The management of colorectal liver metastases: Expanding the role of hepatic resection in the age of multimodal therapy

Impact of Infrared Indocyanine Green Fluorescence imaging-guided Laparoscopic Hepatectomy on Securing the Resection Margin for Colorectal Liver Metastasis

BACKGROUND

Laparoscopic hepatectomy for colorectal liver metastases (CRLM) is performed worldwide. However, owing to a lack of palpatory information and difficulties associated with accurate intraoperative ultrasonographic diagnosis, the tumor may be exposed at the hepatic transection margin. This study aimed to investigate the pathological significance of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG)-guided laparoscopic hepatectomy and determine its usefulness in securing the resection margin for CRLMs.

METHODS

Fifty-nine patients who underwent laparoscopic hepatectomy for CRLM using NIR fluorescence imaging between February 2017 and June 2021 at Sapporo Medical University Hospital were included. Generally, all patients received intravenous ICG (2.5 mg/body) as a fluorescence agent 1 to 2 days before surgery. During the surgical procedure, real-time NIR fluorescence imaging was repeatedly performed to assess the surgical margins.

RESULTS

Of the 94 tumors in 59 patients, laparoscopic NIR fluorescence imaging identified 56 tumors (59.6%) on the liver surface. Pathological analysis indicated clear margins in 96.6% (57/59) of patients. Examination of paraffin-embedded sections, which were successful in only 20 of 94 cases (21.3%), revealed that there were no tumor cells positive for NIR fluorescence, and the median distance of the continuous fluorescent signal from the tumor margin was 1.074 mm.

CONCLUSIONS

We demonstrated a high R0 rate using NIR fluorescence-guided hepatectomy. This technique has the potential to improve intraoperative tumor identification and tumor margin assurance and reduce the rate of positive resection margins in patients with CRLMs.

Efficacy and Safety of Maintenance Therapy Using Cetuximab in Patients with Metastatic Colorectal Cancer: Retrospective Study

Purpose

Cetuximab (CET) combined with chemotherapy significantly improved the survival in RAS and RAF wild-type metastatic colorectal cancer (mCRC) patients, while clinical evidence was lacking on the use of maintenance therapy (MT). The study aimed to explore the role of maintenance therapy following Cetuximab + chemotherapy and the optimal Cetuximab-based maintenance therapy regimen.

Patients and Methods

We retrospectively reviewed data on the efficacy and safety of CET-based MT in patients with mCRC who achieved disease control after induction therapy.

Results

Eighty-one patients with mCRC who achieved disease control after CET + chemotherapy induction were enrolled. Overall median progression-free survival (PFS) was 10.5 (95% CI = 8.8-12.2) months and median maintenance/observation PFS (mnPFS) was 6.0 (95% CI = 5.0-7.0) months. Among these 81 patients, 61 patients were prescribed MT (CET alone for 21 patients and CET + chemotherapy for 40 patients). Median PFS and mnPFS in the MT group were significantly longer than those for the non-MT group. Different MT regimens did not affect PFS and mnPFS significantly. Univariate and multivariate analysis demonstrated MT, complete response/partial response during induction therapy, and absence of peritoneal metastasis to be positively associated with longer PFS and mnPFS. Treatment-related adverse events (AEs) were tolerable during MT, and AE-related deaths were not observed.

Conclusion

MT with CET or CET + chemotherapy was an appropriate option following initial induction chemotherapy for patients with RAS and RAF wild-type mCRC. This strategy endowed survival benefits and a tolerable safety profile.

Reprogramming immunosuppressive myeloid cells facilitates immunotherapy for colorectal cancer

Immune checkpoint blockade (ICB) has a limited effect on colorectal cancer, underlining the requirement of co-targeting the complementary mechanisms. Here, we identified prostaglandin E2 (PGE2 ) receptor 4 (EP4) as the master regulator of immunosuppressive myeloid cells (IMCs), which are the major driver of resistance to ICB therapy. PGE2 -bound EP4 promotes the differentiation of immunosuppressive M2 macrophages and myeloid-derived suppressor cells (MDSCs) and reduces the expansion of immunostimulated M1 macrophages. To explore the immunotherapeutic role of EP4 signaling, we developed a novel and selective EP4 antagonist TP-16. TP-16 effectively blocked the function of IMCs and enhanced cytotoxic T-cell-mediated tumor elimination in vivo. Cell co-culture experiments revealed that TP-16 promoted T-cell proliferation, which was impaired by tumor-derived CD11b+ myeloid cells. Notably, TP-16 and anti-PD-1 combination therapy significantly impeded tumor progression and prolonged mice survival. We further demonstrated that TP-16 increased responsiveness to anti-PD-1 therapy in an IMC-related spontaneous colorectal cancer mouse model. In summary, this study demonstrates that inhibition of EP4-expressing IMCs may offer a potential strategy for enhancing the efficacy of immunotherapy for colorectal cancer.

