KRAS mutation and primary tumor location do not affect efficacy of bevacizumab-containing chemotherapy in stagae IV colorectal cancer patients

Current Targeted Therapy for Metastatic Colorectal Cancer

Colorectal cancer (CRC) is the third most common type of cancer and the second leading cause of cancer deaths worldwide. Surgery or surgery plus radiotherapy and/or chemotherapy for patients with metastatic CRC (mCRC) were accepted as the main therapeutic strategies until the early 2000s, when targeted drugs, like cetuximab and bevacizumab, were developed. The use of targeted drugs in clinical practice has significantly increased patients' overall survival. To date, the emergence of several types of targeted drugs has opened new possibilities and revealed new prospects for mCRC treatment. Therapeutic strategies are continually being updated to select the most suitable targeted drugs based on the results of clinical trials that are currently underway. This review discusses the up-to date molecular evidence of targeted therapy for mCRC and summarizes the Food and Drug Administration-approved targeted drugs including the results of clinical trials. We also explain their mechanisms of action and how these affect the choice of a suitable targeted therapy.

Tumor Region Location and Classification Based on Fuzzy Logic and Region Merging Image Segmentation Algorithm

Early diagnosis of tumor plays an important role in the improvement of treatment and survival rate of patients. However, breast tumors are difficult to be diagnosed by invasive examination, so medical imaging has become the most intuitive auxiliary method for breast tumor diagnosis. Although there is no universal perfect method for image segmentation so far, the consensus on the general law of image segmentation has produced considerable research results and methods. In this context, this paper focuses on the breast tumor image segmentation method based on CNN and proposes an improved DCNN method combined with CRF. This method can obtain the information of multiscale and pixels better. The experimental results show that, compared with DCNN without these methods, the segmentation accuracy is significantly improved.

Hypoxia Signaling in Cancer: From Basics to Clinical Practice

Cancer hypoxia, recognized as one of the most important hallmarks of cancer, affects gene expression, metabolism and ultimately tumor biology-related processes. Major causes of cancer hypoxia are deficient or inappropriate vascularization and systemic hypoxia of the patient (frequently induced by anemia), leading to a unique form of genetic reprogramming by hypoxia induced transcription factors (HIF). However, constitutive activation of oncogene-driven signaling pathways may also activate hypoxia signaling independently of oxygen supply. The consequences of HIF activation in tumors are the angiogenic phenotype, a novel metabolic profile and the immunosuppressive microenvironment. Cancer hypoxia and the induced adaptation mechanisms are two of the major causes of therapy resistance. Accordingly, it seems inevitable to combine various therapeutic modalities of cancer patients by existing anti-hypoxic agents such as anti-angiogenics, anti-anemia therapies or specific signaling pathway inhibitors. It is evident that there is an unmet need in cancer patients to develop targeted therapies of hypoxia to improve efficacies of various anti-cancer therapeutic modalities. The case has been opened recently due to the approval of the first-in-class HIF2α inhibitor.

Influence of Programmed Death Ligand-1-Gene Polymorphism rs822336 on the Prognosis and Safety of Postoperative Patients with NSCLC Who Received Platinum-Based Adjuvant Chemotherapy

Purpose

This study was done to investigate the influence of PDL1-gene polymorphism on the prognosis and safety of postoperative patients with non–small cell lung cancer (NSCLC) who had received platinum-based adjuvant chemotherapy.

Methods

A total of 289 postoperative patients with NSCLC who had received platinum-based adjuvant chemotherapy from January 2012 to June 2019 participated in this study. Recurrence status and adverse reactions were documented during adjuvant chemotherapy. Overall survival (OS) data were obtained through telephone follow-up. DNA extracted from hematologic specimens was genotyped for PDL1-gene polymorphism. Associations between genotype status and prognosis were assessed using Kaplan–Meier survival analysis, and multivariate adjustment was performed using Cox regression analysis.

