Proposal for novel histological findings of colorectal liver metastases with preoperative chemotherapy

Infarct Like Necrosis of Colorectal Liver Metastasis Without Chemotherapy: A Rare Phenomenon

Usual type necrosis (UN) and infarct like necrosis (ILN) occur in CRLMs. ILN is a rare form of necrosis in colorectal liver metastases which is usually seen following chemotherapy. De novo occurrence of ILN is a very rare phenomenon. ILN in CRLM without adjuvant chemotherapy following colorectal resection was not described previously. We describe the presence of complete ILN in a solitary metachronous liver metastasis from right colonic adenocarcinoma without prior chemotherapy.

Efficacy of neoadjuvant chemotherapy for initially resectable colorectal liver metastases: A retrospective cohort study

BACKGROUND

The liver is the most common metastatic site of colorectal cancer. Hepatectomy is the mainstay of treatment for patients with colorectal liver metastases (CRLMs). However, there are cases of early recurrence after upfront hepatectomy alone. In selected high-risk patients, neoadjuvant chemotherapy (NAC) may improve long-term survival.

AIM

To determine the efficacy of NAC for initially resectable CRLMs.

METHODS

Among 644 patients who underwent their first hepatectomy for CRLMs at our institution, 297 resectable cases were stratified into an upfront hepatectomy group (238 patients) and a NAC group (59 patients). Poor prognostic factors for upfront hepatectomy were identified using multivariate logistic regression analysis. Propensity score matching was used to compare clinical outcomes between the upfront hepatectomy and NAC groups, according to the number of poor prognostic factors. Survival curves were estimated using the Kaplan–Meier method and compared using the log-rank test.

RESULTS

Preoperative carcinoembryonic antigen levels (≥ 10 ng/mL) (P = 0.003), primary histological type (other than well/moderately differentiated) (P = 0.04), and primary lymph node metastases (≥ 1) (P = 0.04) were identified as independent poor prognostic factors for overall survival (OS) in the upfront hepatectomy group. High-risk status was defined as the presence of two or more risk factors. After propensity score matching, 50 patients were matched in each group. Among high-risk patients, the 5-year OS rate was significantly higher in the NAC group (13 patients) than in the upfront hepatectomy group (18 patients) (100% vs 34%; P = 0.02).

CONCLUSION

NAC may improve the prognosis of high-risk patients with resectable CRLMs who have two or more risk factors.

Treatment response of colorectal cancer liver metastases to neoadjuvant or conversion therapy: a prospective multicentre follow-up study using MRI, diffusion-weighted imaging and 1H-MR spectroscopy compared with histology (subgroup in the RAXO trial)

BACKGROUND

Colorectal cancer liver metastases respond to chemotherapy and targeted agents not only by shrinking, but also by morphologic and metabolic changes. The aim of this study was to evaluate the value of advanced magnetic resonance imaging (MRI) methods in predicting treatment response and survival.

PATIENTS AND METHODS

We investigated contrast-enhanced MRI, apparent diffusion coefficient (ADC) in diffusion-weighted imaging and 1H-magnetic resonance spectroscopy (1H-MRS) in detecting early morphologic and metabolic changes in borderline or resectable liver metastases, as a response to first-line neoadjuvant or conversion therapy in a prospective substudy of the RAXO trial (NCT01531621, EudraCT2011-003158-24). MRI findings were compared with histology of resected liver metastases and Kaplan-Meier estimates of overall survival (OS).

RESULTS

In 2012-2018, 52 patients at four Finnish university hospitals were recruited. Forty-seven patients received neoadjuvant or conversion chemotherapy and 40 liver resections were carried out. Low ADC values (below median) of the representative liver metastases, at baseline and after systemic therapy, were associated with partial response according to RECIST criteria, but not with morphologic MRI changes or histology. Decreasing ADC values following systemic therapy were associated with improved OS compared to unchanged or increasing ADC, both in the liver resected subgroup (5-year OS rate 100% and 34%, respectively, P = 0.022) and systemic therapy subgroup (5-year OS rate 62% and 23%, P = 0.049). 1H-MRS revealed steatohepatosis induced by systemic therapy.

CONCLUSIONS

Low ADC values at baseline or during systemic therapy were associated with treatment response by RECIST but not with histology, morphologic or detectable metabolic changes. A decreasing ADC during systemic therapy is associated with improved OS both in all patients receiving systemic therapy and in the resected subgroup.

