Does primary tumor location impact the prognosis of colorectal liver metastases patients after microwave ablation? - Lessons from 10 years' experience

Long-term results of liver thermal ablation in patients with hepatocellular carcinoma and colorectal cancer liver metastasis regarding spatial features and tumor-specific variables

PURPOSE

Colorectal cancer liver metastasis (CRLM) and hepatocellular carcinoma (HCC) are widely treated using microwave and radiofrequency ablation. Local tumor progression (LTP) may develop depending on the shortest vascular distance and large lesion diameter. This study aims to explore the effect of these spatial features and to investigate the correlation between tumor-specific variables and LTP.

METHODS

This is a retrospective study covering the period between January 2007 and January 2019. One hundred twenty-five patients (CRLM: HCC: 64:61) with 262 lesions (CRLM: HCC: 142:120) were enrolled. The correlation between LTP and the variables was analyzed using the chi-square test, Fischer's exact test, or the Fisher-Freeman-Halton test where applicable. The local progression-free survival (Loc-PFS) was analyzed using the Kaplan-Meier method. Univariable and multivariable Cox regression analyses were performed to identify prognostic factors.

RESULTS

Significant correlations were observed for LTP in both CRLM and HCC at a lesion diameter of 30-50 mm (P = 0.019 and P < 0.001, respectively) and SVD of ≤3 mm (P < 0.001 for both). No correlation was found between the ablation type and LTP (CRLM: P = 0.141; HCC: P = 0.771). There was no relationship between residue and the ablation type, but a strong correlation with tumor size was observed (P = 0.127 and P < 0.001, respectively). In CRLM, LTP was associated with mutant K-ras and concomitant lung metastasis (P < 0.001 and P = 0.003, respectively). In HCC, a similar correlation was found for Child-Pugh B, serum alpha-fetoprotein (AFP) level of >10 ng/mL, predisposing factors, and moderate histopathological differentiation (P < 0.001, P = 0.008, P = 0.027, and P < 0.001, respectively). In CRLM, SVD of ≤3 mm proved to be the variable with the greatest negative effect on Loc-PFS (P = 0.007), followed by concomitant lung metastasis (P = 0.027). In HCC, a serum AFP level of >10 ng/mL proved to be the variable with the greatest negative effect on Loc-PFS (P = 0.045).

CONCLUSION

In addition to the lesions' spatial features, tumor-specific variables may also have an impact on LTP.

Colorectal Liver Metastases: A Literature Review of Viable Surgical Options with a Special Focus on Microwave Liver Thermal Ablation and Mini-Invasive Approach

Colorectal cancer (CRC) is the third most common tumor worldwide and it is characterized in 20-30% of cases by liver involvement, which strongly affects the long-term patient outcome. There are many available therapies for liver colorectal metastases (CRLMs); the current standard of care is represented by liver resection, and when feasible, associated with systemic chemotherapy. Microwave thermal ablation (MWA) is a viable option in unresectable patients or to achieve treatment with a parenchymal spearing approach. A literature review was performed for studies published between January 2000 and July 2022 through a database search using PUBMED/Medline and the Cochrane Collaboration Library with the following MeSH search terms and keywords: microwave, ablation, liver metastases, colorectal neoplasm, and colon liver rectal metastases. The recurrence rate and overall patients' survival were evaluated, showing that laparoscopic MWA is safe and effective to treat CRLMs when resection is not feasible, or a major hepatectomy in fragile patients is necessary. Considering the low morbidity of this procedure, it is a viable option to treat patients with recurrent diseases in the era of effective chemotherapy and multimodal treatments.

Long-term outcomes following percutaneous microwave ablation for colorectal cancer liver metastases

PURPOSE

To evaluate the overall survival (OS), local progression-free survival (PFS) and prognostic factors of patients with colorectal cancer liver metastases (CRLM) undergoing microwave ablation (MWA).

METHOD

A total of 132 patients were retrospectively enrolled who had been treated between 2010 and 2018. For the evaluation of survival rates, all patients were divided according to their indications (curative n = 57 and debulking (patients with additional non-target extrahepatic metastases) n = 75). In total, 257 ablations were evaluated for prognostic factors: number of liver metastases, primary tumor origin (PTO), diameter and volume of metastases, duration and energy of ablation.

RESULTS

The OS was 32.1 months with 93.2% of patients free from recurrence at 28.3 months (median follow-up time). The one- year and three-year OS were 82.72% and 41.66%, respectively. The OS and recurrence-free survival of the curative group were statistically significantly higher than the debulking group (p < .001). Statistically significant prognostic factors for OS included the location of the primary tumor (p < .038) and the number of metastases (all p < .017). Metastasis diameter and volume and ablation duration and energy had no significant correlation with survival (p > .05).

