Pathological response grade of colorectal liver metastases treated with neoadjuvant chemotherapy

Predicting response to neoadjuvant chemotherapy for colorectal liver metastasis using deep learning on prechemotherapy cross-sectional imaging

BACKGROUND AND OBJECTIVES

Deep learning models (DLMs) are applied across domains of health sciences to generate meaningful predictions. DLMs make use of neural networks to generate predictions from discrete data inputs. This study employs DLM on prechemotherapy cross-sectional imaging to predict patients' response to neoadjuvant chemotherapy.

METHODS

Adult patients with colorectal liver metastasis who underwent surgery after neoadjuvant chemotherapy were included. A DLM was trained on computed tomography images using attention-based multiple-instance learning. A logistic regression model incorporating clinical parameters of the Fong clinical risk score was used for comparison. Both model performances were benchmarked against the Response Evaluation Criteria in Solid Tumors criteria. A receiver operating curve was created and resulting area under the curve (AUC) was determined.

RESULTS

Ninety-five patients were included, with 33,619 images available for study inclusion. Ninety-five percent of patients underwent 5-fluorouracil-based chemotherapy with oxaliplatin and/or irinotecan. Sixty percent of the patients were categorized as chemotherapy responders (30% reduction in tumor diameter). The DLM had an AUC of 0.77. The AUC for the clinical model was 0.41.

CONCLUSIONS

Image-based DLM for prediction of response to neoadjuvant chemotherapy in patients with colorectal cancer liver metastases was superior to a clinical-based model. These results demonstrate potential to identify nonresponders to chemotherapy and guide select patients toward earlier curative resection.

Oncological Outcome of Conversion Surgery After Preoperative Chemotherapy for Metastatic Pancreatic Cancer

OBJECTIVE

To investigate the outcome of conversion surgery in patients with metastatic pancreatic cancer (mPDAC) and to identify patients who may benefit from this approach.

BACKGROUND

The role of conversion surgery in patients with mPDAC and exceptional response to chemotherapy remains unclear.

METHODS

Patients who underwent surgical exploration for mPDAC following chemotherapy between 2006 and 2019 were included. Data on demographics, oncologic treatment, pathology, and postoperative outcomes were analyzed. Univariate and multivariate survival analyses were performed.

RESULTS

Some 173 patients received preoperative chemotherapy and underwent surgical exploration. Ninety-three patients underwent resection of the primary tumor and metastatic sites, 80 patients underwent exploration only. In the resection subgroup, 45 patients had complete pathological response of metastases (ypM0) and 48 patients had residual metastases (ypM1). ypM0 status was associated with lower carcinoembryonic antigen levels and lower ypN stage. Overall survival after resection was 25.5 months in ypM0, 10.7 months in ypM1, and 8.1 months in patients without resection ( P <0.001). Additional adjuvant chemotherapy was significantly associated with prolonged survival in resected patients (29.0 vs 14.8 mo, P =0.024) as well as in ypM0 (29.1 vs 19.2 mo, P =0.047). Multivariable analysis identified conversion surgery, carbohydrate antigen 19-9 (CA19-9) and time of resection as independent prognostic markers for the entire cohort. CA19-9, ypM0 and adjuvant treatment were independent predictors of survival in the resection subgroup.

CONCLUSION

In patients with mPDAC and ypM0 status after chemotherapy, surgical resection is associated with encouraging survival. mPDAC patients with exceptional response to chemotherapy may be candidates for exploration and for resection in ypM0. Adjuvant chemotherapy may provide an additional survival advantage.

Histological tumor response to neoadjuvant chemotherapy correlates to Immunoscore in colorectal cancer liver metastases patients

BACKGROUND

This study investigated the correlation between tumor regression grade (TRG) score and Immunoscore, and prognostic values of TRG score and a risk score in colorectal cancer liver metastases (CRLMs) patients after neoadjuvant chemotherapy.

METHODS

Patients undergoing neoadjuvant chemotherapy from 2014 to 2019 were selected. TRG score and Immunoscore were evaluated in 200 CRLMs. A risk score combining TRG score, Immunoscore, and clinical risk score (CRS) was defined and divided patients into the low-, medium-, and high-risk groups. Differences in relapse-free survival (RFS) and overall survival (OS) between groups were determined.

