Nomogram-Based Prognostic Evaluation of Gastric Cancer Patients with Low Counts of Examined Lymph Nodes Outperforms the Predictive Ability of the 7th and 8th Editions of the American Joint Committee on Cancer Staging System

BACKGROUND

The American Joint Committee on Cancer (AJCC) staging system has limited accuracy in predicting survival of gastric cancer patients with inadequate counts of evaluated lymph nodes (LNs). We therefore aimed to develop a prognostic nomogram suitable for clinical applications in such cases.

METHODS

A total of 1511 noncardia gastric cancer patients treated between 1990 and 2010 in the academic surgical center were reviewed to compare the 7^th and 8^th editions of the AJCC staging system. A nomogram was developed for the prediction of 5-year survival in patients with less than 16 LNs evaluated (n = 546). External validation was performed using datasets derived from the Polish Gastric Cancer Study Group (n = 668) and the SEER database (n = 11,225).

RESULTS

The 8th edition of AJCC staging showed better overall discriminatory power compared to the previous version, but no improvement was found for patients with < 16 evaluated LNs. The developed nomogram had better concordance index (0.695) than the former (0.682) or latest (0.680) staging editions, including patients subject to neoadjuvant treatment, and calibration curves showed excellent agreement between the nomogram-predicted and actual survival. High discriminatory power was also demonstrated for both validation cohorts. Subsequently, the nomogram showed the best accuracy for the prediction of 5-year survival through the time-dependent ROC curve analysis in the training and validation cohorts.

CONCLUSIONS

A clinically relevant nomogram was built for the prediction of 5-year survival in patients with inadequate numbers of LNs evaluated in surgical specimens. The predictive accuracy of the nomogram was validated in two Western populations.

Clinical analysis of systemic and adipose tissue levels of selected hormones/adipokines and stromal-derived factor-1

Recent studies demonstrated that selected hormones/adipokines may be involved into the regulation of bone metabolism and bone marrow-derived hematopoietic stem/progenitor cells (HSPCs) mobilization in humans. Interestingly, in obese individuals significantly higher numbers of spontaneously circulating stem cells are also observed. Therefore in this study we comprehensively examined plasma and AT (subcutaneous and visceral/omental) levels of hormones/adipokines involved in HSPCs mobilization in lean, overweight and obese individuals as well as verified their potential associations with concentrations of HSPCs chemoattractant, stromal-derived factor-1 (SDF-1). Blood and AT samples (35 subcutaneous and 35 omental) were obtained from individuals undergoing elective surgery. Plasma and AT-derived interstitial fluid levels of resistin, visfatin, osteocalcin and SDF-1 were measured using ELISA. In our study obese patients had almost significantly (P&#60;0.06) higher plasma visfatin and resistin levels as well as lower osteocalcin concentrations (P&#60;0.04) than lean individuals. Osteocalcin and resistin concentrations were strongly associated with levels of SDF-1 and metalloproteinases (MMP 2 and 9). AT levels of all examined substances were significantly lower than the corresponding levels in the plasma (in all cases at least P&#60;0.05), and depot-specific differences in the concentrations of these factors were found only in terms of osteocalcin and SDF-1. In addition, subcutaneous and visceral/omental concentrations of osteocalcin and visfatin, but not of resistin, were associated with values of such parameters as age, body mass or adiposity indexes (BMI and BAI, respectively) and/or waist-to-hip ratio (WHR). In summary, our study showed that in obese individuals the biochemical constellation of adipokines/hormones involved in the process of HSPCs mobilization resembles this observed during pharmacological HSPCs mobilization. Moreover, our study offers further indirect translational evidence for existence of a biochemical cross-talk between bone and AT metabolism (so called - bone-fat- axis) in humans.

