Detection of p53 autoantibodies in sera of gastric cancer patients and their prognostic relevance

Isoforms of the p53 Family and Gastric Cancer: A Ménage à Trois for an Unfinished Affair

Simple Summary

The p53 family is a complex family of transcription factors with different cellular functions that are involved in several physiological processes. A massive amount of data has been accumulated on their critical role in the tumorigenesis and the aggressiveness of cancers of different origins. If common features are observed, there are numerous specificities that may reflect particularities of the tissues from which the cancers originated. In this regard, gastric cancer tumorigenesis is rather remarkable, as it is induced by bacterial and viral infections, various chemical carcinogens, and familial genetic alterations, which provide an example of the variety of molecular mechanisms responsible for cell transformation and how they impact the p53 family. This review summarizes the knowledge gathered from over 40 years of research on the role of the p53 family in gastric cancer, which still displays one of the most elevated mortality rates amongst all types of cancers.

Abstract

Gastric cancer is one of the most aggressive cancers, with a median survival of 12 months. This illustrates its complexity and the lack of therapeutic options, such as personalized therapy, because predictive markers do not exist. Thus, gastric cancer remains mostly treated with cytotoxic chemotherapies. In addition, less than 20% of patients respond to immunotherapy. TP53 mutations are particularly frequent in gastric cancer (±50% and up to 70% in metastatic) and are considered an early event in the tumorigenic process. Alterations in the expression of other members of the p53 family, i.e., p63 and p73, have also been described. In this context, the role of the members of the p53 family and their isoforms have been investigated over the years, resulting in conflicting data. For instance, whether mutations of TP53 or the dysregulation of its homologs may represent biomarkers for aggressivity or response to therapy still remains a matter of debate. This uncertainty illustrates the lack of information on the molecular pathways involving the p53 family in gastric cancer. In this review, we summarize and discuss the most relevant molecular and clinical data on the role of the p53 family in gastric cancer and enumerate potential therapeutic innovative strategies.

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.

Autoimmunity and Gastric Cancer

Alterations in the immune response of patients with autoimmune diseases may predispose to malignancies, and a link between chronic autoimmune gastritis and gastric cancer has been reported in many studies. Intestinal metaplasia with dysplasia of the gastric corpus-fundus mucosa and hyperplasia of chromaffin cells, which are typical features of late-stage autoimmune gastritis, are considered precursor lesions. Autoimmune gastritis has been associated with the development of two types of gastric neoplasms: intestinal type and type I gastric carcinoid. Here, we review the association of autoimmune gastritis with gastric cancer and other autoimmune features present in gastric neoplasms.

Serum Anti-p53 Antibodies as a useful Marker for Prognosis of Gastric Carcinoma

Mutations in the TP53 gene are the most common genetic alterations in cancer. Accumulation of mutated protein may induce circulating anti-p53 antibodies (anti-p53Ab) in sera of cancer patients. The aim of our work was to evaluate the presence and prognostic value of anti-p53Ab in gastric cancer patients and to investigate whether their presence is related to p53 overexpression in tumor tissue. Anti-p53Ab were analyzed in sera from 111 patients with gastric carcinoma and from 64 healthy donors by ELISA. p53 expression was also quantified by ELISA in biopsies of 54 gastric cancers and 22 healthy gastric mucosas. Significant anti-p53Ab levels were found in 15.3% of patients, whereas none of the 64 donor sera were positive. High levels of p53 expression were detected only in tumor tissue, in 72.2% of cases. A significant correlation was observed between anti-p53Ab and high levels of mutated p53 in tissue (p<0.05). The survival time of serum-positive patients was significantly longer than that of patients with low/negative serum levels, with a survival rate of 41.2% and 14.9%, respectively, over 48 months (p<0.05). Thus, detection of serum anti-p53Ab in gastric cancer patients can be useful to identify a subset of patients with better prognosis.