PRL-3 Promotes Ubiquitination and Degradation of AURKA and Colorectal Cancer Progression via Dephosphorylation of FZR1

The oncogenic phosphatase PRL-3 is highly expressed in metastatic colorectal cancer but not in nonmetastatic colorectal cancer or noncolorectal cancer metastatic cancers. Although the proinvasive capacity of PRL-3 has been validated in multiple types of cancer, its impact on colorectal cancer progression and the underlying mechanisms remain poorly understood. Here, we report that overexpressed PRL-3 stimulates G₂-M arrest, chromosomal instability (CIN), self-renewal, and growth of colorectal cancer cells in xenograft models, while colorectal cancer cell proliferation is decreased. PRL-3-induced G₂-M arrest was associated with decreased expression of Aurora kinase A (AURKA). PRL-3-promoted slow proliferation, CIN, self-renewal, and growth in xenografts were counteracted by ectopic expression of AURKA. Conversely, knockdown of PRL-3 resulted in low proliferation, S-phase arrest, impaired self-renewal, increased apoptosis, and diminished xenograft growth independently of AURKA. Analysis of colorectal cancer specimens showed that expression of PRL-3 was associated with high status of CIN and poor prognosis, which were antagonized by expression of AURKA. PRL-3 enhanced AURKA ubiquitination and degradation in a phosphatase-dependent fashion. PRL-3 interacted with AURKA and FZR1, a regulatory component of the APC/C^FZR1 complex. Destabilization of AURKA by PRL-3 required PRL-3-mediated dephosphorylation of FZR1 and assembly of the APC/C^FZR1 complex. Our study suggests that PRL-3-regulated colorectal cancer progression is collectively determined by distinct malignant phenotypes and further reveals PRL-3 as an essential regulator of APC/C^FZR1 in controlling the stability of AURKA. SIGNIFICANCE: Dephosphorylation of FZR1 by PRL-3 facilitates the activity of APC/C^FZR1 by destabilizing AURKA, thus influencing aggressive characteristics and overall progression of colorectal cancer.

Knockdown on aPKC-ι inhibits epithelial-mesenchymal transition, migration and invasion of colorectal cancer cells through Rac1-JNK pathway

BACKGROUND

Atypical protein kinase C-ι (aPKC-ι) is an oncogenic factor, and required for the epithelial-mesenchymal transition (EMT) of different types of cancer. Our study aimed to investigate the role of aPKC-ι in the EMT, migration and invasion of colorectal cancer (CRC) cells.

METHODS

Expression of aPKC-ι was evaluated in CRC cell lines treated with TGF-β1 using qPCR and western blot. After aPKC-ι was knocked down using shRNA, migration and invasion abilities of CRC cell lines were evaluated by wound healing assay and transwell assay, respectively. Activation status of downstream signaling factors of aPKC-ι, including Rac1, JNK, STAT3 and β-catenin, was measured using western blot. Furthermore, auranofin, an aPKC-ι inhibitor, was used to treat CRC cell lines to investigate its possible inhibition on the EMT of CRC cell lines, as well as on the expression of aPKC-ι and its downstream signaling factors.

RESULTS

TGF-β1 induced the expression of aPKC-ι in CRC cells, and knockdown on aPKC-ι inhibited the TGF-β1-induced EMT, migration and invasion of CRC cells. Interestingly, Rac1 GTPase level was decreased when aPKC-ι was knocked down, and overexpression of Rac1G12V rescued the cell EMT, migration and invasion in CRC cells as inhibited by sh-aPKC-ι. Moreover, knockdown on aPKC-ι suppressed the phosphorylation of JNK and STAT3, and nuclear translocation of β-catenin. The aPKC- ι inhibitor, Auranofin, showed similar inhibitory effects as aPKC-ι knockdown.

CONCLUSION

Knockdown on aPKC-ι inhibited the EMT, migration and invasion of CRC cells through suppressing of Rac1-JNK pathway. Those findings indicate that aPKC-ι may serve as a novel therapeutic target for CRC.