The effect of PGE administration on the activity of oxidative system in erythrocytes and platelets during ischemia reperfusion injury and on postoperative renal function in patients undergoing open abdominal aortic aneurysm reconstruction

Postoperative decline of renal function remains a common and unpredictable complication after abdominal aortic aneurysm (AAA) reconstruction. The oxidative stress that occurs during perioperative ischemia/reperfusion injury (I/R) may contribute to the development of this complication. In this study, the influence of intraoperative prostaglandin E (alprostadil) administration on erythrocyte and platelet antioxidants as well as postoperative kidney function modulation were verified. AAA patients were randomly divided into control and study/alprostadil groups. Blood samples were collected directly before aortic clamping and 5 min after aortic declamping. Superoxide dismutase, catalase, glutathione, glutathione peroxidase (GPx), and glutathione transferase (GST) were measured using spectrophotometry. During I/R, the activity of catalase (57.14+/-30.65 vs 128.35+/-91.94 U/mg protein; P < 0.009), GPx (0.21+/-0.18 vs 0.35+/-0.21 mU/g protein; P = 0.028), and GST (217.49+/-101.39 vs 310.66+/-88.86 mU/g protein; P = 0.0006) significantly increased in the control group. GST activity before the aortic clamping was significantly lower in the study/alprostadil group (2.84+/-2.28 vs 3.48+/-2.30 U/g Hb; P = 0.05). The activity of the selected antioxidants proved to be of a diagnostic value for predicting postoperative decline in renal function. In conclusion, during I/R after AAA reconstruction, activation of various erythrocyte and platelet antioxidants occurs. Perioperative administration of alprostadil is associated with disruption of this activation.

Implications of overweight in gastric cancer: A multicenter study in a Western patient population

AIMS

The purpose of this study was to evaluate the effects of overweight on surgical and long-term outcomes in a Western population of patients with gastric cancer (GC).

METHODS

An electronic database of all patients with resectable GC treated between 1986 and 1998 at seven university surgical centres cooperating in the Polish Gastric Cancer Study Group was reviewed. Overweight was defined as a body mass index (BMI) of 25 kg/m(2) or higher.

RESULTS

Four hundred and ninety-two of 1992 (25%) patients were overweight. Postoperatively, higher BMI was associated with higher rates of cardiopulmonary complications (16% vs 12%, P = 0.001) and intra-abdominal abscess (6.9% vs 2.9%, P < 0.001). However, other complications and mortality rates were unaffected. The median disease-specific survival of overweight patients was significantly higher (36.7 months, 95% confidence interval (CI) 29.0-44.4) than those with BMI<25 kg/m(2) (25.7 months, 95%CI 23.2-28.1; P = 0.003). These differences were due to the lower frequencies of patients with T3 and T4 tumours, metastatic lymph nodes, distant metastases, and non-curative resections. A Cox proportional hazards model identified age, depth of infiltration, lymph node metastases, distant metastases, and residual tumour category as the independent prognostic factors.

CONCLUSIONS

Overweight is not the independent prognostic factor for long-term survival in a Western-type population of GC.

Helicobacter pylori and CagA status, serum gastrin, interleukin-8 and gastric acid secretion in gastric cancer

BACKGROUND

Despite numerous epidemiological studies, the association between Helicobacter pylori infection and gastric cancer (GC) remains unexplained. This study was designed to determine the seropositivity of H. pylori and cytotoxin-associated gene A (CagA), serum gastrin and interleukin-8 (IL-8) levels as well as basal intragastric pH and maximal histamine-induced gastric acid outputs (MAO) in a large series of GC patients and controls.

METHODS

337 GC patients (118 men and 219 women; median age 59.4; range 21-87) and 337 controls randomized for sex and age entered the study. Serum IgG antibodies to H. pylori and CagA and serum levels of IL-8 were measured by enzyme-linked immunosorbent assay, while serum-amidated gastrin was determined by specific radioimmunoassay and correlated with gastric luminal pH.

RESULTS

The numbers of GC patients and controls involved in the study in various age groups, ranging from 20 to > 70 years, were similar, but overall H. pylori IgG seropositivity in GC patients was significantly higher (90.8%) than in controls (79.2%). The overall CagA seropositivity in GC patients was about double (58.2%) that in controls (25.2%). Serum gastrin levels over the calculated cut-off value (38.88 pM/L) were found in several-fold larger number in GC patients (48%) than in controls (8.3%) and. similarly, serum IL-8 values over the cut-off point (1.77 pg/mL) occurred in almost all (99.7%) GC patients but in only a few controls (0.3%). Basal intragastric pH above the cut-off point (pH = 4.50) was observed in about 58.2% of GC patients compared to 15.1% in controls, and strong correlation between the serum gastrin and gastric pH was found in GC but weak in controls. The cut-off value for MAO was 12.3 mml/h; MAO below this cut-off value occurred in 89.9% of GC patients and in only 4.7% of controls. A summary odds ratio (SOR) in GC for H. pylori IgG was 2.59 (95% Cl: 1.61-4.22) for CagA - 4.12 (95% Cl; 2.93-5.8), for serum gastrin - 10.25 (95%; 6.47-16.47) and for MAO - 15.2 (95% Cl; 9.45-39.82). Multivariable analysis of serum gastrin, IgG and CagA, and luminal pH and MAO values revealed that only gastrin and CagA have significant influence on GC formation (OR > 1 in logistic regression).

