Resection of colorectal liver metastases: is a resection margin of 3 mm enough? : a multicenter analysis of the GAST Study Group

The Effect of Hepatic Surgical Margins of Colorectal Liver Metastases on Prognosis: A Systematic Review and Meta-Analysis

Introduction: Colorectal cancer is the third most common malignancy, with around half of patients developing liver metastases. Hepatectomy is the preferred treatment, but its success depends on several factors, including surgical margins. Various surgical margins have been suggested to achieve optimal results. This systematic review and meta-analysis aim to explore the impact of negative surgical margins ranging from 1 to 10 mm, and >10 mm on survival, with the objective of identifying optimal surgical margins. Methods: A systematic literature search was conducted on the MEDLINE, Scopus, and Cochrane databases. The six included studies that examined the effect of surgical margins at the aforementioned distances on patient survival. Studies were assessed for risk of bias using the Quality in Prognosis Studies tool. Statistical analysis was performed using SPSS software. Results: The results of the meta-analysis revealed the superiority of wider surgical margins (>10) on overall survival compared to smaller margins (1-10 mm), as the HR was calculated to be 1.38 [1.10; 1.73]. Specifically, negative margins between 1 and 10 mm are linked to a 38% increased risk of mortality compared to margins larger than 10 mm. The low heterogeneity indicates consistent findings across studies, and the statistically significant hazard ratio underscores the importance of aiming for larger surgical margins to enhance patient outcomes. In the subgroup that included only studies in which patients received neoadjuvant therapy, the HR was 1.48 [1.06; 2.07], further emphasizing the importance of ensuring negative surgical margins in today's era. Conclusions: In summary, this systematic review and meta-analysis highlights the impact of surgical margin width on the survival of patients with colorectal liver metastases, as well as the importance of margin optimization in surgical management strategies.

Analysis of surgical approach and tumor distance to margin after liver resection for colorectal liver metastasis

This study was undertaken to compare tumor distance to margin after robotic vs. open hepatectomy for colorectal liver metastases (CLM) and to determine the relationship between perioperative variables, surgical approach and tumor distance to margin with overall survival. With IRB approval, we followed 56 patients who underwent a robotic or open hepatectomy for treatment of CLM. The relationships between the tumor distance to margin, operative approach, perioperative variables and survival was determined. The robotic approach yielded greater margins than the open approach (p = 0.04). The robotic vs. open approach had an operative duration of 375 vs. 269 min (p = 0.05), ICU length of stay (LOS) of 0 vs. 1 day (p = 0.01), and hospital LOS of 4 vs. 7 days (p = 0.04). Patients with a tumor distance to margin of ≤ 1 mm and 1.1-9.9 mm had an estimated median survival of 49 months and 24 months, respectively. Estimated median survival for patients with tumor distance to margin of ≥ 10 mm has not been reached but is > 84 months. The use of the robotic approach is associated with greater tumor distance to margin and shorter hospital LOS, but with longer operations. The robotic approach does not compromise oncological margins during resection for CLM.

Prospective Non-Randomized Study of Intraoperative Assessment of Surgical Resection Margin of Colo-Rectal Liver Metastases

Introduction: More than 50% of patients with colorectal cancer (CRC) develop liver metastases during the natural course of disease. Surgical resection is currently the most potentially curative method in the treatment of colorectal liver metastases (CRLM). The goal of surgery is to achieve a negative resection margin (RM) of at least 1 mm, which provides the best prognosis for patients. The RM can be assessed by the pathologist of the resected liver specimen (RLS) and by the surgeon intraoperatively. The aim of this research paper is to determine the degree of agreement on intraoperative assessment of the RM by the surgeon and histopathological RM assessment by the pathologist.

Material and methods: This prospective non-randomized double-blind study was approved by the Ethics Committee of the Oncology Institute of Vojvodina and registered on ClinicalTrials.gov #NCT04634526. The study was conducted at the Oncology Institute of Vojvodina, Sremska Kamenica, Serbia. An experienced hepatobiliary surgeon assessed RM for every specimen intra-operatively, immediately after CRLM resection. Resected CRLM lesions were analyzed by two experienced pathologists. These data were compared with pathological RM assessment as a “gold standard”. RM of 1 mm or more was rated as negative RM (RM-). Disease-free survival (DFS) and recurrence rate was calculated by RM status defined by surgeon and by pathologist.

