Contrast-enhanced intraoperative ultrasound improved hepatic recurrence-free survival in initially unresectable colorectal cancer liver metastases

BACKGROUND

We aimed to evaluate the role of Contrast-enhanced intraoperative ultrasound (CE-IOUS) with perfluorobutane microbubbles (Sonazoid) in improving the prognosis of patients with unresectable colorectal cancer liver metastases (CRLM).

METHODS

A total of 130 Patients with unresectable CRLM who underwent curative hepatic resection at our institute were retrospectively analyzed. Of these 130 enrolled patients, 67 underwent intraoperative ultrasound alone (IOUS group); 63 underwent additional CE-IOUS and IOUS (CE-IOUS group). Normalized inverse probability treatment weighting (IPTW) was employed to balance baseline characteristics between groups. Hepatic recurrence-free survival (HRFS) and overall survival (OS) were compared.

RESULTS

The treatment strategy was altered in 25 patients (25/63, 39.9%) due to the additional use of CE-IOUS. After applying IPTW, the CE-IOUS group exhibited a significantly lower rate of hepatic recurrence (hazard ratio [HR], 0.55; 95% confidence interval [CI] 0.32-0.95; P = 0.032). Subgroup analysis showed that CE-IOUS provided a significant benefit over IOUS in patients with bilobar liver metastases (P = 0.007), or with a number of live tumors < 3 (P = 0.021), or without DLM (P = 0.018), or with extrahepatic metastasis (P = 0.034), or with a minimum of 6 cycles of systemic therapy (P = 0.03).

CONCLUSIONS

CE-IOUS is necessary for unresectable CRLM after preoperative chemotherapy, as it enhances detection accuracy and improves the prognosis of unresectable CRLM patients.

On-site recurrence risk after parenchymal R1 liver resection for colorectal metastases

BACKGROUND

Histologic microscopic positive resection margin is a debated prognostic factor in patients resected for colorectal liver metastases. This study aimed to assess whether patients with R1 resection experience recurrence at the site of the resection (on-site recurrence) and to identify predictive factors for recurrence profiles in patients with R1 margins after resection of colorectal liver metastases.

METHODS

All surgical colorectal liver metastasis resection cases with R1 parenchymal margin from September 2014 to March 2020 in our center were retrospectively included. Imaging was reviewed for each metastasis. All the analyses were performed per metastasis. Recurrence location was examined for each metastasis according to the site of the R1 margin and defined as on-site when recurrence was at the same place of the resected lesion. Prognostic factors for recurrence type were assessed using logistic regression.

RESULTS

Of 700 patients who underwent liver resection for colorectal liver metastases, 105 (15%) had at least 1 metastasis with R1 resection margin, representing 6.8% per metastasis. The median follow-up was 34 months. Overall recurrence occurred in 130 metastases (83.3%) with intrahepatic recurrence in 106 metastases (80.9%). On-site recurrence was observed for 49 metastases (31.4%) and isolated (without an additional recurrence site) for 20 metastases (12.8%). The on-site recurrence did not impact overall survival. Three predictive factors for on-site recurrence were found in the multivariate logistic regression: synchronous metastases, nonanatomic resection, and pathologic response tumor regression grade 4-5.

CONCLUSION

Intrahepatic localization of recurrence is more frequent than on-site recurrence after R1 parenchymal resection. Synchronous metastases, nonanatomic resection, and tumor regression grade 4-5 may impact the risk of on-site recurrence.

Genomic Predictors of Recurrence Patterns After Complete Resection of Colorectal Liver Metastases and Adjuvant Hepatic Artery Infusion Chemotherapy

BACKGROUND

Despite curative hepatectomy, most colorectal liver metastasis (CRLM) patients relapse locally within 2 years. Genomic predictors for hepatic recurrence are poorly understood. This study was designed to identify genomic signatures for recurrence in resected CRLM patients treated with adjuvant hepatic artery infusion (HAI) and/or systemic (SYS) chemotherapy.

METHODS

Patients undergoing curative hepatectomy and adjuvant HAI+SYS or SYS between January 2000 and October 2017 with next-generation sequencing data were catalogued. Gene and signaling-level alterations were checked for association with time to any (AR), liver (LR), and extrahepatic recurrence (ER) by using Kaplan-Meier analysis.

