Determinants of unresectability and outcome of patients with occult colorectal hepatic metastases

Prognostic value of pretreatment F-18 fluorodeoxyglucose PET/CT in colorectal cancer with unresectable metastasis

PURPOSE

The aim of the study was to assess the prognostic value of pretreatment PET/computed tomography (CT) scans in colorectal cancer (CRC) patients with unresectable metastasis.

MATERIALS AND METHODS

We retrospectively reviewed the pretreatment PET/CT images of 82 CRC patients with unresectable metastasis and their medical records. On PET/CT images, maximum standardized uptake value (SUVmax) of primary tumor, highest SUVmax of metastatic tumors and number of metastatic organs were identified. The patients were further divided into single and multiple organ metastases groups according to the extent of disease. Survival analysis was performed with the clinical variables and metabolic parameters from PET/CT.

RESULTS

In a total of 82 patients, the age of patients, highest SUVmax of metastatic tumors and number of metastatic organs were independent prognostic factors for overall survival (OS) (all P < 0.05), whereas the SUVmax of primary tumor was not. On multivariate analysis, only the SUVmax of metastatic tumor was a significant prognostic factor in the single organ metastasis group (P = 0.047), whereas the age and highest SUVmax of metastatic tumors were independent prognostic factors in the multiple organ metastases group (all P < 0.05).

CONCLUSION

The highest SUVmax of metastatic tumors was an independent prognostic factor for OS in CRC patients with unresectable metastasis.

Comparison of Total Tumor Volume, Size and Number of Colorectal Liver Metastases in Prediction of Survival in Patients after Liver Resection

Liver is the most common location of the colorectal cancer metastases occurrence. Liver resection is the only curative method of treatment. Unfortunately it is feasible only in 25% of patients with colorectal liver metastases, often because of the extensiveness of the disease. The aim of the study was to evaluate the predictive value of total tumor volume, size and number of colorectal liver metastases in patients treated with right hemihepatectomy.

MATERIAL AND METHODS

A retrospective analysis was performed in a group of 135 patients with colorectal liver metastases, who were treated with right hemihepatectomy. Total tumor volume was estimated based on the formula (4/3)πr³. Moreover, the study included an analysis of data on the number and size of tumors, radicality of the resection, time between primary tumor resection and liver resection, pre-operative blood serum concentration of carcinoembryonal antigen (CEA) and carcinoma antigen Ca 19-9. The predictive value of the factors was evaluated by applying a Cox proportional hazards model and the area under the ROC curve.

RESULTS

The univariate analysis has shown the predictive value of size of the largest tumor (p=0.033; HR=1.065 per each cm) on the overall survival, however no predictive value of number of tumors (p=0.997; HR=1.000) and total tumor volume (p=0.212; HR=1.002) was observed. The multivariate analysis did not confirm the predictive value of the size of the largest tumor (p=0.141; HR=1.056). In the analysis of ROC curves, AUROC for the total tumor volume, the size of the largest tumor and the number of tumors were 0.629, 0.608, 0.520, respectively.

CONCLUSIONS

Total tumor volume, size and number of liver metastases are not independent risk factors for the worse overall survival of patients with colorectal liver metastases treated with liver resection, therefore increased values of these factors should not be a contraindication for surgical treatment.

Hepatic Parenchymal Heterogeneity on Contrast-enhanced CT Scans Following Oxaliplatin-based Chemotherapy: Natural History and Association with Clinical Evidence of Sinusoidal Obstruction Syndrome

PURPOSE

To evaluate the natural history and contrast material-enhanced computed tomographic (CT) features of postoxaliplatin heterogeneity of liver parenchyma (POHL) and to investigate the association of POHL with clinical factors and biomarkers of sinusoidal obstruction syndrome (SOS).

