Neoadjuvant chemotherapy for resectable colorectal liver metastases: what is the evidence? Results of a systematic review of comparative studies

Surgical Therapy in Patients with Colorectal Liver Metastases

BACKGROUND

Liver metastases (LM) occur in about 50% of patients with colorectal cancer. Besides the multimodal treatment of the primary tumor, the only way to cure patients with colorectal LM (CRLM) is complete resection. Different surgical procedures for this purpose are available depending on location, size, and number of LM. Additional concepts for patients with primary unresectable LM exist, ranging from Chemotherapy to induction of liver hypertrophy and even liver transplantation. This review intends to provide an overview of the surgical approach.

SUMMARY

Surgical options in the treatment of CRLM are defined and limited by their intraparenchymal location and their proximity to major vessels and intrahepatic bile ducts. Lesions located in the periphery can be excised in a parenchymal sparing fashion with a small tumor-surrounding resection margin of healthy liver parenchyma. If this is not possible, anatomical resections based on segmental boundaries are performed. In these cases, a sufficient functional volume of liver parenchyma after resection (future liver remnant volume [FLRV]) has to be preserved. This FLRV depends on various factors such as bodyweight and possible preexisting liver damage, such as cirrhosis, fibrosis, or chemotherapy-induced liver impairment. Liver hypertrophy via partial occlusion of the portal venous system is a standard procedure for patients with primary unresectable LM to increase FLRV. Furthermore, discussion of liver transplantation in cases of unresectable LM is gaining importance again. A combination of surgery and adjuvant and/or neoadjuvant chemotherapy may be indicated in individual cases, but general evidence-based recommendations cannot be given without further studies.

KEY MESSAGES

Surgical removal of all metastases represents the only option of a potentially curative treatment of UICC stage IV colorectal carcinoma with liver involvement. An interdisciplinary approach consisting of chemotherapeutical downsizing and hypertrophy of the FLRV offers potential curative treatment for patients with initially unresectable metastases. For all others, liver transplantation is seeing a revival showing promising results in overall survival compared to chemotherapy alone.

Tailored Systemic Therapy for Colorectal Cancer Liver Metastases

Liver metastases are the most common site of metastatic spread in colorectal cancer. Current treatment approaches involve effective systemic therapies in combination with surgical and/or interventional strategies. Multimodal strategies greatly improved clinical outcomes of patients with metastatic colorectal cancer over the last decades. Identification of predictive and prognostic biomarkers helped to comprehensively refine individual targeted treatment approaches and resulted in median overall survival rates of 30 months or longer. Current guidelines, thus, recommend treatment selection according to patients' performance status, tumor localization and stage as well as the tumor's molecular and genetic status. Here, we outline the latest developments in molecular decision-making for patients with upfront resectable, potentially or initially unresectable and non/never-resectable colorectal cancer liver metastases.

The prognostic significance of a histological response to preoperative chemotherapy in patients with synchronous colorectal liver metastases

Objective: Preoperative chemotherapy (PC) for colorectal liver metastasis (CRLM) is widely used to improve prognosis, but its clinical benefit has not been fully established. This study aimed to assess the effectiveness of PC for synchronous CRLM and the correlation between the histological response to PC and survival. Summary of Background Data: We enrolled 69 patients who underwent initial hepatectomy for synchronous CRLM between 2004 and 2018 at Gifu University Hospital. Methods: We retrospectively analyzed the clinicopathological factors and outcomes of 69 patients who underwent hepatectomy after receiving PC (PC group: n = 43) or who underwent upfront hepatectomy (non-PC group: n = 26). In the PC group, the patients were divided into the Grade 1 (n = 27) and Grade 2/3 (n = 16) groups according to their histological responses to PC. Results: The median survival and 5-year overall survival (OS) rates were 80.9 months and 61.5%, respectively, in the PC group and 71.7 months and 61.5%, respectively, in the non-PC group ( P = 0.867). Regarding recurrence-free survival (RFS) and remnant liver-RFS, there were no significant differences between the two groups ( P = 0.087 and 0.291). However, in a subgroup analysis, the median 5-year OS, RFS, and remnant liver RFS were significantly longer in the Grade 2/3 than Grade 1 group ( P = 0.008, P = 0.002, and P < 0.001, respectively). Conclusions: Some patients benefit from PC, and the histological response to PC had prognostic significance for patients with synchronous CRLM.

Prognostic impact of additive chemotherapy after curative resection of metachronous colorectal liver metastasis: a single-centre retrospective study

Background

A prognostic benefit of additive chemotherapy in patients following resection of metachronous colorectal liver metastases (CRLM) remains controversial. Therefore, the goal of this retrospective study was to investigate the impact of perioperative chemotherapy on disease-free survival (DFS) and overall survival (OS) of patients after curative resection of metachronous CRLM.