Results

Median disease-free survival of the 289 patients with NSCLC was 3.3 years and median OS 4.9 years. With regard to the PDL1 gene polymorphism, only rs822336 was of clinical significance in the subsequent analysis. The minor-allele frequency of rs822336 was 0.21, and distribution of the three genotypes was in accordance with the Hardy–Weinberg equilibrium (P=0.807). Survival analysis according to genotype status suggested that median disease-free survival of patients with GG and GC/CC genotypes was 2.8 and 4.1 years, respectively (P=0.01). Median OS of patients with GG and GC/CC genotypes was 4.1 and 5.4 years, respectively (P=0.008). However, the safety analysis failed to find a significant association between the polymorphism and adverse reactions. Interestingly, expression analysis of RNA extracted from peripheral blood mononuclear cells indicated that PDL1-mRNA expression of patients with the GG genotype was significantly higher than for the GC/CC genotype (P<0.001).

Conclusion

The prognosis of postoperative patients with NSCLC who have received platinum-based adjuvant chemotherapy may be influenced by the rs822336 polymorphism through mediation of the mRNA expression of PDL1.

Overweight is associated with better prognosis in metastatic colorectal cancer patients treated with bevacizumab plus FOLFOX chemotherapy

Introduction

Previous studies showed that high and low body mass index (BMI) was associated with worse prognosis in metastatic CRC (mCRC). Whether BMI is a prognostic or predictive factor in mCRC is unclear. We aimed to assess efficacy outcomes according to BMI in patient with metastatic colorectal cancer treated with bevacizumab plus FOLFOX chemotherapy regimen in second-line treatment.

Material and methods

The analysis of 237 patients with metastatic colorectal cancer treated with bevacizumab plus FOLFOX in the second line (treated from January 2014 to August 2018) in 4 reference oncological centers in Poland.

Results

The median age of the patients was 65 years (range 34-82). The median overall survival (OS) and progression-free survival (PFS) of the all 237 patient was 14.6 and 8.8 months, respectively. Comparison of obese patient (BMI > 30 kg/m²) vs. overweight patients (BMI ≥ 25 to < 30 kg/m²) vs. normal BMI range patients revealed a significant improvement of median OS (17.5 vs. 14.3 vs. 13.1 months, p = 0.01) and median PFS (9.4 vs. 9.1 vs. 7.3 months, p = 0.03). The Cox hazard model showed that the BMI class is an important risk factor. However, the Cox model also showed that the significance of the BMI class applies only to patients with BMI < 25 kg/m². This rule applies to both OS and PFS. The regression analysis also confirmed that there is a statistically significant relationship between the length of OS and PFS and the BMI value. Higher BMI was associated with a better prognosis. There were no differences in responses to treatment bevacizumab and FOLFOX chemotherapy and number adverse events according to BMI values.

Conclusions

Patients with mCRC treated with chemotherapy with bevacizumab in second-line treatment with higher BMI compared with normal weight patients have better prognosis in terms of PFS and OS. In this group, we found no evidence of changes in safety profile depending on BMI. Nevertheless, further large randomized studies are needed to assess the body weight on the effectiveness of chemotherapy in combination with bevacizumab.

The influence of PD-L1 genetic variation on the prognosis of R0 resection colorectal cancer patients received capecitabine-based adjuvant chemotherapy: a long-term follow-up, real-world retrospective study

PURPOSE

This study investigated the influence of PD-L1 genetic variation on the prognosis of R0 resection colorectal cancer (CRC) patients who received capecitabine-based adjuvant chemotherapy in real world.

METHODS

A total of 315 CRC patients underwent R0 surgical resection and received capecitabine-based adjuvant chemotherapy were included. Clinical characteristics were collected from the hospital record system, prognosis was obtained by telephone follow-up. Peripheral blood and peripheral blood mononuclear cell (PBMC) specimen of CRC patients were performed for the genotyping of polymorphism and mRNA expression of PD-L1, respectively. Analysis on the association between genotypes and prognosis was conducted.

