Clinical practice guidelines for molecular tumor marker, 2nd edition review part 2

In recent years, rapid advancement in gene/protein analysis technology has resulted in target molecule identification that may be useful in cancer treatment. Therefore, "Clinical Practice Guidelines for Molecular Tumor Marker, Second Edition" was published in Japan in September 2021. These guidelines were established to align the clinical usefulness of external diagnostic products with the evaluation criteria of the Pharmaceuticals and Medical Devices Agency. The guidelines were scoped for each tumor, and a clinical questionnaire was developed based on a serious clinical problem. This guideline was based on a careful review of the evidence obtained through a literature search, and recommendations were identified following the recommended grades of the Medical Information Network Distribution Services (Minds). Therefore, this guideline can be a tool for cancer treatment in clinical practice. We have already reported the review portion of "Clinical Practice Guidelines for Molecular Tumor Marker, Second Edition" as Part 1. Here, we present the English version of each part of the Clinical Practice Guidelines for Molecular Tumor Marker, Second Edition.

Combination of high anti-SKI and low anti-TMED5 antibody levels is preferable prognostic factor in esophageal carcinoma

Given that esophageal cancer is highly malignant, the discovery of novel prognostic markers is eagerly awaited. We performed serological identification of antigens by recombinant cDNA expression cloning (SEREX) and identified SKI proto-oncogene protein and transmembrane p24 trafficking protein 5 (TMED5) as antigens recognized by serum IgG antibodies in patients with esophageal carcinoma. SKI and TMED5 proteins were expressed in Escherichia coli, purified by affinity chromatography, and used as antigens. The serum anti-SKI antibody (s-SKI-Ab) and anti-TMED5 antibody (s-TMED5-Ab) levels were significantly higher in 192 patients with esophageal carcinoma than in 96 healthy donors. The presence of s-SKI-Abs and s-TMED5-Abs in the patients' sera was confirmed by western blotting. Immunohistochemical staining showed that the TMED5 protein was highly expressed in the cytoplasm and nuclear compartments of the esophageal squamous cell carcinoma tissues, whereas the SKI protein was localized predominantly in the nuclei. Regarding the overall survival in 91 patients who underwent radical surgery, the s-SKI-Ab-positive and s-TMED5-Ab-negative statuses were significantly associated with a favorable prognosis. Additionally, the combination of s-SKI-Ab-positive and s-TMED5-Ab-negative cases showed an even clearer difference in overall survival as compared with that of s-SKI-Ab-negative and s-TMED5-Ab-positive cases. The s-SKI-Ab and s-TMED5-Ab biomarkers are useful for diagnosing esophageal carcinoma and distinguishing between favorable and poor prognoses.

Prognostic Impact of Serum SCC Antigen in the 566 Upfront Surgery Group of Esophageal Squamous Cell Carcinoma: A Multi-Institutional Study of the Japan Esophageal Society

PURPOSE

This study aimed to determine the clinicopathologic and prognostic significance of squamous cell carcinoma antigen (SCC-Ag) in patients with esophageal SCC who underwent radical surgery without neoadjuvant therapy.

METHODS

This study included 566 patients with primary esophageal SCC who underwent radical resection without neoadjuvant therapy at 15 Japanese hospitals between 2008 and 2016. The cutoff value of SCC-Ag was 1.5 ng/mL based on the receiver operating characteristic curves. Preoperative SCC-Ag and postoperative SCC-Ag were analyzed to evaluate clinicopathological and prognostic significance. Survival curves were compared between the SCC-Ag-positive group and the SCC-Ag-negative group. The prognostic impact of SCC-Ag was evaluated using univariate and multivariate analyses.

RESULTS

The preoperative SCC-Ag-positive rate was 23.5% (133/566). SCC-Ag-positive status was significantly associated with old age (p = 0.042), tumor depth (p <0.001), and tumor stages (p <0.001). The preoperative SCC-Ag-positive group had significantly poorer overall survival than the SCC-Ag-negative group (p = 0.030), but it was not an independent predictor of poor prognosis. Postoperative SCC-Ag-positive status was an independent risk factor for poor overall survival (p = 0.034).

CONCLUSION

Both pre- and postoperative SCC-Ag-positive statuses were significantly associated with poor prognosis. Postoperative SCC-Ag-positive status was an independent risk factor for predicting overall survival.

Is High Score of Preoperative Lactate Dehydrogenase to Albumin Ratio Predicting Poor Survivals in Esophageal Carcinoma Patients?

PURPOSE

The lactate dehydrogenase-to-albumin ratio (LAR) has been reported as a potential prognostic biomarker in various cancers; however, only a few pieces of information have been reported on esophageal cancer. Therefore, this study aimed to evaluate the prognostic significance of preoperative LAR in patients with esophageal cancer.

METHODS

This study included 236 patients (193 men and 43 women; mean age of 66 years [range, 41-83 years]) with esophageal cancer who underwent curative surgery between September 2008 and March 2020. A total of 107 patients underwent upfront surgery, and 129 patients received neoadjuvant treatment. Patients were assigned into two groups, high and low LAR, based on preoperative LAR using a cutoff value of 6.2. The clinicopathological and prognostic significance of preoperative LAR was evaluated in univariate and multivariate analyses.

RESULTS

Patients with deep tumors and neoadjuvant treatment were significantly associated with high LAR (p <0.05). The high LAR group showed a significantly poorer prognosis than the low LAR group (p <0.01). The multivariate analysis for the overall survival showed that deep tumors, lymph node metastasis, and high LAR were independent poor prognostic factors (p <0.05).

CONCLUSION

High LAR was a useful poor prognostic biomarker in patients with esophageal cancer.

The combination of positive anti‑WDR1 antibodies with negative anti‑CFL1 antibodies in serum is a poor prognostic factor for patients with esophageal carcinoma

WD repeat-containing protein 1 (WDR1) regulates the cofilin 1 (CFL1) activity, promotes cytoskeleton remodeling, and thus, facilitates cell migration and invasion. A previous study reported that autoantibodies against CFL1 and β-actin were useful biomarkers for diagnosing and predicting the prognosis of patients with esophageal carcinoma. Therefore, the present study aimed to evaluate the serum levels of anti-WDR1 antibodies (s-WDR1-Abs) combined with serum levels of anti-CFL1 antibodies (s-CFL1-Abs) in patients with esophageal carcinoma. Serum samples obtained from 192 patients with esophageal carcinoma and other solid cancers. And s-WDR1-Ab and s-CFL1-Ab titers were analyzed using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay. Compared with those of healthy donors, the s-WDR1-Ab levels were significantly higher in the 192 patients with esophageal, whereas these were not significantly higher in the samples from patients with gastric, colorectal, lung, or breast cancer. In 91 patients treated with surgery, sex, tumor depth, lymph node metastasis, stage and C-reactive protein levels were significantly associated with overall survival, as determined using the log-rank test, whereas the squamous cell carcinoma antigen, p53 antibody and s-WDR1-Ab levels tended to be associated with a worse prognosis. Although no significant difference was observed in the survival between the positive and negative groups of s-WDR1-Abs or s-CFL1-Abs alone in the Kaplan-Meier test, the patients in the s-WDR1-Ab-positive and s-CFL1-Ab-negative groups exhibited a significantly poorer prognosis in the overall survival analysis. On the whole, the present study demonstrates that the combination of positive anti-WDR1 antibodies with negative anti-CFL1 antibodies in serum may be a poor prognostic factor for patients with esophageal carcinoma.