Liver Resection or Resection plus Intraoperative Echo-Guided Ablation in the Treatment of Colorectal Metastases: We are Evaluating Their Effect for Cure

This study determines the oncologic outcome of the combined resection and ablation strategy for colorectal liver metastases. Between January 1994 and December 2015, 373 patients underwent surgery for colorectal liver metastases. There were 284 patients who underwent hepatic resection only (Group 1) and 83 hepatic resection plus ablation (Group 2). Group 2 patients had a higher incidence of multiple metastases (100% in Group 2 vs 28.2% in Group 1; P < 0.001) and bilobar involvement (76.5% in Group 2 vs 12.9% in Group 1; P < 0.001) than Group 1 cases. Perioperative mortality was nil in either group, with a higher postoperative complication rate among Group 1 versus Group 2 cases (18 vs 0, respectively). The median follow-up was 90 months (range, 1–180), with a five-year overall survival for Group 1 and Group 2 of 51 per cent and 80 per cent, respectively (P = 0.193). Mean disease-free survival for patients with R0 resection was 55 per cent, 40 per cent, and 37 per cent at one, two, and three years, respectively, and remained steadily higher (at 50%) in those patients treated with resection combined with ablation up to five years (P = 0.069). The only intraoperative ablation failure was for a large lesion (≥5 cm). Our data support the use of intraoperative ablation when complete hepatic resection cannot be achieved.

Laparoscopic Parenchyma-sparing Liver Resection for Colorectal Metastases

Background

Laparoscopic liver resection (LLR) of colorectal liver metastases (CLM) is increasingly performed in specialized centers. While there is a trend towards a parenchyma-sparing strategy in multimodal treatment for CLM, its role is yet unclear. In this study we present short- and long-term outcomes of laparoscopic parenchyma-sparing liver resection (LPSLR) at a single center.

Patients and methods

LLR were performed in 951 procedures between August 1998 and March 2017 at Oslo University Hospital, Oslo, Norway. Patients who primarily underwent LPSLR for CLM were included in the study. LPSLR was defined as non-anatomic hence the patients who underwent hemihepatectomy and sectionectomy were excluded. Perioperative and oncologic outcomes were analyzed. The Accordion classification was used to grade postoperative complications. The median follow-up was 40 months.

Results

296 patients underwent primary LPSLR for CLM. A single specimen was resected in 204 cases, multiple resections were performed in 92 cases. 5 laparoscopic operations were converted to open. The median operative time was 134 minutes, blood loss was 200 ml and hospital stay was 3 days. There was no 90-day mortality in this study. The postoperative complication rate was 14.5%. 189 patients developed disease recurrence. Recurrence in the liver occurred in 146 patients (49%), of whom 85 patients underwent repeated surgical treatment (liver resection [n = 69], ablation [n = 14] and liver transplantation [n = 2]). Five-year overall survival was 48%, median overall survival was 56 months.

Conclusions

LPSLR of CLM can be performed safely with the good surgical and oncological results. The technique facilitates repeated surgical treatment, which may improve survival for patients with CLM.

Early tumour response as a survival predictor in previously- treated patients receiving triplet hepatic artery infusion and intravenous cetuximab for unresectable liver metastases from wild-type KRAS colorectal cancer

BACKGROUND

Early tumour shrinkage has been associated with improved survival in patients receiving cetuximab-based systemic chemotherapy for liver metastases from colorectal cancer (LM-CRC). We tested this hypothesis for previously treated LM-CRC patients receiving cetuximab (500 mg/m²) and triplet hepatic artery infusion (HAI) within European trial OPTILIV.

METHODS

Irinotecan (180 mg/m²), 5-fluorouracil (2800 mg/m²) and oxaliplatin (85 mg/m²) were given as chronomodulated or conventional delivery. Patients were retrospectively categorised as early responders (complete or partial RECIST response after three courses) or non-early responders (late or no response). Prognostic factors were determined using multivariate logistic or Cox regression models.

RESULTS

Response was assessed in 57 of 64 registered patients (89%), who had previously received one to three prior systemic chemotherapy protocols. An early response occurred at 6 weeks in 16 patients (28%; 9 men, 7 women), aged 33-76 years, with a median of 12 liver metastases (LMs) (2-50), involving five segments (1-8). Ten patients had a late response, and 31 patients had no response. Grade 3-4 fatigue selectively occurred in the non-early responders (0% versus 26%; p = 0.024). Early tumour response was jointly predicted by chronomodulation-odds ratio (OR): 6.0 (1.2-29.8; p = 0.029)-and LM diameter ≤57 mm-OR: 5.3 (1.1-25.0; p = 0.033). Early tumour response predicted for both R0-R1 liver resection-OR: 11.8 (1.4-100.2; p = 0.024) and overall survival-hazard ratio: 0.39 (0.17-0.88; p = 0.023) in multivariate analyses.

CONCLUSIONS

Early tumour response on triplet HAI and systemic cetuximab predicted for complete macroscopic liver resection and prolonged survival for LM-CRC patients within a multicenter conversion-to-resection medicosurgical strategy. Confirmation is warranted for early response on HAI to guide decision making. Protocol numbers: EUDRACT 2007-004632-24 NCT00852228.

