One-millimeter cancer-free margin is curative for colorectal liver metastases: a propensity score case-match approach. Ann Surg. 2014;259:543-548. [PMID: 23732261 DOI: 10.1097/sla.0b013e3182902b6e]

Tumor Biology Rather Than Surgical Technique Dictates Prognosis in Colorectal Cancer Liver Metastases

INTRODUCTION

The interplay of tumor biology and surgical margin status after resection for colorectal liver metastasis (CRLM) remains controversial. Consequently, we sought to determine the impact of surgical margin status on overall survival (OS) stratified by KRAS mutational status.

MATERIALS AND METHODS

Four hundred eighty-five patients with known KRAS mutational status were identified. Clinicopathologic and long-term survival data were collected and assessed.

RESULTS

On pathology, most patients (n = 380; 78.3 %) had an R0 margin, while 105 (21.7 %) had an R1. Roughly two thirds of tumors were KRAS wild type (wtKRAS) (n = 307, 63.3 %), while 36.7 % (n = 178) had KRAS mutations (mutKRAS). Median and 5-year OS of the entire cohort was 65.8 months and 53.8 %, respectively. An R1 resection was associated with worse 5-year OS compared with R0 (42.4 % vs. 57.1 %; hazard ratio (HR) 1.82, 95 % CI 1.28-2.57; P = 0.001). After controlling for KRAS status, the survival benefit associated with an R0 resection persisted only among patients with wtKRAS tumors (HR 2.16, 95 % CI 1.42-3.30; P < 0.001). In contrast, surgical margin had no impact on OS among patients with mutKRAS tumors (5-year OS R0, 40.7 % vs. R1, 46.7 %; HR 1.34, 95 % CI 0.73-2.48; P = 0.348).

CONCLUSION

The impact of margin status differed by KRAS mutation status. An R0 margin only provided a survival benefit to patients with wtKRAS tumors. Tumor biology and not surgical technique determined prognosis.

FIRST BRAZILIAN CONSENSUS ON MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 1: PRE-TREATMENT EVALUATION

Background

: Liver metastases of colorectal cancer are frequent and potentially fatal event in the evolution of patients with these tumors.

Aim

: In this module, was contextualized the clinical situations and parameterized epidemiological data and results of the various treatment modalities established.

Method:

Was realized deep discussion on detecting and staging metastatic colorectal cancer, as well as employment of imaging methods in the evaluation of response to instituted systemic therapy.

Results

: The next step was based on the definition of which patients would have their metastases considered resectable and how to expand the amount of patients elegible for modalities with curative intent.

Conclusion

: Were presented clinical, pathological and molecular prognostic factors, validated to be taken into account in clinical practice.

Parenchymal-sparing hepatectomies (PSH) for bilobar colorectal liver metastases are associated with a lower morbidity and similar oncological results: a propensity score matching analysis

OBJECTIVE

The aim of this study is to evaluate whether a parenchymal-sparing strategy provides similar results in terms of morbidity, mortality, and oncological outcome of non-PSH hepatectomies in a propensity score matched population (PSMP) in case of multiple (>3) bilobar colorectal liver metastases (CLM).

BACKGROUND

The surgical treatment of bilobar liver metastasis is challenging due to the necessity to achieve complete resection margins and a sufficient future remnant liver. Two approaches are adaptable as follows: parenchymal-sparing hepatectomies (PSH) and extended hepatectomies (NON-PSH).

METHODS

A total of 3036 hepatectomies were analyzed from a multicentric retrospective cohort of hepatectomies. Patients were matched in a 1:1 propensity score analysis in order to compare PSH versus NON-PSH resections.

RESULTS

PSH was associated with a lower number of complications (≥1) (25% vs. 34%, p = 0.04) and a lower grade of Dindo-Clavien III and IV (10 vs. 16%, p = 0.03). Liver failure was less present in PSH (2 vs. 7%, p = 0.006), with a shorter ICU stay (0 day vs. 1 day, p = 0.004). No differences were demonstrated in overall and disease-free survival.

