Pretreatment diagnosis factors associated with overtreatment with surgery in patients with differentiated-type early gastric cancer

This study aimed to clarify the pretreatment factors associated with overtreatment with surgery in patients with differentiated-type early gastric cancer. This single-centre, retrospective study included 781 patients with differentiated-type early gastric cancer treated by surgical resection between April 2005 and May 2017. Postoperative pathological results were used to divide patients into the accurate surgical indication group and overtreatment with surgery group; the groups were compared with respect to accurate diagnosis and misdiagnosis based on tumour diameter (≤30 mm or >30 mm), diagnosis of depth, diagnosis of ulcerative findings, and diagnosis of main histology. There were 224 patients in the overtreatment with surgery group. Multivariate analysis revealed significant differences in misdiagnosis of tumour diameter, misdiagnosis of depth, misdiagnosis of ulcerative findings, and misdiagnosis of main histology between the accurate surgical indication group and overtreatment with surgery group. Significant factors for pretreatment misdiagnosis leading to overtreatment in differentiated-type early gastric cancer were tumour diameter, depth, and main histology. It may be acceptable to perform endoscopic resection for patients with pretreatment tumour diameter ≤30 mm, mucosal invasion of pretreatment depth, and undifferentiated-type cancers containing differentiated-type components of pretreatment histology because this reduces overtreatment with surgery.

Prediction of early colorectal cancer metastasis by machine learning using digital slide images

BACKGROUND AND OBJECTIVES

Prediction of lymph node metastasis (LNM) for early colorectal cancer (CRC) is critical for determining treatment strategies after endoscopic resection. Some histologic parameters for predicting LNM have been established, but evaluator error and inter-observer disagreement are unsolved issues. Here we describe an LNM prediction algorithm for submucosal invasive (T1) CRC based on machine learning.

METHODS

We conducted a retrospective single-institution study of 397 T1 CRCs. Several morphologic parameters were extracted from whole slide images of cytokeratin immunohistochemistry using Image J. A random forest algorithm for a training dataset (n = 277) was executed and used to predict LNM for the test dataset (n = 120). The results were compared with conventional histologic evaluation of hematoxylin-eosin staining.

RESULTS

Machine learning showed better LNM predictive ability than the conventional method on some datasets. Cross validation revealed no significant difference between the methods. Machine learning resulted in fewer false-negative cases than the conventional method.

CONCLUSIONS

Machine learning on whole slide images is a potential alternative for determining treatment strategies for T1 CRC.

Epstein-Barr virus status is a promising biomarker for endoscopic resection in early gastric cancer: proposal of a novel therapeutic strategy

BACKGROUND

Epstein-Barr virus-positive gastric cancer (EBVGC) is associated with a low prevalence of lymph node metastasis (LNM); however, EBV status is not considered in the indication of endoscopic resection (ER). We aimed to clarify the implication of EBV status for ER of pT1b GC.

METHODS

Consecutive cases of pT1b GCs treated with surgery between 2005 and 2014 were retrospectively analyzed. Clinicopathological factors and LNM status were compared between EBVGC and non-EBVGC groups.

RESULTS

EBVGC accounted for 7.9% (71 of 898) cases. Compared to non-EBVGC, EBVGC was more frequent in males (p = 0.0055), the upper third region (p < 0.0001), showed elevated growth features (p = 0.0059), and was associated with a lower frequency of accompanying ulceration (p = 0.002), greater depth of submucosal invasion (p = 0.017), and lower frequency of lymphatic invasion (p < 0.0001). Frequency of LNM was significantly lower in EBVGC than in non-EBVGC (4.2% vs. 21.9%, p < 0.0001). In EBVGC, tumors without lymphovascular invasion showed significantly lower frequency of LNM than those with lymphovascular invasion (0 of 50, 0%; vs 3 of 21, 14.3%; p = 0.023). Histologically, 84.5% (60 of 71) of EBVGC included carcinomas with lymphoid stroma and/or lace pattern components.

CONCLUSIONS

pT1b EBVGC is a convincing candidate for ER, regardless of risk factors other than lymphovascular invasion.