Methods

In a retrospective single-centre study, patients after curative resection of metachronous CRLM were included and analysed for DFS and OS with regard to the administration of additive chemotherapy. The Kaplan-Meier method was applied to compare DFS and OS while Cox regression models were used to identify independent prognostic variables.

Results

Thirty-four of 75 patients were treated with additive 5-FU based chemotherapy. OS was significantly prolonged in this patient subgroup (62 vs 57 months; p = 0.032). Additive chemotherapy significantly improved 10-year survival rates (42% vs 0%, p = 0.023), but not 5-year survival (58% vs 42%, p = 0.24). Multivariate analysis identified additive chemotherapy (p = 0.016, HR 0.44, 95% CI 0.23–0.86), more than five CRLM (p = 0.026, HR 2.46, 95% CI 1.16–10.32) and disease recurrence (0.009, HR 2.70, 95% CI 1.29–5.65) as independent risk factors for OS.

Conclusion

Additive chemotherapy significantly prolonged OS and 10-year survival in patients after curative resection of metachronous CRLM. Randomized clinical trials are needed in the future to identify optimal chemotherapy regimens for those patients.

Case Report: Cetuximab in Combination With Chemotherapy for the Treatment of Multifocal Hepatic Metastases From Colorectal Cancer Guided by Genetic Tests

Hepatic metastases were reported in up to 70% of colorectal cancer patients, among which multifocal hepatic metastasis represents one of the complications that lead to poor prognosis. The majority of the patients carrying multifocal hepatic metastases required pharmaceutical treatments to reduce the tumor size prior to surgical resection. However, the clinical responses to pharmaceutical agents were difficult to predict due to the heterogeneous nature of the multifocal tumors. Here, we report a case with multifocal hepatic metastases from colorectal cancer that was resistant to the primary chemotherapy and Bevacizumab plus chemotherapy, but responded to the combined therapy of Cetuximab and FOLFOX. Genetic tests had revealed that the tumor was highly metastatic due to the mutations of the WNT signaling pathway, and the metastatic tumors might be sensitive to Cetuximab. Consistent with the molecular characterizations, the metastatic tumors continue to emerge after chemotherapy, and rapidly relapsed in great numbers after liver resection. However, the combined therapy of Cetuximab and FOLFOX guided by the genetic tests significantly reduced the size and number of metastatic tumors. To conclude, deciphering the mutation profiles of multifocal metastatic tumors may guide the determination of treatment tactics, which may benefit the patients with non-resectable advanced carcinoma.

The survival benefit of neoadjuvant chemotherapy for resectable colorectal liver metastases with high tumor burden score

BACKGROUND

The indications for neoadjuvant chemotherapy (NAC) in resectable colorectal liver metastases (CRLMs) remain unclear. Tumor burden score (TBS) is a prognostic tool based on tumor size and number of tumors. However, its utility in the NAC setting for initially resectable CRLM has never been investigated.

METHODS

TBS is a distance from the origin on a Cartesian plane to the coordinates (x, y) = (tumor size in centimeter, number of tumors). TBS < 3 was defined as "TBS-low", whereas TBS ≥ 3 as "TBS-high". Between 2008 and 2018, 102 patients who underwent hepatectomy for resectable CRLM were retrospectively analyzed using the Kaplan-Meier method and Cox proportional hazards regression models.

RESULTS

Among the TBS-low (n = 46) and TBS-high (n = 56) groups, baseline patient characteristics were mostly similar except for TBS-related parameters. NAC was more frequently administered in the TBS-high group (p = 0.038). The overall survival (OS) rates were similar between the two groups. Subgroup analysis showed that NAC was associated with non-significantly improved 5-year OS in the TBS-high group [76.1% with NAC and 54.9% without NAC (p = 0.093)]. In multivariate analysis, NAC was an independent prognostic factor for favorable OS only in the TBS-high group, while adjuvant chemotherapy (AC) was associated with improved OS only in the TBS-low group.

CONCLUSION

In patients with resectable CRLM, the TBS-high population had a survival benefit from NAC, while the TBS-low population benefited from AC. TBS may serve as an indicator for patients who will benefit from NAC.

Response to preoperative chemotherapy: impact of change in total burden score and mutational tumor status on prognosis of patients undergoing resection for colorectal liver metastases

BACKGROUND

Progression of colorectal liver metastasis (CRLM) on preoperative chemotherapy has been associated with a worse prognosis compared with patients who have responsive disease. Defining response can be challenging as traditional criteria largely assess only tumor size.

METHODS

Patients who underwent hepatectomy between 2010 and 2017 were identified using a multi-centric database. This study aimed to define the impact of preoperative chemotherapy response relative to initial tumor burden score (TBS) and determine impact of clinico-pathological variables on overall survival (OS).

