Applying Fong's CRS Liver Score in Patients with Colorectal Liver Metastases Treated by Cryotherapy

Radiomics analysis of baseline computed tomography to predict oncological outcomes in patients treated for resectable colorectal cancer liver metastasis

OBJECTIVE

The purpose of this study was to determine and compare the performance of pre-treatment clinical risk score (CRS), radiomics models based on computed (CT), and their combination for predicting time to recurrence (TTR) and disease-specific survival (DSS) in patients with colorectal cancer liver metastases.

METHODS

We retrospectively analyzed a prospectively maintained registry of 241 patients treated with systemic chemotherapy and surgery for colorectal cancer liver metastases. Radiomics features were extracted from baseline, pre-treatment, contrast-enhanced CT images. Multiple aggregation strategies were investigated for cases with multiple metastases. Radiomics signatures were derived using feature selection methods. Random survival forests (RSF) and neural network survival models (DeepSurv) based on radiomics features, alone or combined with CRS, were developed to predict TTR and DSS. Leveraging survival models predictions, classification models were trained to predict TTR within 18 months and DSS within 3 years. Classification performance was assessed with area under the receiver operating characteristic curve (AUC) on the test set.

RESULTS

For TTR prediction, the concordance index (95% confidence interval) was 0.57 (0.57-0.57) for CRS, 0.61 (0.60-0.61) for RSF in combination with CRS, and 0.70 (0.68-0.73) for DeepSurv in combination with CRS. For DSS prediction, the concordance index was 0.59 (0.59-0.59) for CRS, 0.57 (0.56-0.57) for RSF in combination with CRS, and 0.60 (0.58-0.61) for DeepSurv in combination with CRS. For TTR classification, the AUC was 0.33 (0.33-0.33) for CRS, 0.77 (0.75-0.78) for radiomics signature alone, and 0.58 (0.57-0.59) for DeepSurv score alone. For DSS classification, the AUC was 0.61 (0.61-0.61) for CRS, 0.57 (0.56-0.57) for radiomics signature, and 0.75 (0.74-0.76) for DeepSurv score alone.

CONCLUSION

Radiomics-based survival models outperformed CRS for TTR prediction. More accurate, noninvasive, and early prediction of patient outcome may help reduce exposure to ineffective yet toxic chemotherapy or high-risk major hepatectomies.

Ablative therapies for colorectal liver metastases: a systematic review

AIM

The standard treatment for colorectal liver metastases (CRLM) is surgical resection. Only 20-30% of patients are deemed suitable for surgery. Recently, much attention has focused on ablative therapies either to treat unresectable CRLM or to extend the margins of resectability. This review aims to assess the long-term outcome and complication rates of various ablative therapies used in the management of CRLM.

METHOD

A literature search was performed of electronic databases including Medline, Cochrane Collaboration Library and the National Library of Medicine's ClinicalTrials.gov. Inclusion criteria were ablation for CRLM with minimum 1 year follow-up and >10 patients, published between January 1994 and January 2010.

RESULTS

In all, 226 potentially relevant studies were identified, of which 75 met the inclusion criteria. Cryotherapy (26 studies) had local recurrence rates of 12-39%, with mean 1-, 3- and 5-year survival rates of 84%, 37% and 17%. The major complication rate ranged from 7% to 66%. Microwave ablation (13 studies) had a local recurrence rate of 5-13%, with a mean 1-, 3- and 5-year survival of 73%, 30% and 16%, and a major complication rate ranging from 3% to 16%. Radiofrequency ablation (36 studies) had a local recurrence rate of 10-31%, with a mean 1-, 3- and 5-year survival of 85%, 36% and 24%, with major complication rate ranging from 0% to 33%.

CONCLUSION

Ablative therapies offer significantly improved survival compared with palliative chemotherapy alone with 5-year survival rates of 17-24%. Complication rates amongst commonly used techniques are low.

Surgical treatment of hepatic colorectal metastasis: evolving role in the setting of improving systemic therapies and ablative treatments in the 21st century

Liver resection has clearly been established as the standard treatment for resectable colorectal liver metastases. This article will review the expanding role for hepatectomy in this disease. Faster and safer hepatectomies are allowing combined resections of the primary cancer and synchronous hepatic metastases. Effective neoadjuvant chemotherapy, as well as increasing data demonstrating effectiveness and safety of combined hepatectomy and ablative therapies, have further expanded the pool of patients now selected for resection. The end result is that increasing numbers of patients are undergoing acceptably aggressive surgical therapies with extension of life and possible cure. Successful multimodality therapies are also now allowing for long-term survival even in patients not cured of cancer. The prolonged survival of most patients treated by hepatectomy has allowed a long-term analysis of the patterns of recurrence, which emphasize the importance of controlling liver disease for prolongation of life. These improvements in treatments for hepatic metastases have come with a precipitous escalation of the costs of care. This will likely require that future clinical trials and algorithms of care not only be based on cancer outcome data but also on value analysis of treatment and follow-up regimens.

