Long-term survival following delayed presentation and resection of colorectal liver metastases

Construction and validation of "WCH-nomogram" for predicting the prognosis after resection of colorectal liver metastases

BACKGROUND

The prognostic predictive tool for patients with colorectal liver metastasis (CRLM) is limited and the criteria for administering preoperative neoadjuvant chemotherapy in CRLM patients remain controversial.

METHODS

This study enrolled 532 CRLM patients at West China Hospital (WCH) from January 2009 to December 2019. Prognostic factors were identified from the training cohort to construct a WCH-nomogram and evaluating accuracy in the validation cohort. Receiver operating characteristic (ROC) curve analysis was used to compare the prediction accuracy with other existing prediction tools.

RESULTS

From the analysis of the training cohort, four independent prognostic risk factors, namely tumor marker score, KRAS mutation, primary lymph node metastasis, and tumor burden score were identified on which a WCH-nomogram was constructed. The C-index of the two cohorts were 0.674 (95% CI: 0.634-0.713) and 0.655 (95% CI: 0.586-0.723), respectively, which was better than the previously reported predication scores (CRS, m-CS and GAME score). ROC curves showed AUCs for predicting 1-, 3-, and 5-year overall survival (OS) of 0.758, 0.709, and 0.717 in the training cohort, and 0.860, 0.669, and 0.692 in the validation cohort, respectively. A cutoff value of 114.5 points was obtained for the WCH-nomogram total score based on the maximum Youden index of the ROC curve of 5-year OS. Risk stratification showed significantly better prognosis in the low-risk group, however, the high-risk group was more likely to benefit from neoadjuvant chemotherapy.

CONCLUSIONS

The WCH-nomogram demonstrates superior prognostic stratification compared to prior scoring systems, effectively identifying CRLM patients who may benefit the most from neoadjuvant chemotherapy.

Distinct role of tumor-infiltrating lymphocytes between synchronous and metachronous colorectal cancer

PURPOSE

Tumor-infiltrating lymphocytes (TILs) may influence the prognosis of colorectal liver metastasis (CRLM). We assessed the prognostic value of evaluating TILs in the primary and metastatic sites of synchronous CRLM as well as metachronous CRLM.

METHODS

We examined 90 patients who underwent curative primary and liver metastasis resection for colorectal cancer. CD8+ TILs (cytotoxic T cells) or CD45RO+ TILs (memory T cells) in both primary and metastatic sites were simultaneously evaluated by immunohistochemistry.

RESULTS

Fifty-one patients had synchronous CRLM, and 39 patients had metachronous CRLM. In synchronous cases, the overall survival (OS) was significantly worse in patients with low CD8+ or CD45RO+ TILs in a metastatic site than in those with high CD8+ or CD45RO+ TILs (P = 0.017 and P = 0.005, respectively). Multivariate analysis showed that age ≥ 65 years (P = 0.043), maximum tumor size ≥ 30 mm (P = 0.003), primary N2-3 (P = 0.019), and low CD8+ TILs in metastatic site (P = 0.046) were independent poor prognostic factors. In contrast, in metachronous cases, OS was significantly worse in patients with low CD45RO+ TILs in a primary site than in those with high CD45RO+ TILs (P = 0.021). CD45RO+ TILs in a primary site (P = 0.044) were determined to be independent prognostic factor on multivariate analysis.

CONCLUSIONS

The immune microenvironment between synchronous and metachronous CRLM might be different, and these differences may affect its prognosis.

Not All Kirsten Rat Sarcoma Viral Oncogene Homolog Mutations Predict Poor Survival in Patients With Unresectable Colorectal Liver Metastasis

Objective: To assess the characteristics of Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations and investigated whether all KRAS mutations predict poor prognosis in patients with unresectable colorectal liver metastasis (CRLM). Methods: Correlations between KRAS-mutation status and clinicopathological characteristics of 93 patients with unresectable CRLM at our institution between 2010 and 2018 were retrospectively analyzed. Kaplan–Meier and Cox proportional hazard models were used to evaluate the prognostic significance of KRAS mutations. Results:KRAS were primarily single-point mutations, identified in 41.9% of patients. There were no significant differences in clinicopathological characteristics between wild-type KRAS and mutant KRAS. Patients with mutant KRAS had significantly worse overall survival (OS) and progression-free survival (PFS) than those with wild-type KRAS. Moreover, patients with codon 12 mutations had worse OS and PFS than those with wild-type KRAS, whereas mutations in codon 13 were not associated with a worse prognosis. Among the 5 most common mutations in codons 12, G12V, and G12D were associated with worse OS, furthermore, G12C mutation seemed to associated with worse PFS than patients with wild-type KRAS. Conclusion:KRAS codon 12 mutations were predictive for a poor prognosis in patients with unresectable CRLM. G12D and G12V mutations were associated with worse OS, whereas G12C mutation seemed to be associated with decreased PFS.

