Prognostic impact of R1 resection margin in synchronous and simultaneous colorectal liver metastasis resection: a retrospective cohort study

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.

Patterns of recurrence after curative intent hepatic resection for colorectal liver metastasis

BACKGROUND

Improved surgical techniques and more intensive systemic therapy have increased the number of patients with oligometastatic colorectal cancer eligible for resection, but a significant percentage of these cases will ultimately recur. Furthermore, distinct recurrence patterns have been associated with different outcomes.

METHODS

Data for 195 patients who underwent curative-intent colorectal liver metastasis (CRLM) resection between 2016 and 2022 at Johns Hopkins Hospital were retrospectively collected. Cox regression univariate and multivariate analyses identified features associated with survival outcomes. Association between risk factors and site of recurrences was conducted via logistic regression with initial recurrences grouped into intrahepatic-only, extrahepatic-only, and concurrent intra- and extrahepatic recurrence.

RESULTS

The 1- and 2-year recurrence-free survival (RFS) rates were 46% and 22%, respectively. The 1- and 2-year overall survival (OS) rates were 95% and 88%, respectively. The median OS was 71.7 months. Multivariate analysis identified age <60 years, N2 nodal status, R1 liver margin, and higher preoperative carcinoembryonic antigen as top prognostic factors for worse RFS. Additionally, patients with left-sided primary tumors had a higher risk of intrahepatic-only recurrence, whereas mutant KRAS was associated with a higher risk of extrahepatic recurrence with or without liver recurrence.

CONCLUSION

These results from a recent cohort of patients treated with current standard-of-care therapies identify features associated with elevated risk and specific patterns of recurrence. These insights into CRLM recurrence patterns support a larger prospective study to identify subgroups of patients who may require additional therapies to prevent recurrence.

Robotic liver parenchymal transection using the SynchroSeal

BACKGROUND

There is much heterogeneity in the instrumentation used for parenchymal transection in minimally invasive liver surgery. Instruments specifically designed for robotic parenchymal transection of the liver are lacking. We aim to gain insight into the safety and effectiveness of the SynchroSeal (Intuitive Surgical, Inc., Sunnyvale, CA), a novel bipolar electrosurgical device, in the context of liver surgery.

METHODS

The present study is a post-hoc analysis of prospectively collected data from patients undergoing robotic liver resection (RLR) using the SynchroSeal in two high-volume centres. The results of the SynchroSeal were compared with that of the previous generation bipolar-sealer; Vessel Sealer Extend (Intuitive Surgical, Inc., Sunnyvale, CA) using propensity score matching, after excluding the first 25 Vessel Sealer procedures per center.

RESULTS

During the study period (February 2020-March 2023), 155 RLRs meeting the eligibility criteria were performed with the SynchroSeal (after implementation in June 2021) and 145 RLRs with the Vessel Sealer. Excellent outcomes were achieved when performing parenchymal transection with the SynchroSeal; low conversion rate (n = 1, 0.6%), small amounts of intraoperative blood loss (median 40 mL [IQR 10-100]), short hospital stays (median 3 days [IQR 2-4]), and adequate overall morbidity (19.4%) as well as severe morbidity (11.0%). In a matched comparison (n = 94 vs n = 94), the SynchroSeal was associated with less intraoperative blood loss (48 mL [IQR 10-143] vs 95 mL [IQR 30-200], p = 0.032) compared to the Vessel Sealer. Other perioperative outcomes were similar between the devices.

CONCLUSION

The SynchroSeal is a safe and effective device for robotic liver parenchymal transection.

Association of preoperative aspartate aminotransferase to platelet ratio index with outcomes and tumour microenvironment among colorectal cancer with liver metastases

This study aims to investigate applicable robust biomarkers that can improve prognostic predictions for colorectal liver metastasis (CRLM) patients receiving simultaneous resection. A total of 1323 CRLM patients from multiple centres were included. The preoperative aspartate aminotransferase to platelet ratio index (APRI) level from blood of patients were obtained. Patients were stratified into a high APRI group and a low APRI group, and comparisons were conducted by analyzing progression-free survival (PFS), overall survival (OS) and postoperative early recurrence. Tumour samples of CRLM were collected to perform single-cell RNA sequencing and multiplex immunohistochemistry/immunofluorescence (mIHC/IF) to investigate the association of APRI levels and the tumour microenvironment of CRLM. Compared with APRI <0.33, PFS disadvantage (IPTW-adjusted HR = 1.240, P = 0.015) and OS disadvantage (IPTW- adjusted HR = 1.507, P = 0.002) of APRI ≥0.33 were preserved in the IPTW-adjusted Cox hazards regression analyses. An APRI ≥0.25 was associated with a significantly increased risk of postoperative early recurrence after adjustment (IPTW-adjusted OR = 1.486, P = 0.001). The external validation showed consistent results with the training cohort. In the high APRI group, the single-cell RNA sequencing results revealed a heightened malignancy of epithelial cells, the enrichment of inflammatory-like cancer-associated fibroblasts and SPP1+ macrophages associated with activation of malignant cells and fibrotic microenvironment, and a more suppressed-function T cells; mIHC/IF showed that PD1+ CD4+ T cells, FOXP3+ CD4+ T cells, PD1+ CD8+ T cells, FOXP3+ CD8+ T cells, SPP1+ macrophages and iCAFs were significantly increased in the intratumoral region and peritumoral region. This study contributed valuable evidence regarding preoperative APRI for predicting prognoses among CRLM patients receiving simultaneous resection and provided underlying clues supporting the association between APRI and clinical outcomes by single-cell sequencing bioinformatics analysis and mIHC/IF.

Simultaneous Resection for Colorectal and Liver Metastases, new equipment and personalized medicine

Nowadays we perform synchronous colorectal cancer resection along with synchronous liver metastases. We investigated whether colon resection first is safer than liver resection first and if simultaneous surgeries are in general safe. Patients and Methods: Twenty patients were included in our multicenter study. In our study patients had simultaneous laparoscopic resection of primary colorectal cancer and liver metastases. The patients included were divided into two groups based on their first surgery. Group A had colon resection first (n = 10) and group B had liver resection first (n = 10). All adverse effects and outcomes were compared after the first day of hospitalization. Results: The only difference between the two groups was the operative blood loss. It was observed to be less in group B. Conclusion: In our study we did not observe any significant difference regarding the order of the operation.