Utility of atherosclerosis-associated serum antibodies against colony-stimulating factor 2 in predicting the onset of acute ischemic stroke and prognosis of colorectal cancer

Introduction

Autoantibodies against inflammatory cytokines may be used for the prevention of atherosclerosis. Preclinical studies consider colony-stimulating factor 2 (CSF2) as an essential cytokine with a causal relationship to atherosclerosis and cancer. We examined the serum anti-CSF2 antibody levels in patients with atherosclerosis or solid cancer.

Methods

We measured the serum anti-CSF2 antibody levels via amplified luminescent proximity homogeneous assay-linked immunosorbent assay based on the recognition of recombinant glutathione S-transferase-fused CSF2 protein or a CSF2-derived peptide as the antigen.

Results

The serum anti-CSF2 antibody (s-CSF2-Ab) levels were significantly higher in patients with acute ischemic stroke (AIS), acute myocardial infarction (AMI), diabetes mellitus (DM), and chronic kidney disease (CKD) compared with healthy donors (HDs). In addition, the s-CSF2-Ab levels were associated with intima-media thickness and hypertension. The analyzes of samples obtained from a Japan Public Health Center-based prospective study suggested the utility of s-CSF2-Ab as a risk factor for AIS. Furthermore, the s-CSF2-Ab levels were higher in patients with esophageal, colorectal, gastric, and lung cancer than in HDs but not in those with mammary cancer. In addition, the s-CSF2-Ab levels were associated with unfavorable postoperative prognosis in colorectal cancer (CRC). In CRC, the s-CSF2-Ab levels were more closely associated with poor prognosis in patients with p53-Ab-negative CRC despite the lack of significant association of the anti-p53 antibody (p53-Ab) levels with the overall survival.

Conclusion

S-CSF2-Ab was useful for the diagnosis of atherosclerosis-related AIS, AMI, DM, and CKD and could discriminate poor prognosis, especially in p53-Ab-negative CRC.

Low anti-CFL1 antibody with high anti-ACTB antibody is a poor prognostic factor in esophageal squamous cell carcinoma

BACKGROUND

Cofilin (CFL1, actin-binding protein) and β-actin (ACTB) are key molecules in the polymerization and depolymerization of actin microfilaments. The levels of these antibodies were analyzed, and the clinicopathological significance in patients with esophageal carcinoma were evaluated.

METHODS

The levels of anti-CFL1 and anti-ACTB antibodies were analyzed in serum samples of patients with esophageal carcinoma and of healthy donors. Eighty-seven cases underwent radical surgery and the clinicopathological characteristics and prognosis was examined.

RESULTS

Serum anti-CFL1 antibody (s-CFL1-Ab) levels and anti-ACTB antibody (s-ACTB-Ab) levels were significantly higher in patients with esophageal carcinoma than in healthy donors. Following the receiver operating characteristic curve analysis between healthy donors and esophageal carcinoma, the sensitivity and specificity for serum anti-CFL1 antibody (s-CFL1-Ab) were 53.3% and 68.8%. The sensitivity and specificity for serum anti-ACTB antibody (s-ACTB-Ab) were 54.9% and 67.7%, respectively. Univariate and multivariate analysis showed that s-CFL1-Ab and s-ACTB-Ab levels were not associated with sex, age, tumor depth, lymph node metastasis, or anti-p53-antibody levels. s-ACTB-Ab levels but not s-CFL1-Ab levels significantly correlated with squamous cell carcinoma antigen. Neither s-CFL1-Ab nor s-ACTB-Ab levels alone were obviously related to overall survival. However, patients with low s-CFL1-Ab levels and high s-ACTB-Ab levels exhibited significantly more unfavorable prognoses than those with high s-CFL1-Ab and low s-ACTB-Ab levels.

CONCLUSIONS

Serum levels of anti-CFL1 and anti-ACTB antibodies were significantly higher in patients with esophageal carcinoma than in healthy donors. A combination of low anti-CFL1 and high anti-ACTB antibodies is a poor prognostic factor in esophageal carcinoma.

Prognostic impact of carcinoembryonic antigen in 1822 surgically treated esophageal squamous cell carcinoma: multi-institutional study of the Japan Esophageal Society

BACKGROUND

Previous studies have evaluated the clinicopathological significance of carcinoembryonic antigen (CEA) of esophageal cancer in relatively small numbers of patients. Therefore, this study aimed to clarify the prognostic significance of CEA in 1822 patients with esophageal squamous cell carcinoma (SCC).

METHODS

Based on the Japanese Esophageal Society nationwide multi-institutional retrospective study, a total of 1,748 surgically treated ESCC from 15 hospitals were enrolled to evaluate prognostic impact of preoperative CEA values. Among them, 605 patients were categorized to up-front surgery group, and 1,217 patients were categorized to neoadjuvant therapy group. The CEA threshold for positivity was 3.7 ng/ml. The clinicopathological and prognostic impact of CEA was evaluated by univariate and multivariate analysis in each treatment modality groups.

RESULTS

In total, the CEA positive rate was 25.8% (470/1822). CEA-positive status was significantly associated with distant metastasis (P = 0.004) but not associated with other factors. CEA-positive status was associated with poor overall survival (P < 0.001) in univariate analysis as well as multivariate analysis (P = 0.003).

CONCLUSIONS

CEA was an independent prognostic determinant of overall survival in esophageal SCC. Based on the subgroup analysis, regardless of the treatment modality, patients with high pretreatment CEA showed poor overall survival.

Vaccine-induced humoral response against SARS-CoV-2 dramatically declined but cellular immunity possibly remained at 6 months post BNT162b2 vaccination

To evaluate vaccine-induced humoral and cell-mediated immunity at 6 months after completion of two doses of BNT162b2 vaccination, immunoglobulin G against SARS-CoV-2 spike protein (SP IgG), 50% neutralizing antibody (NT₅₀), and spot-forming cell (SFC) counts were evaluated by interferon-γ releasing ELISpot assay of 98 healthy subjects (median age, 43 years). The geometric mean titers of SP IgG and NT₅₀ decreased from 95.2 (95% confidence interval (CI) 79.8–113.4) to 5.7 (95% CI 4.9–6.7) and from 680.4 (588.0–787.2) to 130.4 (95% CI 104.2–163.1), respectively, at 3 weeks and 6 months after the vaccination. SP IgG titer was negatively correlated with age and alcohol consumption. Spot-forming cell counts at 6 months did not correlate with age, gender, and other parameters of the patients. SP IgG, NT_50, and SFC titers were elevated in the breakthrough infected subjects. Although the levels of vaccine-induced antibodies dramatically declined at 6 months after vaccination, a certain degree of cellular immunity was observed irrespective of the age.

Serum WT1‑271 IgM antibody as a novel diagnostic marker for Gastric Cancer

The Wilms tumor 1 gene, WT1, is overexpressed in various types of cancer, including gastric cancer. The product of WT1 is highly immunogenic and is a promising target molecule for cancer immunotherapy. The current study aimed to examine the production of WT1-specific IgG and IgM autoantibodies to identify biomarkers of diagnostic value in patients with gastric cancer. IgG antibodies that bind to WT1-derived peptides were obtained, the serum levels of which correlate with those of IgG antibodies against the WT1 protein in patients with intestinal malignancies. The serum levels of IgG and IgM antibodies against the WT1-271 peptide (271-288 amino acids) were examined in 39 healthy individuals and 97 patients with gastric cancer. The positivity cutoff value was determined according to the receiver operating characteristic curve. The association between WT1-271 IgM and the clinicopathological factors and prognosis of patients was additionally analyzed. The results revealed that serum WT1-271 IgM antibody levels in patients with gastric cancer were significantly higher than those in healthy individuals. The sensitivity and specificity of this antibody for gastric cancer were 67.0 and 71.8%, respectively; this sensitivity was improved when compared with conventional tumor markers (P<0.001). There was no statistical difference in WT1-271 IgG antibody levels between patients with gastric cancer and healthy individuals. Serum WT1-271 IgM antibody levels were not significantly associated with clinicopathological factors but were associated with unfavorable prognosis. Serum WT1-271 IgM antibody levels could serve as a diagnostic biomarker in patients with gastric cancer.

