Personalizing prognosis in colorectal cancer: A systematic review of the quality and nature of clinical prognostic tools for survival outcomes

Integrating diverse types of prognostic information into accurate, individualized estimates of outcome in colorectal cancer is challenging. Significant heterogeneity in colorectal cancer prognostication tool quality exists. Methodology is incompletely or inadequately reported. Evaluations of the internal or external validity of the prognostic model are rarely performed. Prognostication tools are important devices for patient management, but tool reliability is compromised by poor quality. Guidance for future development of prognostication tools in colorectal cancer is needed.

Novel methods for clinical risk stratification in patients with colorectal liver metastases

Purpose

Colorectal cancer patients with liver-confined metastases are classified as stage IV, but their prognoses can differ from metastases at other sites. In this study, we suggest a novel method for risk stratification using clinically effective factors.

Materials and Methods

Data on 566 consecutive patients with colorectal liver metastasis (CLM) between 1989 and 2010 were analyzed. This analysis was based on principal component analysis (PCA).

Results

The survival rate was affected by carcinoembryonic antigen (CEA) level (p < 0.001; risk ratio, 1.90), distribution of liver metastasis (p=0.014; risk ratio, 1.46), and disease-free interval (DFI; p < 0.001; risk ratio, 1.98). When patients were divided into three groups according to PCA score using significantly affected factors, they showed significantly different survival patterns (p < 0.001).

Conclusion

The PCA scoring system based on CEA level, distribution of liver metastasis, and DFI may be useful for preoperatively determining prognoses in order to assist in clinical decisionmaking and designing future clinical trials for CLM treatment.

Prognostic models for outcome following liver resection for colorectal cancer metastases: A systematic review

BACKGROUND

Liver resection provides the best chance for cure in colorectal cancer (CRC) liver metastases. A variety of factors that might influence survival and recurrence have been identified. Predictive models can help in risk stratification, to determine multidisciplinary treatment and follow-up for individual patients.

AIMS

To systematically review available prognostic models described for outcome following resection of CRC liver metastases and to assess their differences and applicability.

METHODS

The Pubmed, Embase and Cochrane Library databases were searched for articles proposing a prognostic model or risk stratification system for resection of CRC liver metastases. Search terms included 'colorectal', 'liver', 'metastasis', 'resection', 'prognosis' and 'prediction'. The articles were systematically reviewed.

RESULTS

Fifteen prognostic systems were identified, published between 1996 and 2009. The median study population was 305 patients and the median follow-up was 32 months. All studies used Cox proportional hazards for multi-variable analysis. No prognostic factor was common in all models, though there was a tendency towards the number of metastases, CRC spread to lymph nodes, maximum size of metastases, preoperative CEA level and extrahepatic spread as representing independent risk factors. Seven models assigned more weight to selected factors considered of higher predictive value.

CONCLUSION

The existing predictive models are diverse and their prognostic factors are often not weighed according to their impact. For the development of future predictive models, the complex relations within datasets and differences in relevance of individual factors should be taken into account, for example by using artificial neural networks.

Clinical rescue evaluation in laparoscopic surgery for hepatic metastases by colorectal cancer

AIM

Laparoscopy is an increasingly important tool in the staging and treatment for potentially resectable liver metastases. The clinical risk score (CRS) is useful in selecting patients for diagnostic laparoscopy before planning resection of colorectal metastases. This study evaluates the effect of staging laparoscopy (SL) combined with CRS.

MATERIALS AND METHODS

From January 2004 to December 2007, CRS evaluation and SL were performed in 65 consecutive patients with colorectal metastases, before planned open-exploration and resection. Patients were assigned to a CRS, which is based on 5 factors related to the primary tumor and the hepatic disease. This study was aimed at recognizing occult unresectable metastases, by combining laparoscopy and CRS.

RESULTS

Only 62 patients had a complete SL examination (3 were excluded for dense adhesions). A group of 24 patients was identified as unresectable, and 38 patients as resectable. In the latter group, 3 patients directly had laparoscopic treatment. In all, 38 patients underwent laparotomy (35 resectable, and 3 patients with dense adhesions that could not have a complete laparoscopic treatment).Resection was carried out in 30 of 38 (78.9%) cases, and the remaining 21% gave false-negative results. In all, there were 32 of 65 (49.2%) unresectable patients, and 75% of them were recognized by SL.

CONCLUSIONS

Laparoscopy identified the majority of patients with occult unresectable disease, improved resectability, and it should be a routine in patients being considered for potentially curative hepatic resection. The CRS, earlier shown to predict survival after hepatic resection, identifies high-risk patients, who are most likely to benefit from laparoscopy, and may improve resource utilization.

Relationship between period of survival and clinicopathological characteristics in patients with colorectal liver metastasis

AIM

Cancer death in the early period after hepatectomy still occurs in patients with colorectal liver metastasis (CLM). We examined the relationship between clinicopathological parameters and survival periods in 130 CLM patients who underwent hepatectomy.

PATIENTS/METHODS

Patients were divided into four groups: Group 1 (5-year survivors without tumor relapse), Group 2 (survivors at 2-5 years), Group 3 (cancer death at 2-5 years), and Group 4 (cancer death within 2 years).

RESULTS

A short surgical margin was frequent in Group 4 compared to Group 1 (31 vs. 78%, P<0.05). Primary node-positive status, absence of fibrous pseudo-capsular formation, higher Clinical Risk Score, and tumor recurrence within 12 months were frequent in Group 4 (P<0.05). Multivariate analysis revealed a short surgical margin (HR; 3.5) and early tumor relapse (HR; 5.9) as independently significant related parameters (P<0.05).

CONCLUSIONS

Sufficient surgical margins and careful follow-up for early tumor relapse may be important for improving postoperative outcomes for CLM patients.