RESULTS

Of 172 receiving HAI+SYS, 100 patients recurred, with 69 LR and 83 ER. Five- and ten-year LR-free rates were 57% (95% confidence interval [CI] 48-65%) and 51% (95% CI 41-60%), respectively. Five- and 10-year ER-free, rates were 51% (95% CI 43-58%) and 45% (95% CI 36-54%), respectively. More ER was observed with tumors harboring altered KRAS (38% [95% CI 25-50%] vs. 63% [95% CI 53-71%], p-adj = 0.003) and RAS/RAF (36% [95% CI 25-48%] vs. 66% [95% CI 56-74%], p-adj < 0.001) than wild-type. Co-altered RAS/RAF-TP53 was associated with worse AR (26% [95% CI 14-40%] vs. 48% [95% CI 39-57%], p-unadj < 0.001), ER (30% [95% CI 17-45%] vs. 62% [95% CI 53-70%], p-unadj < 0.001), and LR rate (40% [95% CI 24-57%] vs. 70% [95% CI 60-77%], p-unadj = 0.002). On multivariable analysis, controlling for clinical risk score, ablation, margin status, and primary T-stage, co-altered RAS/RAF-TP53 was associated with increased risk for AR (HR = 2.14, 95% CI 1.38-3.31, p-unadj < 0.001), LR (HR = 1.79, 95% CI 1.06-3.02, p-unadj = 0.029), and ER (HR = 2.81, 95% CI 1.78-4.44, p-unadj < 0.001).

CONCLUSIONS

Altered KRAS, RAS/RAF, and RAS/RAF-TP53 associated with earlier local and distant recurrence in resected CRLM patients receiving adjuvant HAI+SYS. Co-altered RAS/RAF-TP53 was a novel predictor of LR warranting investigation of whether genomic cooperativity is associated with this relapsing phenotype. Systemic therapies tailored to high-risk tumor biology are needed to reduce distant relapse after hepatectomy.

Disappearing Colorectal Liver Metastases: Do We Really Need a Ghostbuster?

The development of new systemic treatment strategies has resulted in a significant increase in the response rates of colorectal liver metastases (CRLM) in the last few years. Although the radiological response is a favorable prognostic factor, complete shrinkage of CRLM, known as disappearing liver metastases (DLM), presents a therapeutic dilemma, and proper management is still debated in the literature. In fact, DLM is not necessarily equal to cure, and when resected, pathological examination reveals in more than 80% of patients a variable percentage of the tumor as residual disease or early recurrence in situ. Moreover, while a higher incidence of intrahepatic recurrence is documented in small series when surgery is avoided, its clinical significance for long-term OS is still under investigation. In light of this, a multidisciplinary approach and, in particular, radiologists’ role is needed to assist the surgeon in the management of DLM, thanks to emerging technology and strategy. Therefore, the aim of this review is to provide an overview of the DLM phenomenon and current management.

Colorectal Liver Micrometastases: Association with RAS/TP53 Co-Mutation and Prognosis after Surgery

BACKGROUND

Micrometastases, defined as microscopic cancer cells spatially separated from the macroscopically evident metastasis, are identified in 24% to 56% of resected colorectal liver metastases (CLMs). Somatic gene mutations have emerged as independent prognostic factors in CLM. This study aimed to determine the prognostic impact and risk factors for the presence of micrometastases, including somatic gene mutations.

STUDY DESIGN

Prospective evaluation for micrometastases was performed at 2 centers in the US and France from 2015 to 2019. CLM specimens were cut radially from the tumor margin to surrounding grossly normal liver for a distance of 2 cm. Depending on CLM size, 3 to 8 specimens per patient were submitted for microscopic analysis. Somatic gene mutations were detected by next-generation sequencing.