Evaluation of peri-operative chemotherapy using a prognostic nomogram for survival after resection of colorectal liver metastases

INTRODUCTION

Nomograms are statistical tools designed to predict outcomes. This study evaluates the effects of peri-operative chemotherapy on the accuracy of a prognostic nomogram for disease-specific survival (DSS) after resection of colorectal liver metastases (CRLM) established at Memorial-Sloan Kettering Cancer Center (MSKCC).

METHODS

An external cohort of 203 patients who underwent resection of CRLM between 1996 and 2006 was used to assess the nomogram.

RESULTS

After median follow-up of 30.4 months (range 0.33-150), Kaplan-Meier (KM) estimates for 3-, 5- and 8-year post-resection DSS were 56%, 41%, and 32%, respectively; similar to nomogram-predicted probabilities for DSS. The concordance index for the nomogram was higher (0.602) than for the Fong colorectal risk score (CRS; 0.533). KM DSS was longer for patients (n= 50) treated with at least 6 months of peri-operative irinotecan or oxaliplatin compared with all other patients (median 66 vs. 40 months, P= 0.06). KM DSS was greater than nomogram predicted DSS for treated patients and less than nomogram predicted DSS for all other patients.

CONCLUSIONS

The CRLM nomogram was validated by an external cohort and more accurately predicted post-resection survival than the commonly used CRS. Differences in observed and nomogram-predicted survival may reflect the effect of treatment factors, such as peri-operative chemotherapy.

American Society of Clinical Oncology 2009 clinical evidence review on radiofrequency ablation of hepatic metastases from colorectal cancer

PURPOSE

To review the evidence about the efficacy and utility of radiofrequency ablation (RFA) for hepatic metastases from colorectal cancer (CRHM).

METHODS

The American Society of Clinical Oncology (ASCO) convened a panel to conduct and analyze a comprehensive systematic review of the RFA literature from Medline and the Cochrane Collaboration Library.

RESULTS

Because data were considered insufficient to form the basis of a practice guideline, ASCO has instead published a clinical evidence review. The evidence is from single-arm, retrospective, and prospective trials. No randomized controlled trials have been included. The following three clinical issues were considered by the panel: the efficacy of surgical hepatic resection versus RFA for resectable tumors; the utility of RFA for unresectable tumors; and RFA approaches (open, laparoscopic, or percutaneous). Evidence suggests that hepatic resection improves overall survival (OS), particularly for patients with resectable tumors without extrahepatic disease. Careful patient and tumor selection is discussed at length in the literature. RFA investigators report a wide variability in the 5-year survival rate (14% to 55%) and local tumor recurrence rate (3.6% to 60%). The reported mortality rate was low (0% to 2%), and the major complications rate was commonly reported to be between 6% and 9%. RFA is currently performed with all three approaches.

CONCLUSION

There is a compelling need for more research to determine the efficacy and utility of RFA to increase local recurrence-free, progression-free, and disease-free survival as well as OS for patients with CRHM. Clinical trials have established that hepatic resection can improve OS for patients with resectable CRHM.

Comparison of clinical risk scores predicting prognosis after resection of colorectal liver metastases

BACKGROUND

The aim of this study was to compare the risk scores of Fong et al., Nordlinger et al., and the TNM classification of colorectal liver metastases proposed by the UICC.

METHODS

Data from 282 consecutive patients undergoing 303 liver resections for metastatic colorectal cancer between 1995 and 2006 at the Department of Surgery, University of Erlangen were analyzed. The median follow-up time was 34 months. A curative (R0) resection was performed in 92% of the patients.

RESULTS

Applying the clinical risk score of Fong with preoperative data identified three risk groups. The survival rates between "low risk" (n = 22) and "intermediate risk" (n = 222) diverged (P = 0.073). The survival rates between "intermediate risk" and "high risk" (n = 59) differed significantly (P = 0.030). Using the risk scoring system of Nordlinger, patients were divided into two risk groups (i.e., "low risk" (n = 218) and "intermediate risk" (n = 68)). Significant differences in survival between the groups were noted (P = 0.012). Applying the clinical TNM classification of colorectal liver metastases revealed no significant differences in survival between the risk groups.

CONCLUSIONS

Our study found the clinical risk score developed by Fong et al. to be a reliable preoperative prognostic tool for selecting patients for surgical resection of colorectal liver metastases.