RESULTS

The densities of CD3⁺ and CD8⁺ immune cells were higher in TRG1-3 group than in TRG4-5 group, and the ratio of high Immunoscores was higher in TRG1-3 group than in TRG4-5 group (60.0% vs. 15.8%, p < 0.001). Patients in TRG1-3 group had significantly longer RFS and OS than those in TRG4-5 group. The low-risk group shows a significantly higher 2-year RFS and 5-year OS rate than the medium- and high-risk group (RFS: 59.9%, 36.2%, and 6.4%, p < 0.001; OS: 82.0%, 41.0%, and 16.9%, p < 0.001).

CONCLUSION

TRG score may be proposed to evaluate the prognosis of neoadjuvant chemotherapy and may be used for predicting the postoperative survival of CRLMs.

Ratio of Pathological Response to Preoperative Chemotherapy in Patients Undergoing Complete Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Metastatic Colorectal Cancer Correlates with Survival

BACKGROUND

Pathological response of colorectal peritoneal metastasis (CRPM) may affect prognosis. We investigated the relationship between oncological outcomes and pathological response to chemotherapy of CRPM following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

We conducted a retrospective analysis of a prospectively maintained Peritoneal Surface Malignancies database between 2015 and 2020. Analysis included patients with CRPM who underwent a CRS/HIPEC procedure (n = 178). The cohort was divided into three groups according to the response ratio (ratio of tumor-positive specimens to the total number of specimens resected): Group A, complete response; Group B, high response ratio, and Group C, low response ratio.

RESULTS

The group demographics were similar, but the overall complication rate was higher in Group C (65.2%) compared with Groups A (55%) and B (42.8%) [p = 0.03]. Survival correlated to response ratio; the estimated median disease-free survival of Group C was 9.1 months (5.97-12.23), 14.9 months (4.72-25.08) for Group B, and was not reached in Group A (p = 0.001). The estimated median overall survival in Group C was 35 months (26.69-43.31), and was not reached in Groups A and B (p = 0.001).

CONCLUSIONS

The pathological response ratio to systemic therapy correlates with survival in patients undergoing CRS/HIPEC. This study supports the utilization of preoperative therapy for better patient selection, with a potential impact on survival.

Effective Strategies to Predict Survival of Colorectal Peritoneal Metastases Patients Eligible for Cytoreductive Surgery and HIPEC

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), often combined with systemic therapy, can be offered to selected colorectal peritoneal metastases (PM) patients. However, clinical heterogeneity and the lack of high-level evidence challenges determination of the correct treatment strategy. This review aims to provide an overview of current strategies to predict survival of colorectal PM patients treated with CRS and HIPEC, guiding clinicians to select a suitable treatment-strategy and to inform patients about their prognosis. First, the prognostic relevance of several clinicopathological prognostic factors, such as extent of PM, location of primary tumor, histology type, and the presence of lymph node or liver metastases will be discussed. Subsequently, special attention will be given to recent developments in several aspects of tumor biology such as RAF/RAS mutations, circulating tumor DNA, immunoprofiling, and consensus molecular subtypes. Finally, currently available prognostic models to predict survival will be evaluated, concluding these models perform moderate to good, but most of them partly rely on intra-operative data. New insights in tumor biology, as well as the reliable assessment of extent of peritoneal disease by diffusion weighted MRI pose promising opportunities to establish an adequate and clinically meaningful preoperative prognostic model in the near future.

Clinicopathological characteristics and survival outcomes for patients with mucinous colorectal cancer liver metastases undergoing hepatic resection: A systematic review and meta-analysis

BACKGROUND

Mucinous adenocarcinoma represents a distinct histological subtype of colorectal cancer. To date there has been limited data available for patients with colorectal cancer liver metastases (CRCLM) derived from mucinous adenocarcinoma. This systematic review and meta-analysis aims to provide data on the clinicopathological and survival outcomes of this cohort.

METHODS

Databases were searched for studies comparing clinicopathological and survival outcomes between patients with mucinous CRCLM and CRCLM from adenocarcinoma not otherwise specified who underwent liver resection. A random-effects model was used for analysis.

RESULTS

Eight studies describing 9157 patients were included. Mucinous CRCLM were positively associated with colon tumors (OR 1⋅64, P = 0⋅01), T3/T4 tumors (OR 1⋅58, P = 0⋅02), node positive tumors (OR 1⋅55, P = 0⋅005). The review also identified a trend towards worse overall survival in patients with mucinous CRCLM.