Effective wound bed preparation using maggot debridement therapy for patients with critical limb ischaemia

OBJECTIVE

Patients with critical limb ischaemia (CLI) lack sufficient blood flow in to the limb, which leads to difficulties in the normal wound healing process. Therefore, maggot debridement therapy (MDT) has not generally been recommended for CLI patients. We evaluated the effectiveness of wound bed preparation by MDT in CLI patients who had undergone mid-foot amputation.

METHODS

Patients who underwent mid-foot amputation after angioplasty between April 2014 and October 2016 were retrospectively investigated by classifying them into an MDT group or a conventional treatment group. The primary outcome was defined as achievement of wound healing. Secondary outcomes were the proportions of amputation-free survival (AFS) and successful ambulatory improvement. Propensity scores were used to evaluate treatment outcomes based on five factors: ankle-brachial index, skin perfusion pressure of the foot, nutritional status, experience with dialysis and age.

RESULTS

A total of 39 patients (39 legs) were included, seven within the MDT group and 32 in the conventional treatment group. Clinical backgrounds of the two groups showed no significant differences except for higher albumin levels for the MDT group (3.5±0.4g/dl; p=0.014). The wound healing proportion was significantly higher in the MDT group (86%) than in the control group (38%) (p=0.035). At 6 months after amputation, no significant differences were found between the two groups for AFS (71% versus 47%; p=0.41) or ambulatory capability (43% versus 28%; p=0.65). This result was also similar to the propensity score adjustment analysis.

CONCLUSIONS

The efficacy of MDT with favourable wound bed preparation was shown in our CLI patients based on effective debridement and granulation formation by maggots, avoiding the loss of their heels. Wound-healing rates after MDT were higher for patients than for those receiving conventional treatment. MDT is considered a valid adjuvant treatment strategy for patients with CLI after revascularisation treatment is conducted. More favourable wound bed preparation and successful graft take were achieved in the MDT group, suggesting the effectiveness of MDT for wound healing in CLI patients.

Immunogenomic profiles associated with response to neoadjuvant chemoradiotherapy in patients with rectal cancer

BACKGROUND

Accumulating evidence suggests that radiotherapy success has an immune-associated component. The immunogenomic profiles associated with responses to chemoradiotherapy (CRT) were assessed in patients with locally advanced rectal cancer in this study.

METHODS

CD8+ tumour-infiltrating lymphocyte (TIL) and stromal lymphocyte densities were assessed by immunohistochemistry using pretreatment biopsies from patients with advanced rectal cancer who had preoperative CRT. Whole-exome sequencing and gene expression microarray analysis were conducted to investigate the genomic properties associated with the response to CRT and CD8+ TIL density. Response to CRT was determined based on Dworak tumour regression grade (TRG); tumours with complete (TRG 4) or near-complete (TRG 3) regression were grouped as good responders, and those with TRG 1 as non-responders.

RESULTS

Immunohistochemical examinations (275 patients) showed that pre-CRT CD8+ TIL density was associated with better response to CRT and improved recurrence-free survival, whereas pre-CRT stromal CD8+ cell density was not associated with either response to CRT or recurrence-free survival. Whole-exome sequencing (74 patients) showed that the numbers of single-nucleotide variations (SNVs) and neoantigens predicted from SNVs were higher in good responders than in non-responders, and these correlated positively with CD8+ TIL density (r_S  = 0·315 and r_S  = 0·334 respectively). Gene expression microarray (90 patients) showed that CD8A expression correlated positively with the expression of programmed cell death 1 (PDCD1) (r_S  = 0·264) and lymphocyte-activation gene 3 (LAG3) (r_S  = 0·507).

CONCLUSION

Pre-CRT neoantigen-specific CD8+ T cell priming may be a key event in CRT responses where immune checkpoint molecules could be useful targets to enhance tumour regression.