CONCLUSIONS

1. CG patients show significantly higher H. pylori IgG and CagA seropositivity than dyspeptic age- and gender-matched controls, confirming that gastric infection with CagA expressing H. pylori greatly increases the risk of GC. 2. Serum gastrin levels in GC but not in controls are correlated with the rise in intragastric pH, indicating that excessive gastrin release in GC is affected by lower intragastric pH. 3. Serum gastrin level and CagA seropositivity are significantly increased in the majority of GC patients, and are the only variables in multivariable analysis to have a predominant influence on GC formation, which suggests that both these parameters may be implicated in H. pylori-related gastric carcinogenesis. 4. H. pylori-infected GC patients produce significantly more IL-8 than do non-GC controls, probably reflecting CagA-positive H. pylori-associated gastritis.

Helicobacter pylori infection, gastrin, cyclooxygenase-2, and apoptosis in colorectal cancer

Helicobacter pylori (HP) infection is usually accompanied by an increased plasma level of gastrin, a potent mitogen able to induce cyclooxygenase (COX)-2. This study examined (a) the seroprevalence of HP, its cytotoxic protein, CagA, and cytokines (tumor necrosis factor alpha, interleukins 1beta and 8) in 80 patients with colorectal cancers, before and after the removal of tumor, compared with 160 age- and gender-matched controls; (b) the gene expression of gastrin and its receptors (CCKB-R) in the cancer tissue, (c) the plasma levels and tumor tissue contents of gastrin, and (d) the mRNA expression of COX-1, COX-2, and apoptotic proteins (Bax and Bcl2) in cancer tissue and intact colonic mucosa. Anti-HP IgG, anti-CagA IgG seroprevalence, and cytokine levels were analyzed by enzyme-linked immunosorbent assay tests; gene expressions of gastrin, CCKB-R, COX-1, COX-2, Bax, and Bcl2 by reverse transcriptase polymerase chain reaction; and gastrin by radioimmunoassay. The seroprevalence of HP, especially that expressing CagA, was significantly higher in cancer patients than in controls and did not change 1 week after tumor resection while plasma cytokines were significantly reduced after this operation. Both gastrin and CCKB-R mRNA were detected in the cancer tissue and the resection margin; similarly, COX-2 mRNA was expressed in most of cancers and their resection margin but not in intact colonic mucosa, where only COX-1 was detected. The colorectal cancer tissue contained several folds more immunoreactive gastrin than cancer resection margin and many folds more than the intact colonic mucosa. We conclude that colon adenocarcinoma and its resection margin overexpress gastrin, its receptors, CCKB-R, and COX-2, and that HP infection may contribute to colonic cancerogenesis via overexpression of gastrin and COX-2, which may account for the stimulation of the tumor growth and the reduction in apoptosis as documented by enhanced mRNA expression of anti-apoptotic Bcl2 over proapoptotic Bax proteins.

Expression of hepatocyte growth factor, transforming growth factor alpha, apoptosis related proteins Bax and Bcl-2, and gastrin in human gastric cancer

BACKGROUND

Gastric cancer is one of the most frequent neoplasms and a leading cause of the death world-wide. In recent years, epidemiological and animal studies demonstrated a link between gastric cancer and chronic infection with H. pylori. The exact mechanism responsible for the development of gastric cancer in H. pylori-infected patients still remains unclear. There is evidence that the up-regulation of certain growth factors could play an important role in the promotion of the gastric carcinogenesis.

AIMS

The present study was designed to determine the gene expression of major known growth factors such as transforming growth factor alpha (TGFalpha), hepatocyte growth factor (HGF) and gastrin in the gastric cancer tissue, the surrounding mucosa and, for comparison, in the normal gastric mucosa. Furthermore, the luminal and plasma levels of gastrin in patients with gastric cancer were determined. In addition, the gene and protein expressions of apoptosis-related proteins such as Bax and Bcl-2 were investigated by reverse transcription-polymerase chain reaction and Western blot. Twenty-five gastric cancer patients and 40 age- and gender-matched control subjects hospitalized with non-ulcer dyspepsia were included into this study.