CONCLUSIONS

Satisfactory OS and local tumor PFS can be achieved in patients with CRLM using MWA with the number of metastases and the location of the primary tumor influencing the outcome of patients. The metastasis's size and the duration and energy used for ablation were not of significant prognostic value.

[Colorectal cancer liver metastases: current state of the problem, priority treatment approaches]

The review is devoted to the world trends in epidemiology of colorectal cancer and treatment of colorectal cancer liver metastases. The authors analyze the effectiveness of traditional (resection) and modern minimally invasive methods of local destruction (radiofrequency thermoablation, microwave ablation, cryoablation), stereotactic radiotherapy, radiosurgery, targeted therapy and endovascular techniques (chemoinfusion, chemoembolization, radioembolization). It was emphasized that searching for new chemotherapeutic and targeted drugs is one of the reserve ways to improve treatment outcomes in patients with potentially resectable colorectal cancer liver metastases. The possibilities and prospects of liver transplantation as a priority treatment strategy for patients with unresectable bilobar colorectal cancer liver metastases are highlighted.

More Liver Metastases Detected Intraoperatively Indicates Worse Prognosis for Colorectal Liver Metastases Patients after Resection Combined with Microwave Ablation

Background

Whether more tumor numbers detected in surgery compared to preoperative image affecting survival of colorectal liver metastases (CRLM) patients after hepatectomy combined with microwave ablation (MWA) remains unclear.

Methods

From 2013 to 2018, 85 CRLM patients who underwent hepatectomy combined with MWA were retrospectively assessed. Compared to the tumor numbers in preoperative image, patients with equal intraoperative tumor numbers were defined as the equal number group (n = 45); patients detected more tumor numbers in surgery were defined as the more number group (n = 40). Clinicopathological factors and prognosis were compared between two groups.

Results

Compared to the equal number group, the more number group was characterized by more lymphatic metastasis, synchronous metastasis of liver lesion, and tumor numbers over 5 (all P < 0.05). Median survival time was 46.7 months and 26.8 months in the equal and more number group. Significantly worse overall survival (OS) was found in more number group to the equal number group (P = 0.027). In Cox analysis, more tumor number than image and high level of carbohydrate antigen 19-9 (CA19-9) were poor prognostic factors for OS.

Conclusion

In patients receiving hepatectomy combined with MWA, detecting more liver metastases in surgery than preoperative image indicates poor long-term survival. These patients were characterized by more lymphatic metastasis, synchronous metastasis of liver lesion, and tumor numbers over 5. Intensive follow-up to detect early recurrence and potent postoperative therapy to improve survival may be justified in patients detected more tumor numbers in surgery with a high CA19-9 level.

Assessing the Impact of Primary Tumour Location on Survival After Resection of Colorectal Liver Metastases: A Propensity Weighted Retrospective Cohort Study

BACKGROUND

Right-sided colonic tumours appear to have poorer survival after resection of colorectal liver metastases, although this may be confounded by various factors including advanced stage and emergency presentation.

METHODS

Medical records of consecutive patients undergoing resection of colorectal liver metastases at a single centre from 2008 to 2015 were retrospectively reviewed. Cases were categorised by primary tumour location (right colon, left colon, rectum). Each primary location was weighted using propensity scores to balance covariates, including staging and mode of presentation. Cox regression was then applied to derive multivariable hazard ratios (HR) of survival after liver resection. Primary outcomes were 10-year overall survival (OS) and 5-year disease-free survival (DFS) after liver resection based on PTL.

RESULTS

414 patients were included in the analysis. Left colonic tumours were significantly associated with higher rates of bilobar liver metastasis (36.2% vs. 20.1% and 30.1%) and larger maximum size of liver metastases compared with rectal and right-sided tumours, respectively. There was no difference in rates of extra-hepatic metastases, recurrence in the liver after resection or RAS, BRAF or p53 mutational status. After propensity weighting and Cox-regression, right-sided tumours were independently associated with significantly reduced 10 year OS (HR 1.56, 95% CI 1.03-2.36, p = 0.04) but not 5 year DFS (HR 1.36, 95% CI 0.89-2.08, p = 0.15).

CONCLUSIONS

Compared with left colonic and rectal tumours, right-sided colonic tumours are independently associated with inferior OS after resection of CRLM. This is despite higher rates of bilobar liver metastases and larger metastases with left-sided tumours.

