Anti-p53 antibodies in patients with Barrett's esophagus or esophageal carcinoma can predate cancer diagnosis

Mutant p53 as an Antigen in Cancer Immunotherapy

The p53 tumor suppressor plays a pivotal role in cancer and infectious disease. Many oncology treatments are now calling on immunotherapy approaches, and scores of studies have investigated the role of p53 antibodies in cancer diagnosis and therapy. This review summarizes the current knowledge from the preliminary evidence that suggests a potential role of p53 as an antigen in the adaptive immune response and as a key monitor of the innate immune system, thereby speculating on the idea that mutant p53 antigens serve as a druggable targets in immunotherapy. Except in a few cases, the vast majority of published work on p53 antibodies in cancer patients use wild-type p53 as the antigen to detect these antibodies and it is unclear whether they can recognize p53 mutants carried by cancer patients at all. We envision that an antibody targeting a specific mutant p53 will be effective therapeutically against a cancer carrying the exact same mutant p53. To corroborate such a possibility, a recent study showed that a T cell receptor-like (TCLR) antibody, initially made for a wild-type antigen, was capable of discriminating between mutant p53 and wild-type p53, specifically killing more cancer cells expressing mutant p53 than wild-type p53 in vitro and inhibiting the tumour growth of mice injected with mutant p53 cancer cells than mice with wild-type p53 cancer cells. Thus, novel antibodies targeting mutant p53, but not the wild-type isoform, should be pursued in preclinical and clinical studies.

Blood-based biomarkers for early detection of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor of the digestive system worldwide, especially in China. Due to the lack of effective early detection methods, ESCC patients often present at an advanced stage at the time of diagnosis, which seriously affects the prognosis of patients. At present, early detection of ESCC mainly depends on invasive and expensive endoscopy and histopathological biopsy. Therefore, there is an unmet need for a non-invasive method to detect ESCC in the early stages. With the emergence of a large class of non-invasive diagnostic tools, serum tumor markers have attracted much attention because of their potential for detection of early tumors. Therefore, the identification of serum tumor markers for early detection of ESCC is undoubtedly one of the most effective ways to achieve early diagnosis and treatment of ESCC. This article reviews the recent advances in the discovery of blood-based ESCC biomarkers, and discusses the origins, clinical applications, and technical challenges of clinical validation of various types of biomarkers.

Autoantibodies: Potential clinical applications in early detection of esophageal squamous cell carcinoma and esophagogastric junction adenocarcinoma

Esophageal squamous cell carcinoma (ESCC) and esophagogastric junction adenocarcinoma (EGJA) are the two main types of gastrointestinal cancers that pose a huge threat to human health. ESCC remains one of the most common malignant diseases around the world. In contrast to the decreasing prevalence of ESCC, the incidence of EGJA is rising rapidly. Early detection represents one of the most promising ways to improve the prognosis and reduce the mortality of these cancers. Current approaches for early diagnosis mainly depend on invasive and costly endoscopy. Non-invasive biomarkers are in great need to facilitate earlier detection for better clinical management of patients. Tumor-associated autoantibodies can be detected at an early stage before manifestations of clinical signs of tumorigenesis, making them promising biomarkers for early detection and monitoring of ESCC and EGJA. In this review, we summarize recent insights into the iden-tification and validation of tumor-associated autoantibodies for the early detection of ESCC and EGJA and discuss the challenges remaining for clinical validation.

p53 molecular approach to diagnosis and treatment of esophageal squamous cell carcinoma

We reviewed our research concerning p53 molecules in esophageal squamous cell carcinoma by focusing on the p53 molecular diagnosis and treatment of esophageal squamous cell carcinoma. First, we developed diagnostic tools to analyze serum p53 autoantibodies to detect esophageal squamous cell carcinoma. Positive rate was around 25% to 30% in all patients and around 20% even in stage I patients. Presence of serum p53 antibodies was significantly associated with overexpression of p53 protein in tumor cells. Seropositive patients were more likely than seronegative patients to be resistant to chemotherapy. Monitoring of the titer of serum p53 autoantibodies was useful in predicting patients at high risk of recurrence and/or treatment response. Second, using Ad5CMV-p53 for 10 patients with advanced esophageal squamous cell carcinoma, we carried out a phase I/II study of adenoviral-mediated p53 gene therapy. Although no complete response was observed, local tumor was stabilized in nine patients. No serious adverse events related to Ad5CMV-p53 were observed in these patients. One patient survived for over 5 years after the start of p53 gene therapy. Intratumoral injection of Ad5CMV-p53 is therefore safe, feasible, and biologically active when given in multiple doses to patients with esophageal squamous cell carcinoma. Our observations from these clinical studies indicate that p53 is a useful molecular target both in the diagnosis and in the treatment of esophageal squamous cell carcinoma.

Development of a multiplexed tumor-associated autoantibody-based blood test for the detection of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignancies worldwide, and early diagnosis is vital to improving prognoses. We explored the diagnostic potential of a multiplex autoantibody panel as a biomarker for the detection of CRC by ELISA.

METHODS

In total, 192 serum samples (92 CRC and 100 matched controls) were tested against a panel of 12 tumor-associated antigens (TAAs): RPH3AL, RPL36, SLP2, p53, survivin, ANAXA4, SEC61B, CCCAP, NYCO16, NMDAR, PLSCR1, and HDAC5. Individual and combined autoantibody signatures were examined.

RESULTS

Compared to individual autoantibody markers, the combinations of TAAs provided better discrimination between tumorous and normal sera. The overall sensitivity of a selected panel of four antibodies (anti-SLP2, -p53, -SEC61B, and -PLSCR1) was 64.1%, with a specificity of 80% that increased to 83.7% when carcinoembryonic antigen (CEA) measurement was added. Furthermore, the sensitivity of the panel of four antibodies for early and advanced stages of CRC was 66.7% and 62%, increasing to 88.3% and 84%, respectively, when CEA was added.

CONCLUSIONS

We identified a panel of four antibodies as a promising diagnostic biomarker for the detection of CRC.

