Circulating Tumor DNA Analysis Detects FGFR2 Amplification and Concurrent Genomic Alterations Associated with FGFR Inhibitor Efficacy in Advanced Gastric Cancer

PURPOSE

FGFR2 amplification is associated with poor prognosis in advanced gastric cancer and its subclonal heterogeneity has been revealed. Here, we examined whether circulating tumor DNA (ctDNA) was useful for detecting FGFR2 amplification and co-occurring resistance mechanisms in advanced gastric cancer.

EXPERIMENTAL DESIGN

We assessed genomic characteristics of FGFR2-amplified advanced gastric cancer in a nationwide ctDNA screening study. We also analyzed FGFR2 amplification status in paired tissue and plasma samples with advanced gastric cancer. In addition, we examined patients with FGFR2-amplified advanced gastric cancer identified by ctDNA sequencing who received FGFR inhibitors.

RESULTS

FGFR2 amplification was more frequently detected by ctDNA sequencing in 28 (7.7%) of 365 patients with advanced gastric cancer than by tissue analysis alone (2.6%-4.4%). FGFR2 amplification profiling of paired tissue and plasma revealed that FGFR2 amplification was detectable only by ctDNA sequencing in 6 of 44 patients, which was associated with a worse prognosis. Two patients in whom FGFR2 amplification was detected by ctDNA sequencing after tumor progression following previous standard chemotherapies but not by pretreatment tissue analysis had tumor responses to FGFR inhibitors. A third patient with FGFR2 and MET co-amplification in ctDNA showed a limitation of benefit from FGFR inhibition, accompanied by a marked increase in the MET copy number.

CONCLUSIONS

ctDNA sequencing identifies FGFR2 amplification missed by tissue testing in patients with advanced gastric cancer, and these patients may respond to FGFR inhibition. The utility of ctDNA sequencing warrants further evaluation to develop effective therapeutic strategies for patients with FGFR2-amplified advanced gastric cancer.

Expression of CD44 variant 9 induces chemoresistance of gastric cancer by controlling intracellular reactive oxygen spices accumulation

BACKGROUND

CD44 variant 9 (CD44v9) has been reported to suppress reactive oxygen spices (ROS) in association with antioxidant factors such as glutathione (GSH) and glutathione peroxidase 2 (GPx2), resulting in promoted tumor growth.

METHODS

CD44v9 and GPx2 expression were investigated by immunohistochemistry in resected specimens from 193 gastric cancer (GC) patients without preoperative chemotherapy and in pretreatment biopsy specimens from 29 GC patients with preoperative chemotherapy. We analyzed the relationship between CD44v9 expression and clinicopathological factors, prognosis, and pathological response to chemotherapy. In GC cell lines, we examined the relationship between CD44v9 expression and chemotherapeutic sensitivity.

RESULTS

In patients without preoperative chemotherapy, CD44v9 expression was significantly associated with depth of invasion, lymphatic permeation, vascular invasion, distant metastasis and GPx2 expression. In multivariate analysis, CD44v9 expression was an independent poor prognosis factor for overall survival and recurrence-free survival. In patients with preoperative chemotherapy, CD44v9 expression was significantly associated with worse pathological response and GPx2 expression. In GC cell lines, downregulation of CD44v9 expression enhanced chemotherapeutic sensitivity to 5-fluorouracil with changing GSH and ROS levels.

CONCLUSIONS

CD44v9-positive expression was associated with chemotherapeutic resistance by controlling intracellular accumulated ROS, suggesting that CD44v9 may be a predictive biomarker for chemotherapy in GC.

New Anastomosis Technique to Prevent Anastomotic Leakage in Laparoscopic Anterior Resection for Rectal Cancer, Especially Upper Rectal Cancer

BACKGROUND/AIM

Anastomotic leakage (AL) is a major problem in rectal cancer surgery. To prevent AL, we developed a side-to-side anastomosis technique using a circular stapler and termed it the circular side stapling technique (CST). We herein report the method and outcome of the CST.

PATIENTS AND METHODS

In this study, we analyzed 154 patients with stage 0 to III rectal cancer who underwent curative laparoscopic low anterior resection. Perioperative factors and complications were compared between the CST and usual double stapling technique (DST).

RESULTS

The CST was performed in 110 of the 154 patients. When comparing the outcomes of patients with upper rectal cancer. AL occurred in no patients in the CST group and in three patients in the DST group (p=0.011). The CST prevented AL in all patients with upper rectal cancer.

CONCLUSION

The CST is a safe and useful procedure in laparoscopic anterior resection. This technique can prevent AL, especially in patients with upper rectal cancer.

Cytolytic activity score as a biomarker for antitumor immunity and clinical outcome in patients with gastric cancer

BACKGROUND

A simple measure of immune cytolytic activity (CYT) base on mRNA expression levels of two genes, GZMA and PRF1, was recently reported. Here, we aimed to evaluate the CYT score's potential as a measure of antitumor immunity and predictor of clinical outcome in gastric cancer (GC) patients.