CONCLUSIONS

Despite the distinct clinicopathological characteristics and impaired long term outcomes of mucinous CRCLM, resection should remain the gold standard where possible.

Quantitative multiparametric MRI allows safe surgical planning in patients undergoing liver resection for colorectal liver metastases: report of two patients

It is not uncommon for clinicians to encounter varying degrees of hepatic steatosis in patients undergoing resection for colorectal liver metastases (CRLM). Magnetic resonance imaging is currently the preferred investigation for identification and pre-operative planning of these patients. An objective assessment of liver quality and degree of steatosis is paramount for planning a safe resection, which is seldom provided by routine MRI sequences. We studied two patients who underwent an additional pre-operative multiparametric MRI scan (LiverMultiScan^TM) as a part of an observational clinical trial (HepaT1ca, NCT03213314) to assess the quality of liver. Outcome was assessed in the form of post-hepatectomy liver failure. Both patients (Patient 1 and 2) had comparable pre-operative characteristics. Both patients were planned for an extended right hepatectomy with an estimated future liver remnant of approximately 30%. Conventional preoperative contrast MRI showed mild liver steatosis in both patients. Patient one developed post-hepatectomy liver failure leading to prolonged hospital stay compared to patient two who had uneventful post-operative course. Retrospective evaluation of multiparametric MRI scan revealed findings consistent with fibro-inflammatory disease and steatosis (cT1 829 ms, PDFF 14%) for patient 1 whereas patient two had normal parameters (cT1 735 ms, PDFF 2.4%). These findings corresponded with the resection specimen histology. Multiparametric MRI can objectively evaluate future liver health and volume which may help refine surgical decision-making and improve patient outcomes.

Histological tumor response assessment in colorectal liver metastases after neoadjuvant chemotherapy: impact of the variation in tumor regression grading and peritumoral lymphocytic infiltration

Background: The objective of this study was to evaluate the prognostic value of the variation in tumor regression grade (TRG) and peritumoral lymphocytic infiltration of colorectal liver metastases (CRLMs) after neoadjuvant chemotherapy (NACT). Methods: A retrospective review was performed in 98 patients with CRLMs who underwent NACT between 2010 and 2016. The TRG scores and counts of TILs at the tumor-normal interface were assessed in all 176 resected liver metastases to determine their association with prognosis. According to the variation in TRG scores, 40 patients with more than one liver metastasis were divided into a decreased TRG group and a stable TRG group. An additional independent cohort of 64 patients with 106 resected liver specimens was established to validate our main findings. Results: In the derivation cohort of 98 patients, 41.8% patients had a favourable pathological response to NACT (TRG 1-3), which were significantly associated with improved prognosis. Seventeen patients (42.5%) showed decreased TRG scores, and the remaining patients had stable scores. The multivariate analysis indicated that patients with decreased TRG scores had a better recurrence-free survival (RFS) compared with those with stable TRG scores (HR=0.42, P=0.034), and a similar trend was observed in the validation cohort (P=0.068). Dense TILs surrounding the metastases were present in 55.1% of the derivation cohort and associated with pathological response (P=0.008). Among patients with a pathological response to NACT, those with dense TILs had a superior RFS compared to those with weak TILs in both cohorts (derivation: HR=0.36, P=0.035; validation: HR=0.34, P=0.016). Conclusions: Variation in TRG scores and peritumoral lymphocytic infiltration may be proposed as secondary pathological parameters to evaluate the pathological response to NACT and predict the risk of recurrence after liver surgery.

Synchronous colorectal liver metastases: a national survey of surgeon opinions on simultaneous resection and multidisciplinary cooperation

Background

The management of patients with synchronous colorectal liver metastases (sCRLM) has evolved significantly (improved chemotherapy, hepatic surgery advancements, colonic stenting, consultation synergies). We sought to better understand surgeon viewpoints on optimal referral patterns and the delivery of simultaneous resections.

Methods

A 40 question on-line survey was offered to members of the Canadian surgical community. Statistical analysis was descriptive.