Preoperative low serum creatine kinase is associated with poor overall survival in the male patients with esophageal squamous cell carcinoma

BACKGROUND

Serum creatine kinase level has been reported to be a prognostic indicator in breast or lung cancers but no reports have been in esophageal cancer. We analyzed the prognostic significance of preoperative serum creatine kinase level in patients with esophageal carcinoma.

METHODS

We evaluated the preoperative serum creatine kinase levels of 148 patients (118 male and 30 female) with esophageal squamous cell carcinoma. According to their median serum creatine kinase levels, we divided the patients into high and low serum creatine kinase groups. Univariate and multivariate analyses were used to evaluate the impact of serum creatine kinase level on the prognosis of the patients.

RESULTS

The tumor depth (P < 0.01) and stage (P < 0.01) were significantly associated with serum creatine kinase levels. The prognosis was worse in the low serum creatine kinase group than in the high serum creatine kinase group (P = 0.02). In the subgroup analysis, although no survival difference was observed in the female patients between the groups (P = 0.171), the survival of low serum creatine kinase group was significantly worse than that of high creatine kinase group in the male patients (P = 0.001). Cox proportional hazard regression analysis revealed that nodal status (P = 0.019) and serum creatine kinase level (P = 0.047) were independent risk factors associated with overall survival in the male patients.

CONCLUSIONS

Preoperative low serum creatine kinase level was useful in predicting overall survival in the male patients with esophageal squamous cell carcinoma.

Antibody titers against the Alpha, Beta, Gamma, and Delta variants of SARS-CoV-2 induced by BNT162b2 vaccination measured using automated chemiluminescent enzyme immunoassay

Background

Levels of 50% neutralizing titer (NT50) reflect the a vaccine-induced humoral immunity after the vaccination against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Measurements of NT50 are difficult to implement in large quantities. A high-throughput laboratory test is expected for determining the level of herd immunity against SARS-CoV-2.

Methods

We analyzed samples from 168 Japanese healthcare workers who had completed two doses of the BNT162b2 vaccine. We analyzed immunoglobulin G (IgG) index values against spike protein (SP) using automated chemiluminescent enzyme immunoassay system AIA-CL and analyzed the background factors affecting antibody titer. SP IgG index was compared with 50% neutralization titers.

Results

The median SP IgG index values of the subjects (mean age = 43 years; 75% female) were 0.1, 1.35, 60.80, and 97.35 before and at 2, 4, and 6 weeks after the first dose, respectively. At 4 and 6 weeks after the first dose, SP IgG titers were found to have positive correlation with NT50 titer (r = 0.7535 in 4 weeks; r = 0.4376 in 6 weeks). Proportions of the SP IgG index values against the Alpha, Beta, Gamma, and Delta variants compared with the original strain were 2.029, 0.544, 1.017, and 0.6096 respectively. Older age was associated with lower SP IgG titer index 6 weeks after the first dose.

Conclusions

SP IgG index values were rised at 3 weeks after two doses of BNT162b2 vaccination and have positive correlation with NT50. SP IgG index values were lower in the older individuals and against Beta and Delta strain.

Prognostic Impact of Pretreatment Serum CYFRA Status in 1047 Patients with Esophageal Squamous Cell Carcinoma Who Underwent Radical Resection: A Japan Esophageal Society Promotion Research

Purpose: The prognostic significance of pretreatment serum C-terminus of cytokeratin 19 (CYFRA21-1, CYFRA) status was evaluated in the patients with surgically treated esophageal squamous cell carcinoma.

Methods: A total of 1047 patients with surgically treated esophageal cancer were enrolled in a multi-institutional study promoted by the Japanese Esophageal Society. This study included an up-front surgery group (n = 412), a neoadjuvant chemotherapy (NAC) group (n = 486), and a neoadjuvant chemoradiation/radiation therapy (NACRT/RT) group (n = 149). The pretreatment CYFRA status was analyzed to assess prognostic significance using multivariate analysis according to treatment modalities.

Results: The CYFRA-positive group was significantly associated with deep tumor. Univariate analysis showed that the overall survival of the CYFRA-positive group was significantly worse than that of the CYFRA-negative group, but the difference was not significant in the multivariate analysis. CYFRA was an independent risk factor for poor prognosis just in the NACRT/RT group.

Conclusions: The CYFRA-positive group was associated with deep tumor and poor survival. Pretreatment CYFRA was not an independent risk factor for poor prognosis in the up-front surgery group or NAC group. It was an independent risk factor for poor prognosis just in the NACRT/RT group.

Identification of serum anti-striatin 4 antibodies as a common marker for esophageal cancer and other solid cancers

Solid cancers have a poor prognosis, and their morbidity and mortality after surgery is high. Even after radical surgery for esophageal cancer, there have been cases of early postoperative death. The present study therefore aimed to explore new tumor markers that can predict the early postoperative prognosis. To identify antibody markers, serological antigens were identified using recombinant cDNA expression cloning (SEREX). The results identified striatin 4 (STRN4) as the antigen recognized by serum IgG antibodies in patients with esophageal cancer. After performing an amplified luminescence proximity homogeneous assay-linked immunosorbent assay (AlphaLISA), it was revealed that when compared with healthy donors, serum anti-STRN4 antibody (STRN4-Ab) levels were significantly higher not only in patients with esophageal cancer but also to lesser extent, in those with gastric cancer, colorectal cancer, lung cancer and breast cancer. Compared with STRN4-Ab-negative patients with esophageal cancer, STRN4-Ab-positive patients had a poorer postoperative prognosis at early stages, suggesting that STRN4-Abs may be useful for predicting poor early-stage prognoses of patients with esophageal cancer. The positive diagnosis rates of esophageal cancer using the STRN4-Ab marker and conventional markers, including squamous cell carcinoma antigen and p53 antibody alone, were 26.4, 35.2 and 19.1% respectively; a result that increased up to 59.1% by combining all three markers. Serum STRN4-Ab may serve as a novel marker of esophageal cancer.

Presence of serum RalA and serum p53 autoantibodies in 1833 patients with various types of cancers

BACKGROUND

RalA is a member of the Ras superfamily of small GTPases. The Anti-RalA autoantibodies (s-RalA-Abs) act as tumor markers in various types of cancer and are negatively associated with the p53 autoantibodies (s-p53-Abs). This study aimed to evaluate the relationship between s-RalA-Abs and s-p53-Abs in various types of cancer.

METHODS

A total of 1833 cancer patients (esophageal cancer, 172; hepatocellular carcinoma, 91; lung cancer, 269; gastric cancer, 317; colon cancer, 262; breast cancer, 364; and prostate cancer, 358) and 73 healthy subjects were enrolled in the study. The levels of s-RalA-Abs and s-p53-Abs were analyzed using enzyme-linked immunosorbent assay, and the positivity rates and relations between the two autoantibodies were evaluated. The cutoff values for s-RalA abs and s-p53 abs were set as mean + 2 standard deviation and the values higher than the cutoff values were defined as positive.

