Clonal analysis of metachronous double biliary tract cancers

The molecular mechanisms underpinning the development of metachronous tumors in the remnant bile duct following surgical resection of primary biliary tract carcinomas (BTCs) are unknown. This study aimed to elucidate these mechanisms by evaluating the clinicopathologic features of BTCs, the alterations to 31 BTC-related genes on targeted sequencing, and the aberrant expression of p53, p16, SMAD4, ARID1A and β-catenin on immunohistochemistry. Twelve consecutive patients who underwent resection of metachronous BTCs following primary BTC resection with negative bile duct margins were enrolled. Among the 12 metachronous tumors, six exhibited anterograde growth in the lower portion and six exhibited retrograde growth in the upper portion of the biliary tree. Surgical resection of metachronous BTCs resulted in recurrence-free survival in seven, local recurrence in five, and death in two patients. Nine achieved 5-year overall survival after primary surgery. Molecular analyses revealed that recurrently altered genes were: TP53, SMAD4, CDKN2A, ELF3, ARID1A, GNAS, NF1, STK11, RNF43, KMT2D and ERBB3. Each of these was altered in at least three cases. A comparison of the molecular features between 12 paired primary and metachronous BTCs indicated that 10 (83%) metachronous tumors developed in clonal association with corresponding primary tumors either successionally or phylogenically. The remaining two (17%) developed distinctly. The successional tumors consisted of direct or evolved primary tumor clones that spread along the bile duct. The phylogenic tumors consisted of genetically unstable clones and conferred a poor prognosis. Metachronous tumors distinct from their primaries harbored fewer mutations than successional and phylogenic tumors. In conclusion, over 80% of metachronous BTCs that develop following primary BTC resection are probably molecularly associated with their primaries in either a successional or a phylogenetic manner. Comparison between the molecular features of a metachronous tumor and those of a preceding tumor may provide effective therapeutic clues for the treatment of metachronous BTC. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Diagnostic utility of EUS-FNA in distinguishing hepatocellular carcinoma from gastric submucosal tumor: A case report

INTRODUCTION AND IMPORTANCE

Extrahepatically growing hepatocellular carcinoma (HCC) account for only 0.3 %-2.4 % of all hepatocellular carcinoma cases. We present the rare case of a patient in whom endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was used to distinguish an extrahepatically growing HCC from a gastric submucosal tumor.

CASE PRESENTATION

The patient was a 44-year-old man who underwent an esophagogastroduodenoscopy (EGD) and was found to have a submucosal tumor (SMT). A gastrointestinal stromal tumor was suspected. Computed tomography (CT) showed an unclear connecting between the tumor and the liver. On immunohistochemical analysis, the tumor cells were positive for CK7, PIVKA-II, and glypican-3, and negative for C-kit. Based on these findings, HCC was suspected, and ethoxybenzyl diethylenetriamine-enhanced magnetic resonance imaging (EOB-MRI) was performed. EOB-MRI revealed the connecting of the tumor and the liver. Thus, the patient was diagnosed as having an extrahepatically protruding HCC, and laparoscopic S2 partial hepatectomy was performed. Pathologically, the tumor was identified as a moderately differentiated HCC. According to the 8th edition of the UICC TNM Classification, the tumor was classified as T1bN0M0 and stage IB.

CLINICAL DISCUSSION

Owing to its rarity, the diagnosis of an extrahepatically protruding HCC is often difficult when the differentiation of a gastric SMT and HCC is unclear on CT. As in this case, if an HCC is also differentiated on hematoxylin and eosin staining after EUS-FNA, immunohistochemistry findings can help in the diagnosis.

CONCLUSION

The findings show that EUS-FNA could be helpful for diagnosis when an HCC needs to be differentiated from a gastric SMT.

