using regression analysis, and internal (n = 76) and external validation cohorts (n = 69) were used for validating the results. Predictive performance of the PGS-LARC model was compared with clinical factors and between subgroups. The PGS-LARC model comprised 15 genes. RESULTS: The area under the curve (AUC) of the PGS model in the training, internal, and external validation cohorts was 0.776 (0.697-0.849), 0.760 (0.644-0.867), and 0.812 (0.690-0.915), respectively, and demonstrated higher AUC, accuracy, sensitivity, and specificity than cT stage, cN stage, carcinoembryonic antigen level, and CA19-9 level for pCR prediction. The predictive performance of the model was superior to clinical factors in all subgroups. For patients with clinical complete response (cCR), the positive prediction value was 94.7%. CONCLUSIONS: The PGS-LARC is a reliable predictive tool for pCR in patients with LARC and might be helpful to enable nonoperative management strategy in those patients who refuse surgery. It has the potential to guide treatment decisions for patients with different probability of tumor regression after neoadjuvant therapy, especially when combining cCR criteria and PGS-LARC.

Efficacy and safety of nimotuzumab in addition to radiotherapy and temozolomide for cerebral glioblastoma: a phase II multicenter clinical trial.

Background: Nimotuzumab is a humanized anti-epidermal growth factor receptor (EGFR) antibody that has shown preclinical and clinical anticancer activity in cerebral glioblastoma multiforme (GBM). We conducted a phase II, single-arm, multicenter clinical trial to evaluate the benefit of adding nimotuzumab to current standard chemo-radiotherapy for patients with GBM with positive EGFR expression. Methods: Newly diagnosed patients with histologically proven single supratentorial GBM and epidermal growth factor receptor (EGFR) positive expressions were recruited. All patients were treated with nimotuzumab, administered once a week intravenously for 6 weeks in addition to radiotherapy with concomitant and adjuvant temozolomide after surgery. The primary endpoints were overall survival (OS) and progression-free survival (PFS). Secondary objectives included objective response rate (ORR) and toxicity. Results: A total of 39 patients were enrolled and 36 patients were evaluated for efficacy. The ORR at the end of RT was 72.2%. Median OS and PFS were 24.5 and 11.9 months. The 1-year OS and PFS rates were 83.3% and 49.3%. The 2-year OS and PFS rates were 51.1% and 29.0%. O (6)-methylquanine DNA methyl-tranferase (MGMT) expression is known to affect the efficacy of chemotherapy and status of its expression is examined. No significant correlation between treatment outcomes and MGMT status was found. Most frequent treatment-related toxicities were mild to moderate and included constipation, anorexia, fatigue, nausea, vomiting, and leucopenia. Conclusions: Our study show that nimotuzumab in addition to standard treatment is well tolerable and has increased survival in newly diagnosed GBM patients with EGFR positive expression.