Clinicopathological features of Epstein–Barr virus associated gastric carcinoma with submucosal invasion

4029

Background: The incidence of lymph node metastasis (LNM) in pathological T1b (pT1b) gastric cancer (GC) is around 20% and the majority of them have no LNM. The Cancer Genome Atlas Research Network proposed the concept of molecular phenotype classifying GC into 4 phenotypes including Epstein-Barr virus-CIMP (EBV). EBV positive gastric cancer (EBVGC) is associated with a low prevalence of LNM; however, EBV status is not considered in the present indication of endoscopic resection (ER). We aimed to clarify the implication of EBV status for ER of pT1b GC. Methods: Consecutive cases of pT1b GCs treated with curative surgery between 2005 and 2014 were retrospectively analyzed. Tissue microarray was made and EBV-encoded RNA in situ hybridization was performed for evaluation of EBV status. Clinicopathological factors and LNM status were compared between EBVGC and non-EBVGC groups. Results: Among the 1221 pT1b GCs that underwent gastrectomy with regional lymph node dissection, 898 pT1bGCs were eligible in this study. EBVGC accounted for 7.9% (71 of 898) cases. Compared to non-EBVGC, EBVGC was more frequent in males (p = 0.0055), the upper third region (p < 0.0001), showed elevated growth features (p = 0.0059), and was associated with a lower frequency of accompanying ulceration (p = 0.002), greater depth of submucosal invasion (p = 0.017), and lower frequency of lymphatic invasion (p < 0.0001). Frequency of LNM was significantly lower in EBVGC than in non-EBVGC (4.2% vs. 21.9%, p < 0.0001). In EBVGC, tumors without lymphovascular invasion showed significantly lower frequency of LNM than those with lymphovascular invasion (0 of 50, 0%; vs 3 of 21, 14.3%; p = 0.023). Histologically, 84.5% (60 of 71) of EBVGC included carcinomas with lymphoid stroma and/or lace pattern components. Conclusions: pT1b EBVGC is a convincing candidate for ER, regardless of risk factors other than lymphovascular invasion.

Enrichment of CLDN18-ARHGAP fusion gene in gastric cancers in young adults

Gastric cancer in young adults has been pointed out to comprise a subgroup associated with distinctive clinicopathological features, including an equal gender distribution, advanced disease, and diffuse‐type histology. Comprehensive molecular analyses of gastric cancers have led to molecular‐based classifications and to specific and effective treatment options. The molecular traits of gastric cancers in young adults await investigations, which should provide a clue to explore therapeutic strategies. Here, we studied 146 gastric cancer patients diagnosed at the age of 40 years or younger at the Cancer Institute Hospital (Tokyo, Japan). Tumor specimens were examined for Helicobacter pylori infection, Epstein‐Barr virus positivity, and for the expression of mismatch repair genes to indicate microsatellite instability. Overexpression, gene amplifications, and rearrangements of 18 candidate driver genes were examined by immunohistochemistry and FISH. Although only a small number of cases were positive for Epstein‐Barr virus and microsatellite instability (n = 2 each), we repeatedly found tumors with gene fusion between a tight‐junction protein claudin, CLDN18, and a regulator of small G proteins, ARHGAP, in as many as 22 cases (15.1%), and RNA sequencing identified 2 novel types of the fusion. Notably, patients with the CLDN18‐ARHGAP fusion revealed associations between aggressive disease and poor prognosis, even when grouped by their clinical stage. These observations indicate that a fusion gene between CLDN18 and ARHGAP is enriched in younger age‐onset gastric cancers, and its presence could contribute to their aggressive characteristics.

Evaluation of the Effects of Cultured Bone Marrow Mesenchymal Stem Cell Infusion on Hepatocarcinogenesis in Hepatocarcinogenic Mice With Liver Cirrhosis

OBJECTIVES

Liver transplantation remains the only curative therapy for decompensated liver cirrhosis. However, it has several limitations, and not all patients can receive liver transplants. Therefore, liver regenerative therapy without liver transplantation is considered necessary. In this study, we attempted minimally invasive liver regenerative therapy by peripheral vein infusion of bone marrow-derived mesenchymal stem cells (BMSCs) cultured from a small amount of autologous bone marrow fluid and evaluated the effects of BMSCs on hepatocarcinogenesis in a mouse model.

METHODS

C57BL/6 male mice were injected intraperitoneally with N-nitrosodiethylamine once at 2 weeks of age, followed by carbon tetrachloride twice a week from 6 weeks of age onwards, to create a mouse model of highly oncogenic liver cirrhosis. From 10 weeks of age, mouse isogenic green fluorescent protein-positive BMSCs (1.0 × 10⁶/body weight) were infused once every 2 weeks, for a total of 5 times, and the effects of frequent BMSC infusion on hepatocarcinogenesis were evaluated.