Area of residual tumor (ART) can predict prognosis after post neoadjuvant therapy resection for pancreatic ductal adenocarcinoma

An increasing number of patients with pancreatic ductal adenocarcinoma (PDAC) have undergone resection after neoadjuvant therapy (NAT). We have reported Area of Residual Tumor (ART) as a useful pathological assessment method to predict patient outcomes after post NAT resection in various cancer types. The aim of this study was to assess the prognostic performance of ART in PDAC resected after NAT. Sixty-three patients with PDAC after post NAT resection were analyzed. The viable residual tumor area was outlined and the measurement of ART was performed using morphometric software. The results were compared with those of the College of American Pathologist (CAP) regression grading. Of 63 cases, 39 (62%) patients received chemoradiation therapy and 24 (38%) received chemotherapy only. The median value of ART was 163 mm2. Large ART with 220 mm2 as the cut-off was significantly associated with lymphatic invasion, vascular invasion and perineural invasion, while CAP regression grading was not associated with any clinicopathological features. By multivariate analysis, large ART (≥220 mm2) was an independent predictor of shorter relapse free survival. Together with our previous reports, an ART-based pathological assessment may become a useful method to predict patient outcomes after post NAT resection across various cancer types.

Correlation between CT morphologic appearance and histologic findings in colorectal liver metastasis after preoperative chemotherapy

PURPOSE

Radiological evaluation of the efficacy of preoperative chemotherapy for colorectal liver metastasis (CRLM) is the most important tool for determining treatment strategies. The aim of this study was to identify a correlation between morphologic appearance on computed tomography (CT) and histologic findings of CRLM after preoperative chemotherapy.

METHODS

We examined 47 patients who had undergone a first hepatic resection for CRLM after preoperative chemotherapy and had received contrast-enhanced CT scans. We assessed the morphologic appearance of the overall attenuation based on metastases changing from heterogeneous to mixed and homogenous lesions, the tumor-liver interface, and the peripheral rim enhancement on CT. Histologic parameters included usual necrosis (UN), infarct-like necrosis (ILN), three-zonal change, dangerous halo, mucous lake, shape of ILN, dominant type of necrosis, and presence of viable tumor cells. The relationship between morphologic appearance and histologic findings was evaluated.

RESULTS

CT overall attenuation revealed that UN predominance was more common in the heterogeneous group than in the mixed and homogeneous groups (P = 0.011). The frequency of ILN increased sequentially from ill-defined to variable and sharp at the tumor-liver interface (P = 0.038), and the frequency of UN decreased sequentially from present to partially resolved and completely resolved in the peripheral rim enhancement (P = 0.023). The histologic presence of viable tumor cells was closely associated with the tumor-liver interface (P = 0.0003) and the peripheral rim enhancement (P = 0.004).

CONCLUSIONS

CT morphologic appearance of CRLM after preoperative chemotherapy is correlated with histologic findings regarding necrosis.

Histogram analysis of apparent diffusion coefficient from whole-body diffusion-weighted MRI to predict early response to chemotherapy in patients with metastatic colorectal cancer: preliminary results

AIM

To evaluate apparent diffusion coefficient (ADC) histogram analysis parameters, acquired from whole-body diffusion-weighted magnetic resonance imaging (DW-MRI), as very early predictors of response to chemotherapy in patients with metastatic colorectal cancer (mCRC).

MATERIALS AND METHODS

This was a single-institution prospective study, approved by the West Midlands-South Birmingham research ethics committee. All patients gave fully informed consent prior to imaging. Sixteen patients with histologically confirmed mCRC were enrolled to the study and 11 were successfully scanned with whole-body DW-MRI before (baseline) and 10.8±2.7 days after commencing chemotherapy (follow-up). Therapy response was assessed by RECIST 1.1. Mean ADC and histogram parameters (skewness, kurtosis, 25^th, 50^th, and 75^th percentiles) were compared between progressors and non-progressors at baseline and follow-up. Receiver operating characteristics (ROC) analysis was performed for the statistically significant parameters. Data from metastases were also compared to normative tissue data acquired from healthy volunteers.

RESULTS

Three patients had progressive disease (progressors) and eight had partial response/stable disease (non-progressors). Mean, 25^th, 50^th, and 75^th percentiles were significantly lower for progressors at baseline (p=0.012, 0.012, 0.012 and 0.025 respectively) with areas under the ROC curves (AUC)=0.58, 0.50, 0.58 and 0.63, respectively. Skewness and kurtosis were significantly lower for non-progressors at follow-up (p=0.001 and 0.003 respectively) with AUC=0.67 and 0.79 respectively.

CONCLUSION

ADC histogram analysis shows potential in discriminating progressive from non-progressive disease in patients with mCRC, who underwent whole-body DW-MRI. The technique can potentially be tested as a response assessment methodology in larger trials.