MATERIALS AND METHODS

The retrospective study was approved by the institutional review board, and informed consent was waived. Two hundred seventy patients (159 men, 111 women; age range, 31-92 years) who underwent oxaliplatin-based chemotherapy (OBC) and serial contrast-enhanced CT were consecutively registered. POHL severity was independently scored by two abdominal imagers, who were blinded to the clinical data, using a six-point scale (POHL presence, ≥4), followed by a consensus review. Complete radiologic remission was determined by consensus on the disappearance of heterogeneity on CT images. The association of POHL severity score with CT-based quantitative (ie, change in spleen size and blood-free hepatic parenchymal attenuation) and laboratory values (ie, aspartate aminotransferase, alanine transaminase, and platelet count), as well as time to complete radiologic remission, were evaluated with the Spearman rank test. Multivariate analysis was performed to determine the association between clinical factors of SOS (ie, age, sex, number of OBC sessions, chemotherapy regimen, bevacizumab use, and presence of concomitant hepatic metastasis) and POHL development. RESULTS Interobserver agreement was excellent (κ = 0.90). POHL was present in 167 (61.9%) of 270 patients, and the number of OBC sessions was significantly associated with POHL development (odds ratio, 1.138; 95% confidence interval: 1.039, 1.245; P = .005). POHL severity score was correlated with quantitative CT and laboratory values (P < .05 for all statistical analysis). Peripheral distribution (103 of 167, 61.7%) and right lobar predominance (103 of 165, 62.4%) were the most common POHL features. The mean time to complete radiologic remission, which was correlated with POHL severity score, was 82.5 days ± 68.8 after OBC discontinuation.

CONCLUSION

POHL development is associated with increased number of OBC sessions, and POHL severity was correlated with various biomarkers of SOS.

Optimal management of colorectal liver metastases in older patients: a decision analysis

BACKGROUND

Comparative trials evaluating management strategies for colorectal cancer liver metastases (CLM) are lacking, especially for older patients. This study developed a decision-analytic model to quantify outcomes associated with treatment strategies for CLM in older patients.

METHODS

A Markov-decision model was built to examine the effect on life expectancy (LE) and quality-adjusted life expectancy (QALE) for best supportive care (BSC), systemic chemotherapy (SC), radiofrequency ablation (RFA) and hepatic resection (HR). The baseline patient cohort assumptions included healthy 70-year-old CLM patients after a primary cancer resection. Event and transition probabilities and utilities were derived from a literature review. Deterministic and probabilistic sensitivity analyses were performed on all study parameters.

RESULTS

In base case analysis, BSC, SC, RFA and HR yielded LEs of 11.9, 23.1, 34.8 and 37.0 months, and QALEs of 7.8, 13.2, 22.0 and 25.0 months, respectively. Model results were sensitive to age, comorbidity, length of model simulation and utility after HR. Probabilistic sensitivity analysis showed increasing preference for RFA over HR with increasing patient age.

CONCLUSIONS

HR may be optimal for healthy 70-year-old patients with CLM. In older patients with comorbidities, RFA may provide better LE and QALE. Treatment decisions in older cancer patients should account for patient age, comorbidities, local expertise and individual values.

The outcome of liver resection and lymphadenectomy for hilar lymph node involvement in colorectal cancer liver metastases

OBJECTIVE

Hepatic hilar lymph node (HLN) involvement is considered as a poor prognostic factor during liver resection in colorectal liver metastases (CLM). The purpose of this study is to identify the clinical factors that distinguish HLN-positive patients from those who are hilar lymph node negative and to evaluate the frequency of macroscopic involvement of hepatic HLN, to investigate the impact of HLN involvement on survival after resection for CLM with lymphadenectomy and adjuvant chemotherapy.

PATIENTS AND METHODS

Between January 2000 and August 2012, 73 selected CLM patients underwent liver resections with lymphadenectomy in the Hepatopancreatobiliary Surgery Department I of Beijing Cancer Hospital. Clinical data, surgical outcome, and prognosis after operation of patients with HLN involvement were compared with that of patients without HLN involvement.