Quantitative multiparametric MRI allows safe surgical planning in patients undergoing liver resection for colorectal liver metastases: report of two patients

It is not uncommon for clinicians to encounter varying degrees of hepatic steatosis in patients undergoing resection for colorectal liver metastases (CRLM). Magnetic resonance imaging is currently the preferred investigation for identification and pre-operative planning of these patients. An objective assessment of liver quality and degree of steatosis is paramount for planning a safe resection, which is seldom provided by routine MRI sequences. We studied two patients who underwent an additional pre-operative multiparametric MRI scan (LiverMultiScan^TM) as a part of an observational clinical trial (HepaT1ca, NCT03213314) to assess the quality of liver. Outcome was assessed in the form of post-hepatectomy liver failure. Both patients (Patient 1 and 2) had comparable pre-operative characteristics. Both patients were planned for an extended right hepatectomy with an estimated future liver remnant of approximately 30%. Conventional preoperative contrast MRI showed mild liver steatosis in both patients. Patient one developed post-hepatectomy liver failure leading to prolonged hospital stay compared to patient two who had uneventful post-operative course. Retrospective evaluation of multiparametric MRI scan revealed findings consistent with fibro-inflammatory disease and steatosis (cT1 829 ms, PDFF 14%) for patient 1 whereas patient two had normal parameters (cT1 735 ms, PDFF 2.4%). These findings corresponded with the resection specimen histology. Multiparametric MRI can objectively evaluate future liver health and volume which may help refine surgical decision-making and improve patient outcomes.

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.

Selection for surgery and survival of synchronous colorectal liver metastases; a nationwide study

BACKGROUND

Resection of colorectal liver metastases (CRLM) is associated with improved survival but we currently have limited population-based data on selection for surgery.

METHODS

Patients in the Swedish Colorectal Cancer Register reported with liver metastases at diagnosis in 2007-2011 were identified. Clinical characteristics including American Society of Anesthesiologists classification, type of hospital and health care region were retrieved. Linkage to the National Patient Register and Statistics Sweden provided information on liver resection and socioeconomic variables.

RESULTS

Synchronous CRLM was found in 4243/27,990 (15.2%) patients, of whom 1094 (25.8%) also had concurrent lung metastases. Of 3149 patients with liver-only metastases, 556 (17.8%) were subjected to liver resection. The resection rate varied by subsite; right-sided 11.7%, left-sided 19.7% and rectal cancer 22.7% (p = 0.001). It varied by type of hospital 14.1-23.6%, by region 11.5-22.7%, and was 19.8% in men and 14.9% in women (all p < 0.001). The adjusted odds were 0.74 (0.59-0.93) for females, 0.58 (0.46-0.74) for general district and 0.50 (0.37-0.68) for district hospital patients, and there were large regional differences. Patients >75 years were very unlikely to receive liver surgery 0.22 (0.15-0.32). In patients subjected to liver surgery, median survival was 57 months, 5-year survival rate was 45.4%, and those with left-sided colon cancer had the best outcome (48.8%; p = 0.02). Five-year hazard ratio for patients not subjected to liver surgery was 4.3 (3.7-5.0).

CONCLUSION

Nationwide outcome after resection of synchronous CRLM was impressing but ambiguous selection mechanisms and inaccessibility need to be resolved. The implications of subsite deserve further attention.

Patterns and management of distant failure in locally advanced rectal cancer: a cohort study

PURPOSE

To determine the long-term outcomes of locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiation (CRT) and surgery, and to analyze the management and survival once distant failure has developed.

METHODS

Data from LARC patients treated from 2000 to 2010 were retrospectively reviewed. CRT protocols were based on fluoropirimidines ± oxaliplatin. Follow-up consisted of physical examination, carcinoembryonic antigen levels, and chest-abdominal-pelvic CT scan.