CONCLUSION

In conclusion, PSH resection for bilobar multiple CLMs represents a valid alternative to NON-PSH resection in selected patients with a reduced morbidity and comparable oncological results.

Validation of clinical risk scores for laparoscopic liver resections of colorectal liver metastases: A 10-year observed follow-up study

OBJECTIVE

The aim of this study was to validate clinical risk scores in patients underwent laparoscopic resection of colorectal liver metastases (CLM) with 5 years follow-up or more, and assess 5- and 10-year actual survival in this group.

METHODS

A total of 516 laparoscopic liver resections were performed in 406 patients with CLM between February 1998 and September 2015. A follow-up of 5 and 10 years could be assessed in 144 and 29 patients, respectively. The Fong score, pre- and postoperative Basingstoke Predictive Index (BPI), Nordlinger score, and Iwatsuki score were validated.

RESULTS

Five- and ten-year cancer-related actual survival was 54% and 32%, respectively. The Fong score, pre- and postoperative BPI and the Nordlinger score divided patients into risk groups with significant difference in survival between the groups. However, predicted 5-year survival rates were lower than the actual 5-year survival (mean difference in 17%,13%, 20%, and 30%, respectively).

CONCLUSION

The Fong score, pre- and postoperative BPI and the Nordlinger score systems can be used to predict survival for laparoscopically operated patients in the era of multimodal-treatment after adjusting of survival rates. The actual five- and 10-year survival after laparoscopic resection of CLM is similar to results previously published for open liver resection. J. Surg. Oncol. 2016;114:757-763. © 2016 Wiley Periodicals, Inc.

Two-dimensional assessment of submillimeter cancer-free margin area in colorectal liver metastases

The aim of the study is to evaluate the prognostic impact of the extent of submillimeter or zero surgical margin (SubMM) area among the patients who underwent liver resection for colorectal liver metastases (CRLM).The influence of suboptimal margin width of <1 mm on long-term outcome is unclear.A total of 423 liver resections for CRLM were performed at Japanese Red Cross Medical Center between 2007 and 2015. Among them, we identified 235 patients who underwent curative initial liver resection and classified them into 2 groups: R0 (margin: ≥1 mm) and R1 (SubMM). The R1 group was further divided into 2 groups by the extent of SubMM area: small SubMM area (≤4 cm) and broad SubMM area (>4 cm).The median tumor number was 4 (range 1-97), 23% had solitary and 37% had 8 or more number of metastases. With a median follow-up period of 30 months, the overall 1-, 3-, 5-year survival for R0 (n = 72) versus R1 (n = 163) groups were 98.4% vs 87.5%, 75.5% versus 57.1%, and 50.1% versus 36.6%, respectively (P = 0.004). After propensity score analysis allowing for matching the tumor number (<8 vs 8 or more), tumor size, and serum carcinoembryonic antigen level, the DFS and OS were significantly higher in the small SubMM area group (P = 0.024, P = 0.049), respectively.Although wide margins >1 mm should be attempted whenever possible, reducing the extent of SubMM area (≤4 cm) can contribute to better long-term outcome when wide margin is not practicable.

Parenchymal-sparing liver surgery in patients with colorectal carcinoma liver metastases

Liver resection is the treatment of choice for patients with colorectal liver metastases (CLM). However, major resections are often required to achieve R0 resection, which are associated with substantial rates of morbidity and mortality. Maximizing the amount of residual liver gained increasing significance in modern liver surgery due to the high incidence of chemotherapy-associated parenchymal injury. This fact, along with the progressive expansion of resectability criteria, has led to the development of a surgical philosophy known as "parenchymal-sparing liver surgery" (PSLS). This philosophy includes a variety of resection strategies, either performed alone or in combination with ablative therapies. A profound knowledge of liver anatomy and expert intraoperative ultrasound skills are required to perform PSLS appropriately and safely. There is a clear trend toward PSLS in hepatobiliary centers worldwide as current evidence indicates that tumor biology is the most important predictor of intrahepatic recurrence and survival, rather than the extent of a negative resection margin. Tumor removal avoiding the unnecessary sacrifice of functional parenchyma has been associated with less surgical stress, fewer postoperative complications, uncompromised cancer-related outcomes and higher feasibility of future resections. The increasing evidence supporting PSLS prompts its consideration as the gold-standard surgical approach for CLM.

