Surgeon's awareness of the synchronous liver metastases during colorectal cancer resection may affect outcome

Synchronous and metachronous liver metastases in patients with colorectal cancer-towards a clinically relevant definition

Background

Approximately 25% of patients with colorectal cancer (CRC) will have liver metastases classified as synchronous or metachronous. There is no consensus on the defining time point for synchronous/metachronous, and the prognostic implications thereof remain unclear. The aim of the study was to assess the prognostic value of differential detection at various defining time points in a population-based patient cohort and conduct a literature review of the topic.

Methods

All patients diagnosed with CRC in the counties of Stockholm and Gotland, Sweden, during 2008 were included in the study and followed for 5 years or until death to identify patients diagnosed with liver metastases. Patients with liver metastases were followed from time of diagnosis of liver metastases for at least 5 years or until death. Different time points defining synchronous/metachronous detection, as reported in the literature and identified in a literature search of databases (PubMed, Embase, Cochrane library), were applied to the cohort, and overall survival was calculated using Kaplan-Meier curves and compared with log-rank test. The influence of synchronously or metachronously detected liver metastases on disease-free and overall survival as reported in articles forthcoming from the literature search was also assessed.

Results

Liver metastases were diagnosed in 272/1026 patients with CRC (26.5%). No statistically significant difference in overall survival for synchronous vs. metachronous detection at any of the defining time points (CRC diagnosis/surgery and 3, 6 and 12 months post-diagnosis/surgery) was demonstrated for operated or non-operated patients. In the literature search, 41 publications met the inclusion criteria. No clear pattern emerged regarding the prognostic significance of synchronous vs. metachronous detection.

Conclusion

Synchronous vs. metachronous detection of CRC liver metastases lacks prognostic value. Using primary tumour diagnosis/operation as standardized cut-off point to define synchronous/metachronous detection is semantically correct. In synchronous detection, it defines a clinically relevant group of patients where individualized multimodality treatment protocols will apply.

Colorectal Cancer Liver Metastases – Understanding the Differences in the Management of Synchronous and Metachronous Disease

Introduction: Metastatic disease to the liver in colorectal cancer is a common entity that may present synchronously or metachronously. While increasing surgical experience has improved survival outcomes, some evidence suggest that synchronous lesions should be managed differently. This review aims to update current literature on differences between the outcomes and management of synchronous and metachronous disease. Materials and Methods: Systematic review of MEDLINE database up till November 2008. Results: Discrete differences in tumour biology have been identified in separate studies. Twenty-one articles comparing outcomes were reviewed. Definitions of metachronicity varied from anytime after primary tumour evaluation to 1 year after surgery for primary tumour. Most studies reported that synchronous lesions were associated with poorer survival rates (8% to 16% reduction over 5 years). Sixteen articles comparing combined vs staged resections for synchronous tumour showed comparable morbidity and mortality. Benefits over staged resections included shorter hospital stays and earlier initiation of chemotherapy. Suitability for combined resection depended on patient age and constitution, primary tumour characteristics, size and the number of liver metastases, and the extent of liver involvement. Conclusions: Surgery remains the only treatment option that offers a chance of long-term survival for patients amenable to curative resection. Synchronicity suggests more aggressive disease although a unifying theory for biological differences explaining the disparity in tumour behaviour has not been found. Combined resection of primary tumour and synchronous metastases is a viable option pending careful patient selection and institutional experience. Given the current evidence, management of synchronous and metachronous colorectal liver metastases needs to be individualised to the needs of each patient. Key words: Colorectal neoplasms, Liver neoplasms, Neoplasm metastasis, Synchronous Cancer, Metachronous cancer

Staged or simultaneous resection of synchronous liver metastases from colorectal cancer--a systematic review

OBJECTIVE

A systematic review of the literature was undertaken to estimate the differences in length of hospital stay, morbidity, mortality and long-term survival between staged and simultaneous resection of synchronous liver metastases from colorectal cancer to determine the level of evidence for recommendations of a treatment strategy.

METHOD

A Pub-med search was undertaken for studies comparing patients with synchronous liver metastases, who either had a combined or staged resection of metastases. Twenty-six were considered and 16 were included based on Newcastle Ottawa Quality Assessment Scale. All studies were retrospective and had a general bias, because the staged procedure was significantly more often undertaken in patients with left-sided primary tumours and larger, more numerous and bi-lobar metastases. Analyses of primary outcomes were performed using the random effects model.

RESULTS

For the reason of the heterogeneity of the observational studies, no odds ratios were calculated. In 11 studies, there was a tendency towards a shorter hospital stay in the synchronous resection group. Fourteen studies compared total perioperative morbidity and lower morbidity was observed in favour of a combined resection. Fifteen studies compared perioperative mortality, which seemed to be lower with the staged approach. Eleven studies compared 5-year survival, which seemed to be similar in the two groups.

CONCLUSION

No randomized controlled trials were identified, and hence a meta-analysis was not performed. The evidence level is II to III with grade C recommendations. Synchronous resections can be undertaken in selected patients, provided that surgeons specialized in colorectal and hepatobiliary surgery are available.