RESULTS

The titers in all cancer types were significantly higher than those in the controls (P < 0.01). The positivity rates for s-RalA-Abs ranged between 11.7 and 21.5%, and those for s-p53-Abs ranged between 12 and 28.5%. A combined assay of the two antibodies revealed positivity rates of 20.9 and 44.2%. In Stage 0/I/II tumors, the positivity rates of the combination of the two antibodies ranged between 21.5 and 42.3%. The two autoantibodies were complementary to each other in the prostate and breast cancers, but independent in other carcinomas.

CONCLUSION

The combined use of s-RalA-Abs and s-p53-Abs tended to increase the positivity rate in all cancers, including Stage 0/I/II cancers.

Preoperative Low Serum Calcium Levels Predict Poor Prognosis for Patients with Esophageal Cancer

Purpose: Hypercalcemia has been reported as a poor prognostic factor in malignant tumors. However, no report has shown the clinical impact of serum calcium levels on patients with esophageal cancer. We evaluated the prognostic impact of preoperative serum calcium levels on patients with esophageal cancer.

Methods: We evaluated 240 patients (197 men, 43 women; mean age, 66 years; age range, 34–85 years) with esophageal cancer who underwent radical surgery between September 2008 and December 2017. After assigning the patients to two groups (high calcium group, 8.8 mg/dL or more and low calcium group, 8.7 mg/dL or less), we compared the groups’ overall survival and the clinicopathological features. The clinicopathological and prognostic significance of preoperative serum calcium levels were evaluated in a univariate and multivariate analysis.

Results: The patients with deep tumors showed low serum calcium levels significantly more frequently (P <0.05). The low calcium group showed a significantly worse prognosis than the high calcium group (P <0.05). However, low serum calcium level was not an independent poor prognostic factor.

Conclusions: Preoperative low serum calcium levels were associated with advanced tumors. Low serum calcium might be associated with esophageal cancer progression.

Association of Serum Anti-PCSK9 Antibody Levels with Favorable Postoperative Prognosis in Esophageal Cancer

Background

Esophageal cancer often appears as postoperative metastasis or recurrence after radical surgery. Although we had previously reported that serum programmed cell death ligand 1 (PD-L1) level correlated with the prognosis of esophageal cancer, further novel biomarkers are required for more precise prediction of the prognosis. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is associated with the cholesterol metabolism. But there was no report of relationship between serum PCSK9 antibody and cancer. Therefore, we investigated whether anti-PCSK9 antibodies could be a novel biomarker for solid cancer.

Methods

Serum levels of anti-PCSK9 antibodies and antigens in patients with solid cancer were analyzed using amplified luminescence proximity homogeneous assay-linked immunosorbent assay (AlphaLISA). The reactivity of serum antibodies against recombinant PCSK9 protein was investigated by Western blotting, and the expression of PCSK9 antigens in esophageal cancer tissues was examined by immunohistochemical staining.

Results

AlphaLISA showed that serum anti-PCSK9 antibody (s-PCSK9-Ab) levels were significantly higher in patients with esophageal cancer, gastric cancer, colorectal cancer, lung cancer, and breast cancer than in healthy donors, and patients with esophageal cancer had the highest levels. The presence of serum antibody in patients was confirmed by Western blotting. There was no apparent correlation between s-PCSK9-Ab and PCSK9 antigen levels. Immunohistochemical staining demonstrated the expression of PCSK9 antigen in both the cytoplasm and nuclear compartments of esophageal squamous cell carcinoma tissue but not in normal tissue. Compared with patients with low s-PCSK9-Ab levels, those with high s-PCSK9-Ab levels had a favorable postoperative prognosis after radical surgery for esophageal cancer. In the multivariate analysis, tumor depth and s-PCSK9-Ab level were identified as independent prognostic factors. In the univariate analysis of clinicopathological features, high PCSK9 antibody levels were not associated with sex, age, location, tumor depth, lymph node status, squamous cell carcinoma antigen, or p53-Ab, whereas they correlated significantly with PD-L1 levels, which were associated with unfavorable prognosis. Correlation between s-PCSK9-Ab and PD-L1 levels was also confirmed in the logistic regression analysis; therefore, low s-PCSK9-Ab levels could discriminate another poor prognosis group other than high-PD-L1 group.

Conclusions

Patients with solid cancer had higher s-PCSK9-Ab levels than healthy donors. High s-PCSK9-Ab levels indicated better prognosis for overall survival after surgery in patients with esophageal cancer.

Taxane-based versus platinum-based chemotherapy in early recurrent gastric cancer after radical surgery with S-1 adjuvant chemotherapy: A multi-institutional retrospective analysis

AIM

This study aimed to compare the efficacy of taxane-based and platinum-based regimens in patients with early recurrent gastric cancer after radical surgery with S-1 adjuvant chemotherapy.

METHODS

The medical records of 118 patients from six institutes with early recurrent stage II/III gastric cancer, who developed recurrence during adjuvant S-1 or within 6 months after completion of adjuvant therapy between January 2006 and December 2017, were retrospectively analyzed. Patients treated with second line chemotherapy were enrolled and followed to the end of December 2019. The impact of two regimens, taxane-based (n = 46) versus platinum-based (n = 31), on treatment outcome were evaluated using multivariate analysis.

RESULTS

Median overall survival was 9.0 months and median progression-free survival was 4.1 months. No difference was observed in overall survival between taxane-based and platinum-based regimens (P = 0.64). Although not significant, the response rate of platinum-based regimens was better than that of taxane-based regimens (16% vs. 6.5%, P = 0.26). Multivariate analysis identified performance status (P = 0.040), multiorgan metastases (P = 0.029), and undifferentiated histological type (P = 0.018) as independent poor prognostic factors. In undifferentiated histological type, multiorgan metastases (P = 0.013) and taxane-based regimens (P = 0.018) were independent prognosis factors characterized by multivariate analysis. Conversion rate to third-line chemotherapy or more was 51% in undifferentiated histological type and 65% in differentiated histological type (P = 0.26).

CONCLUSION

Platinum-based regimens may be recommended for undifferentiated early recurrent gastric cancer after S-1 adjuvant chemotherapy.

Prevalence of serum galectin-1 autoantibodies in seven types of cancer: A potential biomarker

Although serum galectin-1 antibodies (s-GAL-1-Abs) have been evaluated in a small number of patients with cancer, a large series of patients with different cancer types have not been reported. The current study evaluated 1,833 patients with esophageal cancer (n=172), gastric cancer (n=317), colorectal cancer (n=262), hepatocellular carcinoma (n=91), prostate cancer (n=358), breast cancer (n=364), lung cancer (n=269) and 72 healthy individuals. s-GAL-1-Abs levels were analyzed using an originally developed ELISA system. A cut-off optical density value was determined as the mean (0.053) + 3 standard deviations (0.105) of sera from healthy controls. The results revealed that the positive rate of s-GAL-1-Abs in patients with hepatocellular carcinoma (16.7%) and lung cancer (13.8%) were significantly higher compared with the other groups: Esophageal cancer (11.6%), colorectal cancer (11.5%), prostate cancer (7.3%), gastric cancer (6.9%), breast cancer (6.9%) and healthy controls (4.2%). Although the positive rates of s-GAL-1-Abs in different cancer types were relatively low, s-GAL-1-Abs may be useful for patients with hepatocellular carcinoma and lung cancer.