Parenchymal-sparing Hepatectomy in Colorectal Liver Metastasis Improves Salvageability and Survival

OBJECTIVE

To investigate prognostic impact of parenchymal-sparing hepatectomy (PSH) for solitary small colorectal liver metastasis (CLM).

BACKGROUND

It is unclear whether PSH confers an oncologic benefit through increased salvageability or is a detriment through increasing recurrence rate.

METHODS

Database of 300 CLM patients with a solitary tumor (≤ 30 mm in size) was reviewed from 1993 to 2013. A total of 156 patients underwent PSH and 144 patients underwent right hepatectomy, left hepatectomy, or left lateral sectionectomy (non-PSH group).

RESULTS

The rate of PSH increased over the study period (P < 0.01). PSH did not impact negatively on overall (OS), recurrence-free, and liver-only recurrence-free survival, compared with non-PSH (P = 0.53, P = 0.97, and P = 0.69, respectively). Liver-only recurrence was observed in 22 patients (14%) in the PSH and 25 (17%) in the non-PSH group (P = 0.44). Repeat hepatectomy was more frequently performed in the PSH group (68% vs 24%, P < 0.01). Subanalysis of patients with liver-only recurrence revealed better 5-year overall survival from initial hepatectomy and from liver recurrence in the PSH than in the non-PSH group [72.4% vs 47.2% (P = 0.047) and 73.6% vs 30.1% (P = 0.018), respectively]. Multivariate analysis revealed that non-PSH was a risk of noncandidacy for repeat hepatectomy (hazard ratio: 8.18, confidence interval: 1.89-45.7, P < 0.01).

CONCLUSIONS

PSH did not increase recurrence in the liver remnant but more importantly improved 5-year survival in case of recurrence (salvageability). PSH should be the standard approach to CLM to allow for salvage surgery in case of liver recurrence.

RAS Mutation Predicts Positive Resection Margins and Narrower Resection Margins in Patients Undergoing Resection of Colorectal Liver Metastases

BACKGROUND

In patients undergoing resection of colorectal liver metastases (CLM), resection margin status is a significant predictor of survival, particularly in patients with suboptimal response to preoperative therapy. RAS mutations have been linked to more invasive and migratory tumor biology and poor response to modern chemotherapy.

OBJECTIVE

The aim of this study was to evaluate the relationship between RAS mutation and resection margin status in patients undergoing resection of CLM.

METHODS

Patients who underwent curative resection of CLM from 2005 to 2013 with known RAS mutation status were identified from a prospectively maintained database. A positive margin was defined as tumor cells <1 mm from the parenchymal transection line.

RESULTS

The study included 633 patients, of whom 229 (36.2 %) had mutant RAS. The positive margin rate was 11.4 % (26/229) for mutant RAS and 5.4 % (22/404) for wild-type RAS (p = 0.007). In multivariate analysis, the only factors associated with a positive margin were RAS mutation (hazard ratio [HR] 2.439; p = 0.005) and carcinoembryonic antigen level 4.5 ng/mL or greater (HR 2.060; p = 0.026). Among patients presenting with liver-first recurrence during follow-up, those with mutant RAS had narrower margins at initial CLM resection (median 4 mm vs. 7 mm; p = 0.031). A positive margin (HR 3.360; p < 0.001) and RAS mutation (HR 1.629; p = 0.044) were independently associated with worse overall survival.

CONCLUSION

RAS mutations are associated with positive margins in patients undergoing resection of CLM. Tumors with RAS mutation should prompt careful efforts to achieve negative resection margins.