Results: From 01 January 2015 to 31 August 2019, 98 patients were enrolled in the study. There were 219 RLS with 245 CRLM. The surgeon registered positive RM (RM+) of <1mm in 41 (18.7%) RLS. Taking the result of the histopathological assessment (HPA) as the “gold standard”, it was determined that RM was true positive in 32 (14.6%) cases. False positive RM was found in 9 (4.1%) cases. False negative RM was found in 20 (9.1%) cases. True negative RM was found in 158 (72.2%) cases. Sensitivity of surgical assessment (SA) of RM+ was 61.5% (32/52). Specificity of SA of RM+ was 94.6% (158/167). The positive predictive value (PPV) was 78.0% (32/41), while the negative predictive value (NPV) was 88.8% (158/178). The overall accuracy of the RM+ SA was 86.8% (190/219). There was no statistically significant difference in the assessment of RM+ per RLS by surgeon and pathologists (p=0.061), but it was significant when analyses per patients was performed (p=0.017). Recurrence rate for RM+ patients was 48.1% (13/27, p=0.05) for SA and 35.0% (14/40, p=0.17) for HPA. Three year DFS for RM- and RM+ was 66.5% and 27.9% (p=0.04), respectively, by SA, and 64.8% and 42.1% (p=0.106), respectively, by HPA.

Conclusion: Intraoperative assessment of RM- by surgeon of RLS is clinically meaningful. There is not a statistically significant difference in the assessment of RM+ by surgeon and pathologists per RLS, but it was statically significant on a per patient basis. RM determined by surgeon has better prognostic impact on recurrence rate and 1- and 3-year DFS than standard histopathological assessment.

A prospective comparison of growth patterns with radiomorphology in 232 lung metastases-basis for patient tailored resection planning?

Background

The histologic presence of aggressive local growth of pulmonary metastases is associated with an increased risk for local intrapulmonary recurrence after enucleation or wedge resection. Patient tailored resection planning is possible when morphologic pattern of aggressive growth could be identified based on preoperative CT scans.

Methods

Radiomorphology and microscopic growth characteristics from 232 pulmonary metastases from 87 patients were prospectively compared for the presence or absence of aggressive patterns of local intrapulmonary dissemination.

Results

Microscopic aggressive local growth was found: pleural involvement (18.5%), lymphatic invasion (6.9%), vascular invasion (7.3%), interstitial growth (38.4%), micro satellite nodules (24.5%), spread through air spaces (STAS) (13.4%), and a smooth, slightly blurred or irregular surface in 34.1%, 43.1% and 22.8%. The radiologic margin demarcation was smooth in 37.1%, blurred in 27.6% or irregular in 35.3% and spiculae were present in 26.3% of the lesions. The microscopic and radiologic description of the metastasis surface correlated well [correlation coefficient (CC) =0.75, P<0.001]. A smooth surface on CT scan corresponded with a smooth microscopic surface in 72/86 (83.7%) of the lesions. The radiomorphologic feature of an irregular or cloudy surface was highly associated with the presence of at least one aggressive pattern of local dissemination (P<0.001). The presence of spiculae on CT scan was well associated with the presence of aggressive local spread (P<0.001) and the microscopic features corresponding with spiculae were interstitial growth, STAS and L1.

Conclusions

Radiomorphologic characteristics of lung metastases correspond well with the microscopic appearance of the resected lesion. Therefore it seems possible to adjust safety margins based on the radiologic appearance of the metastasis.

The Prognostic Value of Varying Definitions of Positive Resection Margin in Patients with Colorectal Cancer Liver Metastases

BACKGROUND

Varying definitions of resection margin clearance are currently employed among patients with colorectal cancer liver metastases (CRLM). Specifically, a microscopically positive margin (R1) has alternatively been equated with an involved margin (margin width = 0 mm) or a margin width < 1 mm. Consequently, patients with a margin width of 0-1 mm (sub-mm) are inconsistently classified in either the R0 or R1 categories, thus obscuring the prognostic implications of sub-mm margins.

METHODS

Six hundred thirty-three patients who underwent resection of CRLM were identified. Both R1 definitions were alternatively employed and multivariable analysis was used to determine the predictive power of each definition, as well as the prognostic implications of a sub-mm margin.