RESULTS

An overall H. pylori-seropositivity among gastric cancer patients was about 72% and was significantly higher than in the controls (56%). The prevalence of CagA-positive strains was also significantly higher among gastric cancer patients than in controls (56% vs. 32%). The gene expression of HGF and TGFalpha was detected more frequently in gastric cancer tissue samples than in normal gastric mucosa (52% vs. 12% for HGF and 48% vs. 24% for TGFalpha). The extent of protein expression in Western blotting analysis for HGF and TGFalpha correlated with the mRNA expression of these factors. Gene expression of gastrin was detected in the antrum of all tested patients and in the majority (84%) of gastric cancer patients. The median plasma and luminal concentrations of gastrin in gastric cancer patients were significantly higher than in controls. The gene expression of bcl-2 was detected in all (100%) and that of proapoptotic bax only in 56% of gastric cancer samples. In comparison to the surrounding non-tumorous tisssue, the gene expression of bax was significantly down-regulated and the gene expression of bcl-2 was up-regulated in gastric cancer tissue. At the protein level, Bax was not detectable and Bcl-2 was seen in 80% of gastric cancer samples.

CONCLUSIONS

It is concluded that the patients infected with H. pylori, especially with CagA-positive strains, are at a higher risk of developing a gastric cancer. An increased production and release of gastrin, as well as an over-expression of growth factors such as HGF and TGFalpha, might contribute to the gastric carcinogenesis. In addition, a dysregulation of the Bax/Bcl-2 system with significant up-regulation of Bcl-2 is observed in gastric cancer.

Frequency of TPR-MET rearrangement in patients with gastric carcinoma and in first-degree relatives

BACKGROUND

The activation of the c-met protooncogene through a rearrangement has been detected previously in gastric carcinoma tissue and precancerous lesions. In the current study the authors analyzed the rearrangement of TPR-MET in gastric carcinoma patients and in first-degree relatives to evaluate the potential role and timepoint of this genetic alteration in the process of gastric carcinogenesis and its potential value in identifying those individuals with an increased risk of developing gastric carcinoma.

METHODS

The presence of TPR-MET mRNA was determined in gastric tissue from 19 patients with gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. A 205-base pair (bp) cDNA fragment and a 70-bp cDNA fragment spanning the breakpoint were amplified by nested PCR. Amplification products were hybridized with an oligonucleotide labeled at the 3'-end with DIG-11-dUTP spanning the breakpoint using Southern blot analysis. The MNNG-HOS cell line served as a positive control.

RESULTS

TPR-MET mRNA was detected in nine gastric carcinoma patients (47%). Among these patients, TPR-MET mRNA was present in the both tumor and tumor free tissues in 5 patients (26%), in the tumor tissue only in 2 patients (11%), and in the tumor free gastric mucosa only in 2 patients (11%). It is interesting to note that TPR-MET rearrangement also was detected in the gastric corpus mucosa of 1 first-degree relative (6%), but in none of the control subjects.

CONCLUSIONS

The data from the current study indicate that TPR-MET activation may be an early event in gastric carcinogenesis and may be useful for the identification of individuals with an increased risk of developing gastric carcinoma.

Frequency of TPR-MET rearrangement in patients with gastric carcinoma and in first-degree relatives

BACKGROUND

The activation of the c-met protooncogene through a rearrangement has been detected previously in gastric carcinoma tissue and precancerous lesions. In the current study the authors analyzed the rearrangement of TPR-MET in gastric carcinoma patients and in first-degree relatives to evaluate the potential role and timepoint of this genetic alteration in the process of gastric carcinogenesis and its potential value in identifying those individuals with an increased risk of developing gastric carcinoma.

METHODS

The presence of TPR-MET mRNA was determined in gastric tissue from 19 patients with gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. A 205-base pair (bp) cDNA fragment and a 70-bp cDNA fragment spanning the breakpoint were amplified by nested PCR. Amplification products were hybridized with an oligonucleotide labeled at the 3'-end with DIG-11-dUTP spanning the breakpoint using Southern blot analysis. The MNNG-HOS cell line served as a positive control.