Results

A total of 52 surgeons responded. Most colorectal surgeons (CRS) had access to and a good working relationship with regional hepatobiliary (HPB) surgeons (86%) and medical oncologists (100%). The majority (92%) believed there was a role for simultaneous resection of sCRLM, with 69% having first hand experience. Many CRS (62%) discussed all cases of known hepatic metastases with HPB prior to any resection. When a lesion was asymptomatic/minimally symptomatic, most CRS (92%) discussed them with medical oncology/HPB prior to resection (8%). Bilobar metastases (58%), patient comorbidities (35%), portal lymphadenopathy (35%), and patient age (15%) restricted CRS from obtaining HPB consultations. Many CRS (46%) did not believe that resecting hepatic metastases prior to the primary lesion might be beneficial. Most CRS (60%) reported they could not accurately predict hepatic resectability, with only 27% familiarity with evidence-based guidelines. Despite working in smaller hospitals with less access to HPB and less experience with simultaneous resections, non-CR general surgeons more commonly supported a 'liver-first' approach.

Conclusions

There was general agreement between CRS and general surgeons on numerous topics, but additional education is required with regard to HPB surgical capabilities and to provide truly individualized patient-centered care.

Pathological factors and prognosis of resected liver metastases of colorectal carcinoma: implications and proposal for a pathological reporting protocol

Colorectal cancer is a leading cause of death worldwide. The liver is the most common site of distant metastases, and surgery is the only potentially curative treatment, although the recurrence rate following surgery is high. In order to define prognosis after surgery, many histopathological features have been identified in the primary tumour. In turn, pathologists routinely report specific findings to guide oncologists on the decision to recommend adjuvant therapy. In general, the pathological report of resected colorectal liver metastases is limited to confirmation of the malignancy and details regarding the margin status. Most pathological reports of a liver resection for colorectal liver metastasis lack information on other important features that have been reported to be independent prognostic factors. We herein review the evidence to support a more detailed pathological report of the resected liver specimen, with attention to: the number and size of liver metastases; margin size; the presence of lymphatic, vascular, perineural and biliary invasion; mucinous pattern; tumour growth pattern; the presence of a tumour pseudocapsule; and the pathological response to neoadjuvant chemotherapy. In addition, we propose a new protocol for the evaluation of colorectal liver metastasis resection specimens.

Patient selection for cytoreductive surgery and HIPEC for the treatment of peritoneal metastases from colorectal cancer

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is a viable option for selected patients with peritoneal metastases (PM) from colorectal origin, resulting in long-term survival and even cure in some cases. However, adequate patient selection for this treatment is currently one of the major challenges. The aim of this review is to provide a comprehensive overview of clinically relevant factors associated with overall survival. This may help to guide clinicians through the complex interplay of patient, tumor, and treatment characteristics to adequately select patients who benefit the most from this extensive surgical treatment. First, basic principles of colorectal PM and the CRS and HIPEC treatment will be discussed. According to available literature, especially extent of peritoneal disease, completeness of cytoreduction, and signet ring cell histology have great influence on the outcome after CRS and HIPEC. Other factors that seem to have a negative prognostic value are the presence of liver metastases and the absence of treatment with neo-adjuvant systemic therapy. Prognostic models combining the above-mentioned factors, such as the Colorectal Peritoneal Metastases Prognostic Surgical Score nomogram, may provide clinically relevant tools to use in everyday practice.

Assessment of pathological response to therapy using lipid mass spectrometry imaging

In many cancers, the establishment of a patient’s future treatment regime often relies on histopathological assessment of tumor tissue specimens in order to determine the extent of the ‘pathological response’ to a given therapy. However, histopathological assessment of pathological response remains subjective. Here we use MALDI mass spectrometry imaging to generate lipid signatures from colorectal cancer liver metastasis specimens resected from patients preoperatively treated with chemotherapy. Using these signatures we obtained a unique pathological response score that correlates with prognosis. In addition, we identify single lipid moieties that are overexpressed in different histopathological features of the tumor, which have potential as new biomarkers for assessing response to therapy. These data show that computational methods, focusing on the lipidome, can be used to determine prognostic markers for response to chemotherapy and may potentially improve risk assessment and patient care.