Multisciplinary management of patients with liver metastasis from colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related death. Surgery, radiotherapy and chemotherapy have been till now the main therapeutic strategies for disease control and improvement of the overall survival. Twenty-five per cent (25%) of CRC patients have clinically detectable liver metastases at the initial diagnosis and approximately 50% develop liver metastases during their disease course. Twenty-thirty per cent (20%-30%) are CRC patients with metastases confined to the liver. Some years ago various studies showed a curative potential for liver metastases resection. For this reason some authors proposed the conversion of unresectable liver metastases to resectable to achieve cure. Since those results were published, a lot of regimens have been studied for resectability potential. Better results could be obtained by the combination of chemotherapy with targeted drugs, such as anti-VEGF and anti-EGFR monoclonal antibodies. However an accurate selection for patients to treat with these regimens and to operate for liver metastases is mandatory to reduce the risk of complications. A multidisciplinary team approach represents the best way for a proper patient management. The team needs to include surgeons, oncologists, diagnostic and interventional radiologists with expertise in hepatobiliary disease, molecular pathologists, and clinical nurse specialists. This review summarizes the most important findings on surgery and systemic treatment of CRC-related liver metastases.

Can KRAS and BRAF mutations limit the benefit of liver resection in metastatic colorectal cancer patients? A systematic review and meta-analysis

BACKGROUND

Clinical trials investigated the potential role of both KRAS and BRAF mutations, as prognostic biomarkers, in colorectal cancer (CRC) patients who underwent surgical treatment of CRC-related liver metastases (CLM), showing conflicting results. This meta-analysis aims to review all the studies reporting survival outcomes (recurrence free survival (RFS), and/or overall survival (OS)) of patients undergoing resection of CLM, stratified according to KRAS and/or BRAF mutation status.

MATERIALS AND METHODS

Data from all published studies reporting survival outcomes (RFS and/or OS) of CRC patients who received resection of CLM, stratified by KRAS and/or BRAF mutation status were collected, according to the PRISMA guidelines. Pooled HRs were calculated for both the OS and/or RFS.

RESULTS

Seven eligible trials (1403 patients) were included. Pooled analysis showed that KRAS mutations predicted a significantly worse both RFS (HR: 1.65; 95% CI: 1.23-2.21) and OS (HR: 1.86; 95% CI: 1.51-2.30) in patients who underwent surgical resection of CLM. BRAF mutations were also associated with a significantly worse OS (HR: 3.90; 95% CI: 1.96-7.73) in this subgroup of patients.

CONCLUSIONS

This meta-analysis suggests both KRAS and BRAF mutations as poor, prognostic biomarkers, associated with worse survival outcomes, in patients undergoing hepatic resection of CLM.

Impact of early tumour shrinkage and resection on outcomes in patients with wild-type RAS metastatic colorectal cancer

BACKGROUND

Tumour shrinkage (TS) increases the possibility of resection in metastatic colorectal cancer (mCRC) and may improve tumour-related symptoms. Here we report prespecified secondary response-related end-points and exploratory TS/resection outcomes for patients with RAS wild-type (WT) tumours (no mutations in KRAS/NRAS exons 2/3/4) from the PRIME study (NCT00364013).

METHODS

PRIME was a randomised phase 3 study comparing first-line panitumumab+FOLFOX4 versus FOLFOX4 in mCRC patients. Tumour response analyses were conducted to compare response rates and their impact on survival outcomes.

RESULTS

Overall, 505 patients had RAS WT mCRC. More patients receiving panitumumab+FOLFOX4 versus FOLFOX4 had ⩾30% (59% versus 38%; P<0.001) or ⩾20% (72% versus 57%; P<0.001) TS at week 8 (early TS); consistent TS benefits were observed over the first ∼40weeks of treatment. Objective response rate (P=0.003), duration of response (P=0.0027), depth of response (P=0.0149), progression-free survival (PFS; P=0.0015) and overall survival (OS; P=0.0057) were improved in the panitumumab+FOLFOX4 group. Both early TS and resection were associated with improved PFS and OS. 2-year OS rates for patients who did (n=64) versus did not (n=441) undergo resection were 88% versus 40%; 2-year OS rates for patients who did (n=45) versus did not (n=460) undergo complete resection were 96% versus 41%.

CONCLUSIONS

More patients receiving panitumumab+FOLFOX4 versus FOLFOX4 had ⩾30% or ⩾20% TS at week 8; PFS and OS were also improved with panitumumab+FOLFOX4. The clinical value of achieving early TS in mCRC warrants further investigation.

