Neoadjuvant therapy of colorectal liver metastases: Lessons learned from clinical trials

What is the Prognostic Value of a Discordant Radiologic and Pathologic Response in Patients Undergoing Resection of Colorectal Liver Metastases After Preoperative Chemotherapy?

BACKGROUND

The clinical significance of discordant radiological and pathological response to preoperative chemotherapy of colorectal liver metastases (CLM) is unknown.

METHODS

From 2011 to 2016, all eligible patients undergoing resection for CLM after preoperative chemotherapy were included at two centres. Patients were categorized according to radiologic response using RECIST as Rad-responders (complete/partial response) or Rad-non responders (stable disease) and according to Blazer et al. pathologic response grade as Path-responders (complete/major response) or Path-non responders (minor response). Survival outcome was analysed according to radiologic and pathologic response.

RESULTS

Among 413 patients undergoing resection of CLM, 119 fulfilled the inclusion criteria. Among these, 52 (44%) had discordant radiologic and pathologic response including 27 Rad-non responders/path responders and 25 Rad-responders/Path-non responders. Rad-non responders/path responders and Rad-responders/Path-non responders had similar characteristics except for the proportion receiving more than 6 cycles of preoperative chemotherapy (7/27 vs 16/25; P = 0.017). Median disease-free survival was not different in patients with or without discordant radiologic and pathologic responses (P = 0.195) but the type of discordance had an impact on oncologic outcome as median disease-free survival was 13.9 months (95% CI 5.7-22.2 months) in Rad-non responders/Path responders and 8.6 (6.2 - 10.9 months) in Rad-responders/Path-non responders (P = 0.034). Univariate and multivariate analysis showed that major pathologic response was associated with improved disease-free survival (OR 0.583, 95% CI 0.36-0.95, P = 0.031).

CONCLUSION

A discordant radiologic and pathologic response is common after preoperative chemotherapy for CLM. In these patients, pathologic response drives oncologic 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.

Bioluminescence imaging of a tumor-selective, thymidine kinase-defective vaccinia virus Guang9 strain after intratumoral or intraperitoneal administration in mice

Vaccinia virus has been used as an oncolytic virus because of its capacity to preferentially infect tumors rather than normal tissues. The vaccinia Tian Tan strain, used as a vaccine against smallpox for millions of people in China, is a promising candidate for cancer therapy. In this study, we constructed an attenuated Tian Tan strain of Guang9 with a disrupted thymidine kinase gene to enhance tumor selectivity and an inserted firefly luciferase to monitor the viral distribution by in vivo bioluminescence imaging. Living animal imaging confirmed the high specificity of vaccinia Guang9 for tumor targeting after intratumoral and intraperitoneal administration. In addition, the vaccinia Guang9 strain produced higher in vivo luciferase activity and endured longer in immunocompromised nude mice than in immunocompetent C57BL/6 mice, all of which had been tumor-challenged. The luciferase activity and viral titers in excised tissues confirmed these conclusions. These data provide evidence for the safety and efficacy of the clinical application of vaccinia virus, which would be a promising approach for cancer therapy.

Extreme liver surgery as treatment of liver tumors involving the hepatocaval confluence

OBJECTIVE

Analyze the characteristics, surgical technique, morbidity and survival of patients treated with extreme liver surgery.

MATERIALS AND METHODS

We present a series of consecutive patients with malignant liver tumors in hepatocaval confluence treated in a single center with extreme liver surgery (April 2008-March 2015). Data were collected prospectively and analyzed with SPSS 21.0.

RESULTS

12 patients were included. 50 % were male and 50 % were female with a mean age of 59 ± 10 years old. The median of comorbidities was 7 according to the Charlson Age Comorbidity Index. The 75 % of the tumors were metastases, most of them from colorectal cancer. Most of the patients received neoadjuvant chemotherapy and in 58 % preoperative portal embolization was performed. Major hepatectomies were performed (66.7 % extended right hepatectomy, 33.3 % left extended hepatectomy). The 83.3 % of the patients needed vascular reconstruction. Postoperative morbidity was more than grade II in 50 % of the patients according to Dindo-Clavien classification. There was no intraoperative mortality. The postoperative mortality rate at 90 days was 33 % due to hepatic failure and biliary fistula. In December 2015, 33 % of the patients are still alive with a mean survival of 19 months (13-23) with an ECOG Performance Status of 0.

CONCLUSION

Extreme liver surgery carries a high rate of morbidity and mortality that seem to increase with age and with higher tumor volumes, according to the literature. It is a therapeutic option to consider in patients with low comorbidity suffering from malignant neoplasms that involve the hepatocaval confluence, when no other treatment with curative intention can be performed.