Are p53 Antibodies a Diagnostic Indicator for Patients with Oral Squamous Cell Carcinoma? Systematic Review and Meta-Analysis

BACKGROUND

P53 has been reported to be involved with tumorigenesis and has also been implicated as a significant biomarker in oral squamous cell carcinoma(OSCC). However, the diagnostic value of p53 antibodies remains controversial; hence, we comprehensively and quantitatively assessed the potential in the present systematic review.

MATERIALS AND METHODS

A comprehensive search was performed using PubMed and Embase, up to October 31, 2014, without language restriction. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures using diagnostic odds ratios (DORs) and symmetric summary receiver operating characteristic (SROC) curves.

RESULTS

Of 150 studies initially identified, 7 eligible regarding serum p53 antibodies met the inclusion criteria. Some 85.7% (6/7) were of relatively high quality (QUADAS score≥7). The summary estimates for quantitative analysis of serum p53 antibody in the diagnosis of squamous cell carcinoma were: PLR 2.06 [95% confidence interval (CI) : 1.35-3.15], NLR 0.85 (95%CI: 0.80- 0.90) and DOR 2.47 (95%CI: 1.49- 4.12).

CONCLUSIONS

This meta-analysis suggests that the use of s-p53-antibodies has potential diagnostic value with relatively high sensitivity and specificity for OSCC particularly with serum specimens for discrimination of OSCCs from healthy controls. However, its discrimination power is not perfect because of low sensitivity.

BOB CAT: A Large-Scale Review and Delphi Consensus for Management of Barrett's Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia

OBJECTIVES

Barrett's esophagus (BE) is a common premalignant lesion for which surveillance is recommended. This strategy is limited by considerable variations in clinical practice. We conducted an international, multidisciplinary, systematic search and evidence-based review of BE and provided consensus recommendations for clinical use in patients with nondysplastic, indefinite, and low-grade dysplasia (LGD).

METHODS

We defined the scope, proposed statements, and searched electronic databases, yielding 20,558 publications that were screened, selected online, and formed the evidence base. We used a Delphi consensus process, with an 80% agreement threshold, using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to categorize the quality of evidence and strength of recommendations.

RESULTS

In total, 80% of respondents agreed with 55 of 127 statements in the final voting rounds. Population endoscopic screening is not recommended and screening should target only very high-risk cases of males aged over 60 years with chronic uncontrolled reflux. A new international definition of BE was agreed upon. For any degree of dysplasia, at least two specialist gastrointestinal (GI) pathologists are required. Risk factors for cancer include male gender, length of BE, and central obesity. Endoscopic resection should be used for visible, nodular areas. Surveillance is not recommended for <5 years of life expectancy. Management strategies for indefinite dysplasia (IND) and LGD were identified, including a de-escalation strategy for lower-risk patients and escalation to intervention with follow-up for higher-risk patients.

CONCLUSIONS

In this uniquely large consensus process in gastroenterology, we made key clinical recommendations for the escalation/de-escalation of BE in clinical practice. We made strong recommendations for the prioritization of future research.

Diagnostic value of multiple tumor markers for patients with esophageal carcinoma

BACKGROUND

Various studies assessing the diagnostic value of serum tumor markers in patients with esophageal cancer remain controversial. This study aims to comprehensively and quantitatively summarize the potential diagnostic value of 5 serum tumour markers in esophageal cancer.

METHODS

We systematically searched PubMed, Embase, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biomedical Database (CBM), through February 28, 2013, without language restriction. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures using diagnostic odds ratios (DORs) and symmetric summary receiver operating characteristic (SROC) curves.

RESULTS

Of 4391 studies initially identified, 44 eligible studies including five tumor markers met the inclusion criteria for the meta-analysis, while meta-analysis could not be conducted for 12 other tumor markers. Approximately 79.55% (35/44) of the included studies were of relatively high quality (QUADAS score≥7). The summary estimates of the positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) for diagnosing EC were as follows: CEA, 5.94/0.76/9.26; Cyfra21-1, 12.110.59/22.27; p53 antibody, 6.71/0.75/9.60; SCC-Ag, 7.66/0.68/12.41; and VEGF-C, 0.74/0.37/8.12. The estimated summary receiver operating characteristic curves showed that the performance of all five tumor markers was reasonable.

CONCLUSIONS

The current evidence suggests that CEA, Cyfra21-1, p53, SCC-Ag and VEGF-C have a potential diagnostic value for esophageal carcinoma.

Serum autoantibodies in the early detection of esophageal cancer: a systematic review

Antibodies against tumor-associated antigens (TAAs) have been found in serum of patients with various types of cancers and may serve as biomarkers for early detection of esophageal cancer as well. This systematic review aims to give an overview about known autoantibodies and their diagnostic value in esophageal cancer. We conducted a systematic literature search in two databases to identify studies which performed serological testing for autoantibodies in esophageal cancer patients and controls. Data on study characteristics and results were extracted independently by two reviewers. Overall, 45 articles reporting the detection of 35 different autoantibodies met the inclusion criteria of this review. The most common antibody detection method was enzyme-linked immunosorbent assay (ELISA), and the most frequently assessed autoantibody was anti-p53, which was tested in 17 studies and for 15 studies of which a meta-analysis was conducted to comprehensively evaluate the diagnostic value. 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 98.3 %), but sensitivity was mostly rather low (median 26.7 %). 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 esophageal cancer early detection.

Long-term monitoring of serum p53 antibody after neoadjuvant chemotherapy and surgery for esophageal adenocarcinoma: report of a case

We monitored serum p53 antibody (s-p53-Ab) titers in a 76-year-old man with esophageal adenocarcinoma, clinical stage III (T2N2M0), for over 4 years, including during the perioperative period and throughout follow-up after surgery. Screening tests for CA19-9 (205 IU/ml) and s-p53-Abs (381 U/ml) were positive before treatment. After neoadjuvant chemotherapy with 5-FU and cisplatin, CA19-9 decreased to the normal range, but the s-p53-Ab titer remained positive (224 U/ml). Pathological findings of surgically resected specimens showed stage T1b disease and no lymph node metastases. After surgery, s-p53-Ab titers consistently decreased, with no disease recurrence. Although the s-p53-Ab titer remained positive even after 4 years, it decreased to 8.66, 3.59, 2.38, and 1.92 U/ml, 1, 2, 3, and 4 years after surgery, respectively. Thus, monitoring perioperative changes in s-p53-Ab titers proved useful for detecting the presence of residual cancer cells in a patient with superficial esophageal adenocarcinoma.