Current approaches and challenges for monitoring treatment response in colon and rectal cancer

Introduction: With the advent of multidisciplinary and multimodality approaches to the management of colorectal cancer patients, there is an increasing need to define how we monitor response to novel therapies in these patients. Several factors ranging from the type of therapy used to the intrinsic biology of the tumor play a role in tumor response. All of these can aid in determining the ideal course of treatment, and may fluctuate over time, pending down-staging or progression of disease. Therefore, monitoring how disease responds to therapy requires standardization in order to ultimately optimize patient outcomes. Unfortunately, how best to do this remains a topic of debate among oncologists, pathologists, and colorectal surgeons. There may not be one single best approach. The goal of the present article is to shed some light on current approaches and challenges to monitoring treatment response for colorectal cancer.

Methods: A literature search was conducted utilizing PubMed and the OVID library. Key-word combinations included colorectal cancer metastases, neoadjuvant therapy, rectal cancer, imaging modalities, CEA, down-staging, tumor response, and biomarkers. Directed searches of the embedded references from the primary articles were also performed in selected circumstances.

Results: Pathologic examination of the post-treatment surgical specimen is the gold standard for monitoring response to therapy. Endoscopy is useful for evaluating local recurrence, but not in assessing tumor response outside of the limited information gained by direct examination of intra-lumenal lesions. Imaging is used to monitor tumors throughout the body for response, with CT, PET, and MRI employed in different circumstances. Overall, each has been validated in the monitoring of patients with colorectal cancer and residual tumors.

Conclusion: Although there is no imaging or serum test to precisely correlate with a tumor's response to chemo- or radiation therapy, these modalities, when used in combination, can aid in allowing clinicians to adjust medical therapy, pursue operative intervention, or (in select cases) identify complete responders. Improvements are needed, however, as advances across multiple modalities could allow appropriate selection of patients for a close surveillance regimen in the absence of operative intervention.

Retrospective analysis of pathological response in colorectal cancer liver metastases following treatment with bevacizumab

AIMS

Pathological response has been shown to be a predictor for survival after preoperative chemotherapy and surgical resection of colorectal cancer liver metastases. This retrospective analysis evaluated the effect on pathological response of adding bevacizumab to standard neoadjuvant chemotherapy in patients with metastatic colorectal cancer (mCRC) and liver metastases.

METHODS

Patient records from two Spanish centres were retrospectively examined for this analysis. Patients were included if they had stage IV mCRC with liver metastases, were unresectable or marginally resectable tumour before chemotherapy, and had oxaliplatin- or irinotecan-based chemotherapy, with or without bevacizumab, before resection. Tumour response was evaluated using response evaluation criteria in solid tumours (RECIST). Pathological response was assessed by pathologists blinded to treatment.

RESULTS

Ninety-five patients were included. Good pathological responses (PR0/PR1) were observed in 37 patients (39 %). The RECIST response rate was 51 %. Only 42 % of patients with a good pathological response had a complete or partial response according to RECIST, while 57 % of those with a poor pathological response had a complete or partial response according to RECIST. RECIST response rates were similar with and without bevacizumab, although 49 % of bevacizumab-treated patients had a good pathological response versus 27 % of those receiving chemotherapy alone (χ (2) P = 0.0302).

CONCLUSION

Pathological response may be a better indicator of treatment efficacy than RECIST for patients with mCRC receiving bevacizumab in the neoadjuvant setting. Adding bevacizumab to chemotherapy has the potential to increase pathological response rates. Well-designed prospective clinical studies are required to establish the efficacy and tolerability of this approach.

Recommendations of a group of experts for the pathological assessment of tumour regression of liver metastases of colorectal cancer and damage of non-tumour liver tissue after neoadjuvant therapy

Colorectal cancer (CRC) incidence has increased during the past decades in Spain, being the first malignant tumour in incidence. Observed mortality for CRC is mainly due to liver and lung metastases. The only curative treatment is surgery; new surgical techniques and neoadjuvant treatments have increased the number of surgery candidate patients. Patients should be managed with a multidisciplinary approach that includes imaging techniques, chemotherapy, surgery and pathological assessment. As an answer to this approach, a group of pathology experts interested on CRC liver metastases aimed to review the diagnosis and prognosis of liver mestastases and developed practical recommendations for its assessment. The expert group revised the current literature and prepared questions to be discussed based on available evidence and on their clinical practise. As a result, recommendations for the assessment of tumour regression of liver metastases are proposed, which could be implemented in oncology centres allowing assessment standardisation for these patients. Prospective multi-center studies to evaluate these recommendations validity will further contribute to improve the standard care of CRC liver metastases patients.

Histopathological evaluation of resected colorectal cancer liver metastases: what should be done?