Panel of autoantibodies against multiple tumor-associated antigens for detecting gastric cancer

Gastric cancer is the second leading cause of cancer death in the world, and effective diagnosis is extremely important for good outcome. We assessed the diagnostic potential of an autoantibody panel that may provide a novel tool for the early detection of gastric cancer. We analyzed data from patients with gastric cancer and normal controls in test and validation cohorts. Autoantibody levels were measured against a panel of six tumor‐associated antigens (TAAs) by ELISA: p53, heat shock protein 70, HCC‐22‐5, peroxiredoxin VI, KM‐HN‐1, and p90 TAA. We assessed serum autoantibodies in 100 participants in the test cohort. The validation cohort comprised 248 participants. Autoantibodies to at least one of the six antigens showed a sensitivity/specificity of 49.0% (95% confidence interval [CI], 39.2–58.8%)/92.4% (95% CI, 87.2–97.6%), and 52.0% (95% CI, 42.2–61.8%)/90.5% (95% CI, 84.8–96.3%) in the test and validation cohorts, respectively. In the validation cohort, no significant differences were seen when patients were subdivided based on age, sex, depth of tumor invasion, lymph node metastasis, distant metastasis, peritoneal dissemination, or TNM stage. Patients who were positive for more than two antibodies in the panel tended to have a worse prognosis than those who were positive for one or no antibody. Measurement of autoantibody response to multiple TAAs in an optimized panel assay to discriminate patients with early stage gastric cancer from normal controls may aid in the early detection of gastric cancer.

Prognostic Value of Baseline Neutrophil-Lymphocyte and Platelet-Lymphocyte Ratios in Local and Advanced Gastric Cancer Patients

BACKGROUND

We aimed to investigate the prognostic value of baseline neutrophil, lymphocyte, and platelet counts along with the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) in local and advanced gastric cancer patients.

MATERIALS AND METHODS

In this retrospective cross-sectional study, a total of 103 patients with gastric cancer were included. For all, patient characteristics and overall survival (OS) times were evaluated. Data from a complete blood count test including neutrophil, lymphocyte, monocyte, white blood cell (WBC) and platelet (Plt) count, hemoglobin level (Hb) were recorded, and the NLR and PLR were obtained for every patient prior to pathological diagnosis before any treatment was applied.

RESULTS

Of the patients, 53 had local disease, underwent surgery and were administered adjuvant chemoradiotherapy where indicated. The remaining 50 had advanced disease and only received chemotherapy. OS time was 71.6±6 months in local gastric cancer patients group and 15±2 months in the advanced gastric cancer group. Univariate analysis demonstrated that only high platelet count (p=0.013) was associated with better OS in the local gastric cancer patients. In contrast, both low NLR (p=0.029) and low PLR (p=0.012) were associated with better OS in advanced gastric cancer patients.

CONCLUSIONS

This study demonstrated that NLR and PLR had no effect on prognosis in patients with local gastric cancer who underwent surgery and received adjuvant chemoradiotherapy. In advanced gastric cancer patients, both NLR and PLR had significant effects on prognosis, so they may find application as easily measured prognostic factors for such patients.

Systematic review: serum autoantibodies in the early detection of gastric cancer

Antibodies against tumor-associated antigens have been found in serum of patients with various types of cancers and may serve as biomarkers for early detection of gastric cancer as well. This systematic review aims to give an overview about known autoantibodies and their diagnostic value in gastric cancer. We conducted a systematic literature search in two databases to identify studies which performed serological testing for autoantibodies in gastric cancer patients and controls. Data on study characteristics and results were extracted independently by two reviewers. Overall, 39 articles reporting the detection of 34 different autoantibodies met the inclusion criteria for this review. The most common antibody detection method was enzyme-linked immunosorbent assay and the most frequently assessed autoantibody was anti-p53, which was tested in 13 studies. Most antibodies were assessed in only one study and only few authors have evaluated the diagnostic value of combinations of multiple autoantibodies. For single autoantibodies, specificity was generally very high (median: 99.15%), but sensitivity was mostly rather low (median: 12.35%). For some autoantibody combinations, substantially higher sensitivity at reasonably high levels of specificity could be achieved. Development of extended and optimized multimarker panels of autoantibodies might be a promising approach for gastric cancer early detection.