Serum p53 antibody detection in patients with impaired lung function

Background

TP53 gene mutations can lead to the expression of a dysfunctional protein that in turn may enable genetically unstable cells to survive and change into malignant cells. Mutant p53 accumulates early in cells and can precociously induce circulating anti-p53 antibodies (p53Abs); in fact, p53 overexpression has been observed in pre-neoplastic lesions, such as bronchial dysplasia, and p53Abs have been found in patients with Chronic Obstructive Pulmonary Disease, before the diagnosis of lung and other tobacco-related tumors.

Methods

A large prospective study was carried out, enrolling non-smokers, ex-smokers and smokers with or without the impairment of lung function, to analyze the incidence of serum p53Abs and the correlation with clinicopathologic features, in particular smoking habits and impairment of lung function, in order to investigate their possible role as early markers of the onset of lung cancer or other cancers. The p53Ab levels were evaluated by a specific ELISA in 675 subjects.

Results

Data showed that significant levels of serum p53Abs were present in 35 subjects (5.2%); no difference was observed in the presence of p53Abs with regard to age and gender, while p53Abs correlated with the number of cigarettes smoked per day and packs-year. Furthermore, serum p53Abs were associated with the worst lung function impairment. The median p53Ab level in positive subjects was 3.5 units/ml (range 1.2 to 65.3 units/ml). Only fifteen positive subjects participated in the follow-up, again resulting positive for serum p53Abs, and no evidence of cancer was found in these patients.

Conclusion

The presence of serum p53Abs was found to be associated with smoking level and lung function impairment, both risk factors of cancer development. However, in our study we have not observed the occurrence of lung cancer or other cancers in the follow-up of positive subjects, therefore we cannot directly correlate the presence of serum p53Abs with cancer risk.

Elevated serum antibodies against insulin-like growth factor-binding protein-2 allow detecting early-stage cancers: evidences from glioma and colorectal carcinoma studies

BACKGROUND

Tumor-specific immunity of insulin-like growth factor-binding protein-2 (IGFBP-2) has been reported in several cancers. We aimed to assess the role of serum IGFBP-2 antibodies (IGFBP-2 Abs) in early cancer detection.

PATIENTS AND METHODS

Glioma and colorectal carcinoma (CRC) were used as models. Serum IGFBP-2 and IGFBP-2 Abs were measured in 260 tumor patients (145 gliomas, 45 colorectal polyps, and 70 CRCs) and 141 controls. Receiver operating characteristic curves were applied.

RESULTS

Serum IGFBP-2 Ab levels were significantly elevated in tumors (mean: 82 ng/ml, median: 17 ng/ml, range: 0-1387 ng/ml) compared with controls (11, 0, 0-212 ng/ml) (P < 0.0001) and higher in early than advanced cancers opposite of serum IGFBP-2 levels. IGFBP-2 Abs effectively discriminated between controls and grade II and III gliomas [area under the curve (AUC): 0.821-0.864; 95% confidence interval (CI) = 0.762-0.936; P < 0.0001], and CRC I-II (AUC: 0.668; 95% CI = 0.566-0.770; P = 0.002) as well as indicative of advanced polyps at high risk of CRC (AUC: 0.72; 95% CI = 0.630-0.811; P < 0.0001). The sensitivity and specificity for diagnosing grade II-III gliomas reached 66%-84% and 81%. Combined serum IGFBP-2 and IGFBP-2 Abs augmented the discriminative power of all stage tumors (AUC: 0.823), gliomas (AUC: 0.800), and CRCs (AUC = 0.917).

CONCLUSION

Our results first demonstrate IGFBP-2 Abs for early cancer detection and in combination of serum IGFBP-2 for improved cancer diagnosis.

Screening and surveillance for Barrett's esophagus: current issues and future directions

PURPOSE OF REVIEW

Our article discusses the current understanding of screening and surveillance options for Barrett's esophagus and emerging concepts that have the potential to improve the effectiveness and cost-effectiveness of surveillance.

RECENT FINDINGS

Although endoscopic surveillance of patients with Barrett's esophagus is commonly practiced in order to detect high-grade dysplasia and early esophageal adenocarcinoma (EAC), the reported incidence of EAC in Barrett's esophagus patients varies widely. Recent studies found the risk of progression from Barrett's esophagus to EAC to be significantly lower than previously reported, raising concerns regarding the limitations of current surveillance strategies. Advances in imaging techniques and their enhanced diagnostic accuracy may improve the value of endoscopic surveillance. Additionally, various efforts are ongoing to identify biomarkers that identify individuals at higher risk of cancer, possibly allowing for individual risk stratification.

SUMMARY

These new data highlight some of the opportunities to revise and improve surveillance in patients with Barrett's esophagus. The incorporation of new advances such as imaging techniques and biomarkers has the potential to improve the effectiveness and cost-effectiveness of new surveillance regimens.

Potential diagnostic value of serum p53 antibody for detecting esophageal cancer: a meta-analysis

BACKGROUND

Mutant p53 protein overexpression has been reported to induce serum antibodies against p53. Various studies assessing the diagnostic value of serum p53 antibody in patients with esophageal cancer remain controversial. This study aims to comprehensively and quantitatively summarize the potential diagnostic value of serum p53 antibody in esophageal cancer.

METHODS

We systematically searched PubMed and Embase until 31st May 2012, without language restriction. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). Positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures diagnostic odds ratio (DOR) and symmetric summary receiver operating characteristic (sROC). The PLR and NLR and their 95% confidence interval (CI) were calculated using a fixed effects model according to the Mantel-Haensed method and random effects model based on the work of Der Simonian and laird, respectively.

RESULTS

Fifteen studies (cases = 1079, controls = 2260) met the inclusion criteria for the meta-analysis. Approximately 53.33% (8/15) of the included studies were of high quality (QUADAS score≥8), which were retrospective case-control studies. The summary estimates for quantitative analysis of serum p53 antibody in the diagnosis of esophageal cancer were PLR 6.95 (95% CI: 4.77-9.51), NLR 0.75 (95%CI: 0.72-0.78) and DOR 9.65 (95%CI: 7.04-13.22). However, we found significant heterogeneity between NLRs.