Serum anti-AP3D1 antibodies are risk factors for acute ischemic stroke related with atherosclerosis

Atherosclerosis has been considered as the main cause of morbidity, mortality, and disability worldwide. The first screening for antigen markers was conducted using the serological identification of antigens by recombinant cDNA expression cloning, which has identified adaptor-related protein complex 3 subunit delta 1 (AP3D1) as an antigen recognized by serum IgG antibodies of patients with atherosclerosis. Serum antibody levels were examined using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) using a recombinant protein as an antigen. It was determined that the serum antibody levels against AP3D1 were higher in patients with acute ischemic stroke (AIS), transient ischemic attack, diabetes mellitus (DM), cardiovascular disease, chronic kidney disease (CKD), esophageal squamous cell carcinoma (ESCC), and colorectal carcinoma than those in the healthy donors. The area under the curve values of DM, nephrosclerosis type of CKD, and ESCC calculated using receiver operating characteristic curve analysis were higher than those of other diseases. Correlation analysis showed that the anti-AP3D1 antibody levels were highly associated with maximum intima-media thickness, which indicates that this marker reflected the development of atherosclerosis. The results of the Japan Public Health Center-based Prospective Study indicated that this antibody marker is deemed useful as risk factors for AIS.

Serum anti-DIDO1, anti-CPSF2, and anti-FOXJ2 antibodies as predictive risk markers for acute ischemic stroke

BACKGROUND

Acute ischemic stroke (AIS) is a serious cause of mortality and disability. AIS is a serious cause of mortality and disability. Early diagnosis of atherosclerosis, which is the major cause of AIS, allows therapeutic intervention before the onset, leading to prevention of AIS.

METHODS

Serological identification by cDNA expression cDNA libraries and the protein array method were used for the screening of antigens recognized by serum IgG antibodies in patients with atherosclerosis. Recombinant proteins or synthetic peptides derived from candidate antigens were used as antigens to compare serum IgG levels between healthy donors (HDs) and patients with atherosclerosis-related disease using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay.

RESULTS

The first screening using the protein array method identified death-inducer obliterator 1 (DIDO1), forkhead box J2 (FOXJ2), and cleavage and polyadenylation specificity factor (CPSF2) as the target antigens of serum IgG antibodies in patients with AIS. Then, we prepared various antigens including glutathione S-transferase-fused DIDO1 protein as well as peptides of the amino acids 297-311 of DIDO1, 426-440 of FOXJ2, and 607-621 of CPSF2 to examine serum antibody levels. Compared with HDs, a significant increase in antibody levels of the DIDO1 protein and peptide in patients with AIS, transient ischemic attack (TIA), and chronic kidney disease (CKD) but not in those with acute myocardial infarction and diabetes mellitus (DM). Serum anti-FOXJ2 antibody levels were elevated in most patients with atherosclerosis-related diseases, whereas serum anti-CPSF2 antibody levels were associated with AIS, TIA, and DM. Receiver operating characteristic curves showed that serum DIDO1 antibody levels were highly associated with CKD, and correlation analysis revealed that serum anti-FOXJ2 antibody levels were associated with hypertension. A prospective case-control study on ischemic stroke verified that the serum antibody levels of the DIDO1 protein and DIDO1, FOXJ2, and CPSF2 peptides showed significantly higher odds ratios with a risk of AIS in patients with the highest quartile than in those with the lowest quartile, indicating that these antibody markers are useful as risk factors for AIS.

CONCLUSIONS

Serum antibody levels of DIDO1, FOXJ2, and CPSF2 are useful in predicting the onset of atherosclerosis-related AIS caused by kidney failure, hypertension, and DM, respectively.

Prognosis of hemodialysis patients undergoing surgery for gastric cancer: Results of a multicenter retrospective study

BACKGROUND

Little is known about the survival outcomes of and predictive factors for survival in hemodialysis patients undergoing surgery for gastric cancer.

METHODS

We performed a multicenter retrospective study from 9 institutions to investigate the survival outcomes of 75 hemodialysis patients with gastric cancer. Patient characteristics included demographic data, hemodialysis- and gastric cancer-related variables. Multivariate Cox hazards models were applied to determine independent predictors of poor overall survival and non-gastric cancer related death.

RESULTS

Stage I disease was predominant (58.7%) in our series. The overall morbidity and the 30-day mortality rates were 25.3% and 1.3%, respectively. The 5-year overall survival rates of patients with pStages I, II, III, and IV disease were 59.2%, 42.9%, 32.3%, and 0%, respectively. Eleven (14.7%) patients died of gastric cancer, whereas many more (40.0%) died owing to causes other than gastric cancer. Non-gastric cancer-related death was especially prevalent in patients with pStages I (95.2%) and II (75.0%) disease. Multivariable analysis revealed advanced age, long duration of hemodialysis (> 5 years), total gastrectomy, and pStage IV disease to be independently associated with poor overall survival. Notably, advanced age, long duration of hemodialysis, and the presence of cardiovascular disease were all independent predictors of non-gastric cancer-related death. Patients with all 3 factors had very poor survival outcomes (3-year overall survival; 14.3%).

CONCLUSION

The survival outcomes of hemodialysis patients with gastric cancer, especially those with early-stage gastric cancer, were clearly poor, largely owing to the increased risk of non-gastric cancer-related death. Preoperative comorbidities and hemodialytic features were useful for predicting long-term outcomes of this vulnerable population.

Randomized Phase II Study to Comparing Docetaxel/Nedaplatin versus Docetaxel for 5-Fluorouracil/Cisplatin Resistant Esophageal Squamous Cell Carcinoma

Purpose: To compare efficacy and safety of dual docetaxel/nedaplatin treatment versus docetaxel alone as second-line chemotherapy for advanced esophageal cancer.

Methods: In all, 36 patients with metastatic and/or recurrent esophagus squamous cell carcinoma resistant to first-line chemotherapy (fluorouracil/cisplatin) were recruited from 2011 to 2018 and randomized into two groups. Treatment response and survival were compared between the docetaxel/nedaplatin (60/80 mg/m²/day) group and docetaxel (70 mg/m²/day) group. Treatment was repeated every 3 weeks until tumor progression. Patients were followed up until March 2019 or death.

Results: The frequency of Grade 3 or higher adverse events in the docetaxel/nedaplatin group (58.8%) was higher compared with the docetaxel group (26.3%) (P = 0.090). We found a treatment response rate of 52.9% and 36.8% and a median survival of 8.9 and 7.0 months in the docetaxel/nedaplatin-treated and docetaxel-treated group, respectively (P = 0.544).

Conclusion: No significant survival advantage was found for docetaxel/nedaplatin-treated patients, although there was an increased frequency of high-grade adverse events compared to docetaxel-treated patients. Because of the limited cohort size, a Phase III study based on our findings is not warranted to assess the clinical impact of docetaxel/nedaplatin treatment. This trial is registered with the University Hospital Medical Information Network (UMIN 000005877).

New Assay System Elecsys Anti-p53 to Detect Serum Anti-p53 Antibodies in Esophageal Cancer Patients and Colorectal Cancer Patients: Multi-institutional Study

BACKGROUND

Several recent studies suggest that serum anti-p53 antibodies (s-p53-Abs) may be combined with other markers to detect esophageal and colorectal cancer. In this study, we assessed the sensitivity and specificity of s-p53-Abs detection of a new electrochemiluminescence immunoassay (ECLIA; Elecsys anti-p53).

METHODS

Elecsys anti-p53 assay was used to analyze the level of s-p53-Abs in blood sera from patients with esophageal or colorectal cancer taken before treatment. Control blood sera from healthy volunteers, patients with benign diseases, and patients with autoimmune diseases served as a reference. In addition, squamous cell carcinoma antigen (SCC-Ag) and cytokeratin 19 fragments (CYFRA21-1) were assessed in patients with esophageal cancer, and carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 were assessed in patients with colorectal cancer.