MATERIALS AND METHODS

We evaluated the correlations between tumor-infiltrating immune cells and the CYT score in 238 GC samples from The Cancer Genome Atlas (TCGA). Next, we investigated CYT score associations with molecular subtypes, somatic mutation load, and immune checkpoint molecules in GC samples from TCGA and Asian Cancer Research Group (ACRG). Moreover, we evaluated the clinical significance of the CYT score calculated by reverse transcription (RT)-quantitative PCR (qPCR) data in 123 GC samples and the association of the CYT score with the response to anti-PD-1 therapy in 7 GC samples from Kyushu University Hospital.

RESULTS

The CYT score positively correlated with the proportions of tumor-infiltrating CD8+ T cells and macrophages and negatively correlated with the proportion of regulatory T cells in GC tissues. A high CYT score was associated with common immune checkpoint molecules, a high mutation, the Epstein-Barr virus subtype, and the microsatellite instability subtype in GC. Moreover, a low CYT score was a poor prognosis factor in patients with GC. Finally, the CYT score was higher in a responder to anti-PD-1 therapy compared to nonresponders.

CONCLUSION

The CYT score reflects antitumor immunity and predicts clinical outcome in GC patients.

[The Efficacy of topo Ⅰ-pS10 Expression in Gastric Cancer as a Predictive Biomarker for Irinotecan Use]

BACKGROUND

Though irinotecan is commonly used for treating advanced gastric cancer, there is no predictive biomarker to date. We have studied the resistant mechanism for irinotecan and found that phosphorylation of serine 10 residue of topoisomerase Ⅰ(topo Ⅰ)is an important step for irinotecan resistance. We have developed an immunohistochemical staining-based biomarker; topo Ⅰ-pS10, for predicting irinotecan efficacy.

PURPOSE

The purpose of this study is to test the accuracy of topo Ⅰ-pS10 immunohistochemical staining in gastric cancer clinical samples.

METHODS

In this study we performed 2 sets of tests. In the training set, we stained 79 gastric cancer clinical samples which efficacy of irinotecan was measured by succinate dehydrogenase inhibition(SDI)test. In the validation set, we used 27 gastric cancer clinical samples which irinotecan was used and the efficacy was known.

RESULTS

Training set: From the ROC curve the cut-off point was set at 35% positive nuclei. Sixty three cases were positive with topo Ⅰ-pS10 in the nuclei. With the result of irinotecan SDI, the sensitivity was 76.6% and the positive predictive value was 92.5%. This result showed that topo Ⅰ-pS10 positive case does not respond to irinotecan. Validation set: In this set, the sensitivity was 82.4% and the positive predictive value was 82.4%.

CONCLUSION

topo Ⅰ-pS10 staining can be used as a predictive biomarker for irinotecan for gastric cancer patients.

Impact of a Long Linear Staplers on the Incidence of Stricture after Triangulating Esophagogastric Anastomosis

BACKGROUND

Various techniques have been reported for esophagogastric anastomosis to prevent anastomotic leakage. Recently, not only postoperative anastomotic leakage but also anastomotic stricture is considered important because stricture contributes to the patient's postoperative quality of life. However, the best procedure for anastomosis has not been established.

MATERIALS AND METHODS

The authors divided 101 patients with thoracic or abdominal esophageal cancer who underwent cervical triangulating esophagogastric anastomosis using a linear stapler between May 2017 and May 2020 into 2 groups: surgery with a short (45 mm) linear stapler (SS group, n=59) or a long (60 mm) stapler (LS group, n=42). The frequencies of anastomotic leakage and stricture were compared between the 2 groups.

RESULTS

The incidence of anastomotic leakage and stricture without leakage were significantly lower in the LS versus SS group (respectively: leakage: 15% vs. 0%, P=0.01; stricture: 36% vs. 7%, P=0.01). A short linear stapler and anastomotic leakage were independent risk factors for anastomotic stricture in the multivariate analysis (short stapler: odds ratio, 3.27; 95% confidence interval, 1.08-9.9; P=0.03; anastomotic leakage: odds ratio, 2.78; 95% confidence interval, 1.02-8.5; P=0.04).

CONCLUSION

A long linear stapler is preferable for cervical triangulating esophagogastric anastomosis.

Radiomics Texture Analysis for the Identification of Colorectal Liver Metastases Sensitive to First-Line Oxaliplatin-Based Chemotherapy

OBJECTIVE

The aim of this study was to develop a radiomics-based prediction model for the response of colorectal liver metastases to oxaliplatin-based chemotherapy.

METHODS

Forty-two consecutive patients treated with oxaliplatin-based first-line chemotherapy for colorectal liver metastasis at our institution from August 2013 to October 2019 were enrolled in this retrospective study. Overall, 126 liver metastases were chronologically divided into the training (n = 94) and validation (n = 32) cohorts. Regions of interest were manually segmented, and the best response to chemotherapy was decided based on Response Evaluation Criteria in Solid Tumors (RECIST). Patients who achieved clinical complete and partial response according to RECIST were defined as good responders. Radiomics features were extracted from the pretreatment enhanced computed tomography scans, and a radiomics score was calculated using the least absolute shrinkage and selection operator regression model in a trial cohort.