Histological reporting of hepatic resections of colorectal liver metastases (CRLMs) is limited to confirmation of diagnosis and evaluation of resection margins. More exhaustive diagnostic reporting might be warranted. Here, we critically and systematically review the potentially important histological prognostic factors in CRLM. Histological features such as intrahepatic spread, resection margins, and tumour response to neoadjuvant chemotherapy have been defined. Intrahepatic spread (venous, lymphatic, bile duct and perineural invasion) was evaluated in a number of studies. Meta-analysis demonstrated a clear correlation between 5-year overall survival and both portal vein invasion (RR 1.8, 95% CI 1.3-2.5) and lymphatic invasion (RR 1.7, 95% CI 1.4-2.0). The impact of hepatic vein invasion and bile duct invasion on outcome is not clear. Perineural invasion was linked to survival in one study. Resection margin is an important prognostic factor; however, the significance of the width of negative margins remains controversial. Various studies have evaluated tumour response to neoadjuvant chemotherapy, but different grading systems were used, and definite recommendations cannot be made. In conclusion, with the high incidence of CRLM and the increase in the number of hepatic resections, we need well-defined prognostic factors, studied in homogeneous patient populations, to optimize diagnostic work-up. This review identifies several of these factors.

Assessment of chemotherapy response in colorectal liver metastases in patients undergoing hepatic resection and the correlation to pathologic residual viable tumor

BACKGROUND

The Response Evaluation Criteria in Solid Tumors (RECIST), which evaluates maximum tumor diameter only, is commonly used to determine response to chemotherapy in patients with colorectal liver metastases. Limitations of RECIST include its inability to assess the changes in tumor enhancement. The aim of this study was to assess the correlation of these criteria as well as the modified RECIST (mRECIST) with pathologic tumor response. A novel semi-automated volumetric assessment of tumor size was also investigated.

STUDY DESIGN

A review of a 1,948-patient prospective hepatic database to assess response and pathologic criteria was performed. Patients undergoing preoperative chemotherapy before hepatic resection for colorectal liver metastases were reviewed. Radiographic responses according to RECIST and mRECIST were determined. The percentage of viable tumor cells compared with the total tumor area was determined from the pathologic specimens.

RESULTS

We identified 38 patients with adequate imaging who had undergone anatomic hepatic resection and full pathologic evaluation. The percentages of residual viable tumor in the resected specimens were significantly different across RECIST categories (p = 0.045), but not mRECIST (p = 0.305). For mRECIST, there were improved and significant linear trends for residual viable tumor, necrosis, and necrosis + fibrosis when compared with RECIST (p = 0.056). Neither RECIST nor mRECIST responses were predictive of residual viable tumor burden in regression analyses. A novel semi-automated volumetric assessment of tumor size correlated well with pathologic tumor size.

CONCLUSIONS

Neither RECIST nor mRECIST were predictive of residual viable burden, although the linear trend for mRECIST and residual necrosis + fibrosis compared favorably with RECIST. Continued evaluation for tumor enhancement and standardization of tumor size remain a critical unmet need in patients with solid organ disease.

Staged hepatectomy for bilobar colorectal hepatic metastases

OBJECTIVES

This study describes the management of patients with bilobar colorectal liver metastases (CRLM).

METHODS

A retrospective collection of data on all patients with CRLM who were considered for staged resection (n= 85) from January 2003 to January 2011 was performed. Patients who underwent one hepatic resection were considered to have had a failed staged resection (FSR), whereas those who underwent a second or third hepatic resection to produce a cure were considered to have had a successful staged resection (SSR). Survival was calculated from the date of diagnosis of liver metastases. Complete follow-up and dates of death were obtained from the Government of Quebec population database.

RESULTS

Median survival was 46 months (range: 30-62 months) in the SSR group and 22 months (range: 19-29 months) in the FSR group. Rates of 5-year survival were 42% and 4% in the SSR and FSR groups, respectively. Fifteen of the 19 patients who remained alive at the last follow-up date belonged to the SSR group.

CONCLUSIONS

In patients in whom staged resection for bilobar CRLM is feasible, surgery would appear to offer benefit.