RESULTS

Five hundred thirty-nine (85.2%) patients had a margin width ≥ 1 mm, 42 had a sub-mm margin width, and 52 had an involved margin (0 mm). A margin width ≥ 1 mm was associated with improved survival vs. a sub-mm margin (65 vs. 36 months; P = 0.03) or an involved margin (65 vs. 33 months; P < 0.001). No significant difference in survival was detected between patients with involved vs. sub-mm margins (P = 0.31). A sub-mm margin and an involved margin were both independent predictors of worse OS (HR 1.66, 1.04-2.67; P = 0.04, and HR 2.14, 1.46-3.16; P < 0.001, respectively) in multivariable analysis. Importantly, after combining the two definitions, patients with either an involved margin or a sub-mm margin were associated with worse OS in multivariable analysis (HR 1.94, 1.41-2.65; P < 0.001).

CONCLUSIONS

Patients with involved or sub-mm margins demonstrated a similar inferior OS vs. patients with a margin width > 1 mm. Consequently, a uniform definition of R1 as a margin width < 1 mm should perhaps be employed by future studies.

Growth patterns of pulmonary metastases: should we adjust resection techniques to primary histology and size?

OBJECTIVES

Safety margins in pulmonary metastasectomy are not yet well defined. We hypothesize that histological subtype, size of the lesion and local growth characteristics must be taken into consideration during metastasectomy. This study was conducted to examine and classify growth patterns at resection margins and define the relationships between aggressive local growth, metastasis size and local recurrence to direct metastasectomy.

METHODS

Histologic sections of pulmonary metastases were prospectively collected and haematoxylin-eosin stains were systematically evaluated and classified by their pattern of lung tissue infiltration. Logistic regression was used to model the association between the subgroups of colorectal, renal cell and epithelial cancers and melanomas and sarcomas.

RESULTS

From 183 patients, 412 lung specimens were removed, which contained 459 pulmonary metastases. We found that 58% of all lesions had microscopic signs of aggressive local dissemination. The metastases showed histology-specific patterns of local growth: sarcoma was associated with pleural infiltration; colorectal metastases with interstitial spread and aerogenous spread of floating cancer cell clusters; and melanoma with perivascular growth and with lymph vessel involvement. Aggressive patterns of growth had an increasing probability of around 3% for each additional millimetre of metastasis diameter. Local intrapulmonary recurrence was significantly more common in association with interstitial growth and pleural penetration as well as safety margins <7 mm.

CONCLUSIONS

Approximately 40% of all lung metastases have a smooth surface and might be resected with small margins. Growth characteristics within the lung differ with the histologic subtype and safety margins should generally increase with the size of the metastasis.

Session 2: What causes liver metastases - lymph nodes or is it something else?

The traditional view of progression of disease in cancer is the sequential spread of tumour to locoregional lymph nodes and then to distant metastases. However, this view may need to be challenged and modern pathology techniques such as immunohistochemistry and tumour profiling can provide us with a greater insight into the pathways and mechanisms of distant spread. Professor Nagtegaal discusses the evidence for reconsidering the current paradigm and reflects on the need for further investigation into mechanisms of distant metastatic spread.

Prognostic Significance of Surgical Margin Size After Neoadjuvant FOLFOX and/or FOLFIRI for Colorectal Liver Metastases

PURPOSE

Optimal margin size when resecting colorectal liver metastases (CRLM) remains unclear, particularly in the setting of perioperative chemotherapy. We evaluated the prognostic significance of margin size in patients who received neoadjuvant FOLFOX and/or FOLFIRI prior to resection of CRLM.

METHODS

Clinicopathologic factors were collected for patients who underwent curative liver resections for CRLM between 4/2004-1/2016 and received neoadjuvant oxaliplatin and/or irinotecan and 5-FU (FOLFOX, FOLFIRI). Margins were categorized as < 1, ≥ 1-< 5, ≥ 5-< 10, or ≥ 10 mm and evaluated for association with overall survival (OS) and disease-free survival (DFS) by Cox multiple regression analysis. Margin status was classified as positive (< 1 mm) or negative (≥ 1 mm) and similarly evaluated.

RESULTS

Of 227 patients, the median age was 58 years and most had synchronous (80%) lesions. The majority had colon cancers (75%). Margin sizes were 13% < 1 mm, 27% ≥ 1-< 5 mm, 23% ≥ 5-< 10 mm, 36% ≥ 10 mm. Most (63%) received chemotherapy post-liver resection. Five-year OS and DFS were 54% (95% CI 46-62%) and 22% (95% CI 16-28%), respectively. Positive margins significantly increased the risk of death without post-liver resection chemotherapy (HR = 3.32, p = 0.0077), but not with post-liver resection chemotherapy (HR = 1.00, p = 0.99). Negative margin sizes of ≥ 1-< 5, ≥ 5-< 10, and ≥ 10 mm were not significant predictors of OS (p > 0.05).