Is precision medicine for colorectal liver metastases still a utopia? New perspectives by modern biomarkers, radiomics, and artificial intelligence

The management of patients with liver metastases from colorectal cancer is still debated. Several therapeutic options and treatment strategies are available for an extremely heterogeneous clinical scenario. Adequate prediction of patients’ outcomes and of the effectiveness of chemotherapy and loco-regional treatments are crucial to reach a precision medicine approach. This has been an unmet need for a long time, but recent studies have opened new perspectives. New morphological biomarkers have been identified. The dynamic evaluation of the metastases across a time interval, with or without chemotherapy, provided a reliable assessment of the tumor biology. Genetics have been explored and, thanks to their strong association with prognosis, have the potential to drive treatment planning. The liver-tumor interface has been identified as one of the main determinants of tumor progression, and its components, in particular the immune infiltrate, are the focus of major research. Image mining and analyses provided new insights on tumor biology and are expected to have a relevant impact on clinical practice. Artificial intelligence is a further step forward. The present paper depicts the evolution of clinical decision-making for patients affected by colorectal liver metastases, facing modern biomarkers and innovative opportunities that will characterize the evolution of clinical research and practice in the next few years.

Primary Tumor Sidedness, RAS and BRAF Mutations and MSI Status as Prognostic Factors in Patients with Colorectal Liver Metastases Treated with Surgery and Thermal Ablation: Results from the Amsterdam Colorectal Liver Met Registry (AmCORE)

The aim of this study was to assess primary tumor sidedness of colorectal cancer (CRC), rat sarcoma viral oncogene homolog (RAS) and v-raf murine sarcoma viral oncogene homolog B (BRAF) mutations and microsatellite instability (MSI) status as prognostic factors predicting complications, survival outcomes, and local tumor progression (LTP) following surgery and thermal ablation in patients with colorectal liver metastases (CRLM). This Amsterdam Colorectal Liver Met Registry (AmCORE) based study included 520 patients, 774 procedures, and 2101 tumors undergoing local treatment (resection and/or thermal ablation) from 2000 to 2021. Outcomes following local treatment were analyzed for primary tumor sidedness of CRC, RAS, and BRAF mutations and MSI status. The Kaplan–Meier method was used to estimate local tumor progression-free survival (LTPFS), local control (LC), distant progression-free survival (DPFS), and overall survival (OS). Uni- and multivariable analyses were performed based on Cox proportional hazards model. The chi-square test was used to analyze complications. Complications (p = 0.485), OS (p = 0.252), LTPFS (p = 0.939), and LC (p = 0.423) was not associated with tumor-sidedness. Compared to right-sided colon cancer (CC) (reference HR 1.000), DPFS was superior for left-sided CC and rectal cancer (p = 0.018) with an HR for left-sided CC of 0.742 (95% CI, 0.596–0.923) and for RC of 0.760 (95% CI, 0.597–0.966). Regarding RAS mutations, no significant difference was found in OS (p = 0.116). DPFS (p = 0.001), LTPFS (p = 0.039), and LC (p = 0.025) were significantly lower in the RAS mutation group. Though no difference in LTPFS was found between RAS wildtype and RAS mutated CRLM following resection (p = 0.532), LTPFS was worse for RAS mutated tumors compared to RAS wildtype following thermal ablation (p = 0.037). OS was significantly lower in the BRAF mutation group (p < 0.001) and in the MSI group (p < 0.001) following local treatment, while both did not affect DPFS, LTPFS, and LC. This AmCORE based study suggests the necessity of wider margins to reduce LTP rates in patients with RAS mutated CRLM, especially for thermal ablation. Upfront knowledge regarding molecular biomarkers may contribute to improved oncological outcomes.

Long-term outcome for colorectal liver metastases: combining hepatectomy with intraoperative ultrasound guided open microwave ablation versus hepatectomy alone

OBJECTIVE

To compare the long-term outcome of combining hepatectomy with intraoperative ultrasound (IOUS)-guided open microwave ablation (MWA) versus hepatectomy alone in patients with colorectal cancer liver metastases (CRLM).

METHOD

A retrospective analysis of patients with CRLM who underwent hepatectomy alone (HT group; 380 patients) or hepatectomy combined with IOUS-guided open MWA (HT + MWA group; 57 patients) from April 2002 to September 2018 was conducted at our center. A propensity score-matched (PSM) analysis was used to reduce data bias between the two groups.