RESULTS

TPR-MET mRNA was detected in nine gastric carcinoma patients (47%). Among these patients, TPR-MET mRNA was present in the both tumor and tumor free tissues in 5 patients (26%), in the tumor tissue only in 2 patients (11%), and in the tumor free gastric mucosa only in 2 patients (11%). It is interesting to note that TPR-MET rearrangement also was detected in the gastric corpus mucosa of 1 first-degree relative (6%), but in none of the control subjects.

CONCLUSIONS

The data from the current study indicate that TPR-MET activation may be an early event in gastric carcinogenesis and may be useful for the identification of individuals with an increased risk of developing gastric carcinoma.

Frequency of TPR-MET rearrangement in patients with gastric carcinoma and in first-degree relatives

BACKGROUND

The activation of the c-met protooncogene through a rearrangement has been detected previously in gastric carcinoma tissue and precancerous lesions. In the current study the authors analyzed the rearrangement of TPR-MET in gastric carcinoma patients and in first-degree relatives to evaluate the potential role and timepoint of this genetic alteration in the process of gastric carcinogenesis and its potential value in identifying those individuals with an increased risk of developing gastric carcinoma.

METHODS

The presence of TPR-MET mRNA was determined in gastric tissue from 19 patients with gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. A 205-base pair (bp) cDNA fragment and a 70-bp cDNA fragment spanning the breakpoint were amplified by nested PCR. Amplification products were hybridized with an oligonucleotide labeled at the 3'-end with DIG-11-dUTP spanning the breakpoint using Southern blot analysis. The MNNG-HOS cell line served as a positive control.

RESULTS

TPR-MET mRNA was detected in nine gastric carcinoma patients (47%). Among these patients, TPR-MET mRNA was present in the both tumor and tumor free tissues in 5 patients (26%), in the tumor tissue only in 2 patients (11%), and in the tumor free gastric mucosa only in 2 patients (11%). It is interesting to note that TPR-MET rearrangement also was detected in the gastric corpus mucosa of 1 first-degree relative (6%), but in none of the control subjects.

CONCLUSIONS

The data from the current study indicate that TPR-MET activation may be an early event in gastric carcinogenesis and may be useful for the identification of individuals with an increased risk of developing gastric carcinoma.

Role of gastrin in gastric cancerogenesis in Helicobacter pylori infected humans

Numerous epidemiological studies demonstrated the association between Helicobacter pylori (H. pylori) infection and gastric cancer but the mechanism of the involvement of H. pylori in gastric cancerogenesis remains virtually unknown. This study was designed to determine the seropositivity of H. pylori and cytotoxin associated gene A (CagA), serum gastrin and gastric lumen gastrin levels under basal conditions and following stimulation with histamine in gastric cancer patients and controls. 100 gastric cancer patients aging from 21 to 60 years and 300 gender- and age-adjusted controls hospitalized with non-ulcer dyspepsia (NUD) entered this study. 13C-Urea Breath Test (UBT), serum immunoglobulin (IgG) antibodies to H. pylori and CagA were used to assess the H. pylori infection and serum levels of IL-1beta, IL-8 and TNFalpha were measured by enzyme-linked immunosorbent assay (ELISA) to evaluate the degree of gastric inflammation by H. pylori . Gastrin-17 mRNA and gastrin receptors (CCK(B)) mRNA expression in gastric mucosal samples taken by biopsy from the macroscopically intact fundic and antral mucosa as well as from the gastric tumor was determined using RT-PCR. The overall H. pylori seropositivity in gastric cancer patients at age 21-60 years was about 92%, compared, respectively, to 68%, in controls. A summary odds ratio (OR) for gastric cancer in H. pylori infected patients was about 5.0 . The H. pylori CagA seropositivity in gastric cancer patients was about 58.5% compared to 32.4% in controls, giving the summary OR for gastric cancer in CagA positive patients about 8.0. The prevalence of H. pylori- and H. pylori CagA-seropositivity was significantly higher in cancers than in controls, irrespective of the histology of gastric tumor (intestinal, diffuse or mixed type). Median IL-1beta and IL-8 reached significantly higher values in gastric cancer patients (9.31 and 30.8 pg/ml) than in controls (0.21 and 3.12, respectively). In contrast, median serum gastrin in cancers (as total group) was several folds higher (62.6 pM) than in controls (19.3 pM). Also median luminal gastrin concentration in gastric cancer patients was many folds higher (310 pM) than in controls (20 pM). This study shows for the first time that cancer patients are capable of releasing large amounts of gastrin into the gastric lumen to increase luminal hormone concentration to the level that was recently reported to stimulate the growth of H. pylori. There was no any correlation between plasma gastrin levels and gastric luminal concentration of gastrin suggesting that: 1) luminal gastrin originates from different source than plasma hormone, most probably from the cancer cells, 2) cancer cells are capable of expressing gastrin and releasing it mainly into the gastric juice and 3) the gastric cancer cells are equipped with gastrin-specific (CCK(B)) receptor so they exhibit the self-growth promoting activity in autocrine fashion. This notion is supported by direct detection of gastrin mRNA and gastrin receptor (CCK(B)-receptors) mRNA using RT-PCR in cancer tissue. To our knowledge this is the first study showing an important role of gastrin as self-stimulant of cancer cells in patients infected with H. pylori. Basal and histamine maximally stimulated acid outputs were significantly lower in gastric cancer patients than in controls despite of enhanced gastrin release, particularly in cancer patients and this might reflect the mucosal inflammatory changes (increased serum levels of proinflammtory interleukins - IL-1beta and IL-8), that are known to increase gastrin release. We conclude that: 1) H. pylori infected patients, particularly those showing CagA-seropositivity, are at greatly increased risk of development of gastric cancer, 2) H. pylori-infected cancer patients produce significantly more IL-1beta and IL-8 that might reflect an H. (ABSTRACT TRUNCATED)