CONCLUSIONS

The current evidence suggests serum p53 antibody has a potential diagnostic value for esophageal cancer. However, its discrimination power is not perfect because of low sensitivity.

IMPACT

These results suggest that s-p53-antibody may be useful for monitoring residual tumor cells and for aiding in the selection of candidates for less invasive treatment procedures because of the high specificity of s-p53-antibody. Further studies may need to identify patterns of multiple biomarkers to further increase the power of EC detection.

Diagnostic and prognostic significance of circulating tumor suppressor gene p53 autoantibodies in patients with gestational trophoblastic tumors

Seventy-two patients with gestational trophoblastic tumors (GTTs) and 20 first-trimester healthy pregnant women (controls) participated in this study. According to the WHO scoring system, GTTs were subgrouped into 24 hydatiform mole spontaneous regression (HMSR), 18 postmolar high-risk (PMHR) and 16 low- and 14 high-risk cases of choriocarcinoma. Patients with choriocarcinoma were treated with hysterectomy and methotrexate chemotherapy, whereas molar pregnancy was managed by either oxytocin infusion followed by suction evacuation or by hysterectomy. Serum p53 autoantibodies were determined by enzyme-linked immunosorbant assay and serum hCGbeta was determined by radioimmunoassay before and throughout the 12 months after treatment. p53 autoantibodies were not detected in normal pregnancy and cases of HMSR but were detected in all cases of PMHR and choriocarcinoma. Concentrations of p53 autoantibodies were higher in choriocarcinoma than in PMHR cases. Serial measurements of p53 autoantibodies dropped to an undetectable level within 1 and 6 months after treatment in cases of PMHR and low-risk choriocarcinoma, respectively. Decreasing values of p53 autoantibodies in high-risk choriocarcinoma remained higher than the cut-off level of controls. There was a significant positive correlation between p53 autoantibodies and serum hCGbeta concentration in GTTs. In conclusion, detection of p53 autoantibodies has a high potential for the differential diagnosis of GTTs and their serial measurements are clinically useful to monitor disease progression and to assess response to therapy in GTTs.

Barrett's esophagus

Barrett's esophagus is an important step in the pathway to esophageal adenocarcinoma. Since most patients with Barrett's esophagus are undiagnosed and patients present with advanced adenocarcinoma de novo, prognosis for this disease remains poor. To identify those people with Barrett's esophagus who are at particular risk many new technologies are being developed. In association with these advances in risk stratification, progress is being made in the endoscopic treatment of Barrett's. Chemoprevention is also an area of interest and trials are underway.

Cancer-associated antigens and antigen arrays in serological diagnostics of malignant tumors

The appearance of antibodies to cancer-associated antigens in biological fluids (particularly, in blood sera) of cancer patients is now a well-established fact, and their detection by immunochemical methods is a promising approach to diagnostics of malignant neoplasms. In this review, we consider some immunobiological aspects of the most extensively studied cancer-associated B-cell antigens, various applications of autoantibodies as cancer biomarkers, and prospects for the use of antigen arrays for improving diagnostic sensitivity.

Clinical significance of serum p53 antibodies in patients with ulcerative colitis and its carcinogenesis

BACKGROUND

For early detection of ulcerative colitis (UC)-associated colorectal cancer (CRC), surveillance colonoscopy is recommended in UC patients at high risk. However, poor acceptability deteriorates its effectiveness and a suitable marker for selecting patients at high risk is needed. Here we evaluated clinical usefulness of the measurement of anti-p53 antibodies (Abs) by enzyme-linked immunosorbent assay (ELISA) using sera samples from UC patients.

METHODS

Sera from 286 patients with UC, 82 patients with sporadic CRC, and 63 healthy controls (HC) were obtained. Serum anti-p53 antibodies were detected with ELISA. Immunohistochemical detection was also performed in patients who developed dysplasia or CRC.

RESULTS

Serum p53 Ab was positive in 15.0% of UC, while it was positive only in 1.6% of HCs. In sporadic CRCs, 52.4% of 82 patients were positive. In UC patients with disease duration equal to or longer than 8 years, positivity of serum p53 Ab was significantly higher than those in patients with shorter duration. Eight of 13 (61.5%) UC patients with CRC or dysplasia were positive for serum p53 Abs, which was significantly higher than that in patients without neoplasia. All UC patients with CRC were positive for p53 staining, while 2 were negative for serum p53 Ab. Finally, levels of serum p53 Ab had fallen in 4 patients with CRC we could monitor after surgery.

CONCLUSIONS

This study revealed that p53 Ab developed in the progression of UC-associated CRC but not in all patients with neoplasia, suggesting that serological detection of p53 Abs by ELISA is not suitable in primarily selecting patients at high risk; however, it is helpful in salvaging patients who drop from a surveillance program.

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.

Targeting serum antibody for cancer diagnosis: a focus on colorectal cancer

The ability of the immune system to magnify the appearance of disease by generating relatively large amounts of antibody in response to small amounts of disease makes it a natural biosensor, and serum antibodies have emerged as promising biomarkers for the detection of cancer. This review summarizes recent progress in targeting serum antibodies for cancer diagnosis, with a particular focus on colorectal cancer (CRC). Several serum antibodies have been detected at increased levels in CRC patients, including p53, carcinoembryonic antigen, Ras, topoisomerase II-alpha, histone deacetylase 3 and 5, ubiquitin C-terminal hydrolase L3, tropomyosin and cyclin B1. As each antibody is only present in a limited proportion of patients (usually < 40%), a combination of serum antibodies that defines the 'immunological signature' of cancer needs to be developed. High-throughput methods to identify new serum antibodies for cancer diagnosis are also reviewed.

Optical diagnostic technology based on light scattering spectroscopy for early cancer detection

This article reviews the application of optical diagnostic technology based on light scattering spectroscopy for minimally invasive detection of precancerous and early cancerous changes in a variety of organs. Optical spectroscopic techniques have shown promising results in the diagnosis of diseases at the cellular scale. They do not require tissue removal, can be performed in vivo and allow for real-time diagnosis. While fluorescence and Raman spectroscopy are most effective in revealing the molecular properties of tissue, the novel technique, light scattering spectroscopy, is capable of characterizing the structural properties of tissue at the cellular and subcellular scale.