RESULTS

Among 140 patients undergoing CLM resection in the US (n = 84) and France (n = 56), 36 (26%) patients were found to have micrometastases. Five-year overall and recurrence-free survival rates with micrometastases were 39% and 0%, respectively, compared with 61% and 20% without micrometastases (both p < 0.05). In multivariable analyses, the presence of micrometastases was an independent risk factor for worse overall survival (hazard ratio 2.88, 95% CI 1.46 to 5.70, p = 0.002) and recurrence-free survival (hazard ratio 1.56, 95% CI 1.01 to 2.41, p = 0.046). In binary logistic regression analysis, RAS/TP53 co-mutation was found to significantly increase the risk of micrometastases (odds ratio 2.77, 95% CI 1.15 to 6.71, p = 0.024).

CONCLUSIONS

Micrometastases are associated with significantly worse survival after CLM resection. RAS/TP53 co-mutation correlated with increased risk of micrometastases. Further studies are needed to determine strategies to eradicate micrometastases.

Liver transplantation versus liver resection for colorectal liver metastasis: a survival benefit analysis in patients stratified according to tumor burden score

Liver transplantation (LT) for colorectal liver metastasis (CRLM) may provide excellent survival rates in patients with unresectable disease. High tumor load is a risk factor for recurrence and low overall survival (OS) after liver resection (LR). We tested the hypothesis that LT could offer better survival than LR in patients with high tumor load. LR performed at Padua University Hospital for CRLM was compared with LT for unresectable CRLM performed both at Oslo and Padua. High tumor load was defined as tumor burden score (TBS) ≥ 9, and inclusion criteria were as in the SECA-I transplant study. 184 patients were eligible: 128 LRs and 56 LTs. 5-year OS after LR and LT was 40.5% and 54.7% (P = 0.102). In the high TBS cohort, 5-year OS after LR and LT was 22.7% and 52.2% (P = 0.055). In patients with Oslo score ≤ 2 and TBS ≥ 9 (13 LR; 24 LT) the 5-year OS after LR and LT was 14.6% and 69.1% (P = 0.002). The corresponding disease-free survival (DFS) was 0% and 22.9% (P = 0.005). Selected CRLM patients with low Oslo score and high TBS could benefit from LT with survival outcomes that are far better than what is achieved by LR.

Parenchymal-sparing hepatectomy for colorectal liver metastases reduces postoperative morbidity while maintaining equivalent oncologic outcomes compared to non-parenchymal-sparing resection

BACKGROUND

Modern chemotherapy and repeat hepatectomy allow to tailor the surgical strategies for the treatment of colorectal liver metastases (CRLM). This study addresses the hypothesis that parenchymal-sparing hepatectomy reduces postoperative complications while ensuring similar oncologic outcomes compared to the standardized non-parenchymal-sparing procedures.

METHODS

Clinicopathological data of patients who underwent liver resection for CRLM between 2012 and 2019 at a hepatobiliary center in Switzerland were assessed. Patients were stratified according to the tumor burden score [TBS² = (maximum tumor diameter in cm)² + (number of lesions)²)] and were dichotomized in a lower and a higher tumor burden cohort according to the median TBS. Postoperative outcomes, overall survival (OS) and recurrence-free survival (RFS) of patients following parenchymal-sparing resection (PSR) for CRLM were compared with those of patients undergoing non-PSR.

RESULTS

During the study period, 153 patients underwent liver resection for CRLM with curative intent. PSR was performed in 79 patients with TBS <4.5, and in 42 patients with TBS ≥4.5. Perioperative chemotherapy was administered in equal rates in both groups (PSR vs. non-PSR) both in TBS ≥4.5 and TBS <4.5. In patients with lower tumor burden (TBS <4.5), PSR was associated with lower overall complication rate (15.2% vs. 46.2%, p = 0.009), a trend for lower major complication rate (8.9% vs. 23.1%, p = 0.123), and shorter length of hospital stay (5 vs. 9 days, p = 0.006) in comparison to non-PSR. For TBS <4.5, PSR resulted in equivalent 5-year OS (48% vs. 39%, p = 0.479) and equivalent 5-year RFS rates (44% vs. 29%, p = 0.184) compared to non-PSR. For TBS ≥4.5, PSR resulted in lower postoperative complication rate (33.3% vs. 63.2%, p = 0.031), a trend for lower major complication rate (23.8% vs. 42.2%, p = 0.150), lower length of hospital stay (6 vs. 9 days, p = 0.005), equivalent 5-year OS (29% vs. 22%, p = 0.314), and equivalent 5-year RFS rates (29% vs. 18%, p = 0.156) compared to non-PSR. Among all patients treated with PSR, patients undergoing minimal-invasive hepatectomy had equivalent 5-year OS (42% vs. 37%, p = 0.261) and equivalent 5-year RFS (34% vs. 34%, p = 0.613) rates compared to patients undergoing open hepatectomy.

