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

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.

Developments in Point-of-Care Diagnostic Technology for Cancer Detection

Cancer is the cause of death for one in seven individuals worldwide. It is widely acknowledged that screening and early diagnosis are of vital importance for improving the likelihood of recovery. However, given the costly, time-consuming, and invasive nature of the many methods currently in use, patients often do not take advantage of the services available to them. Consequently, many researchers are exploring the possibility of developing fast, reliable, and non-invasive diagnostic tools that can be used directly or by local physicians at the point-of-care. Herein, we look at the use of established biomarkers in cancer therapy and investigate emerging biomarkers exhibiting future potential. The incorporation of these biomarkers into point-of-care devices could potentially reduce the strain currently experienced by screening programs in hospitals and healthcare systems. Results derived from point-of-care tests should be accurate, sensitive, and generated rapidly to assist in the selection of the best course of treatment for optimal patient care. Essentially, point-of-care diagnostics should enhance the well-being of patients and lead to a reduction in cancer-related deaths.

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.

The Prevalence of Cancer-Associated Autoantibodies in Patients with Gastric Cancer and Progressive Grades of Premalignant Lesions

Background: Serum autoantibodies against tumor-associated antigens (TAAs) are detectable in early-stage gastric cancer patients; however, the time point during cancerogenesis when they appear in circulation is still obscure.Methods: In this study, we developed a recombinant antigen microarray and analyzed the prevalence of autoantibodies against 102 TAAs in 829 gastric cancer patients and 929 healthy controls from Caucasian and Asian populations, as well as 100 patients with chronic atrophic gastritis and 775 individuals staged according to different grades of intestinal metaplasia.Results: Six antigens, including CTAG1B/CTAG2, DDX53, IGF2BP2, TP53, and MAGEA3, were predominantly reacting with sera from gastric cancer patients when compared with healthy controls, and the seroreactivity was associated with intestinal-type gastric cancer, but not with patients' Helicobacter pylori status, grade, age, gender, or stage of gastric cancer. We detected gastric cancer-associated seroreactivity in 13% of patients with advanced/severe intestinal metaplasia, which was increased in comparison with mild/moderate intestinal metaplasia (5.3%) and was comparable with that seen in early-stage gastric cancer patients (12%). Moreover, by testing serum samples taken 1 to 9 years before the clinical diagnosis of 18 incident gastric cancer cases, we detected autoantibody responses against several TAAs-SOX2, MYC, BIRC5, IGF2BP1, and MUC1.Conclusions: Our results suggest that humoral immune response against TAAs is generated already during premalignant stages.Impact: Based on the obtained results, cancer-associated autoantibodies might make a valuable contribution to the stratification of high-risk patients with premalignant lesions in the stomach through enhancing the positive predictive power of existing risk models. Cancer Epidemiol Biomarkers Prev; 26(10); 1564-74. ©2017 AACR.

Emerging blood-based biomarkers for detection of gastric cancer

Early detection and efficient monitoring of tumor dynamics are prerequisites for reducing disease burden and mortality, and for improving the management of patients with gastric cancer (GC). Blood-based biomarker assays for the detection of early-stage GC could be of great relevance both for population-wide or risk group-based screening programs, while circulating biomarkers that reflect the genetic make-up and dynamics of the tumor would allow monitoring of treatment efficacy, predict recurrences and assess the genetic heterogeneity of the tumor. Recent research to identify blood-based biomarkers of GC has resulted in the identification of a wide variety of cancer-associated molecules, including various proteins, autoantibodies against tumor associated antigens, cell-free DNA fragments, mRNAs and various non-coding RNAs, circulating tumor cells and cancer-derived extracellular vesicles. Each type of these biomarkers provides different information on the disease status, has different advantages and disadvantages, and distinct clinical usefulness. In the current review, we summarize the recent developments in blood-based GC biomarker discovery, discuss the origin of various types of biomarkers and their clinical usefulness and the technological challenges in the development of biomarker assays for clinical use.

Detection of serum p53 antibodies from Chinese patients with papillary thyroid carcinoma using phage-SP-ELISA: correlation with clinical parameters

The goal of the present study was to investigate whether p53 antibodies (Abs) could be a relevant marker for papillary thyroid carcinoma (PTC). Three types of enzyme-linked immunosorbent assay (ELISA) methods were developed for the detection of p53 Abs, including p53-ELISA, phage-SS-ELISA, and phage-SP-ELISA. A total of 304 patients, including 117 cases with thyroid adenoma and 187 PTC patients, were enrolled in this study. Expression of p53 protein and mutation in BRAF gene were evaluated in paraffin-embedded tissue from 44 patients with PTC, in order to elucidate their correlations with the presence of p53 Abs. Compared with p53-ELISA and phage-SS-ELISA, phage-SP-ELISA presented the highest detection efficiency of p53 Abs in patients with PTC, and a combination of these three ELISA systems could make the detection of p53 Abs more sensitive than using each of the individual ELISA methods. Furthermore, p53 Abs was positively associated with clinical stage (P = 0.044), node metastasis (P = 0.010), and p53 protein accumulation (P = 0.019). These results indicate that serum p53 Abs could be a useful marker for PTC.