RESULTS

The overall survival (OS) and disease-free survival (DFS) were not significantly different between the two groups after matching. Although intrahepatic recurrence was more frequent in the HT + MWA group in both the whole and matched cohort, the two groups exhibited similar rates of extrahepatic recurrence as well as concomitant intra- and extrahepatic recurrence. A higher number of CRLM (>3), larger maximum-size and absence of response to induction chemotherapy were independent risk factors for OS.

CONCLUSION

The oncological outcomes of hepatectomy combined with intraoperative open ablation was not significantly different to hepatectomy alone and should be considered as a safe and fair option for patients with difficultly resectable CRLM.

Primary tumour location is an important prognostic factor in colorectal cancer liver metastases following radiofrequency ablation

AIM

To examine the outcomes and different prognoses for colorectal cancer patients with liver metastases (CRCLM) treated with radiofrequency ablation (RFA) based on the origin of the primary tumour (rectum versus colon).

MATERIALS AND METHODS

Patients diagnosed with CRCLM from July 2011 to June 2018 were assessed in the study. The study included 114 patients with 176 lesions. All of the patients underwent RFA of their CRCLM. The overall survival (OS) and progression-free survival (PFS) were assessed with Kaplan-Meier survival function estimate curves and Cox regression analysis between the group of patients with rectal cancer liver metastases (RCLM) and colon cancer liver metastases (CCLM).

RESULTS

Patients with RCLM exhibited worse OS and PFS than those with CCLM. The 1-, 2-, and 3-year OS rates were 87.5%, 75%, and 54.2% in the RCLM group and 93.9%, 87.8%, and 81.8% in the CCLM group (p=0.001), respectively. The 1-, 2-, and 3-year PFS rates were 43.7%, 22.9%, and 20.8% in the RCLM group and 57.6%, 45.4%, and 36.5% in the CCLM group (p=0.001), respectively. Multivariate analysis showed that primary tumour location, carcinoembryonic antigen (CEA), and response to pre-ablation chemotherapy were independent variables for OS and PFS. The N state of the primary tumour also had a significant impact on OS.

CONCLUSION

This study showed that patients with CCLM had better prognoses than those with RCLM following RFA treatment. If patients intend to undergo RFA for CRCLM, the location of the primary tumour should be considered in the assessment of long-term therapeutic effects.

Impact of primary tumour location on colorectal liver metastases: A systematic review

BACKGROUND

Colorectal cancer (CRC) is the third most common cause of cancer-related death worldwide. Despite significant advances in screening, surgical management and adjuvant therapies, average 5-year survival seldom exceeds 60% in most developed nations. Metastatic disease represents the primary cause of mortality in patients with CRC, and the liver is the most common location for distant tumour spread. Up to 25% of patients are found to have synchronous liver metastases at the time of diagnosis and a further 30%-40% will develop metachronous disease in the course of follow-up. It has been suggested that primary tumour location [right side versus left side, primary tumour location (PTL)] can influence oncological outcomes in this patient group and that this should be considered in prognostic models and therapeutic decision-making algorithms. This suggestion is not universally accepted and there have been conflicting reports in the literature to date.

AIM

To provide a comprehensive summary of the available evidence regarding the impact of PTL on oncological outcomes in patients with colorectal cancer liver metastases (CRCLM).

METHODS

MEDLINE, EMBASE and COCHRANE were searched for relevant publications using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. Data on oncological outcomes was then extracted from full text articles that met the predefined inclusion criteria.

RESULTS

A total of 41 studies were identified that met predefined inclusion criteria for this review. In 21 out of 38 studies that provided data on overall survival, a statistically significant improvement in overall survival was reported in patients with left sided primary tumours. These studies included a total of 13897 patients compared with 4306 patients in the studies that did not show a significant difference. Eight studies noted a similar trend towards improved disease-free or progression-free survival. Several authors observed distinct patterns of relapse after treatment of hepatic metastases according to PTL; for example hepatic recurrence after treatment of CRCLM appears to occur more aggressively with right-sided CRC.

CONCLUSION

Taken together, the findings of the present review indicate that PTL may have a role as an independent prognostic factor when determining treatment and disease surveillance strategies in CRC. The mechanisms responsible for this variation remain poorly understood, but are likely to relate to molecular, histological and embryological differences, as well as inherent differences in therapeutic sensitivity.