CONCLUSION

Patients undergoing liver resection for CRLM should receive post-resection chemotherapy if negative margins (≥ 1 mm) cannot be achieved. For patients receiving FOLFOX and/or FOLFIRI chemotherapy, wider margins did not improve OS.

Aggressive surgical resection for concomitant liver and lung metastasis in colorectal cancer

Backgrounds/Aims

Aggressive surgical resection for hepatic metastasis is validated, however, concomitant liver and lung metastasis in colorectal cancer patients is equivocal.

Methods

Clinicopathologic data from January 2008 through December 2012 were retrospectively reviewed in 234 patients with colorectal cancer with concomitant liver and lung metastasis. Clinicopathologic factors and survival data were analyzed.

Results

Of the 234 patients, 129 (55.1%) had synchronous concomitant liver and lung metastasis from colorectal cancer and 36 (15.4%) had metachronous metastasis. Surgical resection was performed in 33 patients (25.6%) with synchronous and 6 (16.7%) with metachronous metastasis. Surgical resection showed better overall survival in both groups (synchronous, p=0.001; metachronous, p=0.028). In the synchronous metastatic group, complete resection of both liver and lung metastatic lesions had better survival outcomes than incomplete resection of two metastatic lesions (p=0.037). The primary site of colorectal cancer and complete resection were significant prognostic factors (p=0.06 and p=0.003, respectively).

Conclusions

Surgical resection for hepatic and pulmonary metastasis in colorectal cancer can improve complete remission and survival rate in resectable cases. Colorectal cancer with concomitant liver and lung metastasis is not a poor prognostic factor or a contraindication for surgical treatments, hence, an aggressive surgical approach may be recommended in well-selected resectable cases.

Factors affecting surgical margin recurrence after hepatectomy for colorectal liver metastases

BACKGROUND

Hepatic recurrence after resection of colorectal liver metastasis (CLM) occurs in 50% of patients during follow-up, with 2.8% to 13.9% presenting with surgical margin recurrence (SMR). The aim of this study is to analyze factors that related to SMR in patients with CLM undergoing hepatectomy.

METHODS

Demographics, clinical and survival data of patients who underwent hepatectomy were identified from a prospectively maintained, institutional review board (IRB)-approved database between 2000 and 2012. Statistical analysis was performed using univariate Kaplan Meier and Cox proportional hazard model.

RESULTS

There were 85 female and 121 male patients who underwent liver resection for CLM. An R0 resection was performed in 157 (76%) patients and R1 resection in 49. SMR was detected in 32 patients (15.5%) followed up for a median of 29 months (range, 3-121 months). A half of these patients had undergone R1 (n=16) and another half R0 resection (n=16). Tumor size, preoperative carcinoembryonic antigen (CEA) level and margin status were associated with SMR on univariate analysis. On multivariate analysis, a positive surgical margin was the only independent predictor of SMR. The receipt of adjuvant chemotherapy did not affect margin recurrence. SMR was an independent risk factor associated with worse disease-free (DFS) and overall survival (OS).

CONCLUSIONS

This study shows that SMR, which can be detected in up to 15.5% of patients after liver resection for CLM, adversely affects DFS and OS. The fact that a positive surgical margin was the only predictive factor for SMR in these patients underscores the importance of achieving negative margins during hepatectomy.

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.

Microwave ablation in porcine livers applying 5-minute protocols: influence of deployed energy on extent and shape of coagulation

PURPOSE

To evaluate the influence of deployed energy on extent and shape of microwave (MW)-induced coagulation in porcine livers applying 5-minute protocols.

MATERIALS AND METHODS

MW ablations (n = 25) were performed in ex vivo porcine livers (n = 8). Ablation time was 5 minutes. Five study groups were defined, each with different power output: I, 20 W (n = 5); II, 40 W (n = 5); III, 60 W (n = 5); IV, 80 W (n = 5); and V, 105 W (n = 5). Extent and shape of white coagulation was evaluated macroscopically, including short diameter, volume, front margin, coagulation center (distance between center of short diameter of coagulation and applicator tip), and ellipticity index (short diameter/long diameter). Deployed energy was also analyzed.