Complications following hepatectomy

As the number of liver resections in the United States has increased, operations are more commonly performed on older patients with multiple comorbidities. The advent of effective chemotherapy and techniques such as portal vein embolization, have compounded the number of increasingly complex resections taking up to 75% of healthy livers. Four potentially devastating complications of liver resection include postoperative hemorrhage, venous thromboembolism, bile leak, and post-hepatectomy liver failure. The risk factors and management of these complications are herein explored, stressing the importance of identifying preoperative factors that can decrease the risk for these potentially fatal complications.

Patient tailored resection planning in patients undergoing liver surgery for colorectal liver metastases; how and why should you do it?

BACKGROUND

A systematic preoperative evaluation to determine the individual resection strategy in patients with colorectal liver metastases (CRLM) was assessed as to its clinical value.

PATIENTS AND METHODS

From 2009 to 2011, 75 patients with CRLM who were scheduled for surgery were prospectively included and received an additional preoperative systematic evaluation in the presence of a hepatobiliary radiologist and the hepatobiliary surgeon scheduled to perform the surgery. The following items were assessed in a standardized manner: lesion detection and characterization, presence of extrahepatic disease, vascular anatomy, and resection strategy. Intraoperative findings and histopathological results were prospectively recorded.

RESULTS

Five out of 75 patients were not considered to be eligible for surgery due to additional findings, such as additional metastases or extrahepatic disease. Sensitivity and specificity for detection of individual CRLM were 80.9% (95% CI 75.7-86.1%) and 69.1% (95% CI 59.1-79.1%), respectively. Radical resections were performed in 87.1%. There was one futile laparotomy (1.4%).

CONCLUSION

In patients with colorectal liver metastases, standardized preoperative work-up, with subsequent planning of an individualized resection in a jointed meeting of a hepatobiliary radiologist and the surgeon who will perform the operation, leads to a high level of radical resections and a low number of futile laparotomies.

Optimal future liver remnant in patients treated with extensive preoperative chemotherapy for colorectal liver metastases

BACKGROUND

Patients with colorectal liver metastases (CLM) are increasingly treated with preoperative chemotherapy. Chemotherapy associated liver injury is associated with postoperative hepatic insufficiency (PHI) and mortality. The adequate minimum future liver remnant (FLR) volume in patients treated with extensive chemotherapy remains unknown.

METHODS

All patients with standardized FLR > 20 %, who underwent extended right hepatectomy for CLM from 1993-2011, were divided into three cohorts by chemotherapy duration: no chemotherapy (NC, n = 30), short duration (SD, ≤12 weeks, n = 78), long duration (LD, >12 weeks, n = 86). PHI and mortality were compared by using uni-/multivariate analyses. Optimal FLR for LD chemotherapy was determined using a minimum p-value approach.

RESULTS

A total of 194 patients met inclusion criteria. LD chemotherapy was significantly associated with PHI (NC + SD 3.7 vs. LD 16.3%, p = 0.006). Ninety-day mortality rates were 0 % in NC, 1.3 % in SD, and 2.3% in LD patients, respectively (p = 0.95). In patients with FLR > 30 %, PHI occurred in only two patients (both LD, 2/20, 10 %), but all patients with FLR > 30 % survived. The best cutoff of FLR for preventing PHI after chemotherapy >12 weeks was estimated as >30 %. Both LD chemotherapy (odds ratio [OR] 5.4, p = 0.004) and FLR ≤ 30 % (OR 6.3, p = 0.019) were independent predictors of PHI.

CONCLUSIONS

Preoperative chemotherapy >12 weeks increases the risk of PHI after extended right hepatectomy. In patients treated with long-duration chemotherapy, FLR > 30 % reduces the rate of PHI and may provide enough functional reserve for clinical rescue if PHI develops.

A Reappraisal of Chemotherapy-Induced Liver Injury in Colorectal Liver Metastases before the Era of Antiangiogenics

Background and Aims. Chemotherapy of colorectal liver metastases can induce hepatotoxicity in noncancerous liver. We describe these lesions and assess risk factors and impacts on postresection morbidity and mortality in naive patients to chemotherapy before the era of bevacizumab. Methods. Noncancerous liver tissue lesions were analysed according to tumour, chemotherapy, surgery, and patient characteristics. Results. Fifty patients aged 62 ± 9.3 years were included between 2003 and 2007. Thirty-three (66%) received chemotherapy, with Folfox (58%), Folfiri (21%), LV5FU2 (12%), or Xelox (9%) regimens. Hepatotoxicity consisted of 18 (36%) cases of severe sinusoidal dilatation (SD), 13 (26%) portal fibrosis, 7 (14%) perisinusoidal fibrosis (PSF), 6 (12%) nodular regenerative hyperplasia (NRH), 2 (4%) steatosis >30%, zero steatohepatitis, and 16 (32%) surgical hepatitis. PSF was more frequent after chemotherapy (21% versus 0%, P = 0.04), especially LV5FU2 (P = 0.02). SD was associated with oxaliplatin (54.5% versus 23.5%, P = 0.05) and low body mass index (P = 0.003). NRH was associated with oxaliplatin (P = 0.03) and extensive resection (P = 0.04). No impact on mortality and morbidity was observed, apart postoperative elevation of bilirubin levels in case of PSF (P = 0.03), longer hospitalization in case of surgical hepatitis (P = 0.03), and greater blood loss in case of portal fibrosis (P = 0.03). Conclusions. Chemotherapy of colorectal liver metastases induces sinusoidal dilatation related to oxaliplatin and perisinusoidal fibrosis related to 5FU, without any impact on postoperative mortality.