RESULTS

The radiomics score significantly discriminated good responders in both the trial (area under the curve [AUC] 0.8512, 95% confidence interval [CI] 0.7719-0.9305; p < 0.0001) and validation (AUC 0.7792, 95% CI 0.6176-0.9407; p < 0.0001) cohorts. Multivariate analysis revealed that high radiomics scores greater than - 0.06 (odds ratio [OR] 23.803, 95% CI 8.432-80.432; p < 0.0001), clinical non-T4 (OR 6.054, 95% CI 2.164-18.394; p = 0.0005), and metachronous disease (OR 11.787, 95% CI 2.333-70.833; p = 0.0025) were independently associated with good response.

CONCLUSIONS

Radiomics signatures may be a potential biomarker for the early prediction of chemosensitivity in colorectal liver metastases. This approach may support the treatment strategy for colorectal liver metastasis.

Quadruple gastrointestinal cancer with discordance of mismatch repair protein deficiency and microsatellite instability suggesting Lynch syndrome

A 65-year-old woman with prior personal and family histories of cancer was admitted to our hospital for quadruple cancer. Preoperative endoscopy revealed a type 0-II gastric cancer (GC; gastric body), advanced type-II colon cancer (ascending colon), and early-stage recto-sigmoid colon cancers. We diagnosed her with Lynch syndrome (LS) per Amsterdam criteria, and performed distal gastrectomy, ileocecal resection and high anterior resection. Her pathological diagnoses were GC: well-to-poorly differentiated adenocarcinoma (AD, por2 > tub2) with signet-ring cells, ypT1b SM2; ascending colon cancer: AD with focal mucin products (tub2 > muc), SS; sigmoid colon cancer: AD (tub1), M; recto-sigmoid cancer: AD (tub1 > tub2), SM. Immunohistochemical tests revealed that all cancers lacked the MLH1/PMS2 protein. However, the three colon cancers were found to have high microsatellite instability (MSI); the GC was microsatellite stable (MSS). No recurrence or other cancers were observed for 30 months after surgery without adjuvant chemotherapy. As patients with LS may also develop MSS cancers, we should check for MSI in all LS cancers for proper treatment.

A rare case of esophageal adenocarcinoma with urinary bladder metastasis

A 75-year-old man was admitted to our hospital for treatment of esophageal cancer (EC) in March 2017. Esophagogastroduodenoscopy revealed Barrett's esophagus and superficial, distal EC (type 0-IIc). Tumor biopsy showed esophageal adenocarcinoma. Computed tomography revealed no lymph node metastasis but did reveal a 19-mm tumor on the right side of the urinary bladder. Bladder cancer (BC) was also suspected, and the patient underwent endoscopic submucosal dissection for EC and transurethral resection of the bladder tumor. The pathological diagnosis of EC was moderately to poorly differentiated adenocarcinoma (tub2), pT1b (SM), ly0, v0. The pathological horizontal margin was negative and the vertical margin was positive. Additional esophagectomy and lymph node dissection were indicated for curability. Esophagectomy was difficult because the patient had severe cardiovascular disease, so follow-up observation was adopted. BC was classified as urothelial carcinoma Ta, ly0, v0. After 32 months, multiple tumors were found in the bladder, and BC recurrence was suspected. Transurethral resection of the bladder was performed again for seven tumors, and pathological diagnosis was poorly differentiated adenocarcinoma (tub2). The immunohistochemical features matched those of EC. We diagnosed EC metastasis in the urinary bladder. Bladder adenocarcinoma is difficult to distinguish from metastasis from other organs, especially the upper gastrointestinal tract, and cytomorphological features and appropriate clinical history are required.

Obstructive rectal endometriosis treated by robot-assisted laparoscopic surgery: a case report

Background

Rectal endometriosis is a rare disease. A definitive diagnosis prior to surgery is often difficult. We encountered a patient with rectal sub-obstructive endometriosis that was treated by robot-assisted laparoscopic low anterior resection.

Case presentation

A 43-year-old woman visited our hospital with suspected stenosis caused by upper rectal cancer. She had a 2-year history of constipation. We were unable to confirm the diagnosis through detailed examinations, including laparoscopy. Robot-assisted laparoscopic low anterior resection with D3 lymph node dissection was performed for both diagnosis and treatment. The postoperative specimen showed a submucosal tumor. The pathological examination confirmed rectal endometriosis.

Conclusions

We herein describe a rare case of obstructive rectal endometriosis that we were unable to diagnose preoperatively. Robotic surgery was useful in this case, which involved extensive pelvic adhesion.