RESULTS

Short diameter and volume were significantly different (P<.001 and P<.001) between the groups: I, 23.0 mm and 11.1 cm(3); II, 12.4 mm and 12.4 cm(3); III, 27.0 mm and 17.6 cm(3); IV, 31.0 mm and 29.2 cm(3); and V, 35.0 mm and 42.3 cm(3). Front margin and coagulation center were also significantly different (P<.05 and P<.001): I, 6.0 mm and 13.0 mm; II, 8.0 mm and 11.0 mm; III, 8.0 mm and 14.0 mm; IV, 8.0 mm and 18.0 mm; and V, 10.0 mm and 19.0 mm. Ellipticity index was not significantly different. Deployed energy was significantly different (P<.001): I, 5.7 kJ; II, 11.0 kJ; III, 15.5 kJ; IV, 21.6 kJ; and V, 26.6 kJ.

CONCLUSIONS

Extent, but not shape, of MW-induced coagulation depends on the deployed energy. Applying the protocols described in this study, significantly different coagulation volumes can be created with an ablation time of 5 minutes but different power output.

Comparison of liver parenchymal ablation and tissue necrosis in a cadaveric bovine model using the Harmonic Scalpel, the LigaSure, the Cavitron Ultrasonic Surgical Aspirator and the Aquamantys devices

OBJECTIVES

The amount of tissue that is ablated or necrosed at the line of parenchymal transection is of clinical significance in the interpretation of resection margin status following hepatic resection. The aim of this study was to define the extent of parenchymal ablation and necrosis in liver tissue using the Harmonic Scalpel, the LigaSure, the Cavitron Ultrasonic Surgical Aspirator (CUSA) and the Aquamantys dissector ex vivo.

METHODS

Mounted blocks of non-perfused bovine liver were transected using the Harmonic Scalpel, LigaSure, CUSA and Aquamantys devices. Outcome measures included parenchymal ablation (ablation band widths and weights) and tissue necrosis band widths along the line of transection. Each experiment was replicated five times.

RESULTS

All devices were associated with parenchymal ablation (Harmonic Scalpel, 4.73 ± 1.62 mm; LigaSure, 4.55 ± 2.02 mm; CUSA, 7.16 ± 2.87 mm; Aquamantys, 4.75 ± 1.43 mm) and tissue necrosis (Harmonic Scalpel, 1.07 ± 0.46 mm; LigaSure, 1.36 ± 0.36 mm; CUSA, 0.81 ± 0.21 mm; Aquamantys, 0.81 ± 0.36 mm).

CONCLUSIONS

The Harmonic Scalpel, LigaSure, CUSA and Aquamantys devices were associated with bands of tissue loss along the hepatic parenchymal transection line in this benchtop cadaveric model. This should be taken into account in the interpretation of resection margin status following liver resection.

Management of colorectal cancer patients after resection of liver metastases: can we offer a tailored treatment?

Surgical resection remains the only option of cure for patients with colorectal liver metastases, and no patient should be precluded from surgery. There is much controversy not only regarding the most appropriate therapeutic approach in the neoadjuvant setting but also after surgery is performed. Many patients will experience early relapses but others will be long survivors. We need to establish reliable prognostic and predictive factors to offer a tailored treatment. Several prognostic factors after metastasectomy have been identified: high C-reactive protein levels, a high neutrophil-lymphocyte ratio, elevated neutrophil count and low serum albumin are related to a worst outcome. Elevated CEA and Ki 67 levels, intrahepatic and perihepatic lymph node invasion are also some of the markers related to a worst outcome. In contrast, the administration of preoperative chemotherapy has been associated with a better prognosis after hepatectomy. The administration of adjuvant chemotherapy should be done taking in consideration these factors. Regarding predictive factors, determination of ERCC1, TS, TP and DPD and UGT1 polymorphisms assessment could be considered prior to chemotherapy administration. This would avoid treatment related toxicities and increase this population quality of life.

Determinants of short- and long-term outcome in patients undergoing simultaneous resection of colorectal cancer and synchronous colorectal liver metastases

PURPOSE

The optimal surgical strategy for patients presenting with colorectal liver metastases has yet to be determined. Short- and long-term outcomes must be considered if simultaneous resection of primary and liver metastases is to gain acceptance. We examine the prognostic value of patient and tumour characteristics in predicting short- and long-term outcomes following simultaneous resection for synchronous disease.

METHODS

Forty-six patients undergoing simultaneous resection between April 2002 and June 2010 in a single institution were included. Patient characteristics included preoperative ASA grade and POSSUM. Tumour characteristics included TNM stage, Petersen Index and the Clinical Risk Score.

