Histological growth patterns of colorectal cancer liver metastases: a strong prognostic marker associated with invasive patterns of the primary tumor and p53 alteration

The histological growth pattern of liver metastases (desmoplastic, pushing, and replacement patterns) at the tumor-liver parenchymal interface is a prognostic factor in patients with colorectal cancer. However, data regarding its association with the primary tumor characteristics and molecular alterations are limited. This study evaluated the histological growth pattern in 136 cases of colorectal cancer liver metastases without preoperative treatment, comparing it with the clinicopathological features of the primary tumor. Liver metastasis exhibiting predominantly non-desmoplastic pattern (<50%), observed in 74 cases (54%), was associated with hepatic vein invasion (P = 0.025), worse recurrence-free survival (P < 0.001) and overall survival (P = 0.008). In multivariate analyses, multiple tumors (P < 0.001) and non-desmoplastic patterns (P = 0.009) were associated with worse recurrence-free survival, and tumor size (P = 0.025) and non-desmoplastic pattern (P = 0.025) were associated with worse overall survival. In 88 patients with available primary tumor tissue slides, non-desmoplastic pattern in the liver metastasis was associated with high-grade tumor budding (P = 0.002), high-grade poorly differentiated cluster (P = 0.021), absence of mucinous histology (P = 0.016), and aberrant p53 expression (complete loss or overexpression; P < 0.001) of the primary colorectal cancer. In conclusion, the histological growth pattern in liver metastasis was a strong and independent prognostic factor for colorectal cancer. Our observations highlight the significant associations between histological growth patterns in liver metastases and histopathological features of the primary tumor, especially invasive front morphology and p53 aberration.

Novel Prognostic Stratification Factor Based on the Pathological Profile of the Invasive Front in Colorectal Cancer

BACKGROUND/AIM

This study aimed to develop a new pathological finding, namely, invasion front grade and verify its clinical usefulness.

MATERIALS AND METHODS

We re-examined haematoxylin-eosin-stained specimens in 162 stage II-III colorectal cancer patients who underwent radical resection. We assessed the desmoplastic reaction, Klintrup grade, and poorly differentiated cluster. These three findings were combined to form the invasion front grade (good prognosis group; Grade A, poor prognosis group; Grade B), and its reproducibility and prognostic stratification ability were statistically analysed.

RESULTS

Invasion front grade was Grade A in 116 cases and Grade B in 46 cases, and its kappa coefficient was 0.81 for interobserver and 0.74 for intraobserver variability. The 3-year recurrence-free survival rates of Grade A and Grade B were 90.4% and 55.9%. Multivariate analysis showed that invasion front grade was an independent prognostic factor.

CONCLUSION

Invasion front grade is useful as a prognostic stratification factor for stage II-III colorectal cancer.

Primary Tumor Histology Affects Oncological Outcomes Independently of the Anatomical Extent of Disease in Colorectal Liver Metastasis

Introduction

Growing evidence indicates the prognostic importance of the crosstalk between cancer cells and stroma through the induction of epithelial-mesenchymal transition (EMT). This study aimed to clarify the prognostic value of evaluating primary tumor histology with the anatomical extent of disease in patients with colorectal liver metastasis (CRLM).

Methods

Prognostic analyses were performed in 411 CRLM patients who underwent hepatectomy at two institutions. Tumors were graded into one of three histological categories based on integrated assessment of EMT-associated histology (Histology^EMT) in primary tumors, i.e., poorly differentiated clusters (PDCs) and desmoplastic reaction (DR).

Results

A prognostic grouping system for the anatomical extent of disease (N stage, liver metastasis number and size, and extrahepatic disease; Grade^anatomical) stratified patients into three groups with different five-year relapse-free survival (RFS) rates after hepatectomy: A, 31% (191 patients); B, 15% (124 patients); and C, 6% (96 patients; P < 0.0001). Histology^EMT (A, G1 PDC and mature-type DR; C, G3 PDC and immature-type DR; and B, others) identified 49, 120, and 242 patients with 46%, 5%, and 22% five-year RFS, respectively (P < 0.0001). Among prognostic factors, the Akaike information criterion was most favorable in Grade^anatomical, followed by Histology^EMT. Multivariate analysis demonstrated that these two factors independently impacted RFS; two-year RFS after hepatectomy in different patient groups had a wide range (10%-76%).