RESULTS

In the histologic evaluation, no significant differences were observed between the controls and BMSC-administered mice in terms of incidence rate, number, or average size of foci and tumors. However, significant suppression of fibrosis and liver injury was confirmed in the group that received BMSC infusions.

DISCUSSION

Considering that BMSC infusion did not promote carcinogenesis, even in the state of highly oncogenic liver cirrhosis, autologous BMSC infusion might be a safe and effective therapy for human decompensated liver cirrhosis.

Phase II Trial of Neoadjuvant Chemotherapy, Chemoradiotherapy, and Laparoscopic Surgery with Selective Lateral Node Dissection for Poor-Risk Low Rectal Cancer

PURPOSE

The aim of this study is to evaluate the safety and efficacy of induction modified 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus bevacizumab followed by S- 1-based chemoradiotherapy in magnetic resonance imaging (MRI)-defined poor-risk locally advanced low rectal cancer.

PATIENTS AND METHODS

This was a prospective phase II trial at a single comprehensive cancer center. The primary endpoint was the pathological complete response (pCR) rate. Eligible patients had clinical stage II-III low rectal adenocarcinoma with any of the following MRI-defined poor-risk features: circumferential resection margin (CRM) ≤ 1 mm, cT4, positive lateral nodes, mesorectal N2 disease, and/or requiring abdominoperineal resection. Patients received six cycles of mFOLFOX6 with 5 mg/kg bevacizumab followed by oral S-1 (80 mg/m²/day on days 1-14 and 22-35) plus radiotherapy (50.4 Gy). Surgery was conducted through a laparoscopic approach. Lateral node dissection was selectively added when the patient had enlarged lateral nodes.

RESULTS

A total of 43 patients were enrolled. Grade 3-4 adverse events occurred in nine patients during induction chemotherapy and in five patients during chemoradiotherapy. One patient declined surgery with a clinical complete response. Forty-two patients underwent surgery, and 16 had pCR [37.2%, 95% confidence interval (CI) 24.4-52.1%]. All underwent R0 resection without conversion, including combined resection of adjacent structures (n = 14) and lateral node dissection (n = 30). Clavien-Dindo grade 3-4 complications occurred in six patients (14.3%). With median follow-up of 52 months, six developed recurrences (lung n = 5, local n = 1; 3-year relapse-free survival 86.0%).

CONCLUSIONS

This study achieved a high pCR rate with favorable toxicity and postoperative complications in poor-risk locally advanced low rectal cancer. Multicenter study is warranted to evaluate this regimen.

Clinical significance of soluble programmed cell death-1 and soluble programmed cell death-ligand 1 in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Background

Inhibition of the programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) axis in combination with radiotherapy may be a promising approach to treat cancer. In the present study, we aimed to evaluate serum soluble PD-1/PD-L1 levels in patients with advanced rectal cancer treated with neoadjuvant chemoradiotherapy (CRT).

Methods

Serum soluble PD-L1 and PD-1 levels were measured using an enzyme-linked immunosorbent assay before and after CRT in 117 patients with low rectal cancer. Changes in the levels of sPD-L1/PD-1 after CRT, and the correlation between sPD-L1/PD-1 level and clinicopathological characteristics or disease-free survival (DFS) were evaluated.

Results

sPD-L1 levels significantly increased after CRT (p < 0.0001), whereas sPD-1 levels did not change significantly (p = 0.1050). High sPD-L1 before CRT was significantly associated with younger age (p = 0.044), and after CRT, with lymphovascular invasion (p = 0.021). High sPD-1 before and after CRT was significantly associated with a longer distance of the tumor from the anal verge (both p < 0.001). There was no correlation between sPD-L1 level and local PD-L1 expression on stromal immune cells. High sPD-L1 level after CRT tended to be associated with worse DFS (p = 0.0752). The multivariate analysis could not demonstrate an independent association for sPD-L1 levels after CRT with DFS.

Conclusions

Significant increase of sPD-L1 levels after CRT suggests that anti-PD-L1 therapy might be a potential treatment strategy in combination with CRT in advanced rectal cancer.