RESULTS

Among 784 patients who received preoperative chemotherapy, the regimen was oxaliplatin- (66%) or irinotecan-based (34%). Among patients with a TBS<6 at diagnosis, genetic status was the most important prognostic variable. Patients with a TBS<6, 5-year OS was 55%, 35%, and 0% for patients with KRAS/NRAS/BRAF wild-type, KRAS/NRAS, and BRAF mutations, respectively. Among patients who presented with CRLM with a TBS≥6, only Δ-TBS was prognostically important and patients with a Δ-TBS ≥ -10% had a 5-year OS of 27% compared with 49% for patients with a Δ-TBS < -10%.

CONCLUSIONS

Prognostic stratification of patients with CRLM receiving preoperative chemotherapy should be multi-faceted and include consideration of initial tumor burden, change in tumor burden due to chemotherapy, and tumor genetic status.

Initial systemic chemotherapeutic and targeted therapy strategies for the treatment of colorectal cancer patients with liver metastases

Introduction: The liver is the most common metastatic site in colorectal cancer with more than half the patients developing a liver metastasis either at the time of their diagnosis (synchronous) or later (metachronous). Surgical resection remains the principal curative approach that offers significant survival improvements. However, upfront surgery is only possible in about 10-20% of patients at the time of diagnosis, making the consideration of other treatment modalities essential. Areas covered: In this review, the authors provide an overview of the standard approaches for the initial management of patients with colorectal cancer with liver metastases. They then provide an up-to-date discussion of first-line systemic chemotherapy/targeted therapy options in the contexts of initially resectable and unresectable disease and review toxicities and complications following these options. Expert opinion: Advances in chemotherapeutic agents and biological targeted therapies have improved the prognosis of colorectal cancer with liver metastases. However, there is still no 'single best approach', making further trials necessary to provide more evidence.

Implication of primary tumor location for the indication of preoperative chemotherapy in patients with colorectal liver metastases

BACKGROUND

The benefit of preoperative chemotherapy for colorectal liver metastases (CRLM) remains uncertain. The aim was to clarify the effect of preoperative chemotherapy on CRLM according to the primary tumor location.

METHODS

Among a total cohort of 163 patients who underwent curative hepatectomy for CRLM, 36 patients had a right-sided and 127 had a left-sided primary tumor. According to the performance of preoperative chemotherapy, survival analysis was conducted and prognostic factors were identified.

RESULTS

Preoperative chemotherapy was administered to 17 patients (47.2%) with a right-sided and 74 (58.3%) with a left-sided primary tumor (P = 0.24). Among the patients who received preoperative chemotherapy, overall survival (OS) and disease-free survival (DFS) were similar between patients with right- and left-sided primary tumors (P = 0.36 and P = 0.44, respectively). Among the patients who underwent upfront hepatectomy, the OS and DFS of patients with a right-sided primary tumor were worse than those with a left-sided primary tumor (P = 0.02 and P = 0.025, respectively). Among the patients who underwent upfront surgery, the right-sided primary tumor was identified as an independent poor prognostic factor for OS (hazard ratio 3.44, P = 0.021).

CONCLUSION

The existence of a right-sided primary tumor may be an indication of preoperative chemotherapy for patients with CRLM.

Colorectal liver metastases: An update on multidisciplinary approach

Liver metastasis is the commonest form of distant metastasis in colorectal cancer. Selection criteria for surgery and liver-directed therapies have recently been extended. However, resectability remains poorly defined. Tumour biology is increasingly recognized as an important prognostic factor; hence molecular profiling has a growing role in risk stratification and management planning. Surgical resection is the only treatment modality for curative intent. The most appropriate surgical approach is yet to be established. The primary cancer and the hepatic metastasis can be removed simultaneously or in a two-step approach; these two strategies have comparable long-term outcomes. For patients with a limited future liver remnant, portal vein embolization, combined ablation and resection, and associating liver partition and portal vein ligation for staged hepatectomy have been advocated, and each has their pros and cons. The role of neoadjuvant and adjuvant chemotherapy is still debated. Targeted biological agents and loco-regional therapies (thermal ablation, intra-arterial chemo- or radio-embolization, and stereotactic radiotherapy) further improve the already favourable results. The recent debate about offering liver transplantation to highly selected patients needs validation from large clinical trials. Evidence-based protocols are missing, and therefore optimal management of hepatic metastasis should be personalized and determined by a multi-disciplinary team.

Survival and Prognostic Factors of Colorectal Liver Metastases After Surgical and Nonsurgical Treatment

OBJECTIVE

Colorectal cancer is one leading cause of cancer-related death worldwide, and distant metastases determine an unfavorable prognosis. Surgical resection of colorectal liver metastases (CRLM) improves survival and provides the chance for cure. The aim of this study was to prospectively analyze the outcome of patients with CRLM in a population-based manner, and thereby, to compare the prognosis of patients undergoing resection with those receiving nonsurgical treatment. Moreover, we set out to identify and confirm important prognostic factors after resection of CRLM.