RESULTS

Of the 73 patients who underwent liver resections with lymphadenectomy, 12 (16.4 %) patients had HLN involvement identified by pathology. Compared with patients without HLN involvement, the frequency of lymph nodes metastasis for primary tumor was significantly higher in HLN-positive patients (p = 0.023). For CLM patients with and without HLN involvement, 5-year overall survival (OS) was 16.2 and 37.1 %, respectively (p = 0.04). Five-year disease-free survival (DFS) rates were 0 and 32.9 % (p = 0.034). Multivariate analysis showed that involved resected HLN was an independent risk factor for overall survival.

CONCLUSION

We should suspect HLN involvement in patients with colorectal cancer liver metastases when they have regional lymph nodes of primary tumor metastasis. Liver resection with HLN dissection might offer a unique curative opportunity for CLM patients with HLN involvement.

Production and quality control of radioactive yttrium microspheres for medical applications

In this paper, a method for production of yttrium silicate microspheres is reported. Yttrium silicate microspheres with approximate sizes of 20-50µm were obtained when an aqueous solution of Y(NO3)3 was added to tetraethyl orthosilicate (TEOS) and was pumped into silicone oil under constant stirring. The shapes of the particles produced by the proposed method were regular and nearly spherical. The spherical shapes, composition and element distribution were investigated by scanning electron microscopy (SEM), carbon/sulfur analysis and SEM/EDS mapping analysis. Paper chromatography was used to identify radiochemical impurities in the radioactive microspheres. The radionuclide purity was determined using a gamma spectrometry system and an ultra-low-level liquid scintillation spectrometer. The results indicated that the proposed silicone oil spheroidization method is suitable for the production of yttrium silicate microspheres.

Risk of occult irresectable disease at liver resection for hepatic colorectal cancer metastases: a contemporary analysis

INTRODUCTION

Traditionally, rates of irresectable disease at laparotomy for colorectal liver metastases (CRLM) have ranged from 15 to 70%. Diagnostic laparoscopy has been shown to be effective at preventing nontherapeutic laparotomy in selected patients. The purpose of this study was to analyze the resectability rate and role of diagnostic laparoscopy in a contemporary cohort.

METHODS

Using a prospectively maintained database, we identified patients who were explored for presumed resectable CRLM. Clinical and pathologic data associated with the finding of irresectable disease were analyzed.

RESULTS

From 2008-2010, 455 patients were explored. Of these, 35 (7.7%) did not undergo a resection and/or ablation. Of the 35 patients with irresectable disease, 15 (43%) had disease limited to the liver, 17 (49%) had extrahepatic disease (EHD), and 3 (9%) had other reasons precluding resection. Of the whole cohort, 45 patients (9.9%) were found to have EHD, and 27 of these (60%) underwent complete resection or ablation. The only factor associated with irresectable disease was a prior history of EHD, which was present in 29% of those found irresectable versus 13% of those resected (p = 0.022). Diagnostic laparoscopy was performed in 55 patients. Four of these patients had irresectable disease, and three were spared unnecessary laparotomy. Therefore, the yield was 5% and the sensitivity 75%.

CONCLUSIONS

The finding of irresectable disease is a rare event with modern radiologic assessment and the expansion of indications for resection. Diagnostic laparoscopy has a low yield and should be considered if there is a history of EHD or suspicious findings on preoperative imaging.

Positron emission tomography for benign and malignant disease

Functional imaging using radiolabeled probes that specifically bind and accumulate in target tissues has improved the sensitivity and specificity of conventional imaging. Fluorodeoxyglucose (FDG)-positron emission tomography (PET) has shown improved diagnostic accuracy in differentiating benign from malignant lesions in the setting of solitary pulmonary nodules. FDG-PET has become useful in preoperative staging of patients with lung cancer, and is being tested with many other malignancies for its ability to change patient management. This article provides an overview of the current status of FDG-PET and presents the challenges of moving toward routine use.