Primary anorectal malignant melanoma with laparoscopic abdominoperineal resection: a case study and review of the relevant literature

ARMM is a disease with a poor prognosis. ARMM is often diagnosed at an advanced stage, and the 5-year survival rate of ARMM is < 20%. Although the number of case reports on ARMM is gradually increasing, the optimal treatment strategy for ARMM remains controversial. We report the case of an 81-year-old woman who had experienced bloody stool for 6 months before her diagnosis and who had been initially diagnosed with hemorrhoids. The pathological diagnosis of a biopsy specimen was malignant melanoma. Other examinations showed no evidence of lymph node or distant metastasis. Based on these results, laparoscopic abdominoperineal resection was performed. Three months later on her first follow-up examination, distant metastasis to the lung and liver was detected. Immunotherapy using Nivolumab was initiated to treat the recurrent disease. We reviewed the characteristics of a total of 1834 ARMM patients described in previous reports on ARMM for which the full text was available on PubMed. We experienced a case of ARMM. The prognosis of ARMM is still poor, regardless of the surgical procedure. Previous studies and our case report suggest that systemic therapy, such as immunotherapy using an anti-PD-1 ligand may be more important than reinforcement of local control for improving the prognosis of ARMM patients.

Molecular landscape and prognostic value of HER2 low-expression on metastatic colorectal cancer

229

Background: HER2 dual blockade showed the promise in clinical trials in patients (pts) with HER2-positive (HER2-Pos) metastatic colorectal cancer (mCRC). A phase I/II study of a novel anti-HER2 antibody-drug conjugate (HER2-ADC) showed promising activities across different cancer subtypes including HER2-Pos mCRC, and also showed a hint of activity for low-expressing (HER2-L) mCRC, regardless of RAS mutation. However, molecular landscape and prognostic value of HER2-L on mCRC are unclear. Methods: The eligibility included pts with mCRC who had undergone surgical resection of primary tumor. Using the specimen, HER2 expression was evaluated by immunohistochemistry (IHC) and FISH. Definition of HER2 positivity was as follows; HER2-Pos as IHC 3+ or IHC 2+/FISH positive: HER2-L as IHC 2+/FISH negative or IHC 1+: Negative (HER2-Neg) as IHC 0+. NGS tests were also done. Results: Between 2005 and 2015, a total of 370 pts were analyzed; 60% were male, with a median age of 64 y/o. Fifteen pts (4%) with HER2-Pos, 21 (6%) with HER2-L, and 334 (90%) with HER2-Neg were identified. Proportion of left-sided primary tumor was similar among groups ranging from 72% to 78%. No difference was observed in terms of major clinicopathological characteristics. The proportion of co-altered RAS mutations in HER2-L was significantly higher than HER2-Pos ( p = 0.037) and similar to HER2-Neg (27% in HER2-Pos vs. 62% in HER2-L vs. 56% in HER2-Neg). As of median follow-up of 24.8 months, median overall survival (mOS) in HER2-L was significantly better than that in HER2- Pos ( p = 0.029, 18.2 months in HER2-Pos vs. 33.3 in HER2-L vs. 27.9 in HER2-Neg). In 58 pts harboring RAS wild-type who received an anti-EGFR monoclonal antibody therapy, median progression-free survival (mPFS) in HER2-L tended to be better than that in HER2- Pos, with 2.2 months in HER2-Pos, 7.8 in HER2-L, and 5.5 in HER2-Neg ( p = 0.099). Conclusions: Since HER2-L mCRC had the high prevalence of co-altered RAS mutations but showed a better prognosis and might benefit more from an anti-EGFR therapy than HES2-Pos, the HER2-L mCRC seems to have a different biological behavior from HER2-Pos in terms of molecular landscape and prognostic value on mCRC.

Comparison of computed tomography imaging analyses for evaluation after chemotherapy in patients with colorectal cancer: a retrospective pooled analysis of six phase II clinical trials

BACKGROUND

There are several methods for analyzing computed tomography (CT) images to evaluate chemotherapy efficacy in clinical studies. However, the optimal analysis method for each drug is still under debate. We conducted a pooled analysis using data from six phase II studies to evaluate four analysis methods in colorectal cancers (CRCs): morphological responses (MRs), early tumor shrinkage (ETS), depth of response (DpR), and response evaluation criteria in solid tumors (RECIST) ver.1.1.

METHODS

We included 249 patients in this analysis. Pretreatments and findings of subsequent CT imaging were analyzed based on the MR, ETS, DpR, and RECIST ver.1.1. Differences in overall survival (OS) between the responders and non-responders according to each method were evaluated using survival analysis.

RESULTS

The responders had significantly better hazard ratios (HRs) for OS, in terms of DpR (≥ median), ETS, objective response rate (ORR) [complete response (CR) + partial response (PR)], and disease control rate [CR + PR + stable disease (SD)]. Patients with right-sided colon cancers showed better HRs for DpR, but not for ETS and ORR. Contrastingly, patients with left-sided CRCs had better HRs for ETS, DpR, and ORR. MR was not associated with outcomes in this study, even in cases where bevacizumab was used. In patients with liver metastasis, ETS, DpR, and ORR showed better HRs, but not in those with lung metastasis.

CONCLUSION

Early tumor shrinkage and DpR might be predictive markers only in left-sided CRCs with liver metastasis. Each imaging analysis has a different value based on the primary and metastatic sites.