Abstract P3-03-22: Prognostic impact of axillary lymph node status after neoadjuvant chemotherapy for patients with breast cancer

BACKGROUND:

Patients were stratified by final pathological axillary status: ypN0, ypN1, pN0 or pN1.

The prognostic impact of lymph node involvement after neoadjuvant chemotherapy (NAC) for breast cancer is not straightforward. The aim of this study was to compare overall survival (OS) between pathologically

node-positive T1,T2 T3 breast cancer patients treated with NAC, with ypN0 or ypN1 and those treated without NAC with pN0 or pN1.

METHODS:

A total of 3903 consecutive patients with operable breast cancer were prospectively identified at our institution between April 2006 and December 2017. Patients with suspicious axillary LN of breast cancer were assessed using preoperative imaging, underwent fine-needle aspiration cytology or core needle biopsy.

The patients in this study were divided into four groups as follows: the ER(+), the ER(+)/HER2(+) , the HER2(+) and the Triple negative (TN) group.

We evaluate the prognostic impact of the ypN0, ypN1 (with one to three positive lymph nodes after NAC), pN0 and pN1 with no NAC.

The main outcome measures DFS and OS were analyzed using Kaplan–Meier survival analysis.

Result

A number of 270 and 3633 patients were included for NAC and non NAC, respectively. Pathologic nodal status was ypN0 in 58%, ypN1 in 42% for NAC and pN0 in 76%, pN1 in 24% of patients for non NAC.

Overall, 10-year DFS and OS was 81%, 93% in ypN0, 67%, 80% in ypN1, in 90%, 97%, in pN0 and 83%, 94% in pN1 (p &lt;0.001).

In subgroup analysis, 10-year DFS of ypN0, ypN1, pN0 and pN1 was 86%,77%,95% and 80% in the ER group, 91%,56%,93%,and 76% in the ER/HER2 group,89%,55%,91% and 80% in the HER2 group, 85%,59%,92% and 80% in the TN group.

10 years DFS for the ER group were significantly different between ypN0 and pN0 (HR, 2.42 (1.03–4.86, p = 0.04) but were not significantly different between ypN0 and pN0 for the ER/HER2 group (HR 3.58 (0.2–6.88, p = 0.66), for the HER2 group (HR 2.6 (0.78–7.65, p = 0.10) and for the TN group (HR 1.22(0.56–2.38, p = 0.58), respectively).

In all group, DFS for ypN1 was inferior to ypN0.

Conclusions

In the ER group treated with NAC, DFS for ypN0 be inferior to pN0 with adjuvant treatment. In the HER2, the ERHER2 and the TN group treated with NAC, ypN0 is similar to pN0 with adjuvant chemotherapy.

Axillary nodal status ypN1 in each subgroup is associated with a less favorable prognosis compared to ypN0. In conclusion, the HER2 or TN group is highest for predicting ypN0, shown to be most prognostic of long-term survival similar to the patients with pN0. They could be omitted the axillary dissection.

Citation Format: Nakamura R, Yamamoto N, Miyaki T, Itami M. Prognostic impact of axillary lymph node status after neoadjuvant chemotherapy for patients with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-22.

Abstract P3-10-16: Predicting pathological complete response by the combination of microRNAs in patients with HER2-positive primary breast cancer who received neoadjuvant combination therapy of trastuzumab, lapatinib and paclitaxel: Results from JBCRG-16 (NeoLath) study

[Background] JBCRG-16 (NeoLath) study is a five-arm study to evaluate the efficacy and safety of lapatinib and trastuzumab (6 weeks) followed by lapatinib and trastuzumab plus weekly paclitaxel (12 weeks) with/without prolongation of anti-HER2 therapy prior to chemotherapy (18 vs. 6 weeks), and with/without endocrine therapy in patients with HER2+ and/or estrogen receptor (ER)+ disease. The primary endpoint was pathological complete response (pCR) rate and pCR rate was 47.9% (Masuda N, et al. Breast Cancer, 2018). It is recently reported that microRNAs (miRNAs) are stably present in serum and potentially useful in the diagnosis and evaluation of treatment of cancer. We performed exploratory analysis of detecting pCR by comprehensive analysis of serum miRNAs.