Holmium-166 radioembolization for the treatment of patients with liver metastases: design of the phase I HEPAR trial

BACKGROUND

Intra-arterial radioembolization with yttrium-90 microspheres ( 90Y-RE) is an increasingly used therapy for patients with unresectable liver malignancies. Over the last decade, radioactive holmium-166 poly(L-lactic acid) microspheres ( 166Ho-PLLA-MS) have been developed as a possible alternative to 90Y-RE. Next to high-energy beta-radiation, 166Ho also emits gamma-radiation, which allows for imaging by gamma scintigraphy. In addition, Ho is a highly paramagnetic element and can therefore be visualized by MRI. These imaging modalities are useful for assessment of the biodistribution, and allow dosimetry through quantitative analysis of the scintigraphic and MR images. Previous studies have demonstrated the safety of 166Ho-PLLA-MS radioembolization ( 166Ho-RE) in animals. The aim of this phase I trial is to assess the safety and toxicity profile of 166Ho-RE in patients with liver metastases.

METHODS

The HEPAR study (Holmium Embolization Particles for Arterial Radiotherapy) is a non-randomized, open label, safety study. We aim to include 15 to 24 patients with liver metastases of any origin, who have chemotherapy-refractory disease and who are not amenable to surgical resection. Prior to treatment, in addition to the standard technetium-99m labelled macroaggregated albumin ( 99mTc-MAA) dose, a low radioactive safety dose of 60-mg 166Ho-PLLA-MS will be administered. Patients are treated in 4 cohorts of 3-6 patients, according to a standard dose escalation protocol (20 Gy, 40 Gy, 60 Gy, and 80 Gy, respectively). The primary objective will be to establish the maximum tolerated radiation dose of 166Ho-PLLA-MS. Secondary objectives are to assess tumour response, biodistribution, performance status, quality of life, and to compare the 166Ho-PLLA-MS safety dose and the 99mTc-MAA dose distributions with respect to the ability to accurately predict microsphere distribution.

DISCUSSION

This will be the first clinical study on 166Ho-RE. Based on preclinical studies, it is expected that 166Ho-RE has a safety and toxicity profile comparable to that of 90Y-RE. The biochemical and radionuclide characteristics of 166Ho-PLLA-MS that enable accurate dosimetry calculations and biodistribution assessment may however improve the overall safety of the procedure.

Management of the hepatic lymph nodes during resection of liver metastases from colorectal cancer: a systematic review

BACKGROUND

Hepatic lymph node involvement is generally considered a contraindication for liver resection performed for colorectal liver metastases. However, some advocate hepatic lymphadenectomy in the presence of macroscopic involvement and others routine lymphadenectomy. The aim of this review is to assess the role of lymphadenectomy in resection of liver metastases from colorectal cancer.

METHODS

Medline, Embase and Central databases were searched using a formal search strategy. Trials with survival data with a minimum follow-up of 1 year were considered for inclusion. Meta-analysis was performed using Revman.

RESULTS

A total of 4230 references were identified. Ten reports of nine studies including 926 patients qualified for the review. The prevalence of nodal metastases after routine lymphadenectomy was 16.3%. The overall 3-year and 5-year survival rates in node-positive patients were 9/151 (11.3%) and 2/137 (1.5%), respectively, compared to 3-year and 5-year survival rates of 424/787 (53.9%) and 246/767 (32.1%) in node-negative patients. The odds ratios for 3-year and 5-year survivals in node positive disease compared to node-negative disease were 0.12 (95% CI 0.06 to 0.24) and 0.08 (95% CI 0.03 to 0.22). There was no randomized controlled trial which assessed the survival benefit of routine or "selective" lymphadenectomy.

CONCLUSION

Currently, there is no evidence of survival benefit for routine or selective lymphadenectomy. Survival rates are low in patients with positive lymph nodes draining the liver irrespective of whether they are detected by routine lymphadenectomy or by macroscopic involvement. Further trials in this patient group are required.

Surgical resection versus non-surgical treatment for hepatic node positive patients with colorectal liver metastases

BACKGROUND

Involvement of hepatic lymph node in patients with colorectal liver metastases is associated with poor prognosis.

OBJECTIVES

To determine the benefits and harms of curative liver resection with lymphadenectomy versus other treatments for colorectal liver metastases with hepatic node involvement.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and LILACS until September 2009 for identifying the randomised trials.