TiFFANY study: A multicenter phase II basket-type clinical trial to evaluate efficacy and safety of pan-FGFR inhibitor TAS-120 for advanced solid malignancies with FGFR alterations identified by circulating tumor DNA

TPS3156

Background: Approximately 7% of advanced solid malignancies have FGFR gene alterations. However, standard treatment for FGFR-altered malignancies has not been established. Moreover, circulating tumor DNA (ctDNA) analysis has a potential to accurately identify FGFR alterations by assessing spatial and temporal intratumoral heterogeneity, which have shown to be associated with a poor prognosis and resistance to anti-cancer therapy. Methods: We are conducting an investigator-initiated multicenter phase II basket-type trial to investigate efficacy and safety of TAS-120, a highly selective covalent pan-FGFR inhibitor, for the patients with advanced solid malignancies with FGFR alterations identified by ctDNA analysis as a part of the Nationwide Cancer Genome Screening Project (GOZILA study, UMIN000029315). Eligibility criteria include histologically confirmed unresectable advanced or recurrent solid tumors regardless of histology of origin; ECOG PS of 0 or 1; refractory or intolerant to the standard therapies; and clonal FGFR alterations ( FGFR1-3 gain-of-function mutations, FGFR1,2 amplifications and FGFR2,3 fusions) identified by a 73-gene sequencing ctDNA panel (Guardant360). Enrolled patients will receive TAS-120 20 mg once daily, orally, in a 21 day-cycle. The primary endpoint is to clarify objective response rate (ORR) assessed by investigators per RECIST v1.1. The secondary endpoints are to evaluate progression-free survival, duration of response, time to treatment failure, disease control rate, overall survival, ORR by central determination, and incidence of adverse events. Target sample size is determined as 26 to test the null hypothesis of ORR as 5% with one-sided alpha level of 2.5% and power of 80% to detect an expected value of ORR as 25%. Furthermore, tumor tissue and ctDNA will be serially collected and analyzed to investigate the resistance mechanisms and provide clinically meaningful biomarker which may be used for identifying and implementing treatment changes. Clinical trial information: 194624.

Successful multidisciplinary treatment including repeated metastasectomy for recurrent squamous cell esophageal carcinoma: a case report

Background

Recurrences after radical esophagectomy are common. The prognosis for recurrent esophageal cancer is generally poor. Recurrences usually occur between 1 and 3 years of surgery, with the duration of median survival after recurrence ranging from 5 to 10 months. The number of sites and involved organs vary among patients. Consequently, a standard therapeutic strategy has not been established, and the role of surgery in the management of recurrence is unclear.

Case presentation

A 67-year-old man presented with dysphagia 6 months previously and was diagnosed with esophageal squamous cell carcinoma (ESCC) in the upper thoracic region (T2M0M0, stage IB), for which he underwent thoracoscopy-assisted esophagectomy and lymphadenectomy. Adjuvant chemotherapy was not prescribed. Three years after the operation, he developed a solitary metastasis in the left lung, requiring segmentectomy followed by chemotherapy with combined cisplatin (CDDP) and 5-fluorouracil (5-FU). The following year, a metastatic lesion was recognized in the right lung, invading the chest wall, for which he underwent partial lobectomy with local chest wall resection. Multiple mediastinal and abdominal lymph node (LN) metastases were detected in the right lung a year later, which necessitated chemoradiation to a dose of 50.4 Gy with concomitant CDDP and 5-FU. Post-treatment computed tomography (CT) showed a good response. Positron emission tomography (PET)-CT revealed a reduction in the metastatic LNs with no fluoro-deoxy-glucose (FDG) uptake. The following year, metastases were detected in the left cervical LNs. Owing to the limited extent of metastases, resection was followed by chemoradiation to a dose of 50 Gy with CDDP and 5-FU. The following year, metastases were detected in the mediastinal LNs; chemotherapy was administered with nedaplatin and docetaxel. The follow-up CT and PET-CT demonstrated complete disappearance of the tumor, and the patient is currently surviving without recurrence for 11 years from the first curative operation.

Conclusions

This case demonstrates that aggressive multidisciplinary treatment including surgery and radiation to achieve local control could be a meaningful treatment strategy in cases with limited and slowly occurring recurrences.

Prognostic Impact of Programmed Death-Ligand 2 Expression in Primary Lung Adenocarcinoma Patients

BACKGROUND

Programmed death-ligand 1 (PD-L1) expression on lung cancer cells is a prognostic marker and a predictive biomarker for response to immunotherapy. However, previous clinical trials have suggested that other programmed cell death 1 ligands, including programmed death-ligand 2 (PD-L2), might have clinical impacts. This study aimed to analyze the prognostic significance of PD-L2 expression in lung adenocarcinoma patients.

METHODS

The study included 433 patients who underwent surgical resection for lung adenocarcinoma between 2003 and 2012 at Kyushu University Hospital. Both PD-L1 and PD-L2 expression were evaluated by immunohistochemistry. The cutoff value for PD-L2 positivity was set at 1% according to a time-dependent receiver operating characteristic curve for 5-year survival.