Minimally Invasive Liver Surgery for Hepatic Colorectal Metastases

Minimally invasive surgery has been cautiously introduced in surgical oncology over the last two decades due to a concern of compromised oncological outcomes. Recently, it has been adopted in liver surgery for colorectal metastases. Colorectal cancer is a major cause of cancer-related death in the USA. In addition, liver metastasis is the most common site of distant disease and its resection improves survival. While open resection was the standard of care, laparoscopic liver surgery has become the standard of care for minor liver resections. Laparoscopic liver surgery provides equivalent oncological outcomes with better perioperative results compared to open liver surgery. Robotic liver surgery has been introduced as it is believed to overcome some of the limitations of laparoscopy. Finally, laparoscopic radio-frequency ablation and microwave coagulation can be used as adjuncts in minimally invasive surgery to complement or replace surgical resection when not possible.

Surgical Management of Liver Metastases From Colorectal Cancer

Surgical resection remains one of the major curative treatment options available to patients with colorectal liver metastases. Surgery and chemotherapy form the backbone of the treatment in patients with colorectal liver metastases. With more effective chemotherapy regimens being available, the optimal timing and sequencing of treatments are important. A multidisciplinary approach with the involvement of medical oncologists and surgical oncologists from the beginning is crucial. Identification of the clinical and molecular prognostic factors may help personalize the treatment approaches for these patients. This article provides an overview of the surgical management of colorectal liver metastases.

Managing synchronous liver metastases from colorectal cancer: a multidisciplinary international consensus

An international panel of multidisciplinary experts convened to develop recommendations for managing patients with colorectal cancer (CRC) and synchronous liver metastases (CRCLM). A modified Delphi method was used. CRCLM is defined as liver metastases detected at or before diagnosis of the primary CRC. Early and late metachronous metastases are defined as those detected ⩽12months and >12months after surgery, respectively. To provide information on potential curability, use of high-quality contrast-enhanced computed tomography (CT) before chemotherapy is recommended. Magnetic resonance imaging is increasingly being used preoperatively to aid detection of subcentimetric metastases, and alongside CT in difficult situations. To evaluate operability, radiology should provide information on: nodule size and number, segmental localization and relationship with major vessels, response after neoadjuvant chemotherapy, non-tumoral liver condition and anticipated remnant liver volume. Pathological evaluation should assess response to preoperative chemotherapy for both the primary tumour and metastases, and provide information on the tumour, margin size and micrometastases. Although the treatment strategy depends on the clinical scenario, the consensus was for chemotherapy before surgery in most cases. When the primary CRC is asymptomatic, liver surgery may be performed first (reverse approach). When CRCLM are unresectable, the goal of preoperative chemotherapy is to downsize tumours to allow resection. Hepatic resection should not be denied to patients with stable disease after optimal chemotherapy, provided an adequate liver remnant with inflow and outflow preservation remains. All patients with synchronous CRCLM should be evaluated by a hepatobiliary multidisciplinary team.

Resection margin and survival in 2368 patients undergoing hepatic resection for metastatic colorectal cancer: surgical technique or biologic surrogate?

OBJECTIVES

The impact of margin width on overall survival (OS) in the context of other prognostic factors after resection for colorectal liver metastases is unclear. We evaluated the relationship between resection margin and OS utilizing high-resolution histologic distance measurements.

METHODS

A single-institution prospectively maintained database was queried for all patients who underwent an initial complete resection of colorectal liver metastases between 1992 and 2012. R1 resection was defined as tumor cells at the resection margin (0 mm). R0 resection was further divided into 3 groups: 0.1 to 0.9 mm, 1 to 9 mm, and 10 mm or greater.

