The Pathologic Complete Response Ratio of Liver Metastases Represents a Valuable Prognostic Indicator

Computed Tomography-Based Habitat Analysis for Prognostic Stratification in Colorectal Liver Metastases

Background

Colorectal liver metastasis (CRLM) has a poor prognosis, and traditional prognostic models have certain limitations in clinical application. This study aims to evaluate the prognostic value of CT-based habitat analysis in CRLM patients and compare it with existing traditional prognostic models to provide more evidence for individualized treatment of CRLM patients.

Methods

This retrospective study included 197 patients with CRLM whose preoperative contrast-enhanced CT images and corresponding DICOM Segmentation Objects (DSOs) were obtained from The Cancer Imaging Archive (TCIA). Tumor regions were segmented, and habitat features representing distinct subregions were extracted. An unsupervised K-means clustering algorithm classified the tumors into two clusters based on their habitat characteristics. Kaplan-Meier analysis was used to evaluate overall survival (OS), disease-free survival (DFS), and liver-specific DFS. The habitat model's predictive performance was compared with the Clinical Risk Score (CRS) and Tumor Burden Score (TBS) using the concordance index (C-index), Integrated Brier Score (IBS), and time-dependent area under the curve (AUC).

Results

The habitat model identified two distinct patient clusters with significant differences in OS, DFS, and liver-specific DFS (p < 0.01). Compared with CRS and TBS, the habitat model demonstrated superior predictive accuracy, particularly for DFS and liver-specific DFS, with higher time-dependent AUC values and improved model calibration (lower IBS).

Conclusions

CT-based habitat analysis captures spatial tumor heterogeneity and provides enhanced prognostic stratification in CRLM. The method outperforms conventional models and offers potential for more personalized treatment planning.

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.

Pre-hepatectomy dynamic circulating tumor DNA to predict pathologic response to preoperative chemotherapy and post-hepatectomy recurrence in patients with colorectal liver metastases

OBJECTIVE

To evaluate the predictive value of pre-hepatectomy dynamic circulating tumor DNA (ctDNA) on pathologic response to preoperative chemotherapy and recurrence after liver resection for colorectal liver metastases (CRLM).

BACKGROUND

Pathologic response is a predictor of clinical outcomes for patients undergoing hepatectomy for CRLM. Postoperative ctDNA has been proven to be sensitive for recurrence detection. However, few studies investigate the impact of pre-hepatectomy ctDNA on pathologic response and recurrence.

METHODS

Patients with potential resectable CRLM underwent preoperative chemotherapy and hepatectomy between 2018 and 2021 was considered for inclusion. Plasma ctDNA was collected before and after preoperative chemotherapy. Pathologic response was analyzed for all patients after liver resection. Recurrence free survival was compared between patients with different ctDNA status and different pathologic response. The relation between ctDNA and pathologic response was also analyzed.

RESULTS

A total of 114 patients were included. ctDNA was detectable in 108 of 114 patients (94.7%) before chemotherapy, in 56 of 114 patients (49.1%) after chemotherapy. Patients with ctDNA positive at baseline and negative after chemotherapy had significantly longer RFS (median RFS 17 vs 7 months, p = 0.001) and HRFS (median HRFS unreached vs 8 months, p < 0.001) than those with ctDNA persistently positive after chemotherapy. Two patients (1.6%) had a pathologic complete response and 56 patients (45.2%) had a pathologic major response. Post-chemotherapy ctDNA- was associated with improved major pathologic response (53.4% vs 32.1%, p = 0.011). In the multivariable analysis, ctDNA- after chemotherapy (HR 0.51, 95% CI 0.28-0.93), major pathologic response (HR 0.34, 95% CI 0.19-0.62) and surgery combined with radiofrequency ablation (HR 2.62, 95% CI 1.38-5.00) were independently associated with RFS (all p < 0.05).

CONCLUSIONS

Pre-hepatectomy dynamic monitoring of ctDNA could predict pathologic response to preoperative chemotherapy and post-hepatectomy recurrence in CRLM patients. Negative ctDNA after preoperative chemotherapy was associated with better tumor regression grade and recurrence-free survival, which might be used to guide pre-hepatectomy chemotherapy and predict prognosis.