RESULTS

Of the 433 patients, 306 (70.7%) were positive for PD-L2. No significant association between PD-L1 and PD-L2 expression was observed (P = 0.094). The multivariate analysis showed that the independent predictors of PD-L2 positivity were never-smoker status (P = 0.002), poor differentiation grade (P = 0.008), and advanced stage (P = 0.048). The PD-L2-positive patients had significantly shorter disease-free survival (DFS) (P = 0.018) and overall survival (OS) (P = 0.016). Both PD-L1 and PD-L2 positivity were independent predictors of OS (P < 0.001 and P = 0.027, respectively). In the subgroup analysis of the PD-L1-negative patients, PD-L2 positivity was significantly associated with shorter DFS (P = 0.018).

CONCLUSIONS

The study demonstrated that the clinical characteristics of patients with PD-L1 expression may differ from those of patients with PD-L2 expression, and that both might contribute to poor prognoses. The potential role of PD-L2 expression as a predictive biomarker for response to immunotherapy should be investigated in future studies.

C-reactive protein/albumin ratio is a poor prognostic factor of esophagogastric junction and upper gastric cancer

BACKGROUND AND AIM

The C-reactive protein (CRP)/albumin (Alb) ratio has been reported as a novel prognostic marker in several cancers. The objective of this study was to investigate the prognostic value of the CRP/Alb ratio in patients who underwent surgery for adenocarcinoma of the esophagogastric junction (AEG) and upper gastric cancer (UGC).

METHODS

Data for 144 patients who underwent surgery for AEG and UGC were reviewed. The CRP/Alb ratio, neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, Glasgow Prognostic Score, and controlling nutritional status score were calculated, and the relationship between these biomarkers and postoperative prognosis was analyzed.

RESULTS

The optimal cutoff value of the CRP/Alb ratio was determined to be 0.1. According to the cutoff value of CRP/Alb ratio, patients were divided into two groups (CRP/Alb < 0.1, n = 124; CRP/Alb ≥ 0.1, n = 20). The 5-year recurrence-free survival and overall survival (OS) rates were significantly lower in the patients with the CRP/Alb ratio ≥ 0.1 than in those with the CRP/Alb ratio < 0.1 (recurrence-free survival: 44.9% vs 77.9%, P = 0.0011; OS: 43.4% vs 82.0%, P < 0.0001). In the multivariate analyses, the N-stage, and CRP/Alb ratio ≥ 0.1 were identified as independent predictive factors for OS in patients with AEG and UGC (P = 0.0061 and P = 0.0439, respectively).

CONCLUSIONS

The CRP/Alb ratio was strongly associated with poor prognosis in patients who underwent surgery for AEG and UGC.

Changes in HER2 Expression and Amplification Status Following Preoperative Chemotherapy for Gastric Cancer

BACKGROUND

It is essential to establish a strategy for second-line treatment for human epidermal growth factor receptor 2 (HER2)-positive gastric cancer; however, HER2 expression status after chemotherapy treatment is not routinely determined.

MATERIALS AND METHODS

We analyzed 25 cases of gastric cancer that received preoperative chemotherapy and selected the six pre-treatment samples that were HER2-positive. Pre- and post-treatment tumor samples were examined for HER2 expression, and for HER2, epidermal growth factor receptor (EGFR), and hepatocyte growth factor receptor (MET) gene amplification.

RESULTS

Three patients had been treated with trastuzumab plus chemotherapy, and three patients with cytotoxic chemotherapy alone. Only one case that had an initial HER2 score of 3+ and had received trastuzumab plus chemotherapy remained HER2-positive after treatment. Decrease or loss of HER2 expression and amplification was observed in the other five patients. Amplification of EGFR or MET was not observed in any pre- or post-treatment specimens.

CONCLUSION

Our data suggest that trastuzumab plus chemotherapy or chemotherapy alone may induce loss of HER2 positivity.

Radiological Features of Programmed Cell Death-Ligand 2-positive Lung Adenocarcinoma: A Single-institution Retrospective Study

AIM

Programmed cell death-ligand 1 and 2 (PD-L1 and PD-L2) are ligands of the programmed cell death-1 (PD1) receptor. PD1/PD-L1 inhibitors have shown clinical efficacy in non-small cell lung cancer (NSCLC). However, relatively little is known about the expression of PD-L2, or its association with the clinicopathological features of NSCLC. Here, the radiological features of PD-L2-positive lung adenocarcinoma were evaluated.

MATERIALS AND METHODS

PD-L1 and PD-L2 expression were evaluated by immunohistochemical staining of surgically-resected specimens from 393 patients with primary lung adenocarcinoma who underwent preoperative thin-section computed tomography (CT), 222 of whom also underwent ¹⁸F-fluorodeoxyglucose positron-emission tomography/CT (¹⁸F-FDG-PET/CT).

RESULTS

Among the 393 specimens, 132 (33.6%) and 266 (67.7%) were positive for PD-L1 and PD-L2 expression, respectively. Multivariate analysis showed that the absence of surrounding ground glass opacity and the presence of air bronchogram were significantly associated with PD-L2 expression; however, there was no significant association between PD-L2 expression and the consolidation/tumor ratio. In 222 ¹⁸F-FDG-PET/CT, the maximum standardized uptake value was significantly higher in patients with PD-L2-positive compared to those with PD-L2-negative tumors.