[Materials and Methods] Serum samples were obtained from study participants who received neoadjuvant systemic therapy with trastuzumab, lapatinib and paclitaxel. Before profiling of miRNAs, the overall serum samples were randomly devided in two sets, namely the training set and the testing set with pCR or non-pCR. Pathological complete response (pCR) was defined as the absence of residual invasive cancer of the resected breast specimen and all sampled regional lymph nodes. Total RNA was extracted from a 300 ul serum sample using 3D-Gene® RNA extraction reagent from a liquid sample kit. A comprehensive quantitative expression analysis of miRNA was performed using the by DNA chip 3D-Gene®, which was designed to detect 2565 miRNA sequences registered in miRBase release 21 (http://www.mirbase.org/). The expression level of miRNAs were normalized by internal control (miR-2861, miR-149-3p and miR-4463). Clinicopathological data was retrieved from trial data.

[Results] A total of 112 samples were obtained. Seventy were used in the training set and others were used in the testing set. Median age was 54 years (range 26-70). Sixty-five (58%) patients were pre-menopausal. ER was positive in 59 patients (52.7%). Fourteen (12.5%) were T1c, 78 (69.6%) were T2 and 20 (17.9%) were T3. Fifty-seven (50.9%) patients were node-positive. Fifty-nine (52.7%) patients achieved pCR. The formula with the combination of three miRNAs (miR-A, miR-B, miR-C) was found to be able to predict pCR. This set had a sensitivity of 62.5%, specificity of 86.7% and accuracy of 71.8% in the testing cohort. Area under curve of receiver operationg characteristic curve was 0.753.

[Conclusion] The combination of three miRNAs has potential to predict pCR in patients who received neoadjuvant combination therapy of trastuzumab, lapatinib and paclitaxel in HER2-positive primary breast cancer. The further analysis of changing expression of miRNAs during neoadjuvant therapy is underway and further results will be presented in the symposium.

Citation Format: Shimomura A, Masuda N, Kawauchi J, Takizawa S, Ichikawa M, Matasuzaki J, Kuroi K, Hara H, Yamamoto N, Inoue K, Suganuma N, Aogi K, Ohno S, Tamura K, Ochiya T, Toi M. Predicting pathological complete response by the combination of microRNAs in patients with HER2-positive primary breast cancer who received neoadjuvant combination therapy of trastuzumab, lapatinib and paclitaxel: Results from JBCRG-16 (NeoLath) study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-16.

Pan-Asian adapted Clinical Practice Guidelines for the management of patients with metastatic non-small-cell lung cancer: a CSCO-ESMO initiative endorsed by JSMO, KSMO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of metastatic non-small-cell lung cancer (NSCLC) was published in 2016. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and the Chinese Society of Clinical Oncology (CSCO) to convene a special guidelines meeting immediately after the Chinese Thoracic Oncology Group Annual Meeting 2018, in Guangzhou, China. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic NSCLC cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic NSCLC representing the oncological societies of China (CSCO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence, and was independent of both the current treatment practices and the drug availability and reimbursement situations in the six participating Asian countries. During the review process, the updated ESMO 2018 Clinical Practice Guidelines for metastatic NSCLC were released and were also considered, during the final stages of the development of the Pan-Asian adapted Clinical Practice Guidelines.

Glutamine Deprivation Enhances Acetyl-CoA Carboxylase Inhibitor-induced Death of Human Pancreatic Cancer Cells

BACKGROUND/AIM

Acetyl-CoA carboxylase (ACC) is a rate-limiting enzyme in fatty acid synthesis. In this study, we investigated the effect of ACC inhibition on survival of pancreatic cancer cells.

MATERIAL AND METHODS

AsPC-1, BxPC-3 and PANC-1 were used as human pancreatic cancer cell lines. 5-(etradecyloxy)-2-furoic acid (TOFA) and bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES) were used as inhibitors of ACC and glutaminase (GLS) respectively. Apoptotic and live cells were distinguished by annexin-V staining. The activity of caspase-3 was evaluated by measuring the fluorescence intensity of the degradation product of the substrate, N-acetyl-Asp-Glu-Val-Asp-7-amido-4-trifluoromethylcoumarin.