RESULTS

Samples from 281 patients with esophageal cancer, 232 patients with colorectal cancer, and 532 controls were included in the study. The median value of s-p53-Abs in control samples was < 0.02 μg/mL (range < 0.02-29.2 μg/mL). Assuming 98% specificity, the cut-off value was determined as 0.05 μg/mL. s-p53-Abs were detected in 20% (57/281) of patients with esophageal cancer and 18% (42/232) of patients with colorectal cancer. In combination with SCC-Ag and CEA, respectively, s-p53-Abs detected 51% (144/281) of patients with esophageal and 53% (124/232) of patients with colorectal cancer.

CONCLUSIONS

The new s-p53-Abs assay Elecsys anti-p53 was useful in detecting esophageal and colorectal cancers with high specificity. Adding s-p53-Abs to conventional markers significantly improved the overall detection rates.

Prevalence of autoantibodies against Ras-like GTPases, RalA, in patients with gastric cancer

Ras-like GTPases, RalA and RalB, are members of the Ras superfamily of small GTPases. RalA expression has been shown to be associated with aggressive clinicopathological characteristics and progression in cancer. RalA protein has been shown to be involved in immune reactions in some patients with cancer; however, the clinicopathological significance of serum RalA antibody in patients with gastric cancer has not been investigated. Serum samples of 291 patients with gastric cancer and 73 healthy controls were analyzed for serum RalA antibody using enzyme-linked immunosorbent assay. A cut-off optical density value was fixed at 0.255 (mean of control + 2 standard deviations). The clinicopathological and prognostic significance of s-RalA-Abs was evaluated. The positivity rate for serum RalA antibody (s-RalA-Abs) was 15%. The presence of serum RalA antibody was higher in younger patients compared with elderly patients, however this tendency was not statistically significant. s-RalA-Abs was not associated with tumor stage. Since s-RalA-Abs was independent of CEA (carcinoembryonic antigen) and carbohydrate antigen 19-9 (CA19-9), the combination of s-RalA-Abs with CEA and CA19-9 significantly increased the detection rate of gastric cancer at each tumor stage. Patients who were tested positive for s-RalA-Abs showed poor long-term survival; however, this association was not statistically significant by multivariate analysis. In conclusion, s-RalA-Abs may be a candidate serum marker for gastric cancer, when used in combination with CEA and/or CA19-9. Additionally, the presence of s-RalA-Abs, in combination with CEA and/or CA19-9, was associated with poor survival in patients with gastric cancer.

Serum p53 antibody: useful for detecting gastric cancer but not for predicting prognosis after surgery

PURPOSE

To establish the clinicopathological importance of serum p53 autoantibody (s-p53-Ab) titrations in patients with gastric cancer.

METHODS

Preoperative s-p53-Ab titers were analyzed in 448 gastric cancer patients between 2010 and 2017. Seropositive patients were divided into three groups based on their antibody titers: 1.31-10.0 U/mL (low group); 10.1-100 U/mL (medium group); and > 100 U/mL (high group). We evaluated the associations between the s-p53-Abs and clinicopathological factors, carcinoembryonic antigen (CEA) levels, and cancer antigen 19-9 (CA19-9) levels. Overall survival was analyzed by multivariate analyses.

RESULTS

A total of 72 patients (16%) were positive for s-p53-Abs. The rate of positivity for s-p53-Abs + CEA + CA19-9 was significantly higher than that for CEA + CA19-9, even in stage I gastric cancers. Gender, tumor depth, lymphatic node metastases, and distant metastases were all significantly associated with the presence of s-p53-Abs; however, overall survival was not associated with the antibodies. The patients in the high titer group (> 100 U/mL) had a relatively worse survival than those in the other groups.

CONCLUSIONS

Based on our findings, s-p53-Abs improve the overall rate of positivity for detecting gastric cancer, but the prognostic value of a high s-p53-Ab titer for predicting overall survival is limited.

Prognostic impact of p53 and/or NY-ESO-1 autoantibody induction in patients with gastroenterological cancers

BACKGROUND AND AIM

We evaluated the clinicopathological and prognostic significance of serum p53 (s-p53-Abs) and serum NY-ESO-1 autoantibodies (s-NY-ESO-1-Abs) in esophageal squamous cell carcinoma (ESCC), gastric cancer and hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

A total of 377 patients, 85 patients with ESCC, 248 patients with gastric cancer, and 44 patients with HCC were enrolled to measure s-p53-Abs and s-NY-ESO-1-Abs titers by the enzyme-linked immunosorbent assay before treatment. The clinicopathological significance and prognostic impact of the presence of autoantibodies were evaluated. Expression data based on the Cancer Genome Atlas and the prognostic impact of gene expression was also examined for discussion.

RESULTS

The positive rates of s-p53-Abs were 32.9% in ESCC, 15% in gastric cancer, and 4.5% in HCC. The positive rates of s-NY-ESO-1-Abs were 29.4% in ESCC, 9.7% in gastric cancer, and 13.6% in HCC. The presence of s-p53-Abs was not associated with tumor progression in these three cancer types. On the other hand, the presence of s-NY-ESO-1-Abs was significantly associated with tumor progression in ESCC and gastric cancer. The presence of s-p53-Abs and/or s-NY-ESO-1-Abs was significantly associated with poor prognosis in gastric cancer but not in ESCC nor HCC.

CONCLUSIONS

The presence of s-p53-Abs and/or s-NY-ESO-1-Abs was associated with tumor progression in ESCC and gastric cancer. These autoantibodies might have poor prognostic impacts on gastric cancer (UMIN000014530).

Immunohistochemical analysis of tumor budding as predictor of lymph node metastasis from superficial esophageal squamous cell carcinoma

BACKGROUND

Tumor budding is known predictors of lymph node metastasis from esophageal squamous cell carcinoma. However, it is not easy to detect such small cell clusters on hematoxylin-eosin (HE) staining. Therefore, we evaluated tumor budding using immunohistochemistry (IHC) for epithelial cell markers.

METHOD

We analyzed tumor budding in 50 cases of superficial esophageal squamous cell carcinoma. We evaluated the impact of clinicopathological factors and tumor budding to predict lymph node metastasis. A total of 565 tumor sections were assessed using HE staining and IHC for cytokeratin 5/6.

RESULTS

Based on receiver operating characteristic curves, the cut-off values for high-grade tumor budding evaluated using HE staining or IHC were 2 and 11, respectively. High-grade tumor budding evaluated using HE staining (P = 0.007) and IHC (P ≤ 0.001) were significantly correlated with lymph node metastasis. For tumors with pT1a-MM to pT1b-SM1, high-grade tumor budding evaluated using IHC was correlated with lymph node metastasis (P = 0.050).

CONCLUSIONS

Tumor budding was significantly associated with lymph node metastasis. The optimal cut-off values of tumor budding on HE staining and tumor budding on IHC were 2 and 11, respectively. Even though both tumor budding on HE staining and tumor budding on IHC were significantly associated with lymph node metastasis, tumor budding on IHC tend to be more associated with lymph node metastasis.

Clinical application of a new latex photometric immunoassay reagent, LPIA-GENESIS D-dimer, and its performance in patient-derived plasma samples

Introduction

We previously reported an antibody MIF‐220 that recognizes a specific structure induced on the surface of thrombin‐activated E‐domain of one fibrin molecule bound with the D‐domains of other fibrinogen/fibrin molecules. Utilizing MIF‐220, we produced a test kit for cross‐linked fibrin degradation products (XDP), LPIA‐GENESIS D‐dimer (LG‐DD), and evaluated basic performance characteristics for clinical application. We then attempted to apply LG‐DD to see its eligibility in clinical plasma samples.