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.

Serologic autoantibodies as diagnostic cancer biomarkers--a review

Current diagnostic techniques used for the early detection of cancers are successful but subject to detection bias. A recent focus lies in the development of more accurate diagnostic tools. An increase in serologic autoantibody levels has been shown to precede the development of cancer disease symptoms. Therefore, autoantibody levels in patient blood serum have been proposed as diagnostic biomarkers for early-stage diagnosis of cancers. Their clinical application has, however, been hindered by low sensitivity, specificity, and low predictive value scores. These scores have been shown to improve when panels of multiple diagnostic autoantibody biomarkers are used. A five-marker biomarker panel has been shown to increase the sensitivity of prostate cancer diagnosis to 95% as compared with 12.2% for prostate-specific antigen alone. New potential biomarker panels were also discovered for lung, colon, and stomach cancer diagnosis with sensitivity of 76%, 65.4%, and 50.8%, respectively. Studies in breast and liver cancer, however, seem to favor single markers, namely α-2-HS-glycoprotein and des-γ-carboxyprothrombin with sensitivities of 79% and 89% for the early detection of the cancers. The aim of this review is to discuss the relevance of autoantibodies in cancer diagnosis and to outline the current methodologies used in the detection of autoantibodies. The review concludes with a discussion of the autoantibodies currently used in the diagnosis of cancers of the prostate, breast, lung, colon, stomach, and liver. A discussion of the potential future use of autoantibodies as diagnostic cancer biomarkers is also included in this review.

A systematic review of humoral immune responses against tumor antigens

This review summarizes studies on humoral immune responses against tumor-associated antigens (TAAs) with a focus on antibody frequencies and the potential diagnostic, prognostic, and etiologic relevance of antibodies against TAAs. We performed a systematic literature search in Medline and identified 3,619 articles on humoral immune responses and TAAs. In 145 studies, meeting the inclusion criteria, humoral immune responses in cancer patients have been analyzed against over 100 different TAAs. The most frequently analyzed antigens were p53, MUC1, NY-ESO-1, c-myc, survivin, p62, cyclin B1, and Her2/neu. Antibodies against these TAAs were detected in 0-69% (median 14%) of analyzed tumor patients. Antibody frequencies were generally very low in healthy individuals, with the exception of few TAAs, especially MUC1. For several TAAs, including p53, Her2/neu, and NY-ESO-1, higher antibody frequencies were reported when tumors expressed the respective TAA. Antibodies against MUC1 were associated with a favorable prognosis while antibodies against p53 were associated with poor disease outcome. These data suggest different functional roles of endogenous antibodies against TAAs. Although data on prediagnostic antibody levels are scarce and antibody frequencies for most TAAs are at levels precluding use in diagnostic assays for cancer early detection, there is some promising data on achieving higher sensitivity for cancer detection using panels of TAAs.

Relationship between VEGF and p53 expression and tumor cell proliferation in human gastrointestinal carcinomas

PURPOSE

The vascular endothelial growth factor (VEGF) and p53 play important roles in the growth of tumor. However, the relationship between the expression of VEGF and p53 and tumor cell proliferation in human gastrointestinal cancer remains unknown. In the present study, therefore, we have examined the relationship between VEGF and p53 expression and tumor cell proliferation in gastrointestinal carcinoma (GITC), as well as the association between these biomarkers and clinicopathological factors.

METHODS

Surgical specimens from 30 patients with GITC were examined for VEGF, p53, and proliferating cell nuclear antigen (PCNA) expression by immunohistochemical staining.

RESULTS

We found a predominant VEGF expression of moderate intensity in 16(54.84%) of 30 GITC cases, while p53 expression was mainly high in 13(45.16%) of 30 GITC cases. PCNA expression was high in 20(64.52%) of 30 GITC cases. Tumor size, infiltration, vascular invasion, and gastritis were significantly correlated with VEGF, p53, and PCNA expression. There was a significant correlation between VEGF and p53 expression (P = 0.0001), VEGF and PCNA expression (P = 0.00004), and between p53 expression and PCNA expression (P = 0.0016). When the VEGF and p53 expression, and PCNA expression were considered together, both VEGF and p53 expression were not significantly associated with PCNA. A significant correlation between the PCNA expression and the mitotic index (P = 0.0016) was also found.

CONCLUSION

These results demonstrate that VEGF and p53 expression are significantly correlated as independent prognostic factors with tumor cell proliferation, and might be associated with relevant events involved in gastrointestinal tumor biology.