PATIENTS AND METHODS

We analyzed the outcome of 506 patients diagnosed with CRLM in our institution from 1996 to 2011. Survival and the impact of clinical and pathologic factors were analyzed by univariate analysis. Important independent prognostic factors were analyzed by multivariate analysis.

RESULTS

The 5-year overall survival rate (5y-OSR) for patients receiving resection of CRLM (n = 152) was 46% (95% confidence interval (CI), 37%-54%) compared with a 5y-OSR of 6% (95% CI, 4%-9%) for patients treated nonsurgically (n = 354). There was no perioperative mortality. Multivariate analysis revealed, among other factors, good performance status of the patient (low American Society of Anesthesiologists score), the absence of extrahepatic metastases, < 5 metastatic lesions, and a tumor-free resection margin (R0) as important, independent prognostic factors. Importantly, repeated hepatic resections of CRLM performed in 13 patients were associated with an excellent outcome (5y-OSR, 47%; 95% CI, 17%-72%).

CONCLUSION

Surgical resection, which can be performed with tolerable site-effects, is the first choice for patients diagnosed with metachronous and synchronous CRLM. Of note, repeated resections should be advised in recurrent intrahepatic colorectal cancer whenever possible.

Preoperative selection of patients with colorectal cancer liver metastasis for hepatic resection

Surgical resection of colorectal liver metastases (CRLM) has a well-documented improvement in survival. To benefit from this intervention, proper selection of patients who would be adequate surgical candidates becomes vital. A combination of imaging techniques may be utilized in the detection of the lesions. The criteria for resection are continuously evolving; currently, the requirements that need be met to undergo resection of CRLM are: the anticipation of attaining a negative margin (R0 resection), whilst maintaining an adequate functioning future liver remnant. The timing of hepatectomy in regards to resection of the primary remains controversial; before, after, or simultaneously. This depends mainly on the tumor burden and symptoms from the primary tumor. The role of chemotherapy differs according to the resectability of the liver lesion(s); no evidence of improved survival was shown in patients with resectable disease who received preoperative chemotherapy. Presence of extrahepatic disease in itself is no longer considered a reason to preclude patients from resection of their CRLM, providing limited extra-hepatic disease, although this currently is an area of active investigations. In conclusion, we review the indications, the adequate selection of patients and perioperative factors to be considered for resection of colorectal liver metastasis.

Predictive factors for time to recurrence, treatment and post-recurrence survival in patients with initially resected colorectal liver metastases

BACKGROUND

Despite progress in resection for colorectal liver metastases (CLM), the majority of patients experience recurrence. We aimed to evaluate factors influencing time to recurrence (TTR), treatment and post-recurrence survival (PRS) related to site of recurrence.

METHODS

This is a retrospective population-based cohort study (1998-2012) of consecutive patients without extrahepatic disease treated with resection for CLM in a referral centre.

RESULTS

A total of 311 patients underwent resection for CLM. After a median follow-up of 4.2 years (range 1.2-15.2), 209 (67.4 %) patients developed recurrence, hepatic 90, extrahepatic 59 and both 60. Median TTR was 14.0 months, and 5-year recurrence-free status was 25.7 %. Five- and 10-year overall survival (OS) was 38.8 and 22.0 %, respectively. Median OS was 45 months. A multivariate analysis displayed synchronous disease (hazard ratio (HR) 1.50), American Society of Anaesthesiologists (ASA) score (HR 1.40), increasing number (HR 1.24) and size of metastases (HR 1.08) to shorten TTR (all p < 0.05). Perioperative chemotherapy (n = 59) increased overall TTR (HR 0.63) and overall survival (OS; HR 0.55). Hepatic TTR was correlated to synchronous disease (HR 2.07), number of lesions (HR 1.20), R1 resection (HR 2.00) and ASA score (HR 1.69), whereas extrahepatic TTR was correlated to N stage of the primary (HR 1.79), number (HR 1.27) and size of metastases (HR 1.16). Single-site recurrence was most common (135 of 209, 64.5 %), while 58 patients had double- and 16 triple-site relapses. Median PRS was 24.3 months. There was a difference in median PRS (months) according to site of relapse: liver 30.5, lung 32.3, abdominal 22.0, liver and lung 14.3, others 14.8 (p = 0.002). Repeated liver resections were performed in n = 57 patients resulting in 40.6 months median OS and 36.8 % 5-year OS.

CONCLUSIONS

An adverse overall TTR was correlated to number and size of metastases, ASA score and synchronous disease. Perioperative chemotherapy increased TTR and OS after surgery for CLM. Patients with solitary post-resection relapse in the liver or lungs had the potential for longevity due to multimodal treatment.