Ral GTPase promotes metastasis of pancreatic ductal adenocarcinoma via elevation of TGF-β1 production

Pancreatic ductal adenocarcinoma (PDAC), caused by activating mutations in K-Ras, is an aggressive malignancy due to its early invasion and metastasis. Ral GTPases are activated downstream of Ras and play a crucial role in the development and progression of PDAC. However, the underlying mechanisms remain unclear. In this study, we investigated the mechanism of Ral-induced invasion and metastasis of PDAC cells using RalGAPβ-deficient PDAC cells with highly activated Ral GTPases. Array analysis and enzyme-linked immunosorbent assays revealed increased expression and secretion of TGF-β1 in RalGAPβ-deficient PDAC cells compared to control cells. Blockade of TGF-β1 signaling suppressed RalGAPβ deficiency-enhanced migration and invasion in vitro and metastasis in vivo to levels similar to controls. Phosphorylation of c-Jun N-terminal kinase (JNK), a repressor of TGF-β1 expression, was decreased by RalGAPβ deficiency. These results indicate that Ral contributes to invasion and metastasis of PDAC cells by elevating autocrine TGF-β1 signaling at least in part by decreasing JNK activity.

Prognostic significance of the mean corpuscular volume (MCV) and red cell distribution width (RDW) in obstructive colorectal cancer patients with a stent inserted as a bridge to curative surgery

PURPOSE

The prognostic significance of the mean corpuscular volume (MCV) and red cell distribution width (RDW) in patients with malignancy have not been intensely investigated and are largely overlooked. We, therefore, investigated the clinical significance of MCV and RDW in non-metastatic obstructive colorectal cancer (OCRC) patients with a self-expandable metallic stent inserted as a bridge to curative surgery.

METHODS

Eighty-five pathological stage II and III OCRC patients were retrospectively evaluated. The associations of the preoperative MCV and RDW values with short- and long-term outcomes were examined.

RESULTS

There were 50 males and 35 females, and the median age was 71 years old. The median interval between stenting and surgery was 17 days, and the median postoperative hospital stay was 16 days. Fifty-six patients were in the MCV ≥ 87 group, and 47 were in the RDW ≥ 13.8 group. Multivariate analyses revealed the MCV ≥ 87 status to be independently associated with a poor relapse-free survival (hazard ratio [HR] = 4.70, 95% confidence interval [CI] 1.52-14.58, P = 0.007). The RDW ≥ 13.8% was an independent predictor of postoperative infectious complications (HR = 7.28, 95% CI 1.24-42.70, P = 0.028).

CONCLUSION

The MCV and RDW are simple but strong predictors of postoperative outcomes in OCRC patients.

Impact of Sarcopenia on Postoperative Complications in Obstructive Colorectal Cancer Patients Who Received Stenting as a Bridge to Curative Surgery

Objectives:

Understanding the relationship between sarcopenia and malignancy is increasingly important since they inevitably affect the aging population. We investigated the clinical significance of sarcopenia in nonmetastatic obstructive colorectal cancer (OCRC) patients who were inserted self-expandable metallic stent and underwent curative surgery.

Methods:

Plain cross-sectional CT images obtained before stenting were retrospectively analyzed in 92 patients. Muscle volume loss (myopenia) and decreased muscle quality (myosteatosis) were evaluated as skeletal muscle index (SMI) and intramuscular adipose tissue content (IMAC), respectively.

Results:

This study included 54 men and 38 women, with a median age of 70.5 years. The median interval between SEMS placement and the surgery was 17 days (range, 5-47). There were 35 postoperative complications. The median postoperative hospital stay was 15.5 days (range, 8-77). Twenty-eight patients (41.3%) were classified as SMI-low, and 31 (34.1%) patients were classified as IMAC-high. In multivariate analysis, IMAC-high [hazard ratio (HR) = 7.68, 95% confidence interval (CI) 2.22-26.5, P = 0.001] and right-sided tumor (HR = 5.79, 95% CI 1.36-24.7, P = 0.018) were independent predictors of postoperative complications. IMAC-high (HR = 23.2, 95% CI 4.11-131, P < 0.001) and elevated modified Glasgow prognostic score (mGPS) (HR = 5.85, 95% CI 1.22-28.1, P = 0.027) were independent predictors of infectious complications. Relapse-free survival and overall survival were not significantly different regardless of the SMI or IMAC status.