Panitumumab in Metastatic Colorectal Cancer: The Importance of Tumour RAS Status

Tumour biomarker status is being used more and more frequently to guide treatment decisions in patients with metastatic colorectal cancer (mCRC). Continued cycles of hypothesis generation and biomarker testing in retrospective, prospective-retrospective and prospective analyses from studies of the epidermal growth factor (EGFR)-targeted monoclonal antibodies (mAbs), panitumumab and cetuximab, have resulted in improved patient selection in mCRC. Initial data suggested EGFR-targeted mAb treatment should be limited to patients with KRAS exon 2 wild-type (WT) tumours, but the availability of tumour samples from large phase III studies permitted evaluation of additional potential biomarkers of activity for these agents. Subsequent analyses further refined the target population to those patients whose tumours were WT for KRAS and NRAS exons 2, 3 and 4 (i.e., those with RAS WT status). Here, we review key clinical data for panitumumab in mCRC across the lines of treatment, assessing in detail the impact of more comprehensive RAS selection on patient outcomes. Panitumumab data across first- to third-line therapy consistently demonstrate that by testing tumour RAS status, it is possible to select patients more likely to benefit from treatment.

Risk factors for complications after laparoscopic major hepatectomy

BACKGROUND

Although laparoscopic major hepatectomy (MH) is becoming increasingly common in several specialized centres, data regarding outcomes are limited. The aim of this study was to identify the risk factors for postoperative complications of purely laparoscopic MH at a single centre.

METHODS

All patients who underwent purely laparoscopic MH between January 1998 and March 2014 at the authors' institution were enrolled. Demographic, clinicopathological and perioperative factors were collected prospectively, and data were analysed retrospectively. The dependent variables studied were the occurrence of overall and major complications (Dindo-Clavien grade III or above).

RESULTS

A total of 183 patients were enrolled. The types of MH included left-sided hepatectomy in 40 patients (21·9 per cent), right-sided hepatectomy in 135 (73·8 per cent) and central hepatectomy in eight (4·4 per cent). Median duration of surgery was 255 (range 100-540) min, and median blood loss was 280 (10-4500) ml. Complications occurred in 100 patients (54·6 per cent), and the 90-day all-cause mortality rate was 2·7 per cent. Liver-specific and general complications occurred in 62 (33·9 per cent) and 38 (20·8 per cent) patients respectively. Multivariable analysis identified one independent risk factor for global postoperative complications: intraoperative simultaneous radiofrequency ablation (RFA) (odds ratio (OR) 6·93, 95 per cent c.i. 1·49 to 32·14; P = 0·013). There were two independent risk factors for major complications: intraoperative blood transfusion (OR 2·50, 1·01 to 6·23; P = 0·049) and bilobar resection (OR 2·47, 1·00 to 6·06; P = 0·049).

CONCLUSION

Purely laparoscopic MH is feasible and safe. Simultaneous RFA and bilobar resection should probably be avoided.

β-1,4-Galactosyltransferase III suppresses β1 integrin-mediated invasive phenotypes and negatively correlates with metastasis in colorectal cancer

Metastasis often occurs in colorectal cancer (CRC) patients and is the main difficulty in cancer treatment. The upregulation of poly-N-acetyllactosamine-related glycosylation is found in CRC patients and is associated with progression and metastasis in cancer. β-1,4-Galactosyltransferase III (B4GALT3) is an enzyme responsible for poly-N-acetyllactosamine synthesis, and therefore, we investigated its expression in CRC patients. We found that B4GALT3 negatively correlated with poorly differentiated histology (P < 0.001), advanced stages (P = 0.0052), regional lymph node metastasis (P = 0.0018) and distant metastasis (P = 0.0463) in CRC patients. B4GALT3 overexpression in CRC cells suppressed cell migration, invasion and adhesion, whereas B4GALT3 knockdown enhanced malignant cell phenotypes. The β1 integrin-blocking antibody reversed the B4GALT3-mediated increase in cell invasion. B4GALT3 expression altered glycosylation on the N-glycan of β1 integrin probably through changes in poly-N-acetyllactosamine expression. Furthermore, more activated β1 integrin along with the activation of its downstream signaling transduction were found in B4GALT3 knockdown cells, whereas overexpression of B4GALT3 suppressed the expression of active β1 integrin and inhibited its downstream signaling. Our results suggest that B4GALT3 is negatively associated with CRC metastasis and suppresses cell invasiveness through inhibiting activation of β1 integrin.

Evaluation of YO-PRO-1 as an early marker of apoptosis following radiofrequency ablation of colon cancer liver metastases