Molecular biologic staging of esophageal cancer

The molecular biology of esophageal cancer is characterized by a series of genetic mutations that occur throughout the progression from normal squamous epithelium to carcinoma. The most important risk factor for the development of adenocarcinoma, which is increasing in incidence, is the presence of CLE. The pathophysiology of CLE appears to be related to duodenogastroesophageal reflux, also increasing in incidence. The genetic mutations that are responsible for tumorigenesis have been described, although the precise sequence of mutations is variable. Analysis of molecular biologic factors that are important in tumorigenesis may be used in clinical applications: establishing diagnosis, assessing prognosis, and assigning therapy. The development of molecular biologic substaging of patients with CLE may potentially identify patients with elevated malignant potential and expedite therapy. The ability of molecular markers to predict resistance to chemotherapy and radiation therapy represents an important potential advantage, with two possible applications. Predictable resistance to a particular chemotherapeutic agent would allow the selection of a alternative agent, with a greater potential for efficacy. Furthermore, known mechanisms of resistance, which have been analyzed using molecular markers, may be inhibited or reversed. The molecular biology of esophageal cancer requires further study. The molecular events and factors that are involved may be important in the diagnosis, staging, and treatment of esophageal cancer, in addition to the description of tumorigenesis.

Molecular targets for treatment of Barrett's esophagus

SUMMARY. Esophageal cancer is one of the most deadly forms of gastrointestinal cancer with a mortality rate exceeding 90%. The major risk factors for esophageal adenocarcinoma are gastroesophageal reflux disease (GERD) and its sequela, Barrett's esophagus. GERD commonly leads to esophagitis. In a minority of patients however, ongoing GERD leads to replacement of esophageal squamous mucosa with metaplastic, intestinal-type Barrett's mucosa. In the setting of continued peptic injury, Barrett's mucosa can give rise to esophageal adenocarcinoma. Despite the widespread use of potent acid suppressive therapies for patients with GERD, the incidence of esophageal adenocarcinoma, among white men in the USA, the UK and Europe has continued to rise. Cancers in Barrett's esophagus arise through a sequence of genetic events that endow the cells with six essential physiologic hallmarks of cancer as described by Hanahan and Weinberg in 2000. These cancer hallmarks include the ability to proliferate without exogenous stimulation, to resist growth-inhibitory signals, to avoid triggering the programmed death mechanism (apoptosis), to resist cell senescence, to develop new vascular supplies (angiogenesis), and to invade and metastasize. While the acquisition of these essential attributes is not specific to the neoplastic progression of Barrett's esophagus, this review will focus on the genetic alterations that occur in Barrett's cells that contribute to the acquisition of each of the hallmarks. Moreover, potential diagnostic and therapeutic strategies for Barrett's patients aimed at each of these cancer hallmarks will be reviewed.

Preferential humoral immune response in prostate cancer to cellular proteins p90 and p62 in a panel of tumor-associated antigens

BACKGROUND

Cytoplasmic p90 autoantigen was recently cloned from a cDNA expression library using serum antibody from a cancer patient. The humoral immune response to p90 in prostate cancer and benign prostatic hyperplasia (BPH) was examined.

METHODS

An antigenic fragment of recombinant p90 protein and several other tumor-associated antigens (TAAs) were used in ELISA and Western blotting to detect antibodies in sera from patients with prostate cancer, BPH, and other controls.

RESULTS

Autoantibodies to p90 were detected in 30.8% of 133 prostate cancer patients versus 1.5% in 68 BPH patients. When a selected panel of six TAAs including p90 were used for immunoscreening, the cumulative positive reactions in prostate cancer sera reached 92.5%, significantly higher than in BPH and other control sera. Antibodies to p90 showed the highest frequency in prostate cancer (30.8%), followed by antibodies to p62 (22.6%).

CONCLUSIONS

A panel of six selected TAAs was shown to have high sensitivity and specificity as immunodiagnostic markers in prostate cancer.

Biomarkers of esophageal adenocarcinoma and Barrett's esophagus

The rising incidence and poor prognosis of esophageal adenocarcinoma in the Western world have intensified research efforts into earlier methods of detection of this disease and its relationship to Barrett's esophagus. The progression of Barrett's esophagus to adenocarcinoma has been the focus of particular scrutiny, and a number of potential tissue and serum-based disease biomarkers have emerged. The epidemiology and pathogenesis of esophageal adenocarcinoma are outlined. Tissue biomarkers allowing risk stratification of Barrett's are reviewed as well as strategies currently being used to discover novel biomarkers that will facilitate the early detection of esophageal adenocarcinoma. Finally, the uses of biomarkers as predictive tests for targeted treatments and as surrogate endpoints in chemoprevention trials are considered.

Histopathological study of intraductal papillary mucinous tumor of the pancreas: special reference to the roles of Survivin and p53 in tumorigenesis of IPMT

AIM

In this study, we investigated the tissue expression of Survivin, p53, and Bcl-2 in intraductal papillary-mucinous tumor (IPMT) of the pancreas to identify their roles in tumorigenesis of IPMT, and examined their correlations with tumor cell apoptosis and proliferation in IPMT. The diagnostic values of the expression of Survivin, p53, and Bcl-2 and the apoptotic index (AI) and Ki-67 labeling index (Ki-67 LI) in IPMT were also examined.

METHODS

Twenty-two lesions from 17 patients with IPMT, including 12 benign (IPMT Adenoma) and 10 malignant (IPMT Carcinoma In Situ [CIS] (n = 4) and Invasive IPMT (n = 6) lesions, were immunostained for Survivin, p53, Bcl-2 and Ki-67. The apoptotic cells were detected by the Apop Tag(R) In Situ Oligo Ligation (ISOL) method.

RESULTS

The immunoreactivities for Survivin and p53 significantly increased in the transition from IPMT Adenoma to IPMT CIS (p < 0.05 for both). This transition was associated with a significant decrease in tumor cell apoptosis ( p < 0.001). The expression of Survivin was significantly associated with AI in IPMT ( p < 0.01), but not with Ki-67 LI. The expressions of Survivin and p53, and AI and Ki-67 LI were also significantly different between benign IPMT and malignant IPMT. Bcl-2 was not expressed in IPMT.