5T4 oncofetal antigen in gastric carcinoma and its clinical significance

OBJECTIVE

To evaluate the role of 5T4 antigen in gastric cancer progression and prognosis.

DESIGN

A prospective study of 5T4 antigen expression in primary, secondary and recurrent gastric carcinoma, the relationship to selected prognostic parameters and the course of disease.

PATIENTS

Eighty six patients operated on for gastric cancer. TISSUE: One hundred and twenty two gastric tumours were studied, including 86 primary carcinomas, 32 coexisting lymph node metastases and four recurrent carcinomas.

METHODS

Immunohistochemistry using 5T4 monoclonal antibody on frozen sections.

RESULTS

The 5T4 antigen was detected in 41% of primary gastric tumours including early gastric cancer. A strong relationship was found between 5T4 positivity and tumour histology. Thus, 52% of gastric carcinomas of intestinal type expressed 5T4 antigen compared with 28% of the diffuse type (P = 0.028). Among 16 sets of primary gastric carcinomas and regional lymph node metastases, coordinate 5T4 expression was seen in 14 cases; the other two showed acquisition of positivity on metastatic tumour cells (carcinomas of diffuse type). 5T4 antigen was detected more frequently in carcinomas with p53 accumulation compared with those with undetectable p53 levels (P = 0.015). The presence of 5T4 in cancer cells was correlated with poor short-term prognosis (24% vs 49% of 2 year survival for 5T4 positive and negative tumours respectively, P = 0.024). The effect on survival was evident in the p53 negative group, with patients 5T4 positive showing worse survival (28% vs 60% in 2 years).

CONCLUSIONS

Our results suggest that the assessment of 5T4 expression in gastric carcinoma can be helpful in identifying patients with poor short-term prognosis.

Accumulation of p53 in relation to long-term prognosis in colorectal carcinoma

OBJECTIVE

To evaluate the prognostic value of p53 in colorectal cancer.

DESIGN

A retrospective study to investigate the correlation between p53 in tumour tissue and the course of patients' disease.

PATIENTS

One hundred and two patients who underwent radical surgery for colorectal cancer and were followed up for a minimum of 5 years, or until death, were included in this study.

METHODS

The p53 expression in tumour tissue was studied by immunohistochemistry using CM1 polyclonal rabbit antibody and formalin-fixed, paraffin-embedded material.

RESULTS

p53 accumulation was detected in 46% (47/102) of the tumours. There was no significant difference in long-term survival between the patients with p53 positive and negative tumours (P=0.86). Five-year survival rates were 55% for p53 positive tumours compared with 56% for patients with p53 negative tumours. However, patients with p53 overexpressing tumours showed a higher local recurrence rate than those having carcinomas with undetectable levels of p53, 23% versus 9% respectively; the 2-year actuarial rates of 26% and 9% were statistically different (P=0.015).

CONCLUSION

The results suggest that in colorectal carcinoma accumulation of p53 is not associated with a difference in long-term prognosis. However, this phenomenon might be useful in the identification of patients with a high risk of local recurrence.