Method

The characteristic performances requested for clinical use were studied including limit of quantitation, within‐run imprecision, day‐to‐day imprecision, antigen excess, interference study, and method comparison with LPIAACE‐Ddimer (ACE‐DD) available on the market.

Results

The performance characteristics were all satisfactory. Extraordinarily high concentrations of XDP are occasionally obtained by ACE‐DD in samples with collection problems, but not by LG‐DD, indicating that a certain XDP species present in the former was not measured by LG‐DD. Structural studies suggested that the “B‐b” set of polymerization sites must be involved as well in the maintenance of cross‐linked fibrin in vivo.

Conclusion

LG‐DD was able to measure a wide range of XDP, that is, 0.20‐35.0 μg FEU/mL that covers the levels of XDP in most of the clinical samples. LG‐DD was found to almost avoid false‐positive results noticed in samples as mentioned above, and this feature seems to be preferable to established kits for the measurement of XDP.

High serum PD-L1 level is a poor prognostic biomarker in surgically treated esophageal cancer

Background

Programmed death ligand 1 (PD‐L1) inhibitor has been approved as one of the standard therapies for various cancers. Some reports have shown that serum PD‐L1 level is associated with advanced tumor stages and poor prognosis; however, corresponding pathological information in esophageal cancer patients is lacking. Therefore, we evaluated the clinicopathological and prognostic impact of serum PD‐L1 levels in surgically treated esophageal cancer.

Methods

A total of 150 patients who underwent radical resection for esophageal cancer were included in the study. Preoperative serum PD‐L1 levels were analyzed using the enzyme‐linked immunosorbent assay kit. A cutoff level of 65.6 pg/mL was used to divide the patients into two groups, and univariate and multivariate analyses were conducted to compare the clinicopathological characteristics and prognoses between these two groups.

Results

Although significant associations between serum PD‐L1 levels and clinicopathological variables were observed, serum PD‐L1 level was significantly associated with high neutrophil counts, high CRP levels, low albumin levels, and high squamous cell carcinoma antigen levels. Furthermore, serum PD‐L1 level was associated with poor overall survival independent to TNM factors.

Conclusions

High preoperative level of serum PD‐L1 is a prognostic factor for poor overall survival in patients with surgically treated esophageal cancer.

Does Preoperative Low HbA1c Predict Esophageal Cancer Outcomes?

BACKGROUND

Although several reports have shown that diabetes is a poor prognostic factor for esophageal cancer, no reports assessed prognostic impact of hemoglobin A1c (HbA1c) in the patients with esophageal cancer. Therefore, we evaluated the prognostic significance of HbA1c in patients with esophageal cancer.

METHODS

A total of 137 patients with esophageal carcinoma surgically treated at our institute between 2009 and 2017 were enrolled in this retrospective study. We divided these patients into quarters according to pretreatment levels of HbA1c. We used 5.5% as a cutoff for classifying patients into low (Q1; n = 30) and high (Q2, Q3, Q4; n = 107) HbA1c groups. Univariate and multivariate analyses were then used to evaluate the clinicopathological and prognostic significance of pretreatment level of HbA1c.

RESULTS

There was no significant relationship between HbA1c level and clinicopathological factors. The low HbA1c group had a significantly worse survival rate as compared to that of the high HbA1c group (overall survival p = 0.04, relapse-free survival p = 0.02). However, the difference was not confirmed in the multivariate analysis.

CONCLUSION

Although low level of pretreatment HbA1c might be associated with poor prognosis for patients with esophageal cancer, low HbA1c was not an independent risk factor.

The effectiveness of serum midkine in detecting esophageal squamous cell carcinoma

BACKGROUND

Studies investigating serum midkine (s-MK) concentrations have employed a polyclonal antibody enzyme-linked immunosorbent assay system (ELISA), because the targeted polyclonal antibody has low specificity. We used a newly developed monoclonal antibody ELISA to investigate the prognostic and diagnostic capabilities of s-MK in patients with esophageal squamous cell carcinoma.

METHODS

Serum samples from 102 patients with esophageal squamous cell carcinoma were analyzed using a newly developed monoclonal antibody ELISA specifically developed to detect s-MK. s-MK cutoff value was set at 421 pg/mL (mean + 2 SD) based on data from healthy controls. Clinicopathological characteristics, including tumor stage and positivity rates for two conventional tumor markers, serum p53 (s-p53-Abs) antibodies and SCC-antigen, were evaluated to assess a possible correlation with s-MK. The prognostic capability of a high s-MK level was evaluated using univariate and multivariate methods.

RESULTS

Overall positive rate for s-MK concentrations: 21%. Large tumors (> 50 mm) showed significantly higher concentrations than smaller specimens, but other clinicopathological factors were not associated with s-MK. A combination assay using SCC-antigen together with s-p53-Abs and s-MK clearly increased our capability to detect esophageal squamous cell carcinoma. Although the difference was not statistically significant (P = 0.310), the high s-MK group experienced worse overall survival than our low s-MK group.

CONCLUSIONS

s-MK and conventional tumor marker combination increased our capability to detect esophageal squamous cell carcinoma. Although s-MK might be associated with esophageal squamous cell carcinoma progression, it was not an independent risk factor reducing patient survival. This study was registered as UMIN000014530.

An Interlaboratory Validation Study of the Improved Transformation Assay Employing Balb/c 3T3 Cells: Results of a Collaborative Study on the Two-stage Cell Transformation Assay by the Non-genotoxic Carcinogen Study Group

The Non-genotoxic Carcinogen Study Group of the Environmental Mutagen Society of Japan organised the first step of an interlaboratory validation study on an improved cell transformation assay employing Balb/c 3T3 A31-1-1 cells. Nineteen laboratories participated in this study. The modified transformation assay was evaluated for its responsiveness, its inter-laboratory reproducibility and its transferability. In this study, a mixture of Dulbecco's modified Eagle's medium and nutrient mixture F12, supplemented with insulin–transferrin– ethanolamine–sodium selenite and 2% fetal bovine serum (FBS) was used during the period of expression of transformed foci, intead of the usual minimum essential medium with 10% FBS. 20-Methylcholanthrene (MCA) and 12 -O-tetradecanoylphorbol-13-acetate (TPA) were selected as a prototype initiator and a tumour promoter, respectively. Two series of experiments were conducted. In the first series, the transformation activity of MCA was examined at various concentrations. In the absence of the promoting treatment with TPA, exposure to MCA only weakly induced transformed foci. In the presence of 0.1μg/ml TPA, all laboratories observed significant dose-dependent increases in the number of transformed foci with increasing MCA concentrations. In the second series of experiments, various concentrations of TPA were tested. In the absence of initiating treatment with MCA, exposure to TPA weakly induced transformed foci in about half of the laboratories. In the presence of 0.2μg/ml MCA, all the laboratories observed significant dose-dependent increases in the number of transformed foci with increasing TPA concentrations. The results from this study support the usefulness of this modified two-stage transformation assay with Balb/c 3T3 cells.