Conclusions:

IMAC was associated with postoperative complications and infectious complications. Myosteatosis might be a stronger predictor of postoperative complications than myopenia.

Prognostic Significance of Preoperative Globulin-to-albumin Ratio in Obstructive Colorectal Cancer Patients Who Underwent Curative Surgery after Stenting

Objectives:

It has been increasingly recognized that the progression of cancer is dependent not only on the tumor characteristics but also on the nutritious and inflammatory condition of the host. We investigated the relationship between the globulin-to-albumin ratio (GAR) and long-term outcomes in obstructive colorectal cancer (OCRC) patients who were inserted self-expandable metallic stent as a bridge to curative surgery.

Methods:

A total of 75 pathological stage II and III OCRC patients between 2013 and 2020 were retrospectively evaluated. The associations of the preoperative GAR with clinicopathological factors and patient survival were examined.

Results:

Receiver operating characteristic curve analysis demonstrated that the optimal cutoff value was 0.88. The GAR ≥ 0.88 status was significantly associated with the absence of lymph node metastasis (P = 0.011), longer postoperative hospital stay (17 days vs 15 days, P = 0.042), and not receiving adjuvant chemotherapy (P = 0.011). Relapse-free survival and cancer-specific survival were significantly shorter in the GAR ≥ 0.88 group (P = 0.007 and P = 0.023, respectively). Multivariate analyses revealed that the GAR ≥ 0.88 was independently associated with relapse-free survival [hazard ratio (HR) = 4.17, 95% confidence interval (CI) 1.32-13.14, P = 0.015)]. Moreover, CA19-9 ≥ 37 (HR = 6.56, 95% CI 2.12-20.27, p = 0.001) and not receiving adjuvant chemotherapy (HR = 4.41, 95% CI 1.28-15.26, p = 0.019) were independent poor prognostic factors for relapse-free survival.

Conclusions:

The results demonstrated that the GAR was a significant prognostic factor for OCRC patients.

A longer interval after stenting compromises the short- and long-term outcomes after curative surgery for obstructive colorectal cancer

PURPOSE

Intestinal decompression using self-expandable metallic colonic stents (SEMSs) as a bridge to surgery is now considered an attractive alternative to emergency surgery. However, data regarding the optimal timing of surgery after stenting are limited.

METHODS

We investigated the impact of the interval between stenting and surgery on short- and long-term outcomes in 92 obstructive colorectal cancer (OCRC) patients who had a SEMS inserted and subsequently received curative surgery.

RESULTS

The median age of the patients was 70.5 years, and the median interval between SEMS insertion and the surgery was 17 (range 5-47) days. There were 35 postoperative complications, including seven major postoperative complications. An interval of more than 16 days was an independent predictor of a poor relapse-free survival (hazard ratio [HR] = 3.12, 95% confidence interval [CI] 1.24-7.81, p = 0.015). An interval of more than 35 days was independently associated with major postoperative complications (HR = 16.6, 95% CI 2.21-125, p = 0.006).

CONCLUSION

A longer interval between stenting and surgery significantly compromised the short- and long-term outcomes. Surgery within 16 days after stenting might help maximize the benefit of SEMS without interfering with short- and long-term outcomes.

Ral GTPase-activating protein regulates the malignancy of pancreatic ductal adenocarcinoma

The small GTPases RalA and RalB are members of the Ras family and activated downstream of Ras. Ral proteins are found in GTP-bound active and GDP-bound inactive forms. The activation process is executed by guanine nucleotide exchange factors, while inactivation is mediated by GTPase-activating proteins (GAPs). RalGAPs are complexes that consist of a catalytic α1 or α2 subunit together with a common β subunit. Several reports implicate the importance of Ral in pancreatic ductal adenocarcinoma (PDAC). However, there are few reports on the relationship between levels of RalGAP expression and malignancy in PDAC. We generated RalGAPβ-deficient PDAC cells by CRISPR-Cas9 genome editing to investigate how increased Ral activity affects malignant phenotypes of PDAC cells. RalGAPβ-deficient PDAC cells exhibited several-fold higher Ral activity relative to control cells. They had a high migratory and invasive capacity. The RalGAPβ-deficient cells grew more rapidly than control cells when injected subcutaneously into nude mice. When injected into the spleen, the RalGAPβ-deficient cells formed larger splenic tumors with more liver metastases, and unlike controls, they disseminated into the abdominal cavity. These results indicate that RalGAPβ deficiency in PDAC cells contributes to high activities of RalA and RalB, leading to enhanced cell migration and invasion in vitro, and tumor growth and metastasis in vivo.