RESULTS

A total of 4915 liver resections were performed at Memorial Sloan Kettering Cancer Center between 1992 and 2012, from which 2368 patients were included in the current study. Half of the patients presented with synchronous disease, 43% had solitary metastasis, and the median tumor size was 3.4 cm. With a median follow-up for survivors of 55 months, the median OS of the R1, 0.1 to 0.9 mm, 1 to 9 mm, and 10 mm or more groups was 32, 40, 53, and 56 months, respectively (P < 0.001). Compared with R1 resection, all margin widths, including submillimeter margins correlated with prolonged OS (P < 0.05). The association between the margin width and OS remained significant when adjusted for all other clinicopathologic prognostic factors.

CONCLUSIONS

Resection margin width is independently associated with OS. Wide margins should be attempted whenever possible. However, resection should not be precluded if narrow margins are anticipated, as submillimeter margin clearance is associated with improved survival. The prolonged OS observed with submillimeter margins is likely a microscopic surrogate for the biologic behavior of a tumor rather than the result of surgical technique.

Safety analysis of the oncological outcome after vein-preserving surgery for colorectal liver metastases detached from the main hepatic veins

PURPOSE

Recent studies have reported that margins alone do not predict survival in patients with a positive chemotherapy response. The aim of this retrospective study is to analyze the surgical and oncological outcomes of patients who underwent chemotherapy and liver resection for colorectal liver metastases (CRLM) with lesions detached from the main hepatic veins, comparing the vein-preserving (VP) approach with traditional surgery.

METHODS

Fourteen patients undergoing VP surgery from January 2006 to January 2013 were matched in a 1:2 ratio with a control group (CG) of 28 patients undergoing traditional resection.

RESULTS

The median follow-up was 43 months. The radiological response was classified as 'partial response' in eight VP patients and 11 controls (57 vs. 39 %, p = 0.249) and as 'stable disease' in three VP patients and 9 controls (21 vs. 32 %, p = 0.465). Ten VP (71.4 %) and twenty CG patients (71.4 %) experienced tumor relapse (p = 0.99). No venous edge recurrences were recorded in the VP group, whereas 1/13 (7.7 %) was observed in the control group (p = 0.99). The pathological response rate was 64 vs. 39 % (p = 0.037) in VP and CG patients, respectively. The 5-year recurrence-free survival rate was 24 % for VP patients and 25 % for CG patients (p = 0.431).

CONCLUSION

In patients with a positive CT response, CRLM can be detached from the hepatic veins, as the oncological outcome is similar to that of a larger resection. The VP approach offers the possibility to enlarge the surgical indications, thus optimizing future surgical treatment chances.

Long-term outcomes of laparoscopic versus open liver resection for liver metastases from colorectal cancer: A comparative analysis of 168 consecutive cases at a single center

BACKGROUND

Laparoscopic liver resection for liver metastases from colorectal cancer (CRLM) is performed in a relatively small number of institutions. Its operative results have been reported to be comparable with that of open laparotomy; however, information on its oncologic outcomes is scarce. This study aimed to compare the long-term outcomes of laparoscopic hepatectomy (LH) and open hepatectomy (OH) to treat CRLM at a single institution.

METHODS

We retrospectively reviewed data from 168 consecutive patients who underwent LH (n = 100) or OH (n = 68) for CRLM. The tumor characteristics, operative results, overall survival (OS) rate, recurrence-free survival (RFS) rate, and recurrence patterns were analyzed and compared. A previously published survival-predicting nomogram was applied to compare OS and RFS between the 2 patient groups.

RESULTS

The largest tumor diameter and the number of tumors were significantly larger in the OH group than in the LH group; however, no differences in other tumor factors were observed between the 2 groups. When matched by the nomogram, OS and RFS remained comparable between the 2 groups in every examined stratum, not only for low-risk patients but also for those with high risk. The recurrence patterns also were similar (liver: 30.2% vs 26.8%, P = .72; lung: 22.6% vs 34.1%, P = .22; peritoneum: 7.6% vs 4.9%, P = .45).

CONCLUSION

The long-term outcomes of laparoscopic liver resection for CRLM were comparable with those of the open procedure in not only low-risk but also high-risk patients.