An Inter-laboratory Collaborative Study by the Non-Genotoxic Carcinogen Study Group in Japan, on a Cell Transformation Assay for Tumour Promoters Using Bhas 42 cells

The Bhas promotion assay is a cell culture transformation assay designed as a sensitive and economical method for detecting the tumour-promoting activities of chemicals. In order to validate the transferability and applicability of this assay, an inter-laboratory collaborative study was conducted with the participation of 14 laboratories. After confirmation that these laboratories could obtain positive results with two tumour promoters, 12- O-tetradecanoylphorbol-13-acetate (TPA) and lithocholic acid (LCA), 12 coded chemicals were assayed. Each chemical was tested in four laboratories. For eight chemicals, all four laboratories obtained consistent results, and for two of the other four chemicals, only one of the four laboratories showed inconsistent results. Thus, the rate of consistency was high. During the study, several issues were raised, each of which were analysed step-by-step, leading to revision of the protocol of the original assay. Among these issues were the importance of careful maintenance of mother cultures and the adoption of test concentrations for toxic chemicals. In addition, it is suggested that three different types of chemicals show positive promoting activity in the assay. Those designated as T-type induced extreme growth enhancement, and included TPA, mezerein, PDD and insulin. LCA and okadaic acid belonged to the L-type category, in which transformed foci were induced at concentrations showing growth-inhibition. In contrast, M-type chemicals, progesterone, catechol and sodium saccharin, induced foci at concentrations with little or slight growth inhibition. The fact that different types of chemicals similarly induce transformed foci in the Bhas promotion assay may provide clues for elucidating mechanisms of tumour promotion.

Diagnostic impact of high serum midkine level in patients with gastric cancer

AIM

We evaluated the diagnostic impact of serum midkine (s-MK) levels in patients with gastric cancer using a monoclonal antibody enzyme-linked immunosorbent assay system (ELISA) to detect s-MK levels.

METHODS

Serum samples were obtained from 131 patients with gastric cancer including stage I (n = 71), stage II (n = 28), stage III (n = 16), and stage IV (n = 16) before surgery. Serum samples were analyzed using ELISA to detect soluble midkine. A cut-off value was fixed at 421 pg/mL, and the sample divided into two groups: a high s-MK group and a low s-MK group. Clinicopathological factors and prognosis were compared between these two groups using univariate and multivariate analyses. Comparison of two groups was analyzed by Fisher's exact probability test. Statistical significance was considered at P < 0.05.

RESULTS

High s-MK was significantly associated with high carcinoembryonic antigen (CEA) (P < 0.01). Positive rate of s-MK was higher than the positive rates of CEA in patients with stage I/II gastric cancer. Combination with CEA + CA19-9 + s-MK increased the positive rates of patients with stage I/II gastric cancer. No other clinicopathological factors were associated with s-MK. Although the high s-MK group showed worse overall survival than the low s-MK group, the difference was not statistically significant.

CONCLUSION

s-MK level is increased even during early-stage gastric cancer. Combined with s-MK, the positive rate of CEA + CA19-9 was increased in patients with stage I/II gastric cancer.

Prognostic significance of high serum p53 antibody titers in patients with esophageal squamous cell carcinoma

BACKGROUND

The p53 protein overexpression that usually results from genetic alterations reportedly induces serum antibodies against p53. However, little information is available about the prognostic significance of perioperative serum p53 antibody (s-p53-Abs) titers in patients with esophageal squamous cell carcinoma.

METHODS

In this study, we retrospectively evaluated the clinical significance of perioperative s-p53-Abs in 135 patients with esophageal squamous cell carcinoma. Of these, 58 patients received neoadjuvant chemotherapy comprising 5-FU and CDDP. While the cutoff level at 1.3 U/ml indicated seropositive patients, level of 13.4 U/ml was used to identify high-titer patients. We monitored serum titers seropositive patients after surgery and evaluated the prognostic significance by the univariate and multivariate analyses.

RESULTS

In this study, 29 patients (21.5%) were positive for s-p53-Abs before treatment. The frequency of both seropositive patients and high-titer patients (> 13.4 U/ml) was not significantly associated with tumor progression. While seropositive patients did not demonstrate significant poor overall survival, high-titer patients demonstrated significant poor overall survival based on the multivariate analysis (P < 0.001). Moreover, the s-p53-Abs titer did not correlate with the response to neoadjuvant chemotherapy. Among seropositive patients, the negative conversion of s-p53-Abs more likely led to be long-term survival.

CONCLUSIONS

This study determined that the high-titer of s-p53-Abs was an independent risk factor to reduce the overall survival of patients with esophageal cancer patients. The negative conversion of s-p53-Abs could be a good indicator of favorable prognosis.

Is high serum programmed death ligand 1 level a risk factor for poor survival in patients with gastric cancer?

BACKGROUND AND AIM

Although the clinicopathological significance of the expression of programmed death ligand 1(PD-L1) in various cancer tissues has been reported, serum PD-L1 level has not been evaluated in patients with surgically treated gastric cancer. Therefore, we evaluated the clinicopathological characteristics and prognostic significance of preoperative serum PD-L1 levels in patients with gastric cancer.

PATIENTS AND METHODS

Serum samples were obtained before surgery from 152 patients with gastric cancer, including 75 patients with stage I, 31 with stage II, 23 with stage III, and 23 with stage IV gastric cancer. The samples were analyzed using enzyme-linked immunosorbent assay to detect soluble PD-L1. Using the median serum PD-L1 level of 50 pg/mL, patients were divided into two groups, namely high serum and low serum PD-L1 level groups. Clinicopathological characteristics and prognosis were compared between these two groups using univariate and multivariate analysis.

RESULTS

Serum PD-L1 level was significantly associated with older age, positive cancer antigen 19-9 (CA19-9), C-reactive protein levels, and albumin levels but not with tumor stage. Patients in the high serum PD-L1 group showed significantly worse overall survival and recurrence-free survival than those in the low serum PD-L1 group (P < .05). Multivariate analysis showed that high serum PD-L1 level was an independent risk factor for poor overall survival (P = .02).

CONCLUSION

High serum PD-L1 level was a prognostic factor for reduced overall survival in patients with surgically treated gastric cancer.

Identification and initial characterization of novel neural immediate early genes possibly differentially contributing to foraging-related learning and memory processes in the honeybee

Despite possessing a limited number of neurones compared to vertebrates, honeybees show remarkable learning and memory performance, an example being 'dance communication'. In this phenomenon, foraging honeybees learn the location of a newly discovered food source and transmit the information to nestmates by symbolic abdomen vibrating behaviour, leading to navigation of nestmates to the new food source. As an initial step toward understanding the detailed molecular mechanisms underlying the sophisticated learning and memory performance of the honeybee, we focused on the neural immediate early genes (IEGs), which are specific genes quickly transcribed after neural activity without de novo protein synthesis. Although these have been reported to play an essential role in learning and memory processes in vertebrates, far fewer studies have been performed in insects in this regard. From RNA-sequencing analysis and subsequent assays, we identified three genes, Src homology 3 (SH3) domain binding kinase, family with sequence similarity 46 and GB47136, as novel neural IEGs in the honeybee. Foragers and/or orientating bees, which fly around their hives to memorize the positional information, showed induced expression of these IEGs in the mushroom body, a higher-order centre essential for learning and memory, indicating a possible role for the novel IEGs in foraging-related learning and memory processes in the honeybee.

Negative conversion of high serum p53 antibody titers in a patient with gastric cancer at 31 months after surgery

We performed distal gastrectomy with D2 lymph node dissection, pathological stage was Stage IB (T2N0M0), in a 68-year-old male with gastric adenocarcinoma. We then monitored serum p53 antibody titers for 5 years and found it consistently decreased, without disease recurrence. Although the s-p53-Ab titer remained positive even after 2 years, it decreased to 16.5, 4.45, 2.66, 1.55, and 1.18 U/ml at 3 months, 7 months, 1 year, 2 years and 3 years after surgery, respectively. The s-p53-Ab titer finally converted from positive to negative at 31 months postoperatively without any sign of recurrence by computed tomography examination at 5 years after surgery. This case report shows that the changing pattern of s-p53-Ab titer after surgery may be useful to identify patients without recurrence. Further studies are required to gain a more precise understanding of the clinical impact of s-p53-Ab titer monitoring in gastric adenocarcinoma.