Radiofrequency (RF) ablation (RFA) is a minimally invasive treatment for colorectal-cancer liver metastases (CLM) in selected nonsurgical patients. Unlike surgical resection, RFA is not followed by routine pathological examination of the target tumor and the surrounding liver tissue. The aim of this study was the evaluation of apoptotic events after RFA. Specifically, we evaluated YO-PRO-1 (YP1), a green fluorescent DNA marker for cells with compromised plasma membrane, as a potential, early marker of cell death. YP1 was applied on liver tissue adherent on the RF electrode used for CLM ablation, as well as on biopsy samples from the center and the margin of the ablation zone as depicted by dynamic CT immediately after RFA. Normal pig and mouse liver tissues were used for comparison. The same samples were also immunostained for fragmented DNA (TUNEL assay) and for active mitochondria (anti-OxPhos antibody). YP1 was also used simultaneously with propidium iodine (PI) to stain mouse liver and samples from ablated CLM. Following RFA of human CLM, more than 90 % of cells were positive for YP1. In nonablated, dissected pig and mouse liver however, we found similar YP1 signals (93.1 % and 65 %, respectively). In samples of intact mouse liver parenchyma, there was a significantly smaller proportion of YP1 positive cells (22.7 %). YP1 and PI staining was similar for ablated CLM. However in dissected normal mouse liver there was initial YP1 positivity and complete absence of the PI signal and only later there was PI signal.

CONCLUSION

This is the first time that YP1 was applied in liver parenchymal tissue (rather than cell culture). The results suggest that YP1 is a very sensitive marker of early cellular events reflecting an early and widespread plasma membrane injury that allows YP1 penetration into the cells.

Laparoscopic Hepatectomy is a Safe and Effective Approach for Resecting Large Colorectal Liver Metastases

Hepatectomy is an accepted treatment modality for large (greater than 5 cm) colorectal liver metastases (CLM). Recently, laparoscopic hepatectomy has emerged as a viable option; however, its use for patients with large CLM is undefined. A retrospective analysis of a single institution's prospective database was performed for patients with large CLM resected between 1995 and 2010. Patients were stratified by operative approach. Patient characteristics, tumor burden, operative factors, hospital course, and long-term outcomes were compared using nonparametric, Fisher's exact, and Kaplan-Meier testing. Eighty-four patients were identified. Eight patients (9.5%) underwent laparoscopic resection. Age (59.5 vs 60 years), body mass index (26.8 vs 27.5 kg/m2), size of largest tumor (6.8 vs 7.5 cm), R0 resection (100 vs 89.5%), hepatic recurrence (25 vs 43.4%), and transfusion rate (14.3 vs 30.9%) of laparoscopic compared with open resection were similar. However, complication rate (12.5 vs 60.5%; P = 0.0192), blood loss (225 vs 400 mL; P = 0.0427), and length of stay (3.5 vs 7.0 days; P = 0.0005) were significantly higher in the open resection cohort. Median disease-free survival was 14.4 and 13.2 months for laparoscopic and open patients, respectively. Laparoscopic resection appears to be a safe approach for resecting large CLM. Tumor size does not preclude laparoscopic hepatectomy.

Targeted therapy in metastatic colorectal cancer -- an example of personalised medicine in action

In metastatic colorectal cancer (mCRC), an improved understanding of the underlying pathology and molecular biology has successfully merged with advances in diagnostic techniques and local/systemic therapies as well as improvements in the functioning of multidisciplinary teams, to enable tailored treatment regimens and optimized outcomes. Indeed, as a result of these advancements, median survival for patients with mCRC is now in the range of 20-24months, having approximately tripled in the last 20years. The identification of KRAS as a negative predictive marker for activity of epidermal growth factor receptor (EGFR)-targeted monoclonal antibodies (mAbs), such as panitumumab (Amgen, Thousand Oaks, USA) and cetuximab (ImClone, Branchburg, USA), has perhaps had the greatest impact on patient management. This meant that, for the first time, mCRC patients unlikely to respond to a targeted therapy could be defined ahead of treatment. Ongoing controversies such as whether patients with KRAS G13D- (or BRAF V600-) mutated tumours can still respond to EGFR-targeted mAbs and the potential impact of inter- and intra-tumour heterogeneity on tumour sampling show that the usefulness of KRAS as a biomarker has not yet been exhausted, and that other downstream biomarkers should be considered. Conversely, a predictive biomarker for anti-angiogenic agents such as bevacizumab (Genentech, San Francisco, USA) in the mCRC setting is still lacking. In this review we will discuss the discovery and ongoing investigation into predictive biomarkers for mCRC as well as how recent advances have impacted on clinical practice and ultimately the overall cost of treatment for these patients.