The oncosurgery approach to managing liver metastases from colorectal cancer: a multidisciplinary international consensus

An international panel of multidisciplinary experts convened to develop recommendations for the management of patients with liver metastases from colorectal cancer (CRC). The aim was to address the main issues facing the CRC hepatobiliary multidisciplinary team (MDT) when managing such patients and to standardize the treatment patients receive in different centers. Based on current evidence, the group agreed on a number of issues including the following: (a) the primary aim of treatment is achieving a long disease-free survival (DFS) interval following resection; (b) assessment of resectability should be performed with high-quality cross-sectional imaging, staging the liver with magnetic resonance imaging and/or abdominal computed tomography (CT), depending on local expertise, staging extrahepatic disease with thoracic and pelvic CT, and, in selected cases, fluorodeoxyglucose positron emission tomography with ultrasound (preferably contrast-enhanced ultrasound) for intraoperative staging; (c) optimal first-line chemotherapy-doublet or triplet chemotherapy regimens combined with targeted therapy-is advisable in potentially resectable patients; (d) in this situation, at least four courses of first-line chemotherapy should be given, with assessment of tumor response every 2 months; (e) response assessed by the Response Evaluation Criteria in Solid Tumors (conventional chemotherapy) or nonsize-based morphological changes (antiangiogenic agents) is clearly correlated with outcome; no imaging technique is currently able to accurately diagnose complete pathological response but high-quality imaging is crucial for patient management; (f) the duration of chemotherapy should be as short as possible and resection achieved as soon as technically possible in the absence of tumor progression; (g) the number of metastases or patient age should not be an absolute contraindication to surgery combined with chemotherapy; (h) for synchronous metastases, it is not advisable to undertake major hepatic surgery during surgery for removal of the primary CRC; the reverse surgical approach (liver first) produces as good an outcome as the conventional approach in selected cases; (i) for patients with resectable liver metastases from CRC, perioperative chemotherapy may be associated with a modestly better DFS outcome; and (j) whether initially resectable or unresectable, cure or at least a long survival duration is possible after complete resection of the metastases, and MDT treatment is essential for improving clinical and survival outcomes. The group proposed a new system to classify initial unresectability based on technical and oncological contraindications.

Detailed liver-specific imaging prior to pre-operative chemotherapy for colorectal liver metastases reduces intra-hepatic recurrence and the need for a repeat hepatectomy

BACKGROUND

Neoadjuvant chemotherapy for colorectal liver metastases (CRLM) reduces the accuracy of liver imaging which may understage patients pre-operatively. Retrospective review of a prospective database to determine whether liver-specific magnetic resonance imaging (MRI) prior to pre-operative chemotherapy affects intra-hepatic recurrence and long-term outcome after hepatectomy.

PATIENTS AND METHODS

Between 2003 and 2009, 242 patients with CRLM underwent a hepatectomy after ≥3 cycles of oxaliplatin or irinotecan-based chemotherapy. All had a liver-specific MRI immediately pre-operatively. The outcome of patients who had a liver-specific MRI prior to chemotherapy (PCI group, n= 92) was compared with those who did not (non-PCI group, n= 150).

RESULTS

A liver-specific MRI pre-chemotherapy changed the staging in 56% of patients. At a median (range) follow-up of 55 (6-94) months, there was a higher incidence of intra-hepatic recurrence at a new site in the non-PCI group (65% vs. 48% in the PCI group, P= 0.041) and an increased rate of recurrence in patients with the same number of lesions pre- and post-chemotherapy [hazard ratio (HR) 2.02, 1:10-3.37, P= 0.024]. The non-PCI group underwent more repeat hepatectomies than the PCI group (24.7% vs. 13%, P= 0.034), achieving similar long-term survival.

CONCLUSIONS

A liver-specific MRI prior to chemotherapy reduces intra-hepatic recurrence and avoids a repeat hepatectomy.

Complete clinical response of liver metastasis after chemotherapy: To resect or not?

This paper aims to update the therapeutical strategies in liver metastasis with complete clinical response (CCR) after chemotherapy and to determine if surgery is always necessary after CCR. The aim of chemotherapy is to achieve a good clinical response rather than CCR of liver metastasis. The CCR of liver metastasis after chemotherapy cannot be considered synonymous with a cure. The resection of the hepatic segment where there was hepatic metastases with CCR after chemotherapy theoretically prevents recurrence, improves survival and makes it possible to confirm whether there has been a complete pathological response. However, the medical literature about this topic is scarce and sometimes contradictory.