Open versus laparoscopic liver resection for colorectal liver metastases (the Oslo-CoMet Study): study protocol for a randomized controlled trial

BACKGROUND

Laparoscopic liver resection is used in specialized centers all over the world. However, laparoscopic liver resection has never been compared with open liver resection in a prospective, randomized trial.

METHODS/DESIGN

The Oslo-CoMet Study is a randomized trial into laparoscopic versus open liver resection for the surgical management of hepatic colorectal metastases. The primary outcome is 30-day perioperative morbidity. Secondary outcomes include 5-year survival (overall, disease-free and recurrence-free), resection margins, recurrence pattern, postoperative pain, health-related quality of life, and evaluation of the inflammatory response. A cost-utility analysis of replacing open surgery with laparoscopic surgery will also be performed. The study includes all resections for colorectal liver metastases, except formal hemihepatectomies, resections where reconstruction of vessels/bile ducts is necessary and resections that need to be combined with ablation. All patients will participate in an enhanced recovery after surgery program. A biobank of liver and tumor tissue will be established and molecular analysis will be performed.

DISCUSSION

After 35 months of recruitment, 200 patients have been included in the trial. Molecular and immunology data are being analyzed. Results for primary and secondary outcome measures will be presented following the conclusion of the study (late 2015). The Oslo-CoMet Study will provide the first level 1 evidence on the benefits of laparoscopic liver resection for colorectal liver metastases.

TRIAL REGISTRATION

The trial was registered in ClinicalTrals.gov (NCT01516710) on 19 January 2012.

The clinical relevance of the Fong and the Nordlinger scores in the era of effective neoadjuvant chemotherapy for colorectal liver metastasis

PURPOSE

The clinical risk scores (CRSs) of Fong and Nordlinger are used to predict the outcome of patients with colorectal liver metastases (CRLMs). This study investigated whether CRSs could predict the overall survival of patients with CRLM treated with or without neoadjuvant chemotherapy prior to resection.

METHODS

Patients with CRLM undergoing liver resection were analyzed retrospectively. The primary outcome measure was overall survival with vs. without neoadjuvant chemotherapy.

RESULTS

Between August 2002 and October 2011, 300 patients underwent liver resection for CRLMs at a large university hospital in Germany. Group A comprised 117 patients who received neoadjuvant chemotherapy and group B comprised 71 patients who did not. The Fong score predicted overall survival for patients who did not receive chemotherapy (p = 0.02), but not for those treated with chemotherapy (p = 0.69). The Nordlinger score was not predictive for either of the groups (p = 0.71 vs. p = 0.08 for groups A and B, respectively). Subgroup analysis of the Nordlinger score identified better overall survival in the high-risk group treated with chemotherapy (p = 0.05). Multivariate analysis identified a resection margin of <1 cm [OR 0.622 (95% CI: 0.17-2.31); p = 0.044], age >60 years [OR 0.535 (95% CI: 0.16-1.77); p = 0.022] and number of metastases >4 [OR 0.189 (95% CI: 0.06-0.61); p = 0.018] as independent prognostic factors for overall survival.

CONCLUSION

Thus, CRSs were not reliable prognostic tools for patients treated with neoadjuvant chemotherapy before liver resection in this analysis.

Impact of surgical margins on overall and recurrence-free survival in parenchymal-sparing laparoscopic liver resections of colorectal metastases

BACKGROUND

The relationship between the width of surgical margins and local and distant recurrence of colorectal liver metastases (CRLM) remain controversial. We analyzed the impact of surgical margins in laparoscopic liver resections (LLR) for CRLM, using the parenchymal-sparing approach on overall (OS) and recurrence-free survival (RFS).

METHODS

From January 2005 to October 2012, 114 first LLR for CRLM were performed and retrospectively analyzed. The ultrasonic aspirator was used for parenchyma division. R1 margins were defined when the tissue width was <1 mm.