RESULTS

The median disease-free survival (DFS) of the 315 CRC patients was 5.1 years, the median overall survival (OS) was 6.0 years. Regarding the PD-L1 gene polymorphism analysis, the prevalence of 901T>C among the CRC patients was as follows: TT genotype 221 cases (70.16%), TC genotype 86 cases (27.30%), CC genotype 8 cases (2.54%), the minor allele frequency was 0.16, the distribution of three genotypes was in accordance with Hardy-Weinberg equilibrium (P = 0.915). Moreover, the prognosis analysis indicated that the median DFS of patients with TT and TC/CC genotype was 5.4 and 4.0 years, respectively (P = 0.008). The median OS of patients with the two genotypes was 6.4 and 5.0 years (P = 0.007). The multivariate Cox regression analysis showed that the TC/CC genotypes were an independent factor for DFS (odds ratio = 1.56, P = 0.018). Furthermore, the mRNA expression results indicated that the mRNA expression of PD-L1 in PBMC of the patients with TC/CC genotype was significantly higher than patients with TT genotype (P < 0.001).

CONCLUSION

The prognosis of R0 resection CRC patients received capecitabine-based adjuvant chemotherapy in real world may be influenced by PD-L1 901T>C polymorphism through mediation of the mRNA expression of PD-L1.

Extracellular vesicle-miRNAs as liquid biopsy biomarkers for disease identification and prognosis in metastatic colorectal cancer patients

Disseminated disease is present in ≈50% of colorectal cancer patients upon diagnosis, being responsible for most of cancer deaths. Addition of biological drugs, as Bevacizumab, to chemotherapy, has increased progression free survival and overall survival of metastatic colorectal cancer (mCRC) patients. However, these benefits have been only reported in a small proportion of patients. To date, there are not biomarkers that could explain the heterogeneity of this disease and would help in treatment selection. Recent findings demonstrated that microRNAs (miRNAs) play an important role in cancer and they can be encapsulated with high stability into extracellular vesicles (EVs) that are released in biological fluids. EVs can act as cell-to-cell communicators, transferring genetic information, such as miRNAs. In this context, we aimed to investigate serum EV associated miRNAs (EV-miRNAs) as novel non-invasive biomarkers for the diagnosis and prognosis of Bevacizumab-treated mCRC patients. We observed that baseline miRNA-21 and 92a outperformed carcinoembryonic antigen levels in the diagnosis of our 44 mCRC patients, compared to 17 healthy volunteers. In addition, patients who died presented higher levels of miRNA-92a and 222 at 24 weeks. However, in the multivariate Cox analysis, higher levels of miRNA-222 at 24 weeks were associated with lower overall survival. Altogether, these data indicate that EV-miRNAs have a strong potential as liquid biopsy biomarkers for the identification and prognosis of mCRC.

Primary Tumor Sidedness Predicts Bevacizumab Benefit in Metastatic Colorectal Cancer Patients

The emerging debate between primary tumor location and clinical outcome of bevacizumab treated metastatic colorectal cancer (mCRC) continues. The aim of the present study is to investigate the association between the primary tumor location and clinical outcome of 115 mCRC patients receiving bevacizumab based treatment. A meta-analysis including 21 studies was carried out to confirm the conclusion. In our prospective study, we found that right-sided mCRC commonly occurred in older cases (p = 0.03) with multiple-site metastasis (p = 0.03). Progression-free survival (PFS) of the left-sided patients undergoing bevacizumab plus a FOLFIRI regimen was superior to the right-sided cases (p = 0.03, crude HR = 0.31, 95%CI = 0.11-0.87; adjusted HR = 0.21, 95%CI = 0.06-0.66). The meta-analysis confirmed that efficacy of bevacizumab-based treatment in left-sided mCRC patients was better than the right-sided cases in the overall population (P h = 0.24, combined OR = 1.36, 95%CI = 1.07-1.72), RAS/BRAF wild-type (P h = 0.19, combined OR = 1.66, 95%CI = 1.17-2.34), clinical trial (P h = 0.23, combined OR = 1.42, 95%CI = 1.07-1.88), Caucasian population (P h = 0.18, combined OR = 1.37, 95%CI = 1.02-1.85) and first-line (P h = 0.19, combined OR = 1.48, 95%CI = 1.13-1.96) subgroups. Improved survival of bevacizumab plus chemotherapy treated left-sided mCRC patients was observed in the overall population [P h < 0.01, combined MSR = 1.09, 95%CI = 1.00-1.18 for PFS; P h < 0.01, combined MSR = 1.24, 95%CI = 1.13-1.36 for overall survival (OS)], especially in the RAS/BRAF wild-type (P h = 0.09, combined MSR = 1.10, 95%CI = 1.03-1.19 for PFS; P h = 0.02, combined MSR = 1.34, 95%CI = 1.21-1.49 for OS). These findings indicate that primary tumor sidedness can predict clinical outcome of bevacizumab-treated RAS/BRAF wild-type mCRC patients and the left-sided patients may benefit more from bevacizumab plus FOLFIRI.