SELECTION CRITERIA

We considered only randomised clinical trials (irrespective of language, blinding, or publication status) comparing liver resection (alone or in combination with radiofrequency ablation or cryoablation) versus other treatments (neo-adjuvant chemotherapy, chemotherapy, or radiofrequency ablation) in patients with colorectal liver metastases with hepatic node involvement.

DATA COLLECTION AND ANALYSIS

Two authors independently identified trials for inclusion.

MAIN RESULTS

We were unable to identify any randomised clinical trial fulfilling the inclusion criteria of this review. We were also unable to identify any quasi-randomised or cohort studies, which could meaningfully answer this important issue.

AUTHORS' CONCLUSIONS

There is no evidence in the literature to assess the role of surgery versus other treatments for patients with colorectal liver metastases with hepatic node involvement. High quality randomised clinical trials are feasible and are necessary to determine the optimal management of patients with colorectal liver metastases with hepatic node involvement.

Monitoring and predicting response to therapy with 18F-FDG PET in colorectal cancer: a systematic review

Molecular imaging with (18)F-FDG PET has been proven useful in the management of colorectal cancer. (18)F-FDG PET plays a pivotal role in staging before surgical resection of recurrent colorectal cancer and metastases, in the localization of recurrence in patients with an unexplained rise in serum carcinoembryonic antigen levels, and in the assessment of residual masses after treatment. Currently, there is increasing interest in the role of (18)F-FDG PET beyond staging. The technique appears to have significant potential for the characterization of tumors and for the prediction of prognosis in the context of treatment stratification and early assessment of tumor response to therapy. This systematic review provides an overview of the literature on the value of (18)F-FDG PET for monitoring and predicting the response to therapy in colorectal cancer. The review covers chemotherapy response monitoring in advanced colorectal cancer, monitoring of the effects of local ablative therapies, and preoperative radiotherapy and multimodality treatment response evaluation in primary rectal cancer. Given the added value of (18)F-FDG PET for these indications, implementation in clinical practice and systematic inclusion in therapeutic trials to exploit the potential of (18)F-FDG PET are warranted.

Trends in nontherapeutic laparotomy rates in patients undergoing surgical therapy for hepatic colorectal metastases

Surgery is the treatment of choice in selected patients with hepatic colorectal metastases. Despite improvements in preoperative imaging, patients can undergo unnecessary nontherapeutic laparotomy. The aim of this study was to examine trends in nontherapeutic laparotomy rates in patients undergoing planned surgical therapy for hepatic colorectal metastases. Data from 530 operations (461 patients) undergoing potentially curative surgical therapy for colorectal liver metastases between 1994 and 2005 were analyzed. The incidence of nontherapeutic laparotomy was determined and factors associated with nontherapeutic laparotomy were identified. Overall, 49 nontherapeutic laparotomies were performed (9.2%). Higher nontherapeutic laparotomy rates were seen in patients with multiple metastases and tumor size >5 cm (both P < 0.05). Preoperative positron emission tomography (PET) imaging was associated with lower risk of nontherapeutic laparotomy [5.6% versus 12.4%, P = 0.009, odds ratio (OR) = 0.42]. At laparotomy, extrahepatic findings were the reason for nontherapeutic laparotomy in 44.9% of cases. The nontherapeutic laparotomy rate significantly decreased over time (14.9% for 1994-1997 versus 9.6% for 1998-2001 versus 4.7% for 2002-2005; P = 0.003). While patients in each time period were similar with regard to tumor specific factors, utilization of PET imaging (P < 0.001) as well as resection plus ablation (P = 0.004) increased over time. We conclude that prevalence of nontherapeutic laparotomy for patients undergoing surgical exploration for hepatic colorectal metastases has decreased significantly in recent years to less than 5%. The reasons for this trend are probably multifactorial and may include improved preoperative assessment, such as PET imaging, as well as salvage surgical options.