CONCLUSION

These results suggest that Survivin and p53 may play important roles in the transition from IPMT Adenoma to IPMT CIS. This transition is accompanied by a significant decrease in tumor cell apoptosis. Survivin is significantly associated with the change in AI in IPMT. The immunohistochemical detection of Survivin and p53 as well as the determination of the AI and Ki-67 LI have useful roles in the diagnosis of IPMT.

Oesophagectomy for early adenocarcinoma and dysplasia arising in Barrett's oesophagus

BACKGROUND

Oesophagectomy for high-grade dysplasia is controversial.

METHODS

A prospective study was carried out on all patients who presented between 1993 and 2001 with dysplasia or early adeno-carcinoma who were considered fit for surgery. Details of endoscopic biopsies, appearance, surveillance, operative pathology and outcome were recorded.

RESULTS

Of 18 patients, one had low-grade dysplasia, six had high-grade dysplasia and 11 had early adenocarcinoma. No patient had their biopsy diagnosis down-staged following final pathology, but two patients with high-grade dysplasia on biopsy were upstaged to adenocarcinoma. Our only death from disease occurred in a 39-year-old man who had undergone yearly surveillance for 86 months until adenocarcinoma was confirmed. There was no operative mortality.

CONCLUSION

Oesophagectomy for early adenocarcinoma and dysplasia in Barrett's oesophagus can be done with acceptable rates of mortality and morbidity. Surveillance until adenocarcinoma is confirmed does not guarantee curable disease.

Serum p53 antibodies in patients with lung cancer: correlation with clinicopathologic features and smoking

Abnormalities of p53 gene can lead to the production of p53 antibodies (p53-Abs) in the serum of cancer patients. This study was designed to investigate the prevalence of p53-Abs in 133 lung cancer patients and the distribution of these antibodies to clinicopathologic features and smoking status. Twenty five (18.8%) lung cancer patients were found to have p53-Abs. The presence of p53-Abs did not correlate with sex or age but showed frequent association with tumors of squamous cell carcinoma (31%) in comparison with adenocarcinoma (13.6%) (P=0.052). There was a statistically significant difference in the incidence of p53-Abs between early disease group (stage I-II) and the advanced group (stage III-IV) (P=0.036), however, there was no relationship between the presence of p53-Abs and overall survival. Interestingly, the frequent of p53-Abs was higher in smokers (27.1%) than in non-smokers (13.6%), though the difference was of borderline of statistical significance (P=0.061). These findings suggested that p53-Abs could be a potential biomarker for the study of individual with lung cancer.

Detection of serum p53 protein in patients with different gastrointestinal cancers

Overexpression of p53 has been found in many types of human malignancy. The present study aimed to detect preoperative serum p53 among 158 patients with different gastrointestinal cancers using ELISA technique based on mouse anti-p53 DO-7 monoclonal antibody and anti-p53 rabbit polyclonal antibody. A single band of 53kDa was detected in nuclear protein tissue extracts of selected cancer patients and in 96% of the corresponding sera using Western blot assay. The ELISA technique revealed that the serum p53 was detected in 100% of patients with cholangiocarcinoma, 76% of pancreatic carcinoma, 75% of hepatocellular carcinoma, 70% of colon cancer, 60% of esophagus carcinoma, and 35% of gastric carcinoma. The serum p53 concentrations of the positive patients were highly elevated (P<0.001) compared with healthy individuals. These results suggest that immunodetection of serum p53 could be valuable for post-operative monitoring during follow up in preoperatively positive patients with gastrointestinal cancers.

Molecular staging of lung and esophageal cancer

In both esophageal and NSCLC, the TNM stage at diagnosis remains the most important determinant of survival. Significant research to investigate the biology of NSCLC and esophageal carcinoma is ongoing, and the roles of proto-oncogenes, tumor suppressor genes, angiogenic factors, extracellular matrix proteases, and adhesion molecules are being elucidated. While evidence is accumulating that various markers are involved in NSCLC and esophageal tumor virulence, the current studies are compromised by small sample sizes, heterogeneous populations, and variations in techniques. Large prospective studies with homogenous groups designed to evaluate the role of these various markers should clarify their potential involvement in NSCLC and esophageal cancer. Identification of occult micrometastases in lymph nodes and bone marrow using immunohistochemical techniques and rt-PCR is intriguing. These techniques are promising as a method to more accurately stage patients, and therefore to predict outcomes and to determine therapies. Perhaps the most promising area of research is the development of novel drugs whose mechanism of action targets the pathways of various molecular markers. Molecular biologic substaging offers an opportunity to individualize a chemotherapeutic regimen based on the molecular profile of the tumor, thus providing the potential for improved outcomes with less morbidity in patients with both NSCLC and esophageal cancer.

Appearance and prognosis of dysplasia in Barrett's esophagus

Dysplasia in a patient who has Barrett's esophagus (BE) is the first step in the neoplastic process. The grade of dysplasia correlates with the likelihood of developing adenocarcinoma of the esophagus during follow-up surveillance endoscopy and biopsy. Surveillance intervals are proposed based on the existing data of the likelihood of developing adenocarcinoma. In the future these intervals will be refined as a result of better definition of the risk factors the development of adenocarcinoma of the esophagus. Risk stratification of the individual patients by age, gender, grade of dysplasia, length of BE, length of hiatal hernia, and presence of genetic mutations will be possible.

Apoptosis: life through planned cellular death regulating mechanisms, control systems, and relations with thyroid diseases

Apoptosis is an active biologic process that represents a form of programmed cellular suicide, activated either by genetic factors or by cellular lesions caused by various extracellular traumatic agents. The alterations of its functional mechanisms control cellular homeostasis are involved in the genesis of many illnesses. There are different control systems that can both stimulate and inhibit apoptosis, such as the p53 and Bcl-2 proteins. Different injuries may cause a rapid increase in the levels of p53 and the activation of the complex mechanism which leads either to damage repair or cellular apoptosis. The concept of tumor growth as a dynamic balance between cellular development and death is well applicable to differentiated thyroid carcinomas, which are generally not highly invasive and present excellent prognosis. On the contrary, in aggressive anaplastic thyroid carcinoma there is an increase in p53, whereas in normal thyroid cells there is a high expression of Bcl-2, so as to interfere with apoptosis when physiologic hormone levels are normal. However, only some of the biomolecular mechanisms behind the genesis of thyroid tumors have been explained, and the role of apoptosis in thyroid diseases has not been well defined. This review provides information about relationship between apoptosis and thyroid diseases.