TP53 DNA Binding Domain Mutations Predict Progression-Free Survival of Bevacizumab Therapy in Metastatic Colorectal Cancer

(1) Background: Bevacizumab-based regimens are a standard treatment for metastatic colorectal cancer (mCRC) patients, however meaningful clinical biomarkers for treatment benefit remain scarce. (2) Methods: Tumor samples from 36 mCRC patients treated with bevacizumab-based chemotherapy underwent comprehensive genomic profiling. Alterations in frequently altered genes and important signaling pathways were correlated with progression-free survival (PFS). (3) Results: Overall genetic alteration analysis of investigated genes and pathways did not identify promising new predictors of PFS. However, when considering mutation subtypes, TP53 DNA binding domain (DBD) missense mutations were associated with prolonged PFS (HR, 0.41; 95% CI, 0.13−0.65; p = 0.005). In contrast, TP53 truncating mutations were associated with short PFS (HR, 2.95; 95% CI, 1.45−27.50; p = 0.017). Importantly, neither TP53 mutation subtype was associated with overall response rate. In multivariate analysis, TP53 DBD missense mutations remained an independent PFS predictor (HR, 0.31; 95% CI, 0.13–0.77; p = 0.011). The other genetic factor independently associated with PFS were PTPRT/PTPRD deleterious alterations, which we previously identified in a screen for biomarkers of bevacizumab response. (4) Conclusions: TP53 DBD missense mutations may predict prolonged PFS in mCRC patients treated with bevacizumab-based therapy. Analyses of TP53 mutations as clinical biomarkers should take the biological impact of different mutation subtypes into consideration to improve patient stratification.

Survival in signet ring cell carcinoma varies based on primary tumor location: a Surveillance, Epidemiology, and End Results database analysis

BACKGROUND

The aim of this study was to investigate the survival of patients with signet ring cell carcinoma (SRCC) based on primary tumor location.

METHODS

Patient data were obtained from the Surveillance, Epidemiology, and End Results database (1988-2012) with ≥200 cases per tumor location. Cox regression analysis was used to investigate prognostic factors of cause-specific survival (CSS).

RESULTS

We identified 24,171 patients. Of the patients, 63.4% had gastric SRCC, followed by colon (18.2%), esophageal (5.0%), rectal (3.5%), lung (3.1%), pancreatic (1.8%), breast (1.5%), bladder (1.3%), small intestine (1.1%), and gallbladder SRCC (1.0%). The 5-year CSS was 22.1%, 69.0%, 33.2%, 28.1%, 24.8%, 16.1%, 13.6%, 12.6%, 11.0%, 6.4% in patients with gastric, breast, colon, rectum, bladder, small intestine, esophageal, gallbladder, lung, and pancreatic SRCC, respectively (P < 0.001). Multivariate analyses showed that the primary tumor location was an independent prognostic factor of survival. Patients with lung, small intestine, and bladder SRCC had a comparable CSS to gastric SRCC, while breast and colorectal SRCC had better survival than gastric SRCC. Esophageal, gallbladder, and pancreatic SRCC were significantly associated with poor CSS compared with gastric SRCC.

CONCLUSION

Our study suggests a major difference in survival of SRCC based on the primary tumor locations.