Conclusions

Histological assessment of dedifferentiation and the stromal environment of primary tumors contributed to effective risk stratification of early relapse after hepatectomy, which could be useful to determine clinical management for CRLM patients.

Highly expressed tumoral emmprin and stromal CD73 predict a poor prognosis for external auditory canal carcinoma

Squamous cell carcinoma of the external auditory canal (SCC-EAC) is rare and has a poor prognosis. The SCC-EAC cases with high-grade tumor budding (TB) or poorly differentiated clusters (PDCs) are associated with shorter survival than those with low-grade TB or PDCs. Extracellular matrix metalloproteinase inducer (emmprin) is a protein expressed in tumor cells that stimulates the production of MMP-2 by stromal fibroblasts to facilitate tumor invasion. Recently, we reported that emmprin forms a complex with CD73 to regulate MMP-2 production from fibroblasts in vitro. Here, we examined the association of emmprin and CD73 expression with TB or PDCs as well as with survival in 34 biopsy specimens of SCC-EAC patients. High tumoral emmprin expression was associated with high-grade TB, whereas high stromal CD73 expression was associated with high-grade PDCs. Furthermore, concurrent elevated expression of tumoral emmprin and stromal CD73 was determined to be an independent poor prognostic factor. In immunoprecipitation analyses, complex formation between emmprin and CD73 was demonstrated in vitro. Production of MMP-2 from fibroblasts was more abundant when cocultured with tumor cells than from fibroblasts cultured alone. Furthermore, MMP-2 production was reduced by the transfection of CD73 siRNA in fibroblasts cocultured with tumor cells. The colocalization of emmprin and CD73 was enhanced in not only the peripheral cells of the tumor cell clusters that interact with fibroblasts but also in the cells of intratumor clusters. Overall, this study provides novel insights into the roles of emmprin, CD73, and MMP-2 in tumor invasiveness.

Separation of Low- Versus High-grade Crohn's Disease-associated Small Bowel Carcinomas is Improved by Invasive Front Prognostic Marker Analysis

BACKGROUND AND AIMS

Crohn's disease-associated small bowel carcinoma is a rare event, usually reported to have a severe prognosis. However, in previous investigations we have found a minority of cases displaying a relatively favourable behaviour, thus outlining the need to improve the histopathological prediction of Crohn's disease-associated small bowel carcinoma prognosis.

METHODS

As in recent studies on colorectal cancer, a substantial improvement in prognostic evaluations has been provided by the histological analysis of the tumour invasive front; we therefore systematically analysed the tumour budding and poorly differentiated clusters in the invasive front of 47 Crohn's disease-associated small bowel carcinomas collected through the Small Bowel Cancer Italian Consortium.

RESULTS

Both tumour budding and poorly differentiated cluster analyses proved highly effective in prognostic evaluation of Crohn's disease-associated small bowel carcinomas. In addition, they retained prognostic value when combined with two other parameters, i.e. glandular histology and stage I/II, both known to predict a relatively favourable small bowel carcinoma behaviour. In particular, association of tumour budding and poorly differentiated clusters in a combined invasive front score allowed identification of a minor subset of cancers [12/47, 25%] characterised by combined invasive front low grade coupled with a glandular histology and a low stage [I or II] and showing no cancer-related death during a median follow-up of 73.5 months.

CONCLUSIONS

The improved distinction of lower- from higher-grade Crohn's disease-associated small bowel carcinomas provided by invasive front analysis should be of potential help in choosing appropriate therapy for these rare and frequently ominous neoplasms.