Blood neutrophil-lymphocyte ratio predicts survival for stages III-IV gastric cancer treated with neoadjuvant chemotherapy

Background

Accurate predictors of survival for patients with advanced gastric cancer treated with neoadjuvant chemotherapy are currently lacking. In this study, we aimed to evaluate the prognostic significance of the neutrophil-lymphocyte ratio (NLR) in patients with stage III-IV gastric cancer who received neoadjuvant chemotherapy.

Methods

We enrolled 46 patients in this study. The NLR was divided into two groups: high (>2.5) and low (≤2.5). Univariate analysis on progression-free survival (PFS) and overall survival(OS) was performed using the Kaplan-Meier and log-rank tests, and multivariate analysis was conducted using the Cox proportional hazards regression model. We analyzed whether chemotherapy normalized high NLR or not, and evaluated the prognostic significance of normalization on survival.

Results

The univariate analysis showed that PFS and OS were both worse for patients with high NLR than for those with low NLR before chemotherapy (median PFS 16 and 49 months, respectively, P = 0.012; median OS 21 and 52 months, P = 0.113). PFS and OS were also worse for patients with high NLR than for those with low NLR before surgery (median PFS 12 and 35 months, P = 0.019; median OS 21 and 52 months, P = 0.082). Multivariate analysis showed that both NLR before chemotherapy and surgery were independent prognostic factors of PFS. Neoadjuvant chemotherapy normalized high NLR in 11 of 24 patients, and these 11 patients had better median PFS and OS than the 13 patients who had high NLR both before chemotherapy and before surgery (PFS: 35.0 and 10.0 months, P = 0.003; OS: 60 and 16 months, P = 0.042).

Conclusions

NLR may serve as a potential biomarker for survival prognosis in patients with stage III-IV gastric cancer receiving neoadjuvant chemotherapy.

Epidemiologic perspective on immune-surveillance in cancer

Common 'themes' in epidemiology related to cancer risk beg a comprehensive mechanistic explanation. As people age, risk for cancer increases. Obesity and smoking increase the risk for many types of cancer. History of febrile childhood diseases lowers the risk for melanomas, leukemias, non-Hodgkin's lymphoma (NHL), and ovarian cancer. Increasing number of ovulatory cycles uninterrupted by pregnancies correlate positively with breast, endometrial, and ovarian cancer risk while pregnancies and breastfeeding lower the risk for these cancers as well as cancers of the colon, lung, pancreas, and NHL. Chronic inflammatory events such as endometriosis or mucosal exposure to talc increase the risk for several types of cancer. Mechanisms so far considered are site specific and do not explain multiple associations. We propose that most of these events affect cancer immunosurveillance by changing the balance between an effective immune response and immune tolerance of an emerging cancer. We review recently published data that suggest that immune mechanisms underlie most of these observed epidemiologic associations with cancer risk.

The clinical significance of autoantibodies in gastrointestinal malignancies: an overview

Autoimmunity can be associated with cancer and one of the forms of its expression is the development of antibodies to autologous cellular antigens. The types of cellular proteins which induce autoantibody responses in gastrointestinal malignancies are quite varied and include cellular proteins encoded by mutated normal genes (p53), cellular proteins that are overexpressed and/or aberrantly expressed in malignant tissues (carcinoembryonic antigen), inhibitors of apoptosis (survivin and livin), major components of mucus (mucins), surface receptors of apoptosis (Fas) and nuclear-restricted proteins (double-stranded DNA, single-stranded DNA and Sm family proteins). In the past few years, due to the great clinical interest and the advancement in detection techniques, the above list has grown significantly and a large number of cancer-related antigens, which trigger a specific humoral immune response to the host, have also been identified. The authors review the autoantibodies associated with gastrointestinal malignancies and their clinical implications.

The detection of serum anti-p53 antibodies from patients with gastric carcinoma in China

BACKGROUND

Gastric carcinoma is one of the most frequently occurring cancers. The aim of this research was to increase the detection efficiency of anti-p53 antibodies in the sera of patients with gastric carcinoma and to improve the diagnosis for patients with gastric carcinoma.

