Rate of Curative Surgery in Real-world Patients with Unresectable Metastatic Colorectal Cancer Treated with FOLFOXIRI ± Bevacizumab: A Western Canadian Province Experience

BACKGROUND

Recent evidence from randomized trials suggests that FOLFOXIRI (fluorouracil, oxaliplatin, and irinotecan) ± bevacizumab is associated with higher response rates, with the potential for conversion of unresectable to resectable disease in metastatic colorectal cancer (mCRC). However, limited evidence is available on the efficacy and safety of this regimen in real-world patients with mCRC. The current study aims to evaluate the conversion rate and safety of FOLFOXIRI ± bevacizumab in real-world patients with unresectable mCRC.

METHODS

In this retrospective multicenter population-based cohort study, patients who were diagnosed with unresectable mCRC between January 2015 and December 2018 in Saskatchewan and received FOLFOXIRI ± bevacizumab were assessed. Kaplan-Meier survival methods and the log-rank test were performed.

RESULTS

A total of 28 eligible patients with a median age of 51 years (interquartile range 39-60) and a male:female ratio of 11:17 were identified; 39% had rectal cancer, 46% had extrahepatic disease, and 46% had bilobar liver metastases. Overall, 63% of the patients had a positive response to FOLFOXIRI ± bevacizumab and 53% underwent metastasectomy. Of all patients 60% had grade 3/4 toxicity and 32% required hospital admission. No treatment-related mortality was noted. After 4 years, 50% of the patients were alive. Median progression-free survival of patients who underwent surgery was 18 months (95% CI 11.3-24.7) versus 11 months (4-18.1) without surgery (p = 0.28). Median overall survival of patients with surgery was 33 months (17.5-48.5) versus 16 months (8.3-23.7) without surgery (p = 0.03).

CONCLUSION

The current study suggests that FOLFOXIRI ± bevacizumab therapy in real-world patients with mCRC is associated with a high rate of conversion from unresectable to resectable metastatic disease. Patients with metastasectomy had better survival.

The ILK-MMP9-MRTF axis is crucial for EndMT differentiation of endothelial cells in a tumor microenvironment

Increasing evidence indicates that the tumor microenvironment is a critical factor supporting cancer progression, chemoresistance and metastasis. Recently, cancer-associated fibroblasts (CAFs) have been recognized as a crucial tumor stromal component promoting cancer growth and invasiveness via modulation of the extracellular matrix (ECM) structure, tumor metabolism and immune reprogramming. One of the main sources of CAFs are endothelial cells undergoing the endothelial-mesenchymal transition (EndMT). EndMT is mainly promoted by the Transforming Growth Factor-β (TGF-β) family secreted by tumor cells, though the role of particular members in EndMT regulation remains poorly understood. Our findings demonstrate that TGF-β2 induces mesenchymal transdifferentiation of human microvascular endothelial cells (HMEC-1 cells) to CAF-like cells in association with elongated cell morphology, modulation of stress fiber organization, higher α-SMA protein levels and activation of RhoA and Rac-1 pathways. Such regulation is similar to that observed in cells maintained using conditioned medium from invasive colorectal cancer cell line culture. Furthermore, TGF-β2 stimulation resulted in myocardin-related transcription factor (MRTF) activation and upregulation. Our results demonstrate for the first time that such interaction is sufficient for integrin-linked kinase (ILK) overexpression. ILK upregulation also enhanced MRTF activation via RhoA and Rac-1-MMP9 via inside-out integrin activation. Herein, we propose a new ILK-MMP9-MRTF axis that appears to be critical for EndMT differentiation of endothelial to CAF-like cells. Thus, it might be an attractive target for cancer treatment.

Regional Lymph Nodes Status and Ratio of Metastatic to Examined Lymph Nodes Correlate with Survival in Stage IV Colorectal Cancer

BACKGROUND

Although lymph nodes status and the ratio of metastatic to examined lymph node (LNR) are important prognostic factors in early-stage colorectal cancer (CRC), their significance in patients with metastatic disease remains unknown. The study aims to determine prognostic importance of nodal status and LNR in patients with stage IV CRC.

METHODS

A cohort of 1109 eligible patients who were diagnosed with synchronous metastatic CRC in Saskatchewan during 1992-2010 and underwent primary tumor resection was evaluated. We conducted the Cox proportional multivariate analyses to determine the prognostic significance of nodal status and LNR.

RESULTS

Median age was 70 years (22-98) and M:F was 1.2:1. Rectal cancer was found in 26 % of patients; 96 % had T3/T4 tumor, and 82 % had node positive disease. The median LNR was 0.36 (0-1.0). Fifty-four percent received chemotherapy. Median overall survival of patients who had LNR of <0.36 and received chemotherapy was 29.7 months (95 % CI 26.6-32.9) compared with 15.6 months (95 % CI 13.6-17.6) with LNR of ≥0.36 (P < .001). On multivariate analyses, no chemotherapy (HR 2.36 [2.0-2.79]), not having metastasectomy (HR 1.94 [1.63-2.32]), LNR ≥0.36 (HR 1.59 [1.38-1.84]). nodal status (HR 1.34 [1.14-1.59]), and T status (HR 1.23 [1.07-1.40]) were correlated with survival. Test for interaction was positive for LNR and high-grade cancer (HR 1.51 [1.10-2.10]).

CONCLUSIONS

Our results suggest that nodal status and LNR are important prognostic factors independent of chemotherapy and metastasectomy in stage IV CRC patients.

Advances in the management of colorectal cancer: from biology to treatment

BACKGROUND

Colorectal cancer (CRC) is the third most common malignant neoplasm worldwide and the fourth leading cause of cancer-related deaths. This article reviews the epidemiology, risk factors, pathogenesis, and prognosis of CRC with special emphasis on advances in the management of CRC over the past decade.

METHODS

A review of the published English literature was conducted using the search engines PubMed, Medline, EMBASE, and Google Scholar. A total of 127 relevant publications were identified for further review.

RESULTS

Most CRC are sporadic and are due to genetic instability and multiple somatic mutations. Approximately 80% of cancers are diagnosed at the early stage and are curable. The pathologic stage at presentation is the most important predictor of outcome after resection of early stage cancer. Surgery is the primary treatment modality for localized CRC. Advances in (neo)adjuvant chemotherapy and radiation have reduced the disease recurrence and increased survival in high risk diseases. Although recent advancements in combination chemotherapy and target agents have increased the survival of incurable CRC, it is remarkable that only selected patients with advanced CRC can be cured with multimodality therapy.

CONCLUSION

Over the past decade, there has seen substantial progress in our understanding of and in the management of CRC.