RESULTS

After a mean follow-up of 30.9 ± 1.71 months, OS was 97.1-73.9-58.9% and the RFS 64.2-35.2-31% at 1-3-5 years, respectively. The major resection rate was 7%. The median margin width was 3 (0-40) mm, and R1 resection was recorded in 14 (12.3%) cases. Twenty-two patients (33.3%) with hepatic recurrence underwent a repeat hepatectomy. R1 margins were significantly related to lower RFS survival (p = 0.038) but did not affect OS. Multivariate analysis showed that lesions located in postero-superior segments (HR = 2.4, 95% CI 1.24-4.61, p = 0.009) as well as blood loss (HR = 3.2, 95% CI 1.23-7.99, p = 0.012) were independent risk factors for tumor recurrence. The carcinoembryonic antigen level >10 mcg/L affected OS (HR = 4.2 95% CI 2.02-16.9, p = 0.001), and the resection of more than two tumors was significantly associated with R1 margins (HR = 9.32, 95% CI 1.14-32.5, p = 0.037).

DISCUSSION

Laparoscopic parenchymal-sparing surgery of CRLM does not compromise the oncological outcome, allowing a higher percentage of repeat hepatectomy. R1 margins are a risk factor for tumor recurrence but not for overall survival. The presence of multiple lesions is the only independent risk factor of R1 margins and also the major disadvantage of this technique.

Surgery for colorectal liver metastases: the impact of resection margins on recurrence and overall survival

Background

Several reports have presented conflicting results regarding the association between resection margins (RMs) and outcome after surgery for colorectal liver metastases (CLM), especially in the era of modern chemotherapy. The purpose of this study was to evaluate the impact of RMs on overall survival (OS), time to recurrence (TTR) and local recurrence (LR) status, particularly for patients treated with preoperative chemotherapy.

Methods

A combined retrospective (1998 to 2008) and prospective (2008 to 2010) cohort study of consecutive patients with CLM without extrahepatic disease treated with primary resection at a medium volume centre.

Results

A total of 253 patients with known R status and 242 patients with defined margin width were included in the study. Patients were stratified according to margin width; A: R1, <1 mm (n = 48, 19%), B: 1 to 4 mm (n = 77), C: 5 to 9 mm (n = 46) and D: ≥10 mm (n = 71). Median time to recurrence was 12.8 months, and after five years 21.5% had no recurrence. LR (inclusive combined recurrence in other hepatic sites or extrahepatic) occurred in 40 (16.5%) cases, most frequently seen with RMs below 5 mm. Five-year OS was 42.5% in R0 and 16.1% in R1 resections (P = 0.011). Patients were also stratified according to preoperative chemotherapy (n = 88), and the difference in five-year OS between R0 (45.1%) and R1 (14.7%) was maintained (P = 0.037). By multiple Cox regression analysis R1 resections tended to an adverse outcome (P = 0.067), also when adjusting for preoperative chemotherapy (P = 0.081).

Conclusions

R1 resections for colorectal liver metastases predict adverse outcome. RMs below 5 mm increased the risk for LR and shortened the time to recurrence. Preoperative chemotherapy did not alter an adverse outcome in R1 vs. R0 patients.

Limits of colorectal liver metastases resectability: how and why to overcome them? For progress in cancer research

Offering surgery is to date the best case scenario for patients with colorectal liver metastases (CRLM). Few oncological topics have progressed as much as the treatment of CRLM. New surgical techniques, conversion therapies, and imaging allow us to pursue the ultimate limit for surgery of CLM before compromising patient benefits. Pushing the limits of surgery involves pushing the limits of conversion therapies too, increasingly taking risks in the surgical process. Finally, toxicities add up and the patient benefit could disappear. The apparent paradox of efficiency and toxicity might be addressed by separating the two treatment targets: (1) The metastatic burden for which a clear escalation in medical and surgical aggressiveness is still required. (2) The healthy parenchyma which should be preserved as much as possible and for which a clear de-escalation is anticipated. A new strategy exists that integrates both fundamental endpoints in the battle against CLM.