RESULTS

The study included 228 patients with a mean age of 59 years. Forty-eight (21.1 %) patients had distant recurrence and 6 patients (2.6 %) had local recurrence. Median follow-up was 49 months. The 5- and 10-year actuarial disease free survival was 75.3 and 65.0 %, respectively. The 5- and 10-year actuarial overall survival (OS) was 89.6 and 71.2 %, respectively. Patients were classified as having liver (14 patients) or lung (27 patients) relapse according to the organ firstly metastasized. The variables significantly associated by univariate Cox analysis to survival were the achievement of an R0 metastases resection and the Köhne risk index, while the metastatic site showed a statistical trend. By multivariate Cox analysis, the only variable associated with survival was a R0 resection (HR = 16.3, p < 0.001). Median OS for patients undergoing a R0 resection was 73 months (95 % CI 67.8-78.2) compared to 25 months (95 % CI 5.47-44.5) in those non-operated patients (p < 0.001).

CONCLUSIONS

Combined treatment for LARC obtains a 5-year OS rounding 90 %. Follow-up based on thoracic-abdominal CT scan allows an early diagnosis of metastatic lesions. Surgical resection of metastases, regardless of their location, greatly increases the patient's survival rate.

Heat Sink Phenomenon of Bipolar and Monopolar Radiofrequency Ablation Observed Using Polypropylene Tubes for Vessel Simulation

Background. Radiofrequency ablation (RFA) is widely used for treating liver tumors; recurrence is common owing to proximity to blood vessels possibly due to the heat sink effect. We seek to investigate this phenomenon using unipolar and bipolar RFA on an egg white tumor tissue model and an animal liver model. Materials and methods. Temperature profiles during ablation (with and without vessel simulation) were studied, using both bipolar and unipolar RFA probes by 4 strategically placed temperature leads to monitor temperature profile during ablation. The volume of ablated tissue was also measured. Results. The volume ablated during vessel simulation confirmed the impact of the heat sink phenomenon. The heat sink effect of unipolar RFA was greater compared with bipolar RFA (ratio of volume affected 2:1) in both tissue and liver models. The volume ablated using unipolar RFA was less than the bipolar RFA (ratio of volume ablated = 1:4). Unipolar RFA achieved higher ablation temperatures (122°C vs 98°C). Unipolar RFA resulted in tissue damage beyond the vessel, which was not observed using bipolar RFA. Conclusion. Bipolar RFA ablates a larger tumor volume compared with unipolar RFA, with a single ablation. The impact of heat sink phenomenon in tumor ablation is less so with bipolar than unipolar RFA with sparing of adjacent vessel damage.

The analytical landscape of static and temporal dynamics in transcriptome data

Interpreting gene expression profiles often involves statistical analysis of large numbers of differentially expressed genes, isoforms, and alternative splicing events at either static or dynamic spectrums. Reduced sequencing costs have made feasible dense time-series analysis of gene expression using RNA-seq; however, statistical methods in the context of temporal RNA-seq data are poorly developed. Here we will review current methods for identifying temporal changes in gene expression using RNA-seq, which are limited to static pairwise comparisons of time points and which fail to account for temporal dependencies in gene expression patterns. We also review recently developed very few number of temporal dynamic RNA-seq specific methods. Application and development of RNA-specific temporal dynamic methods have been continuously under the development, yet, it is still in infancy. We fully cover microarray specific temporal methods and transcriptome studies in initial digital technology (e.g., SAGE) between traditional microarray and new RNA-seq.

All-trans-retinoic acid counteract the tumor-stimulating effect of hepatectomy and increases survival of rats bearing liver metastases

BACKGROUND

We previously demonstrated a stimulating effect of hepatectomy on residual tumor cells after resection of liver metastases. The aim of this study was to analyze the effect of all-trans-retinoic acid (ATRA) on the protumor effect of hepatectomy and survival of hepatectomized rats bearing liver metastases. We also explored whether ATRA interfered with the tumor promoting effect of hepatotropic growth factors (GFs).

METHODS

The in vitro effect of ATRA on proliferation of S4MH rhabdomyosarcoma tumor cells was assessed when cultured with laparotomized or hepatectomized rat serum (HRS), or in the presence of GFs (hepatocyte growth factor, insulin growth factor 2, Platelet Derived Growth Factor (PDGF)-BB, and vascular endothelial growth factor). For the in vivo studies, rats were partially hepatectomized on day 10 after metastasis induction, one group being treated with ATRA from day 7 to 14, and a second receiving cyclophosphamide (CY; on days 10 and 14) alone or with ATRA. We determined the size and number of liver and lung metastases. Finally, we analyzed the effect of treatments on rat survival.

RESULTS

Hepatotropic GFs increased cell proliferation in a similar manner to HRS. In vitro, ATRA blocked the protumor effect of both HRS and GFs. In vivo, ATRA reduced the size and number of liver and lung metastases, and significantly increased rat survival. Furthermore, adding ATRA to CY significantly increased survival compared with CY alone.