RESULTS

TOFA increased the number of annexin V-positive cells and enhanced caspase-3 activity in AsPC-1 and BxPC-3, but not in PANC-1 cells. The number of PANC-1 cells increased after 48 h in Earle's balanced salt solution. Interestingly, proliferation of PANC-1 cells was drastically suppressed by glutamine deprivation, but not by inhibition of glycolysis. BPTES also induced cell death to the same extent as glutamine deprivation. In addition, TOFA induced cell death of PANC-1 cells, both in the presence of BPTES and with glutamine deprivation, suggesting that inhibition of glutaminolysis causes cell death and enhances the effect of TOFA in PANC-1 cells.

CONCLUSION

These findings suggest that glutaminolysis is important for the survival of pancreatic cancer cells showing tolerance to nutrient starvation such as PANC-1 cells, and use of a combination of inhibitors of ACC and GLS may be a new strategy for treatment of pancreatic cancer.

Clinical significance of intratumoral HER2 heterogeneity on trastuzumab efficacy using endoscopic biopsy specimens in patients with advanced HER2 positive gastric cancer

BACKGROUND

We recently reported the clinical significance of intratumoral HER2 heterogeneity on trastuzumab efficacy using surgical specimens; patients with homogeneously HER2 positive gastric cancer benefitted more from trastuzumab. However, the majority of patients are diagnosed by endoscopic biopsy, and surgical specimens are not available in these patients. The aim of this study is to verify clinical significance of HER2 heterogeneity on trastuzumab efficacy using biopsy specimens.

METHODS

Eighty-seven patients, who received trastuzumab-based chemotherapy and whose endoscopic biopsy specimens were available for HER2 assessment, were consecutively enrolled. When all tumor cells in all biopsy specimens overexpressed HER2 protein, it was defined as homogeneously HER2 (homo-HER2) positive group, and the others were defined as heterogeneously HER2 (hetero-HER2) positive group. Progression-free survival (PFS), overall survival (OS) and objective response rate (ORR) were evaluated.

RESULTS

Thirty-four patients (39%) were diagnosed as the homo-HER2 group and 53 patients (61%) were the hetero-HER2 group. After the median follow-up period of 17.8 months, the median PFS and OS were 7.6 and 17.8 months, respectively. Significant survival differences were shown between the two groups; the homo-HER2 group showed significantly longer PFS (10.8 vs. 6.1 months, HR 0.469 95% CI 0.29-0.77, p = 0.003) and OS (29.3 vs. 14.4 months, HR 0.352 95% CI 0.20-0.61, p < 0.001). ORR was 68.6% in this cohort. Higher response rate (85.2% vs 58.1%, p = 0.020) and deeper response (- 49.0% vs - 40.0%, p = 0.018) were also found in the homo-HER2 group.

CONCLUSIONS

Similar to surgical specimens, we verified clinical significance of HER2 heterogeneity on trastuzumab efficacy using endoscopic biopsy specimens.

Gastric Adenocarcinoma of Fundic Gland Type with Aggressive Transformation and Lymph Node Metastasis: a Case Report

A 55-year-old man visited our hospital for a detailed examination of a gastric submucosal tumor that was first detected 10 years prior. The tumor continued to grow and had developed a depressed area in its center. A histopathological examination of biopsy specimens revealed gastric adenocarcinoma of the fundic gland type (GA-FG). It was diagnosed as T2 based on the invasion depth as determined by white-light endoscopy and endoscopic ultrasonography. A total gastrectomy with lymphadenectomy was performed and a GA-FG in the mucosa and submucosa was confirmed histopathologically. However, there was a gradual transition to an infiltrative tubular adenocarcinoma with poorly differentiated components in the muscular and subserosal layers. Metastasis was identified in a dissected lymph node (LN). This is the first report of a GA-FG progressing to an aggressive cancer with LN metastasis. These findings modify our understanding of the pathophysiology of GA-FG.