CONCLUSION

PD-L2-positive lung adenocarcinomas are less radiologically malignant and invasive than their PD-L1-positive counterparts.

Primary amelanotic malignant melanoma of the esophagus: a case report

Background

Primary amelanotic malignant melanoma of esophagus, which is a subtype of primary malignant melanoma of the esophagus (PMME), is a very rare disease with a poor prognosis. We herein report a case of the amelanotic type of PMME.

Case presentation

An 86-year-old woman was admitted to our hospital with symptoms of dysphagia. An endoscopic examination and constructed radiography revealed an elevated and semipedunculated lesion with an ulcer in the lower thoracic esophagus accompanied by another submucosal lesion of the esophagus. She was diagnosed with esophageal squamous cell carcinoma by a preoperative endoscopic biopsy. We performed thoracoscopy- and laparoscopy-assisted subtotal esophagectomy with lymphadenectomy. Based on the surgical specimens, although there were no melanocytes, we made a diagnosis of a malignant melanoma immunohistochemically; the tumor cells were positive for S-100 protein and HMB45 focally and partially for Melan-A.

Conclusion

We experienced a case of primary amelanotic malignant melanoma, and the patient has remained disease-free for 1 year since the surgery. Since the diagnosis of amelanotic type of PMME is difficult, it should be made by the combination of a morphological examination, pathological examination, and immunohistochemistry.

BUBR1 Insufficiency Is Correlated with eNOS Reduction Experimentally In Vitro and In Vivo, and in Gastric Cancer Tissue

BACKGROUND/AIM

Budding uninhibited by benzimidazole-related 1 (BUBR1) and endothelial nitric oxide synthase (eNOS) are related to aging and angiogenesis. This study examined the effect of low BUBR1 expression on eNOS expression in vivo, in vitro, and human gastric cancer tissues.

MATERIALS AND METHODS

Human umbilical vein endothelial cells (HUVECs) were passaged to investigate the effect of aging on BUBR1 and eNOS expression; expression of eNOS and phospho-eNOS protein was assessed in BUBR1 siRNA-transfected HUVECs. Additionally, guanosine 3',5' cyclic monophosphate (cGMP) and eNOS protein levels were measured in BUBR1-insufficient mice (Bubr1^L/-). BUBR1 and eNOS expression levels were also evaluated in human gastric cancer tissues.

RESULTS

BUBR1 and eNOS, but not p-eNOS, levels were reduced significantly in aged and BUBR1 siRNA-transfected HUVECs. Additionally, cGMP production and the eNOS protein level were reduced in Bubr1^L/- mice. Human gastric cancer tissues with low BUBR1 expression showed no eNOS expression.

CONCLUSION

A decrease in BUBR1 reduced eNOS bioavailability through a pathway other than eNOS phosphorylation.

Neoadjuvant Chemoradiotherapy for Patients with cT3/Nearly T4 Esophageal Cancer: Is Sarcopenia Correlated with Postoperative Complications and Prognosis?

BACKGROUND

Since the clinical impact of sarcopenia on multimodal therapy for patients with esophageal cancer is not well understood, this study was conducted to determine the influence of sarcopenia on the efficacy of neoadjuvant chemoradiotherapy (NACRT) for locally advanced esophageal cancer.

METHODS

The skeletal muscle index was quantified at the level of the third lumbar vertebra on computed tomography images, and sarcopenia was defined as a skeletal muscle index that was less than the average for each gender. We compared treatment outcomes in patients with cT3 and nearly T4 thoracic esophageal squamous cell carcinoma between the sarcopenia group (n = 85) and the non-sarcopenia group (n = 72).

RESULTS

The 5-year survival rates were 33.4% in the non-sarcopenia group and 31.5% in the sarcopenia group; these differences were not significant. The prognosis of the patients with sarcopenia was worse than that of the patients without sarcopenia in the surgery-alone group, but there was no difference between patients with and without sarcopenia in the NACRT group.

CONCLUSIONS

NACRT could be a useful option for patients with locally advanced esophageal squamous cell carcinoma, even for those with sarcopenia, without increasing the incidence of morbidity and mortality.

PD-L2 Expression as a Potential Predictive Biomarker for the Response to Anti-PD-1 Drugs in Patients with Non-small Cell Lung Cancer

BACKGROUND/AIM

To investigate the role of programmed cell death-ligand 2 (PD-L2) expression as a predictive biomarker for response to anti-programmed cell death-1 (PD-1) drugs in patients with non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Ten patients who had undergone curative lung resection and received the anti-PD-1 drugs for the recurrence were enrolled. The cut-off value for PD-L2 (antibody clone 176611) expression on tumor cells was set at 50%. Tumor response was evaluated according to immune-related response criteria.