RESULTS

There were no postoperative deaths. The most common complications were atrial fibrillation (seven patients) and pneumonia (seven patients). Mean hospital stay with an uncomplicated postoperative recovery was 11 days versus 17 days with complicated recovery. Age (p = 0.015), ASA grade (p = 0.010) and POSSUM score (p = 0.032) were associated with postoperative complications. No pathological characteristics of the primary or secondary tumours related to surgical morbidity. Median follow-up was 37 months (5-87) during which 24 patients died, 23 from cancer. Twenty-seven had disease recurrence. N stage of the primary (p = 0.035), high-risk Petersen Index of the primary (p = 0.010) and Clinical Risk Score ≥ 3 (p = 0.005) were associated with poorer recurrence-free and cancer-specific survival.

CONCLUSIONS

Post operative morbidity was determined by patient factors rather than operative or tumour characteristics. In addition to the Clinical Risk Score, pathological characteristics of the primary are important determinants of long-term outcome following simultaneous resection for synchronous disease.

Lack of Anatomical Concordance between Preablation and Postablation CT Images: A Risk Factor Related to Ablation Site Recurrence

Objective. Variation in the position of the liver between preablation and postablation CT images hampers assessment of treatment of colorectal liver metastasis (CRLM). The aim of this study was to test the hypothesis that discordant preablation and postablation imaging is associated with more ablation site recurrences (ASRs). Methods. Patients with CRLM were included. Index-tumor size, location, number, RFA approachs and ablative margins were obtained on CT scans. Preablation and postablation CT images were assigned a "Similarity of Positioning Score" (SiPS). A suitable cutoff was determined. Images were classified as identical (SiPS-id) or nonidentical (SiPS-diff). ASR was identified prospectively on follow-up imaging. Results. Forty-seven patients with 97 tumors underwent 64 RFA procedures (39 patients/63 tumors open RFA, 25 patients/34 tumours CT-targeted RFA, 12 patients underwent >1 RFA). Images of 52 (54%) ablation sites were classified as SiPS-id, 45 (46%) as SiPS-diff. Index-tumor size, tumor location and number, concomitant partial hepatectomy, and RFA approach did not influence the SiPS. ASR developed in 11/47 (23%) patients and 20/97 (21%) tumours. ASR occurred less frequently after open RFA than after CT targeted RFA (P < 0.001). ASR was associated with larger index-tumour size (18.9 versus 12.8 mm, P = 0.011). Cox proportional hazard model confirmed SiPS-diff, index-tumour size >20 mm and CT-targeted RFA as independent risk factors for ASR. Conclusion. Variation in anatomical concordance between preablation and postablation images, index-tumor size, and a CT-targeted approach are risk factors for ASR in CRLM.

Surgical management of colorectal liver metastases

Colorectal cancer is the third most commonly diagnosed cancer with approximately half of the patients developing liver metastases during the course of their disease. Modern multimodal therapies have improved the overall survival. Liver resection remains the most important modality in the treatment of colorectal liver metastases. The evolution of the criteria for resectability has resulted in more patients being offered a hepatectomy. This is further augmented with the utilization of adjuncts to liver resection, including portal vein embolization and local ablative techniques. Two-stage hepatectomy is also being used to increase resectability. Overall survival is improved by the deployment of new chemotherapeutic agents and the use of combination chemotherapy. Neoadjuvant chemotherapy is a promising development in the treatment of colorectal liver metastases. Patients with colorectal liver metastases can achieve long-term survival. A multidisciplinary approach is essential in the management of these patients.

Liver resection for colorectal cancer metastases involving the caudate lobe

BACKGROUND

Up to 5 per cent of liver resections for colorectal cancer metastases involve the caudate lobe, with cancer-involved resection margins of over 50 per cent being reported following caudate lobe resection.

METHODS

Outcomes of consecutive liver resections for colorectal metastases involving the caudate lobe between 1996 and 2009 were reviewed retrospectively, and compared with those after liver surgery without caudate resection.

RESULTS

Twenty-five patients underwent caudate and 432 non-caudate liver resection. Caudate resection was commonly performed as part of extended resection. There were no differences in operative complications (24 versus 21·1 per cent; P = 0·727) or blood loss (median 300 versus 250 ml; P = 0·234). The operating time was longer for caudate resection (median 283 versus 227 min; P = 0·024). Tumour size was larger in the caudate group (median 40 versus 27 mm; P = 0·018). Resection margins were smaller when the caudate lobe was involved by tumour, than in resections including tumour-free caudate or non-caudate resection; however, there was no difference in the proportion of completely excised tumours between caudate and non-caudate resections (96 versus 96·1 per cent; P = 0·990). One-year overall survival rates were 90 and 89·3 per cent respectively (P = 0·960), with 1-year recurrence-free survival rates of 62 and 71·2 per cent (P = 0·340).