Detection of anti-p53 antibodies by ELISA using p53 synthetic or phage-displayed peptides

Anti-p53 antibodies have been detected in the sera of patients with various types of cancers. In this report, we describe the development of a new ELISA aimed at detecting anti-p53 antibodies using two peptides belonging to immunodominant epitopes of the p53 N-terminal region. We first tested the reactivity of the sera by an indirect ELISA using the peptides as a capture system. Then, the specificity of the reaction was confirmed by an inhibition assay. Two systems of peptide presentation, phage display and the streptavidin/biotin system, were evaluated. Using a panel of sera from cancer patients, both systems were found to be equally reliable, demonstrating that both peptide-based ELISAs can be used for the specific detection of anti-p53 antibodies. The presence of anti-p53 antibodies was associated with p53 alteration whether it be mutation or accumulation.

Screening and surveillance for complications related to gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) and columnar-lined esophagus with intestinal metaplasia (Barrett's esophagus) are the major recognized risk factors for adenocarcinoma of the esophagus. The American College of Gastroenterology recommends that patients with long-standing GERD symptoms (particularly those 50 years of age or older) undergo endoscopic screening to identify Barrett's esophagus and that those patients who have Barrett's esophagus undergo regular endoscopic surveillance. These recommendations are made with the expectation that screening and surveillance will decrease mortality from esophageal cancer, although this association is unclear. Nonetheless, retrospective studies have shown that endoscopic surveillance can detect some early, curable neoplasms in patients with Barrett's esophagus. Dysplasia in Barrett's esophagus is widely regarded as the precursor of invasive malignancy. Although grading dysplastic changes is largely subjective, dysplasia remains the most appropriate biomarker for clinical evaluation of Barrett's esophagus. Flow-cytometric and p53 abnormalities may be earlier and more specific markers for cancer development, but application of these abnormalities is not yet recommended for clinical practice. Endoscopic surveillance also is adversely affected by biopsy sampling error. Techniques that may minimize biopsy sampling error include chromoendoscopy, endosonography, optical coherence tomography, and fluorescence detection techniques. Further studies are needed to clearly define the role of these techniques in surveillance, and none is practical for routine clinical use at this time. Although not specifically recommended, experimental ablative therapies, such as photodynamic therapy, can be considered by physicians for their patients with high-grade dysplasia in Barrett's esophagus, if they are provided as part of an established, approved research protocol.

Extent of high-grade dysplasia in Barrett's esophagus correlates with risk of adenocarcinoma

BACKGROUND & AIMS

The identification of any high-grade dysplasia (HGD) in Barrett's esophagus has been considered to be an indication for esophagectomy because of the increased risk of cancer. The aim of this study was to determine if a limited extent of HGD has the same potential for cancer as diffuse HGD.

METHODS

A retrospective cohort study was performed to assess the risk of developing adenocarcinoma in relationship to the extent of HGD found on endoscopic surveillance. The extent of HGD was defined as focal if cytologic and/or architectural changes of HGD were limited to a single focus of 5 or fewer crypts and diffuse if more than 5 crypts were involved in a single biopsy specimen or if HGD involved more than one biopsy fragment. The relative risk of cancer was assessed using a Cox proportional hazard model, and cancer-free survival was determined using survival curves.

RESULTS

Sixty-seven patients with diffuse HGD and 33 with focal HGD satisfied selection criteria. Cancer-free survival rates at 1 and 3 years were 93% and 86% for focal HGD compared with 62% and 44% for diffuse HGD (P < 0.001). On univariate analysis, extent of HGD (relative risk, 5.36; 95% confidence interval, 1.84-15.56), nodularity on endoscopy (relative risk, 3.98; 95% confidence interval, 1.97-8.04), and lack of acid suppression (relative risk, 2.48; 95% confidence interval, 1.16-5.28) were associated with an increased risk of esophageal adenocarcinoma. Diffuse HGD had a 3.7-fold increase in the risk of esophageal cancer compared with focal HGD (P = 0.02) on multivariate analysis.

CONCLUSIONS

Patients with focal HGD are less likely to have cancer during the first year after diagnosis or on subsequent follow-up compared with diffuse HGD.

Dysplasia in Barrett's Esophagus

Dysplasia is the most important marker of progression to invasive cancer in Barrett's esophagus. Intensive endoscopic surveillance with biopsy may identify invasive cancer in a patient with high-grade dysplasia (HGD). Close relationship with an experienced gastrointestinal pathologist and thoracic surgeon will improve treatment decisions and patient outcomes. No intervention is required in patients with low-grade dysplasia (LGD); continued surveillance is recommended. Surgical resection is the currently accepted therapy for high-grade dysplasia. Endoscopic ablative therapy remains experimental.

Serum p53 antibody is a useful tumor marker in superficial esophageal squamous cell carcinoma

BACKGROUND

Patients with superficial (mucosal or submucosal) esophageal carcinoma (SEC) have significantly better survival rates than patients with advanced carcinoma. Some patients with advanced esophageal carcinoma have been reported to test positive for serum p53 antibodies (Abs). Because very few patients with superficial carcinoma have been examined, the aim of this study was to evaluate the clinical significance of serum p53-Abs in patients with superficial esophageal squamous cell carcinoma (SESCC).

METHODS

Thirty-five consecutive patients with SESCC were studied for serum p53-Abs by enzyme-linked immunoabsorbent assay before and after treatment. The clinicopathologic features of p53 seropositive and p53 negative patients were compared. The relation between the presence of serum p53-Abs and p53 immunoreactivity of the resected specimens was examined. Three tumor markers (squamous cell carcinoma antigen [SCC-Ag], CYFRA21-1, and carcinoembryonic antigen [CEA]) were assessed to compare their sensitivities with serum p53-Abs.