Prognostic impact of intraoperative peritoneal cytology after neoadjuvant therapy for potentially resectable pancreatic cancer

BACKGROUND

Neoadjuvant therapy (NAT) is considered a potential approach to improve survival for patients with pancreatic adenocarcinoma (PA). The objective of this study was to identify the clinical implications of washing peritoneal cytology (CY) status after NAT.

METHODS

Between 2005 and 2016, 151 consecutive patients with resectable (R)/borderline resectable (BR) PA underwent NAT with intention of subsequent resection at our institution. Of them, 13 and 123 patients underwent pancreatectomies with positive (CY+) and negative (CY-) cytology, respectively, while the remaining 15 patients did not undergo resection due to gross metastases at laparotomy. The clinicopathological factors influencing overall survival were clarified by the uni- and multivariate analyses.

RESULTS

The postoperative overall survival (OS) and disease-free survival (DFS) were markedly worse in patients who underwent resection with CY+, compared with those who were CY- (median OS, 14.8 m vs 30.8 m, p = 0.026, and median DFS 6.0 m vs 15.1 m, p = 0.008). According to the resectability by NCCN guidelines, CY+ indicates worse prognosis than CY- in R-PA patients (mOS: 30.1 m vs 71.1 m: p = 0.080). Similarly, in BR-PA patients, CY+ showed the significantly worse prognosis than CY- (mOS: 13.8 m vs 24.5 m: p = 0.048), which prognosis is comparable with patients who did not undergo resection. The multivariate analysis revealed that resectability, CY status and the induction of adjuvant therapy were significant predictors of postoperative OS (p = 0.007: Hazard ratio 2.264, 0.040:2.094 and 0.002:3.246, respectively).

CONCLUSIONS

CY+ is a significant predictor of poorer prognosis in PA patients after NAT. The subsequent pancreatectomies with CY+ after NAT do not contribute to prolonged survival.

Ral GTPase Activation by Downregulation of RalGAP Enhances Oral Squamous Cell Carcinoma Progression

Ral small GTPases, consisting of RalA and RalB, are members of the Ras family. Their activity is upregulated by RalGEFs. Since several RalGEFs are downstream effectors of Ras, Ral is activated by the oncogenic mutant Ras. Ral is negatively regulated by RalGAP complexes that consist of a catalytic α1 or α2 subunit and its common partner β subunit and similarly regulate the activity of RalA as well as RalB in vitro. Ral plays an important role in the formation and progression of pancreatic and lung cancers. However, the involvement of Ral in oral squamous cell carcinoma (OSCC) is unclear. In this study, we investigated OSCC by focusing on Ral. OSCC cell lines with high Ral activation exhibited higher motility. We showed that knockdown of RalGAPβ increased the activation level of RalA and promoted the migration and invasion of HSC-2 OSCC cells in vitro. In contrast, overexpression of wild-type RalGAPα2 in TSU OSCC cells attenuated the activation level of RalA and inhibited cell migration and invasion. Real-time quantitative polymerase chain reaction analysis of samples from patients with OSCC showed that RalGAPα2 was downregulated in oral cancer tissues as compared with normal epithelia. Among patients with OSCC, those with a lower expression of RalGAPα2 showed a worse overall survival rate. A comparison of DNA methylation and histone modifications of the RalGAPα2 gene in OSCC cell lines suggested that crosstalk among DNA methylation, histone H4Ac, and H3K27me2 was involved in the downregulation of RalGAPα2. Thus, activation of Ral GTPase by downregulation of RalGAP expression via a potential epigenetic mechanism may enhance OSCC progression.