CONCLUSIONS

PSR for CRLM is associated with lower postoperative morbidity, shorter length of hospital stay, and equivalent oncologic outcomes compared to non-PSR, independently of tumor burden. Our findings suggest that minimal-invasive PSR should be considered as the preferred method for the treatment of curatively resectable CRLM, if allowed by tumor size and location.

Recurrence at surgical margin following hepatectomy for colorectal liver metastases is not associated with R1 resection and does not impact survival

BACKGROUND

Resection margin status has traditionally been associated with tumor recurrence and oncological outcome following liver resection for colorectal liver metastases. Previous studies, however, did not address the impact of resection margin on the site of tumor recurrence and did not differentiate between true local recurrence at the resection margin and recurrence elsewhere in the liver. This study aimed to determine whether positive resection margins determine local recurrence and whether recurrence at the surgical margin influences long-term survival.

METHODS

Clinicopathological data and oncological outcomes of patients who underwent curative resection for colorectal liver metastases between 2012 and 2017 at 2 major hepatobiliary centers (Bern, Switzerland, and Berlin, Germany) were assessed. Cross-sectional imaging following hepatectomy was reviewed by radiologists in both centers to distinguish between recurrence at the resection margin, defined as hepatic local recurrence, and intrahepatic recurrence elsewhere. The association between surgical margin status and location of tumor recurrence was evaluated, and the impact on overall survival was determined.

RESULTS

During the study period, 345 consecutive patients underwent hepatectomy for colorectal liver metastases. Histologic surgical margins were positive for tumor cells (R1) in 63 patients (18%). After a median follow-up time of 34 months, tumor recurrence was identified in 154 patients (45%). Hepatic local recurrence was not detected more frequently after R1 than after R0 resection (P = .555). Hepatic local recurrence was not associated with worse overall survival (P = .436), while R1 status significantly impaired overall survival (P = .025). Additionally, overall survival was equivalent between patients with hepatic local recurrence and patients with any intrahepatic and/or extrahepatic recurrence. In patients with intrahepatic recurrence only, oncological outcomes improved if local hepatic therapy was possible (resection or ablation) in comparison to patients treated only with chemotherapy or best supportive care (3-year overall survival: 85% vs 39%; P < .0001).

CONCLUSION

The incidence of hepatic local recurrence after hepatectomy for colorectal liver metastases is independent of R1 resection margin status. Additionally, hepatic local recurrence at the resection margin is not associated with worse overall survival compared with any other intra- or extrahepatic recurrence. Therefore, R1 status at hepatectomy seems to be a surrogate factor for advanced disease without influencing location of recurrence and thereby oncological outcome. This finding may support decision-making when extending the indication for surgery in borderline resectable colorectal liver metastases.

Liver Transplantation for Colorectal Liver Metastasis

Purpose of Review

Accumulating evidence suggest that selected patients with nonresectable liver only metastases from colorectal cancer can be offered liver transplantation with acceptable outcome. This review provides an update on the scientific literature.

Recent Findings

The SECA-I study showed an estimated 5-year survival of 60% in a heterogenous patient population and guided the development of the first clinical selection criteria. In the sequel SECA-II trial, an estimated 5-year survival of 83% was obtained. A recent study shows that an Oslo score of 0–2, a metabolic tumor volume below 70 cm3 on PET-CT or Fong score of 0–2 at time of listing, can stratify patients with superior survival. Recurrence is common, but about 70% are slow-growing lung metastases, whereof the majority are resectable.

Summary

Liver transplantation for colorectal liver metastasis is an option in highly selected patients. Futile use of grafts can be avoided by applying stringent selection criteria.