RESULTS

Fourteen of 35 patients (40%) were p53 seropositive. Relatively few patients tested positive for the other tumor markers: CEA, 11.4%; SCC-Ag, 14.3%; CYFRA21-1, 5.7%. There were no significant correlations between clinicopathologic features and p53 seropositivity except for tumor location. A strong correlation between p53 immunostaining and the presence of serum p53-Abs was observed (P = 0.003). Of the 14 patients with seropositive results, 12 turned seronegative after resection, and the other 2 experienced disease recurrence.

CONCLUSIONS

Surveillance of serum p53-Abs is superior to the three tumor markers for detecting SESCC. This serum marker is also useful for the detection of p53 protein overexpression and for the monitoring of residual tumor cells.

Endoscopic mapping and surrogate markers for better surveillance in Barrett esophagus. A study of 700 biopsy specimens

Surveillance methods in Barrett esophagus (BE) using light microscopic examination of random biopsy specimens may miss focal dysplasia. In addition, dysplastic foci identified initially may not be relocated subsequently, making chemoprevention studies difficult. By using a special gastroscope, systematic mapping (4-quadrant biopsy specimens at 1-cm intervals) was performed in 22 patients (33 total mappings yielding 700 biopsy specimens). H&E, immunohistochemistry, and DNA ploidy analysis were performed. c-erbB-2 and positive Ki-67 were detected only in dysplastic sites; thus, their detection did not precede morphologically identifiable dysplasia. On the other hand, aneuploidy and p53 were detected in dysplastic and nondysplastic areas. p53 was correlated with dysplasia, and S-phase narrowly missed correlation, while aneuploidy was not correlated. PCNA and bcl-2 were ubiquitous, limiting their usefulness. On second maps, epithelial type was reidentified with 81% accuracy. A significant correlation was found between p53 and dysplasia. Sites of dysplasia and abnormal biomarkers could be relocated accurately by using endoscopic mapping. Therefore, mapping combined with biomarker studies may provide better surveillance and serve as a useful technique in chemoprevention studies.

The p53 tumor suppressor gene: from molecular biology to clinical investigation

The tumor suppressor p53 is a phosphoprotein barely detectable in the nucleus of normal cells. Upon cellular stress, particularly that induced by DNA damage, p53 can arrest cell cycle progression, thus allowing the DNA to be repaired; or it can lead to apoptosis. These functions are achieved, in part, by the transactivational properties of p53, which activate a series of genes involved in cell cycle regulation. In cancer cells bearing a mutant p53, this protein is no longer able to control cell proliferation, resulting in inefficient DNA repair and the emergence of genetically unstable cells. The most common changes of p53 in human cancers are point missense mutations within the coding sequences of the gene. Such mutations are found in all major histogenetic groups, including cancers of the colon (60%), stomach (60%), breast (20%), lung (70%), brain (40%), and esophagus (60%). It is estimated that p53 mutations are the most frequent genetic event in human cancers, accounting for more than 50% of cases. One of the most striking features of the inactive mutant p53 protein is its increased stability (half-life of several hours, compared to 20 min for wild-type p53) and its accumulation in the nucleus of neoplastic cells. Therefore, positive immunostaining is indicative of abnormalities of the p53 gene and its product. Several studies have shown that p53 mutations are associated with short survival in colorectal cancer, but the use of p53 as a tumoral marker is still a matter of debate.

Recent developments in Barrett's esophagus

Barrett's esophagus is a precancerous condition in which the squamous esophageal epithelium is replaced by a columnar epithelium. Although different types of columnar epithelium have been described, the most frequently encountered is specialized columnar epithelium or intestinal metaplasia. Most investigators believe that increased cancer risk is only associated with this type. Esophageal adenocarcinoma is increasing in frequency in the United States and in Western Europe. Recent studies highlight the importance of gastroesophageal reflux disease in esophageal adenocarcinoma. Bile-acid reflux may also play a role. Increasing interest has been expressed in short-segment (2-3 cm) Barrett's esophagus. The contribution of short-segment Barrett's esophagus to cancer at the gastroesophageal junction is currently being studied. Although regular surveillance is often recommended, the commonness of Barrett's esophagus makes such a practice impractical for every patient. Biomarker development is needed to identify patients at greatest risk, with p53 a promising candidate based on recent studies. Initial data suggest that redox mechanisms may be involved in Barrett's esophagus. Several methods have recently been described for reversing Barrett's esophagus to squamous epithelium, but the significance of this practice in terms of reducing cancer risk remains to be demonstrated.

Detection of circulating anti-p53 antibodies in esophageal cancer patients

It has been reported that circulating anti-p53 antibodies (p53-Ab) in the serum are detected in some cancers. To investigate the usefulness of detecting p53-Ab, we measured the circulating p53-Ab in comparison with squamous cell carcinoma antigen (SCC-Ag) in patients with esophageal carcinoma. Serum specimens from 46 esophageal cancer patients (42 squamous cell carcinomas, 3 mucoepidermoid carcinomas and 1 basaloid squamous carcinoma) and 13 healthy subjects were studied. Serum p53-Ab was measured by an enzyme-linked immunosorbent assay. Surgically resected specimens from 43 patients were immunohistochemically stained for p53. Serum SCC-Ag was measured by a radioimmunoassay. The results were analyzed with the clinical data and outcome. Serum p53-Ab was detected in 13 (28%) of the 46 patients, but not in any of the healthy subjects. The positive rate was 0% (0/6) in stage I, 60% (3/5) in stage IIA, 30% (3/10) in stage IIB, 29% (7/24) in stage III and 0% (0/1) in stage IV. There was no difference in the outcome between the p53-Ab-positive and p53-Ab-negative patients. Immunohistochemically, 30 (70%) of the 43 specimens stained positively for p53. Serum p53-Ab was detected in 43% (13/30) of the patients with tumors which stained positively for p53. There was a close correlation between positivity for p53 immunostaining and positivity for p53-Ab (p<0.01). An elevated level of SCC-Ag was found in only 13%of the patients, and most patients positive for SCC-Ag already had advanced disease with lymph node metastasis and invasion to the adventitia. In conclusion, serum p53-Ab was detected in Japanese esophageal cancer patients at a frequency similar to that reported in Western countries. Serum p53-Ab may be a potentially useful molecular marker for detection and screening of esophageal cancer. Further studies of a large population may be required to elucidate the true diagnostic usefulness of measuring the serum p53-Ab.