Simultaneous surgery for primary colorectal cancer and metastatic lesions?

Approximately 20-25% of patients with colorectal cancer present with liver metastases at the time of diagnosis. Traditionally, resection of the primary tumor has been advocated in order to prevent complications of the primary tumor colorectal cancer in patients with synchronous liver metastases. The published data concerning long-term prognosis in this group of patients are discordant. Although some of the reports show survival benefits from resection of the primary tumor, these studies are retrospective with small number of patients and using single drug chemotherapy. For patients with resectable liver metastases, new studies indicate that progression-free survival is best in patients receiving perioperative chemotherapy. In patients with synchronous nonresectable liver metastases and colorectal cancer, there is no published prospective randomized study comparing initial surgery of the primary tumor with neoadjuvant chemotherapy. However, recent publications show that in patients receiving chemotherapy based on oxaliplatin or irinotecan combined with targeted treatments, the complications associated with the primary tumor are less than 10%. The conclusion should be that today prophylactic surgery of asymptomatic primary colorectal cancer in patients with liver metastases cannot be recommended.

A novel genetically modified oncolytic vaccinia virus in experimental models is effective against a wide range of human cancers

BACKGROUND

Replication-competent oncolytic viruses have shown great promise as a potential cancer treatment. This study aimed to determine whether a novel vaccinia virus, GLV-1h151, with genetic modifications enhancing cancer specificity and enabling virus detection, is effective against a range of human cancers and is safe when administered in preclinical models.

METHODS

GLV-1h151 was modified with deletion of thymidine kinase enhancing specificity and insertion of the green fluorescent protein (GFP) gene. The virus was tested in several human cancer cell lines for cytotoxicity including breast, lung, pancreatic, and colorectal. Virus replication was assessed via visualization of GFP expression and bioluminescence, and viral plaque assays. Finally, GLV-1h151 was administered systemically or intratumorally in mice with pancreatic cancer xenografts (PANC-1) to assess virus biodistribution, toxicity, and effect on tumor growth.

RESULTS

GLV-1h151 effectively infected, replicated in, and killed several cancer cell types. Detection and visualization of virus replication was successful via fluorescence imaging of GFP expression, which was dose dependent. When administered intravenously or intratumorally in vivo, GLV-1h151 regressed tumor growth (P < 0.001) and displayed a good biosafety profile. GLV-1h151 infection and replication in tumors was successfully visualized via GFP and bioluminescence, with virus presence in tumors confirmed histologically.

CONCLUSIONS

GLV-1h151 is effective as an oncolytic agent against a wide range of cancers in cell culture and is effective against pancreatic human xenografts displaying a good biosafety profile and ability to be detected via optical imaging. GLV-1h151 thus adds another potential medium for the killing of cancer and detection of virus in infected tissue.

Treatment of Liver Metastases From Colorectal Cancer: Medico-Surgical Strategies

BACKGROUND

The management of hepatic metastases from colorectal cancer can be understood only as part of a multidisciplinary strategy. Progress experienced by medical treatment, surgical techniques and ways of imaging, has improved the prognosis of patients with liver metastases of colorectal cancers. This work displays the experience of Medical Oncology unit at the Military training hospital in Rabat.

METHODS

From January 2007 to December 2009, 60 patients with liver metastases from colorectal cancer, synchronous or metachronous were supported in the Medical Oncology unit at the Military training hospital in Rabat.

RESULTS

Liver metastases were synchronous in 41 (68%) patients and metachronous in 19 (32%). Patients were classified into 3 categories according to their resectability: 14 (22%) were resectable at the outset, 28 (47%) were unresectable and 18 (31%) were considered uncertain resectability. Thirty-five patients (58%) received neoadjuvant chemotherapy before surgical gesture, 25 (42%) received chemotherapy after resection of primary tumor. This chemotherapy enabled the resection of liver metastases in 5 patients initially deemed uncertain resectability. The average objective responses to chemotherapy were in the range of 59% with 4 complete responses and one confirmed histologically. Twenty-three patients (38%) underwent surgery including 15 liver resections with R0 (25%). The median progression-free survival in this series was 15.5 months. Some minor side effects were noted, which have not entered the prognosis of patients.

CONCLUSIONS

Hepatic resection remains the only potentially curative treatment of liver metastases of colorectal cancers. Perioperative chemotherapy is a promising standard, which has improved the prognosis of patients historically associated with a poor prognosis.