RESULTS

Seven patients (70.0%) were positive for PD-L2. The response rates were 28.6% (2/7) and 33.3% (1/3) in patients with PD-L2-positive and PD-L2-negative NSCLC, respectively. Disease control was obtained in 2 patients despite the programmed cell death-ligand 1 (PD-L1)-negativity (antibody clone 22C3: 0%, antibody clone SP142: 0%), and these tumors expressed PD-L2 (≥1%).

CONCLUSION

PD-L2 expression may be a target of immunotherapy in patients with PD-L1-negative NSCLC.

Non-familial juvenile polyposis of the stomach with gastric cancers: a case report

Background

Juvenile polyposis is an autosomal dominant inherited disease characterized by the development of numerous hamartomatous and nonneoplastic polyps of the gastrointestinal tract. Juvenile polyposis has also recently been reported as a predisposition for gastrointestinal cancer.

Case presentation

A 63-year-old man underwent esophagogastroduodenoscopy because of anemia and hypoalbuminemia during a follow-up for gastric polyposis, which showed multiple reddish polyps and two elevated lesions in the stomach. The elevated lesions were diagnosed as well-differentiated adenocarcinomas by biopsy. He had no specific physical findings or family history. Computed tomography showed gastric wall thickening without lymphadenopathy or distant metastasis. Colonoscopy showed an adenoma in the transverse colon. He underwent laparoscopy-assisted total gastrectomy with Roux-en-Y esophagojejunostomy. The resected specimen revealed numerous variously sized non-pedunculated polyps throughout the stomach, diagnosed histopathologically as hamartomatous polyps. The two elevated lesions were diagnosed as a well-differentiated adenocarcinoma restricted to the mucosa and a well-to-poorly differentiated adenocarcinoma invading the submucosa with prominent lymphatic permeation, respectively. Genetic analysis failed to identify any germline mutations in the genes usually associated with juvenile polyposis, including SMAD4 and BMPR1A. However, based on the few characteristic physical findings and histopathological features, the final diagnosis was juvenile polyposis restricted to the stomach.

Conclusions

This patient represented a rare case of non-familial juvenile polyposis of the stomach with gastric cancers. Juvenile polyposis has malignant potential, and patients should therefore be carefully followed up. Surgical treatment, particularly total gastrectomy, is recommended as a standard treatment in patients with juvenile polyposis of the stomach with gastric cancer.

Gastric Cancer of "Crawling Type" Detected by Additional Gastrectomy After Endoscopic Submucosal Resection

"Crawling type" gastric cancer (GC) is known as a rare variant of early GCs, which is difficult to diagnose at an early stage because of low-grade nuclear atypia and a morphology mimicking intestinal metaplasia. This is a case report of a 69-year-old woman who was diagnosed with early-stage gastric cancer. She had endoscopic submucosal resection (ESD) and histologically, both horizontal and vertical margins were negative. Seven months after ESD, a new lesion of the stomach was detected by follow-up gastroscopy. Laparoscopic distal gastrectomy was performed and "crawling type" glands were observed throughout the whole area of the tumor. We should keep this variant in mind, especially when a tumor is superficial depressed or superficial flat type in the middle of the stomach. Careful observation with multiple biopsies of all mucosal layer and a re-biopsy is the key procedure for obtaining the right diagnosis. Endoscopic and histological characteristics should also be reviewed.

Chemoradiotherapy for Solitary Skeletal Muscle Metastasis from Oesophageal Cancer: Case Report and Brief Literature Review

BACKGROUND

The incidence of skeletal muscle metastasis from oesophageal cancer is very low, and the treatment strategy has not been established.

CASE REPORT

A 77-year-old man underwent oesophagectomy following neoadjuvant chemotherapy for oesophageal squamous cell carcinoma (CT-pT3 N0 M0, CT-pStage II). Fourteen months after surgery, he became aware of a subcutaneous tumour in his left forearm. Computed tomography and fluorodeoxyglucose positron-emission tomography revealed a 65×75 mm intramuscular nodular lesion with a standardized uptake value of 8.5. Further examination by biopsy strongly suggested this was a solitary metastasis from oesophageal cancer. The patient received chemoradiotherapy with two cycles of 5-fluorouracil combined with cisplatin and radiation. Clinical complete response was confirmed by imaging 7 months after chemoradiation and no recurrence has occurred at 20 months since chemoradiation.

CONCLUSION

Radiotherapy or chemoradiotherapy can be an alternative locoregional therapy to surgery for solitary skeletal muscle metastasis.

[Resected Pulmonary Cryptococcosis Suspected as Lung Cancer;Report of a Case]

We report a case of pulmonary cryptococcosis suspected of lung cancer. A 65-year-old woman had an abnormal shadow on chest X-ray. A solitary nodule, 12 mm in size, with pleural indentation and spicula in S3 of the left lung was found on chest computed tomography. A serum cryptococcal antigen was negative. An abnormal accumulation of fluoro-2-deoxy-D-glucose(FDG)in the nodule was found with the standardized uptake value (SUV) max 5.04, suggesting lung cancer. The nodule was diagnosed as pulmonary cryptococcosis by surgical resection.