CONCLUSION

Caudate lobe surgery for colorectal cancer liver metastases does not increase the incidence of resection margin involvement, although when the caudate lobe contains metastases the margins are significantly closer than in other resections.

Surgical management of colorectal liver metastases

Colorectal cancer is the third most commonly diagnosed cancer with approximately half of the patients developing liver metastases during the course of their disease. Modern multimodal therapies have improved the overall survival. Liver resection remains the most important modality in the treatment of colorectal liver metastases. The evolution of the criteria for resectability has resulted in more patients being offered a hepatectomy. This is further augmented with the utilization of adjuncts to liver resection, including portal vein embolization and local ablative techniques. Two-stage hepatectomy is also being used to increase resectability. Overall survival is improved by the deployment of new chemotherapeutic agents and the use of combination chemotherapy. Neoadjuvant chemotherapy is a promising development in the treatment of colorectal liver metastases. Patients with colorectal liver metastases can achieve long-term survival. A multidisciplinary approach is essential in the management of these patients.

Contrast-enhanced ultrasound in planning thermal ablation of liver metastases: Should the hypervascular halo be included in the ablation volume?()

INTRODUCTION

Liver metastases often exhibit a hypervascular halo during the arterial phase of contrast-enhanced ultrasonography (CEUS). This finding has no correlates on baseline gray-scale imaging, and it has never been characterized. The aim of this study was to identify the features of this halo and determine whether it should be included in the ablation volume during thermal ablation procedures.

MATERIALS AND METHODS

We prospectively enrolled 25 patients referred to our department for thermal ablation of liver metastases. Before treatment all patients underwent CEUS, and the maximum diameter of the metastatic lesion was measured before administration of the ultrasound contrast agent and during the arterial and portal venous phases of the contrast contrast-enhanced study. Maximum diameters in the different vascular phases were compared with the Turkey-Kramer test. Two biopsies were obtained from each lesion with a 21-gauge needle: 1) one from the center of the metastasis to confirm the diagnosis and 2) one from the hypervascular peripheral halo identified in the arterial phase at CEUS.

RESULTS

The mean (±standard deviation) maximum lesion diameter was 2.67 ± 1.2 cm before contrast agent injection, 3.50 ± 1.4 cm during the arterial phase, and 2.71 ± 1.2 cm during the venous phase. The difference between maximum diameters measured before contrast enhancement and in the arterial phase was highly significant (mean: 0.84 ± 0.45 cm, p < 0.0001). Histological examination of halo specimens revealed inflammatory infiltrates with no evidence of tumor infiltration in 24/25 (96%) cases and normal hepatic parenchymal tissue in the 25th specimen.

DISCUSSION

The hypervascular halo surrounding liver metastases during the arterial phase of CEUS represents a chronic inflammatory infiltrate, not tumor infiltration. However, since chronic inflammation appears to promote neovascularization and the production of tumoral growth factors, it seems wise to include the hypervascular halo in the intended-to-treat volume when planning the ablation procedure.

Surgery for colorectal liver metastases

In this review the surgery of colorectal liver metastases is discussed. It has long been known that liver surgery can cure metastatic colorectal cancer although in only a small proportion of the population with the disease. However with better understanding of the natural history of the condition and advances in technique more patients can have safe, potentially curative surgery. The multidiscipline management of patients with effective chemotherapy has led to more patients benefiting from surgery after reducing the size of the metastases and allowing operation on patients who were previously inoperable. Chemotherapy also improves at least the medium-term outcome in those who are operable at the outset. Minimally invasive techniques have been developed so that major hepatectomy may be accomplished in up to half of such cases with a very short hospital stay and limited interference with quality of life. Lastly, using portal vein embolisation to cause hypertrophy of the future liver remnant and on occasions combining it with staged liver resection allows potentially curative surgery on patients who previously could not have survived resection. These developments have led to more patients being cured of advanced colorectal cancer.

Evaluation of peri-operative chemotherapy using a prognostic nomogram for survival after resection of colorectal liver metastases

INTRODUCTION

Nomograms are statistical tools designed to predict outcomes. This study evaluates the effects of peri-operative chemotherapy on the accuracy of a prognostic nomogram for disease-specific survival (DSS) after resection of colorectal liver metastases (CRLM) established at Memorial-Sloan Kettering Cancer Center (MSKCC).