FDG-PET in colorectal cancer

[18F]Fluorodeoxyglucose (FDG) positron emission tomography (PET) is a useful imaging tool in the evolving management of patients with colorectal carcinoma. This technique is able to measure and visualize metabolic changes in cancer cells. This feature results in the ability to distinguish viable tumor from scar tissue, in the detection of tumor foci at an earlier stage than possible by conventional anatomic imaging and in the measurement of alterations in tumor metabolism, indicative of tumor response to therapy. Nowadays, FDG-PET plays a pivotal role in staging patients before surgical resection of recurrence and metastases, in the localization of recurrence in patients with an unexplained rise in serum carcinoembryonic antigen and in assessment of residual masses after treatment. In the presurgical evaluation, FDG-PET may be best used in conjunction with anatomic imaging in order to combine the benefits of both anatomical (CT) and functional (PET) information, which leads to significant improvements in preoperative liver staging and preoperative judgment on the feasibility of resection. Integration of FDG-PET into the management algorithm of these categories of patients alters and improves therapeutic management, reduces morbidity due to futile surgery, leads to substantial cost savings and probably also to a better patient outcome. FDG-PET also appears to have great potential in monitoring the success of local ablative therapies soon after intervention and in the prediction and evaluation of response to radiotherapy, systemic therapy, and combinations thereof. This review aims to outline the current and future role of FDG-PET in the field of colorectal cancer.

Complete response of colorectal liver metastases after chemotherapy: does it mean cure?

PURPOSE

Most patients with colorectal liver metastases (LMs) receive systemic chemotherapy. This study aimed to determine the significance of a complete response on imaging of LMs after chemotherapy.

PATIENTS AND METHODS

Between 1998 and 2004, 586 patients were treated for colorectal LMs in one institution. Of these, 38 with the following criteria were included in the study: fewer than 10 LMs before chemotherapy; disappearance of one or several LMs on computed tomography (CT) scan and ultrasound; surgery with intraoperative ultrasound within 4 weeks of imaging; no extrahepatic disease; follow-up at least 1 year after surgery.

RESULTS

Overall, 66 LMs disappeared after chemotherapy as seen on CT scan. Persistent macroscopic disease was observed at surgery at the site of 20 of 66 LMs, despite CT scan showing a complete response. The sites of 15 initial LMs that were not visible at surgery were resected. Pathologic examination of these sites of LMs, considered in complete response, showed viable cancer cells present in 12 of 15 cases. The sites of 31 initial LMs that were not visible at surgery were left in place during surgery; after 1 year of follow-up, 23 of 31 LMs considered in complete response had recurred in situ. Overall, persistent macroscopic or microscopic residual disease or early recurrence in situ were observed in 55 (83%) of 66 LMs having a complete response on imaging.

CONCLUSION

In most patients receiving chemotherapy for colorectal LMs, a complete response on CT scan does not mean cure.

FDG-PET for prediction of survival of patients with metastatic colorectal carcinoma

BACKGROUND

The current study focuses on the prognostic value of pretreatment metabolic activity in metastases as measured with [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET), as an indicator of survival in colorectal cancer.

PATIENTS AND METHODS

In a prospective series of 152 patients with metastatic colorectal cancer, of whom 67 were treated with resection of metastases and 85 with chemotherapy, standardized uptake values (SUV) as measured with FDG-PET, were calculated prior to treatment. Survival probabilities were estimated by Cox proportional regression analysis. For Kaplan-Meier analysis SUV was stratified by the median value. Survival differences were assessed using the log-rank test.

RESULTS

SUV in metastases was a significant predictor for overall survival (hazard ratio 1.17, 95% confidence interval 1.06-1.30, P = 0.002), independent of the subsequent treatment. According to the median value of the patient population a low (SUV <4.26) and high uptake group (SUV >4.26) was defined. The median survival and the 2- and 3-year survival rates were 32 months, 59% and 45%, respectively, in the low-uptake group and 19 months, 37% and 28%, respectively, in the high-uptake group (P = 0.017).

CONCLUSION

A significant survival benefit was observed in patients with low FDG uptake in metastases of colorectal cancer.