METHODS

We prepared phage-displayed peptide DO7 and established an enzyme-linked immunosorbent assay method to detect the anti-p53 antibodies. We detected the anti-p53 antibodies of 61 patients with gastric carcinoma using the method and our previous ELISA method assisted by the recombinant wild-type human p53 protein to detect the anti-p53 antibodies. We studied the correlation between the anti-p53 antibodies and the clinicopathological data including sex, age, carcinoembryonic antigen, tumor size, tumor TNM staging, and lymph-node status.

RESULTS

The anti-p53 antibodies positive rate for patients with gastric carcinoma was increased (31.1%, 19/61) through the combination of p53-ELISA and phage-ELISA. We found that the positive anti-p53 antibodies correlated significantly with tumor size (P=0.047). The combination of the anti-p53 antibodies and carcinoembryonic antigen could improve the diagnosis for patients with gastric carcinoma.

CONCLUSIONS

This approach indicated an increased anti-p53 antibodies positive rate for patients with gastric carcinoma and provided a useful marker for clinical diagnosis for patients with gastric carcinoma.

Titration of serum p53 antibodies in patients with gastric cancer: a single-institute study of 40 patients

BACKGROUND

Alterations of the p53 tumor suppressor gene are the most commonly observed genetic abnormalities in many different types of human malignancies. The accumulation of mutant p53 often leads to the production of p53 antibody (p53-Ab) in the sera of patients with various cancers. To evaluate the clinical implications of serum p53-Abs in patients with gastric cancer, we compared p53-Abs with conventional tumor markers such as carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9.

METHODS

Serum samples were obtained preoperatively from 40 patients with histologically confirmed gastric adenocarcinoma, including 28 (70%) patients in stage Ia. The serum p53-Abs were assessed by enzyme-linked immunosorbent assay, using a new version of a highly specific, quantitative p53-Abs Kit (MESACUP Kit II).

RESULTS

p53-Abs were detected in 6 (15%) of 40 patients with gastric cancer, including 3 patients with early gastric cancer. Seven (17.5%) of the 40 patients were positive for CEA in serum. However, none of 7 patients with high CEA levels were positive for p53-Abs. No significant correlation of p53-Abs with patient age, sex, pathological parameters, tumor markers such as CEA and CA19-9, or poor survival (P = 0.116) was observed.

CONCLUSION

Although we employed the latest version of the p53-Abs Kit, the sensitivity of serum p53-Ab in gastric cancer patients was relatively low. No correlation was found between the presence of p53-Ab and the staging of cancer or survival. However, serum p53-Ab was detectable in patients with gastric cancer even in the early stages of disease. In addition, it may be independent of CEA and CA19-9.

Low detection rate of p53 antibodies in sera of soft tissue sarcoma patients

Accumulation of the p53 gene product can lead to its immunogenic appearance and the generation of p53 serum antibodies (p53ab). In different cancer types the occurrence of detectable p53ab has an independent prognostic impact. In spite of the known p53 protein overexpression rate in soft tissue sarcomas (STS), up to 70%, there have been no investigations done on p53ab in serum in STS patients. In this prospective study of 50 STS patients, we investigated the presence of serum p53ab using an enzyme-linked immunosorbent assay system and the presence of p53 overexpression in the appropriate tissue specimen immunohistochemically. Using Kruskal-Wallis chi(2) and Kaplan-Meier tests the results were then correlated to histopathological and clinical data. Six of the 50 patients (12%) showed p53ab detectable in the serum, and 56% (28/50) of the tumors were p53 immunohistochemically positive. Four of the six p53ab positives (66%) had immunohistochemically p53 positive and two (33%) had negative tumors. Altogether four of the 50 patients (8%) were positive for p53ab in serum as well as for p53 immunohistochemistry in tumor tissue specimens. Twenty patients (40%) were negative for both. All of the p53ab positive patients had stage I or II tumors. Excluding tumor stage there was no p53ab correlation to histopathological, clinical or prognostic parameters. We conclude that in STS patients, p53ab also occurs but in contrast to other tumor types at a relatively low frequency. According to our results, the clinical value of p53ab seems to be limited in STS patients.