METHODS

An external cohort of 203 patients who underwent resection of CRLM between 1996 and 2006 was used to assess the nomogram.

RESULTS

After median follow-up of 30.4 months (range 0.33-150), Kaplan-Meier (KM) estimates for 3-, 5- and 8-year post-resection DSS were 56%, 41%, and 32%, respectively; similar to nomogram-predicted probabilities for DSS. The concordance index for the nomogram was higher (0.602) than for the Fong colorectal risk score (CRS; 0.533). KM DSS was longer for patients (n= 50) treated with at least 6 months of peri-operative irinotecan or oxaliplatin compared with all other patients (median 66 vs. 40 months, P= 0.06). KM DSS was greater than nomogram predicted DSS for treated patients and less than nomogram predicted DSS for all other patients.

CONCLUSIONS

The CRLM nomogram was validated by an external cohort and more accurately predicted post-resection survival than the commonly used CRS. Differences in observed and nomogram-predicted survival may reflect the effect of treatment factors, such as peri-operative chemotherapy.

Resection margin and recurrence-free survival after liver resection of colorectal metastases

BACKGROUND

Optimal margin width is uncertain because of conflicting results from recent studies using overall survival as the end-point. After recurrence, re-resection and aggressive chemotherapy heavily affect survival time; the potential confounding effect of such factors has not been investigated. Use of recurrence-free survival (RFS) may overcome this limitation. The aim of this study is to evaluate the impact of width of resection margin on RFS and site of recurrence after hepatic resection for colorectal metastases (CRM).

METHODS

From a prospectively maintained institutional database (1/1999-12/2007) we identified 314 patients undergone hepatectomy for CRM (1/1999-12/2007) with detailed pathologic analysis of the surgical margin and complete follow-up imaging studies documenting disease status and site of recurrence, which was categorized as: resection margin (M(arg)), other intra-hepatic ((other)IH), lung (L) or other extra-hepatic ((other)EH). Recurrence-free estimation was the survival end-point.

RESULTS

Median follow-up was 56.5 months. Two hundred and fifteen patients (68.8%) recurred at 288 sites after a mean of 15.5 months. A positive resection margin was associated with an increased risk of M(arg) recurrence (P < 0.001). The presence of >or=2 metastases was the only factor increasing the risk of positive margins (P < 0.05). The width of the negative resection margin (>or=1 cm versus >1 cm) was not a prognostic factor of worse RFS (30.2% versus 37.3%, P = 0.6). Node status of the primary tumour, and size and number of CRM were independent predictors of RFS.

CONCLUSIONS

Tumour biology and not the width of the negative resection margin affect RFS.

Influence of resection margin on survival in hepatic resections for colorectal liver metastases

BACKGROUND

Traditionally a 1-cm margin has been accepted as the gold standard for resection of colorectal liver metastases. Evidence is emerging that a lesser margin may provide equally acceptable outcomes, but a critical margin, below which recurrence is higher and survival poorer, has not been universally agreed. In a recent publication, we reported peri-operative morbidity and clear margin as the two independent prognostic factors. The aim of the current study was to further analyse the effect of the width of the surgical margin on patient survival to determine whether a margin of 1 mm is adequate.

METHODS

Two hundred and sixty-one consecutive primary liver resections for colorectal metastases were analysed from 1992 to 2007. The resection margins were assessed by microscopic examination of paraffin sections. The initial analysis was performed on five groups according to the resection margins: involved margin, 0-1 mm, >1-<4 mm, 4-<10 mm and > or = 10 mm. Subsequent analysis was based on two groups: margin <1 mm and >1 mm.

RESULTS

With a median follow-up of 4.7 years, the overall 5-year patient and disease-free survival were 38% and 22%, respectively. There was no significant difference in patient- or disease-free survival between the three groups with resection margins >1 mm. When a comparison was made between patients with resection margins < or = 1 mm and patients with resection margins >1 mm, there was a significant 5-year patient survival difference of 25% versus 43% (P < 0.04). However, the disease-free survival difference did not reach statistical significance (P = 0.14).

CONCLUSIONS

In this cohort of patients, we have demonstrated that a resection margin of greater than 1 mm is associated with significantly improved 5-year overall survival, compared with involved margins or margins less than or equal to 1 mm. The possible beneficial effect of greater margins beyond 1 mm could not be demonstrated.