Broad-spectrum antibiotic prescriptions are discontinued unevenly throughout the week

In order to investigate prescribing patterns of in-hospital broad-spectrum antibiotics (antimeticillin-resistant Staphylococcus aureus drugs, carbapenems and piperacillin/tazobactam), data on the distribution of antibiotic initiation and discontinuation throughout the week were analysed at Osaka University Hospital, Japan. No significant differences in the number of initiations were found between weekdays. However, broad-spectrum antibiotics were disproportionately discontinued on Tuesdays or on the second day after a holiday. This study suggests that broad-spectrum antibiotics tend to be continued over weekends or holidays and discontinued thereafter; this is likely to be due to behavioural factors beyond medical indications, and needs to be addressed in future antimicrobial stewardship initiatives.

Diagnostic accuracy of demarcation using magnifying endoscopy with narrow-band imaging for Helicobacter pylori-uninfected undifferentiated-type early gastric cancer

BACKGROUND

It is unknown how the accuracy rate of diagnostic demarcation of undifferentiated-type early gastric cancers (UD-type EGCs) differs between patients uninfected with Helicobacter pylori (H. pylori) and patients with and without H. pylori eradication. This study assessed and compared the diagnostic accuracy rate in the H. pylori-uninfected group and the non-H. pylori eradication and H. pylori eradication groups.

METHODS

Subjects were 81 patients with 81 lesions who underwent endoscopic submucosal dissection between January 2010 and January 2015. There were 21 lesions in the H. pylori-uninfected group, 27 in the H. pylori eradication group, and 33 in the non-H. pylori eradication group. The rate in the H. pylori-uninfected group was separately compared with the rates in the non-H. pylori eradication and H. pylori eradication groups, as was inflammatory cell infiltration.

RESULTS

The diagnostic accuracy rates were 60.6% in the non-H. pylori eradication group, 92.2% in the H. pylori eradication group, and 100% in the H. pylori-uninfected group; the rate was significantly higher in the H. pylori-uninfected group than in the non-H. pylori eradication group, but no significant difference was observed between the H. pylori-uninfected group and the H. pylori eradication group. In addition, the H. pylori-uninfected and H. pylori eradication groups showed no significant differences in neutrophil infiltration and intestinal metaplasia, whereas the state in the H. pylori-uninfected group was significantly milder.

CONCLUSIONS

Because neutrophil infiltration was classified as mild or none, the accuracy of diagnostic demarcation was high in the H. pylori-uninfected and H. pylori eradication groups.

Clinical impact of intratumoral HER2 heterogeneity on trastuzumab efficacy in patients with HER2-positive gastric cancer

BACKGROUND

There is growing interest in the clinical significance of intratumoral HER2 heterogeneity. Its prognostic and predictive impacts on trastuzumab efficacy were demonstrated in breast cancer. However, its clinical significance in gastric cancer is still unclear.

METHODS

Twenty-eight HER2-positive gastric cancer patients who had gastrectomy prior to trastuzumab-based chemotherapy were consecutively enrolled. Intratumoral HER heterogeneity was evaluated using whole-tissue sections by immunohistochemistry. When all tumor cells overexpressed HER2 protein, the tumor was defined as homogeneously HER2 (Homo-HER2)-positive group. The others were defined as heterogeneously HER2 (Hetero-HER2)-positive group.

RESULTS

There was no significant difference in clinicopathological features between the two groups. The median progression-free survival (PFS) and overall survival (OS) in the Homo-HER2-positive group were significantly longer than those in the Hetero-HER2-positive group (PFS; 20.0 months [95% CI 17.8-22.2] vs. 6.0 months [95% CI 2.3-9.7]; HR 0.11; 95% CI 0.03-0.41; p < 0.001, OS; not reached vs. 14.0 months [95% CI 11.9-16.1]; HR 0.18; 95% CI 0.06-0.61; p = 0.003). In the multivariate analysis, these associations remained significant both in PFS (HR 0.12; 95% CI 0.03-0.46, p = 0.002) and OS (HR 0.21; 95% CI 0.06-0.72, p = 0.013). With respect to response rate, no statistical difference was found between two groups. However, deeper tumor shrinkage was obtained in the Homo-HER2-positive group compared with the Hetero-HER2-positive group (p = 0.046).

CONCLUSIONS

Intratumoral HER2 heterogeneity may have robust clinical impact on trastuzumab efficacy in patients with HER2-positive gastric cancer. These findings should be validated by larger independent cohorts and further molecular correlative analyses are warranted.