Clinical significance of serum p53 antibody detection on chemosensitivity assay in human colorectal cancer

BACKGROUND AND OBJECTIVES

Alteration of the p53 gene product occurs frequently during progression of colorectal cancer. Recently, mutated p53 protein was found to induce the production of anti-p53 antibodies in the serum of patients. The purpose of this study was to evaluate the relationship between p53 status in serum and chemosensitivity in resectable colorectal cancer patients.

METHODS

A total of 22 patients with primary colorectal cancer who underwent surgical treatment were examined for chemosensitivity with iable tumor samples using the Histoculture Drug Response Assay (HDRA). Serum samples of these patients for p53 antibodies were obtained before tumor resection and assayed in duplicate using an enzyme-linked immunosorbent assay kit.

RESULTS

The inhibition index of 5-fluorouracil and cis-diamminedichloroplatinum (CDDP), determined by the HDRA method, in the seropositive group was significantly lower than that in the seronegative group (P < 0.01). Furthermore, significant statistical differences in chemosensitivity to 5-fluorouracil and CDDP were revealed depending on the presence of serum p53 antibodies.

CONCLUSIONS

Detection of serum p53 antibodies, which reflects p53 mutations in tumor tissue, is a simpler method which correlates with chemosensitivity and may contribute to the selection of favorable chemotherapeutic strategies for colorectal cancer.

Serum anti-p53 antibodies in gastric adenocarcinoma patients are associated with poor prognosis, lymph node metastasis and poorly differentiated nuclear grade

Mutation of the p53 tumour suppressor gene often leads to the accumulation of mutant p53 protein in tumour cells. Many cancer patients develop antibodies that recognize the overexpressed p53 protein. The presence of these antibodies is, in some tumour types, associated with poor prognosis. Gastric cancer is a highly prevalent disease associated with a high rate of mortality, there is a need for improved clinical and biological markers for disease behaviour. To investigate the clinical relevance of serum anti-p53 antibodies in patients with gastric adenocarcinoma, we have examined the sera of 501 gastric cancer patients for the presence of serum antibodies against the p53 protein. By immunoblotting analysis using a cell lysate containing overexpressed p53 protein as well as affinity-purified recombinant p53 protein as antigens, we have detected anti-p53 antibodies in 11.2% (61 of 501) of gastric cancer patients, but in none of 46 cancer-free individuals. The presence of anti-p53 antibodies was tightly associated with tumours of higher nuclear grade and lymph node metastasis, and a negative association was found between the presence of anti-p53 antibodies and survival. These results suggest that a preoperative test of serum anti-p53 antibodies in gastric cancer patients can be useful to identify subset of patients who may need gastrectomy with lymph node dissection and post-operative adjuvant therapy.

Prognostic significance of p53 gene mutations in laryngeal cancer

OBJECTIVE/HYPOTHESIS

We examined whether p53 gene mutations were predictive of clinical behavior in laryngeal cancer.

STUDY DESIGN

Retrospective study of 45 patients with laryngeal cancer from 1985 to 1997.

METHODS

DNA was extracted from tumor tissue and subject to polymerase chain reaction single-strand conformational polymorphism (PCR-SSCP) as well as DNA sequencing. The clinical outcome was correlated to the presence or absence of a p53 mutation.

RESULTS

The p53 gene was analyzed by direct DNA sequencing and was found to be mutated in 33% (15/45) of patients. The presence of a p53 mutation was associated with a significant improvement in overall survival (80% vs. 43%, P < .03) and a trend toward improved disease-free survival (87% vs. 60%, P = .08). When other prognostic factors were adjusted, multivariate analysis revealed a trend toward improvement in overall survival as well as disease-free survival.

CONCLUSION

Depending on the location of a p53 mutation, the suppressive functions or clinical outcome may or may not be affected. Fifty-three percent of mutations were detected in nonconserved regions as opposed to 17% as reported in colon cancer. In colon cancer, mutations in conserved regions of the p53 gene predicted a poorer survival, whereas nonconserved gene mutations were not predictive. In our group of patients. p53 mutations predicted a better prognosis, which may be due to a large proportion of mutations that lie within nonconserved areas. The predictive power of p53 gene mutations may depend on functional loss and inactivation of highly conserved areas and must be tested in a prospective trial.