Cediranib plus FOLFOX/CAPOX versus placebo plus FOLFOX/CAPOX in patients with previously untreated metastatic colorectal cancer: a randomized, double-blind, phase III study (HORIZON II)

PURPOSE

Cediranib is a highly potent inhibitor of vascular endothelial growth factor (VEGF) signaling with activity against all three VEGF receptors. HORIZON II [Cediranib (AZD2171, RECENTIN) in Addition to Chemotherapy Versus Placebo Plus Chemotherapy in Patients With Untreated Metastatic Colorectal Cancer] assessed infusional fluorouracil, leucovorin, and oxaliplatin/capecitabine and oxaliplatin (FOLFOX/CAPOX) with or without cediranib in patients with previously untreated metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

Eligible patients were initially randomly assigned 1:1:1 to receive cediranib (20 or 30 mg per day) or placebo plus FOLFOX/CAPOX. In an early analysis of this and two other cediranib studies (HORIZON I [Cediranib Plus FOLFOX6 Versus Bevacizumab Plus FOLFOX6 in Patients With Previously Treated Metastatic Colorectal Cancer] and HORIZON III [Cediranib Plus FOLFOX6 Versus Bevacizumab Plus FOLFOX6 in Patients With Untreated Metastatic Colorectal Cancer]), the 20-mg dose met the predefined criteria for continuation. Subsequent patients were randomly assigned 2:1 to the cediranib 20 mg or placebo arms. Progression-free survival (PFS) and overall survival (OS) were coprimary end points.

RESULTS

In all, 860 patients received cediranib 20 mg (n = 502) or placebo (n = 358). The addition of cediranib to FOLFOX/CAPOX resulted in PFS prolongation (hazard ratio [HR], 0.84; 95% CI, 0.73 to 0.98; P = .0121; median PFS, 8.6 months for cediranib v 8.3 months for placebo) but had no impact on OS (HR, 0.94; 95% CI, 0.79 to 1.12; P = .5707; median OS, 19.7 months for cediranib v 18.9 months for placebo). There were no significant differences in the secondary end points of objective response rate, duration of response, or liver resection rate. Median chemotherapy dose-intensity was decreased by approximately 10% in patients treated with cediranib. Adverse events (AEs) associated with cediranib were manageable. CONCLUSION Addition of cediranib 20 mg to FOLFOX/CAPOX resulted in a modest PFS prolongation, but no significant difference in OS. The cediranib AE profile was consistent with those from previous studies. Because of the lack of improvement in OS, cediranib plus an oxaliplatin-based regimen cannot be recommended as a treatment for patients with mCRC.

Optimized mouse model for the imaging of tumor metastasis upon experimental therapy

Development of new cancer treatments focuses increasingly on the relation of cancer tissue with its microenvironment. A major obstacle for the development of new anti-cancer therapies has been the lack of relevant animal models that would reproduce all the events involved in disease progression from the early-stage primary tumor until the development of mature metastatic tissue. To this end, we have developed a readily imageable mouse model of colorectal cancer featuring highly reproducible formation of spontaneous liver metastases derived from intrasplenic primary tumors. We optimized several experimental variables, and found that the correct choice of cell line and the genetic background, as well as the age of the recipient mice, were critical for establishing a useful model system. Among a panel of colorectal cancer cell lines tested, the epithelial carcinoma HT29 line was found to be the most suitable in terms of producing homogeneous tumor growth and metastases. In our hands, SCID mice at the age of 125 days or older were the most suitable in supporting consistent HT29 tumor growth after splenic implantation followed by reproducible metastasis to the liver. A magnetic resonance imaging (MRI) protocol was optimized for use with this mouse model, and demonstrated to be a powerful method for analyzing the antitumor effects of an experimental therapy. Specifically, we used this system to with success to verify by MRI monitoring the efficacy of an intrasplenically administered oncolytic adenovirus therapy in reducing visceral tumor load and development of liver metastases. In summary, we have developed a highly optimized mouse model for liver metastasis of colorectal cancer, which allows detection of the tumor load at the whole body level and enables an accurate timing of therapeutic interventions to target different stages of cancer progression and metastatic development.

Improvements in population-based survival of patients presenting with metastatic rectal cancer in the south of the Netherlands, 1992-2008

We analysed population-based treatment and survival data of patients who presented with metastatic rectal cancer. All patients diagnosed with primary synchronous metastatic rectal cancer between 1992 and 2008 in the Eindhoven Cancer Registry area were included. Date of diagnosis was divided into three periods (1992–1999, 2000–2004, 2005–2008) according to the availability of chemotherapy type. We assessed treatment patterns and overall survival according to period of diagnosis. The proportion of patients diagnosed with stage IV disease increased from 16% in 1992–1999 to 20% in 2005–2008 (P < 0.0001). Chemotherapy use increased from 5% in 1992 to 61% in 2008 (P < 0.0001). Resection rates of the primary tumour decreased from 65% in 1992 to 27% in 2008 (P < 0.0001), while metastasectomy rates remained constant since 1999 (9%). Median survival increased from 38 weeks (95% confidence interval (CI) 32–44) in 1992–1999 to 53 weeks (95% CI 48–61) in 2005–2008. Among patients not receiving chemotherapy median survival remained approximately 30 weeks. Multivariable analysis confirmed the lower risk of death among patients diagnosed in more recent years. Increased use of chemotherapy went together with improved median survival among patients with metastatic rectal cancer in the last two decades. Stage migration as an effect of more effective imaging procedures is likely to be partly responsible for this improved survival.