CONCLUSIONS

In our model, ATRA minimizes the tumor-stimulating effect of hepatectomy, reducing the number and size of liver metastases and improving survival. The results suggest that the ATRA may be useful for blocking the growth-promoting effect of hepatotropic GFs released after liver metastasis resection.

Changing trends in the presentation of colorectal liver metastases in a single hepatobiliary tertiary referral centre over fourteen years

AIM

National Institute for Clinical Excellence guidelines suggest that patients who have undergone potentially curative treatment for colorectal cancer (CRC) should be followed up for 3 years. The aim of this study was to investigate whether the time to presentation with colorectal liver metastases (CRLM) has changed over time. This information, which is currently unknown, may inform future decisions regarding follow-up.

METHODS

Patients presenting with metachronous isolated liver metastases between 1997 and 2011 were included. Timings of presentation with CRLM, rates of liver resection, survival data and factors associated with delayed presentation were investigated.

RESULTS

269 patients were included in the study. Those having their primary CRC resection between 1997 and 2007 presented earlier with liver metastases over time (r = -0.33, 95% CI -0.45 to -0.20). However, 26% of patients who developed CRLM did so beyond 3 years. There was no significant difference in rates of liver resections for those presenting within, or beyond, 3 years (p = 0.21). There was no significant difference in survival for those presenting with resectable CRLM within, or beyond, 3 years (Exp(b) = 0.60, 95% CI 0.28-1.28). No factors associated with late presentation were identified.

CONCLUSIONS

These results suggest that CRC follow-up should be extended to 5 years. Follow-up interventions should be more frequent in the early stages reflecting the trend towards earlier presentation with CRLM. The economic implications of extending follow-up compare favourably to other NHS funded initiatives.

The tumour biology of synchronous and metachronous colorectal liver metastases: a systematic review

Forty to fifty percent of colorectal cancer (CRC) patients develop colorectal liver metastases (CLM) that are either synchronous or metachronous in presentation. Clarifying whether there is a biological difference between the two groups of liver metastases or their primaries could have important clinical implications. A systematic review was performed using the following resources: MEDLINE from PubMed (1950 to present), Embase, Cochrane and the Web of Knowledge. Thirty-one articles met the inclusion criteria. The review demonstrated that the majority of studies found differences in molecular marker expression between colorectal liver metastases and their respective primaries in both the synchronous and metachronous groups. Studies investigating genetic aberrations demonstrated that the majority of changes in the primary tumour were 'maintained' in the colorectal liver metastases. A limited number of studies compared the primary tumours of the synchronous and metachronous groups and generally demonstrated no differences in marker expression. Although there were conflicting results, the colorectal liver metastases in the synchronous and metachronous groups demonstrated some differences in keeping with a more aggressive tumour subtype in the synchronous group. This review suggests that biological differences may exist between the liver metastases of the synchronous and metachronous groups. Whether there are biological differences between the primaries of the synchronous and metachronous groups remains undetermined due to the limited number of studies available. Future research is required to determine whether differences exist between the two groups and should include comparisons of the primary tumours.

Radiofrequency ablation or percutaneous ethanol injection for the treatment of liver tumors

The liver is a common location of both primary and secondary malignancies. For unresectable liver cancer, many local ablative therapies have been developed. These include e.g., percutaneous ethanol injection (PEI), percutaneous acetic acid injection, radiofrequency ablation (RFA), cryoablation, microwave ablation, laser-induced thermotherapy, and high-intensity focused ultrasound. RFA has recently gained interest and is the most widely applied thermoablative technique. RFA allows more effective tumor control in fewer treatment sessions compared with PEI, but with a higher rate of complications. However, there are certain circumstances where PEI therapy represents a better strategy to control liver tumors than RFA, especially in situations where RFA is difficult, for example when large vessels surround the tumor. In the context of hepatocellular carcinoma (HCC), both RFA and PEI are feasible and of benefit in non-operable patients. RFA seems superior to PEI in HCC > 2 cm, and the combination of interventions may be of benefit in selected patients. Liver resection is superior to RFA for patients with HCC meeting the Milan criteria, but RFA can be employed in tumors ≤ 3 cm and where there is an increased expected operative mortality. In addition, some lines of evidence indicate that RFA and PEI can be employed as a bridge to liver transplantation. The use of RFA in colorectal liver metastases is currently limited to unresectable disease and for patients unfit for surgery. The aim of this article is to summarize the current status of RFA in the management of liver tumors and compare it to the cheap and readily available technique of PEI.

Counting the cost of cancer surgery for advanced and metastatic disease

Putting cancer surgery into context is vital