SMAD4 alteration associates with invasive-front pathological markers and poor prognosis in colorectal cancer

Aims

SMAD4 acts as a tumour suppressor, and the loss of SMAD4 is associated with poor prognosis in colorectal cancer (CRC) patients. Although next‐generation sequencing (NGS) enabled us to detect numerous genetic alterations in a single assay, the clinical significance of SMAD4 alteration detected with NGS has not been fully investigated. The aim of this study was to evaluate the clinicopathological characteristics and clinical significance of SMAD4 alteration detected with NGS in CRC.

Methods and results

We retrospectively investigated 201 patients with stage I–IV CRC, by using a 415‐gene panel. To analyse the relationship between SMAD4 alteration and other clinicopathological characteristics, we evaluated clinicopathological variables, including invasive‐front pathological markers: tumour budding, poorly differentiated cluster, and Crohn‐like lymphoid reaction. Fifty‐six patients (28%) had SMAD4 alteration: 24 and 32 patients had SMAD4 mutation and deletion, respectively. SMAD4 alteration was significantly associated with T category (P = 0.027), N category (P = 0.037), M category (P = 0.028), and invasive‐front pathological markers, such as poorly differentiated cluster grade 3 (P = 0.020) and absence of Crohn‐like lymphoid reaction (P = 0.004). Immunohistochemistry revealed that SMAD4 alteration was significantly associated with loss of SMAD4 (P = 0.023). In 90 patients with stage I–III disease, SMAD4 alteration was significantly associated with poor prognosis for relapse‐free and overall survival (P = 0.047; P = 0.022, respectively). Conversely, in 111 patients with stage IV disease, SMAD4 alteration was not significantly associated with overall survival.

Conclusion

SMAD4 alteration is associated with invasive‐front pathological markers and poor prognosis in stage I–III CRC patients.

Association between poorly differentiated clusters and efficacy of 5-fluorouracil-based adjuvant chemotherapy in stage III colorectal cancer

Objective

Although poorly differentiated cluster has been reported to be a useful grading system for predicting prognosis in colorectal cancer, its relationship to chemotherapy efficacy has not been demonstrated. We aimed to investigate the association between poorly differentiated cluster and the efficacy of 5-fluorouracil-based adjuvant chemotherapy in stage III colorectal cancer.

Methods

This retrospective study enrolled 131 patients with stage III colorectal cancer who underwent curative resection: 72 received 5-fluorouracil-based adjuvant chemotherapy (chemotherapy group) and 59 did not (surgery-alone group). Poorly differentiated cluster was defined as a cancer cluster of ≥5 cancer cells without gland-like structure, and was classified into poorly differentiated cluster G1, G2 and G3 according to the number of clusters. The benefit of 5-fluorouracil-based adjuvant chemotherapy was evaluated based on poorly differentiated cluster grade.

Results

Thirty-nine, 40 and 52 patients were classified as poorly differentiated cluster G1, G2 and G3, respectively. Significant differences in the 5-year cumulative recurrence rate and relapse-free survival were observed between poorly differentiated cluster G1/G2 and G3 (26.7% vs. 47.5%, P = 0.010; 66.0% vs. 43.9%, P = 0.004). A comparison of cumulative recurrence rate and relapse-free survival between the chemotherapy and surgery-alone groups showed a significant benefit of adjuvant chemotherapy in poorly differentiated cluster G1/G2 patients (cumulative recurrence rate: 17.4% vs. 37.3%, P = 0.035; relapse-free survival: 79.5% vs. 51.9%, P = 0.002), but not in poorly differentiated cluster G3 patients (cumulative recurrence rate: 48.6% vs. 44.8%, P = 0.885; relapse-free survival: 51.4% vs. 32.7%, P = 0.068).

Conclusions

In stage III colorectal cancer, poorly differentiated cluster G1/G2 predicts a significant benefit from 5-fluorouracil-based adjuvant chemotherapy, whereas poorly differentiated cluster G3 predicts a poor response to it.