Primary tumor location affects recurrence-free survival for patients with colorectal liver metastases after hepatectomy: a propensity score matching analysis

Background

Whether primary tumor location of colorectal cancer (CRC) affects survival of patients after resection of liver metastases remains controversial. This study was conducted to investigate the differences in clinicopathological characteristics and prognosis between right-sided CRC and left-sided CRC patients with liver metastases after hepatectomy.

Methods

From 2002 to 2018, 611 patients with colorectal liver metastases (CRLM) who underwent hepatectomy at our center were reviewed. Primary tumors located from the cecum to transverse colon were defined as right-sided group (n = 141); tumors located from the splenic flexure to rectum were defined as left-sided group (n = 470). Patients were compared between two groups before and after a 1:1 propensity score matching (PSM) analysis.

Results

Before PSM, median survival time and 5-year overall survival (OS) rate in right-sided group were 77 months and 56.3%, and those in left-sided group were 64 months and 51.1%, respectively. After PSM, median survival time and 5-year OS rate in right-sided group were 77 months and 55.9%, and those in left-sided group were 58.8 months and 47.3%, respectively. The OS rates did not differ between two groups before and after PSM (P = 0.575, P = 0.453). However, significant different recurrence-free survival (RFS) rate was found before and after PSM between right-sided and left-sided group (P = 0.028, P = 0.003).

Conclusions

Compared to patients with left-sided primary tumors, patients with right-sided primary tumors had a worse RFS but similar OS. Careful preoperative evaluation, intensive preoperative chemotherapy, and frequent follow-up to detect early recurrence might be justified for CRLM patients with right-sided primary tumors.

Primary tumor location and the prognosis of patients after local treatment of colorectal liver metastases: a systematic review and meta-analysis

BACKGROUND

Recently numerous studies have reported primary tumor location as a potential prognostic factor after surgery for colorectal liver metastases (CRLM). The aim of this study was to comprehensively review and analyze all the available literature on the impact of primary tumor location in patients after local treatment of CRLM.

METHODS

Studies examining the association of right- and left-sided colorectal cancer and overall survival (OS) and recurrence free survival (RFS) after local treatment (resection and/or ablation) of CRLM were identified. Random-effects models were used for both clinicopathological and outcome variables. Pooled hazard ratios (HR) with 95% confidence intervals (95% CI) were shown for both OS and RFS.

RESULTS

Ten studies (including 11 patient cohorts) were eligible for inclusion, representing 3962 patients. Right-sided tumors (i.e. proximal to the splenic flexure) were observed in 1340 patients (33.8%). Median follow-up ranged from 25 to 137 months. Patients with right-sided tumors had a significantly decreased OS (HR 1.60, 95% CI 1.30-1.98, p < 0.001) and RFS (HR 1.35, 95% CI 1.04-1.77, p = 0.03), when compared to patients with left-sided tumors.

CONCLUSION

This meta-analysis suggests that patients with right-sided primaries suffer from a worse prognosis, compared to patients with left-sided primaries in patients after local treatment of CRLM.

The primary tumor location impacts survival outcome of colorectal liver metastases after hepatic resection: A systematic review and meta-analysis

OBJECTIVE

Location of the primary tumor side has become an increasingly prognostic factor for colorectal liver metastasis. The present study was to perform a meta-analysis to investigate if primary right-sided tumor impacted on long-term survival outcome of colorectal liver metastases following local treatment.

METHOD

Eligible trials were identified from the Embase, PubMed, Web of Science and the Cochrane database that were published before October in 2018. English language trials that compared long-term survival outcome of primary left-sided tumor with right-sided tumor colorectal liver metastases following local treatment were included. Hepatic resection for colorectal liver metastases was investigated. The main study outcomes included overall survival and disease free survival of primary right-sided colorectal liver metastases following local treatment. The risk factors of largest tumor size, primary node metastases, multiple tumor and RAS mutation were also analyzed. A systematic review and meta-analysis was done using a fixed-effects model. Hazard ratio with a 95% confidence interval was used to measure the pooled effect.

RESULTS

A total of twelve studies with 6387 patients were included. For primary right-sided colorectal liver metastases patients following hepatic resection, the overall pooled HR for 5-year overall survival rate was 1.354 (95% CI: 1.238-1.482; p = 0.000; I² = 33.7%, p = 0.138). The pooled HR for 5-year disease free survival rate of primary right-sided CRLM in the included studies calculated using the fix-effects model was 1.104 (95% CI: 0.987-1.235; p = 0.084; I² = 0%, p = 0.477).

CONCLUSION

It demonstrated that primary right-sided for colorectal liver metastases location was a significantly worse prognostic factor in terms of overall survival.