A New TNM Classification for Breast Cancer to Meet the Demands of the Present and the Challenges of the Future

In this article we will describe our proposed changes to the breast cancer tumor node metastasis (TNM) classification which, while retaining TNM structure to ensure backwards compatibility, will render it more useful and better able to accommodate future developments. We propose changing T to specify exact tumor size (a tumor of pathological diameter 1.7 cm would be pT1.7); changing N to specify the number of metastatic lymph nodes over the total number removed (e.g., pN5/21); adding suffixes to M to indicate metastatic site; removing in situ neoplasms from the classification, since they are not carcinomas and are incapable of metastasizing; and removing the terms ‘infiltrating’ and ‘invasive’ since they are redundant. Finally, we would include hormone receptor, HER2, and other biological indicators of prognosis, as they are verified, in a placeholder system appended to the TNM. These proposals shift the emphasis from the quantity of tumor present to the quality of the cancer.

Laparoscopic resection of colorectal liver metastases: surgical and long-term oncologic outcome

OBJECTIVE

To analyze the immediate and long-term outcome after laparoscopic resection of colorectal liver metastases and difference between observed and predicted [Fong's and Basingstoke Predictive Index (BPI) scores] survivals.

BACKGROUND

: Laparoscopic liver resection has been reported safe and feasible and improves postoperative course. The oncologic outcomes after resection of colorectal metastases are poorly reported.

METHODS

Between August 1998 and January 2010, 122 patients underwent laparoscopic resection for colorectal liver metastases during 135 procedures at Rikshospitalet. Patients undergoing surgery between August 1998 and June 2009 were included in research analysis. The patients had median Fong's and BPI's scores of 2 (0-5) and 7 (0-23), respectively. Mainstream analysis of hospital data was done on intent-to-treat basis. Intraoperative incidents and postoperative complications were analyzed according to the Satava and Clavien-Dindo classifications. Median follow-up was 24 (0-100) months.

RESULTS

One hundred fifty-one liver resections were performed in 107 patients during 118 procedures: 117 nonanatomic and 34 anatomic liver resections. There were 5 conversions to laparotomy (4.2%). The resection margin was free of tumor tissue in 141 (93.4%) of 151 specimens, and the distance between the resection margin and tumor tissue was median 6 (0-40) mm. Intraoperative incidents occurred in 14 cases (11.9%), including 5 (4.2%), 8 (6.8%), and 1 (0.8%) cases of grades I, II, and III, respectively. Postoperative complications were observed in 16 cases (14.3%), including 2, 3, 7, 3, 0, and 1 cases of grades I, II, IIIa, IIIb, IV, and V, respectively. During follow-up, 21 patients received repeat liver resection of recurrences (11 by laparoscopy and 10 by laparotomy). The 5-year overall survival rates were 51% as laparoscopically completed cases and 47% as intent-to-treat. The observed actuarial survival values exceeded the values expected by Fong's and BPI's score, with 10.2% and 6.7% as laparoscopically completed cases and with 3.8% and 2.4% as intent-to-treat, respectively.

CONCLUSIONS

Laparoscopic resection is a favorable alternative to open liver resection for patients with colorectal liver metastases. The observed actuarial survival values after laparoscopic resection surpass the values expected by major scoring systems.

Gene expression profiling of primary and metastatic colon cancers identifies a reduced proliferative rate in metastatic tumors

The objective of this study was to gain insights into the biological basis of the metastatic process by characterizing the gene expression differences between primary and metastatic colon cancers. Recent studies have demonstrated that few new mutational changes are acquired during the metastatic progression of colon tumors [Jones et al., Proc Natl Acad Sci USA 105 (11): 4283-4288, 2008]. However, the extent to which epigenetic and transcriptional changes occur between primary and metastatic colon cancer remains unknown. We approached these issues using Affymetrix microarrays to assess the similarities and differences in gene expression profiles between macro-dissected primary and metastatic colon tumors. Unexpectedly, we found that expression of a number of cell proliferation markers were reduced in the liver metastases of colon tumors when compared to primary tumors. This finding was validated by immunohistochemical staining of Ki67 and Cyclin D1 in Formalin-Fixed Paraffin-Embedded (FFPE) section of the same samples, and in an independent cohort of FFPE matched tumor and metastatic tissue samples. These results indicate that significant transcriptional differences exist between primary and metastatic colon tumors, and demonstrate that metastatic lesions have a lower proliferative rate compared to primary tumors. These findings may have implications for interpreting differences in response rates between primary and metastatic lesions and suggest that measurement of expression-based biomarkers in metastatic tissue will be most informative for understanding the basis of response of metastatic tumors to therapeutic intervention.