The clinical significance of p53 accumulation in gastric carcinoma

BACKGROUND

Alterations in the expression of p53 tumor suppressor protein is a frequent event in human cancer but the practical implications of this phenomenon are yet to be fully exploited. The objective of this study was to determine the value of p53 accumulation as a marker of tumor progression and prognosis of gastric carcinoma patients and to evaluate whether this parameter can be properly assessed prior to surgery.

METHODS

The expression of p53 was studied immunohistochemically in 200 gastric carcinomas using paraffin embedded surgical specimens and endoscopic biopsies. The correlation between p53 expression in tumor tissue, selected clinicopathologic variables, and the course of the patients' disease were analyzed.

RESULTS

Results showed that 42.5% of the gastric carcinomas expressed elevated levels of p53 protein. P53 accumulation positivity correlated with increasing tumor stage and size (P < 0.001 and P = 0.025, respectively). P53 positive tumors had a higher propensity for lymph node and distant metastases (P < 0.001). P53 accumulation was also more frequently detected in carcinoma from proximal rather than distal stomach (P = 0.027). In patients receiving potentially curative resection for advanced cancer, p53 accumulation was an independent parameter and the strongest for poor prognosis (RR = 3.7, P < 0.001). There was complete concordance between immunohistochemical detection of p53 in endoscopic and surgical material.

CONCLUSIONS

A preoperative assessment of p53 expression in gastric carcinoma can be helpful to identify patients at high risk of metastatic spread to regional lymph nodes and independently to identify those with especially poor prognosis. When combined with routine procedures, this simple and inexpensive test might allow appropriate planning of better treatment strategies.

Survival of patients with limited small cell lung cancer in whom complete remission was obtained (a non-randomised retrospective study of 124 consecutive patients

The aim of this study was to assess whether thoracic radiotherapy (TRT) is necessary for those patients (pts) with limited small cell lung cancer (SCLC) who obtained CR after induction chemotherapy (ChT). The analysis include retrospective material of 124 consecutive pts with limited SCLC. All pts had induction ChT (3-5 courses): 78 with CAVE (cyclophosphamide, doxorubicine, etoposide) and 46--with other regimens without etoposide. After induction ChT 55 pts were irradiated on tumor and mediastinum and in 69 the same ChT was continued for 6-8 courses or till progression. After induction ChT CR was obtained in 31 pts, PR in 67 and NR in 26. TRT significantly increased the number of CR among those pts who did not achieve satisfactory tumor response after induction ChT. The median survival was 24 months for those patients who obtained CR, 12 months for those who obtained PR and 9 months for those who did not respond. In the group of patients who obtain CR, survival was the same for those treated with ChT alone and for those treated with ChT and TRT. We conclude that in the treatment of individual patient with limited SCLC TRT is indicated for those who did not obtain CR after ChT. Whether patients in whom CR after chemotherapy was obtained can further gain by application of TRT is worth further randomised studies.

5T4 oncofetal antigen expression in ovarian carcinoma

5T4 oncofetal antigen is defined by a monoclonal antibody raised against human placental trophoblast, and recognizes a 72 kD glycoprotein expressed in many different carcinomas but detected only at low levels in some normal epithelia. Analysis of the patterns of expression of 5T4 oncofetal antigen in colorectal carcinomas has indicated a significant association between the presence of the antigen in tumor cells and metastatic spread. The 5T4 antigen expression of 72 epithelial ovarian carcinomas has been investigated by immunohistochemistry; 71% of the carcinomas demonstrated positive 5T4 immunoreactivity in adenocarcinoma cells and/or associated stromal tissue. In order to assess any relationship to prognosis, the 5T4 phenotypes were analyzed with respect to various clinicopathologic features of the tumors and the clinical outcome of the patients assessed by survival and disease-free interval. There was a significant correlation between 5T4 expression and more advanced stage of disease (FIGO stages III and IV) (P < 0.001) and with poorly differentiated tumors (P = 0.036) compared to well or moderately differentiated tumors. Patients with tumors expressing 5T4 were less likely to respond well to adjuvant therapy (P = 0.030) and had a significantly worse outlook in terms of survival (P = 0.033) and disease-free interval (P = 0.033). This significance was not demonstrated as acting independently of FIGO stage and tumor differentiation.

The expression of p53 tumor-suppressor protein during progression of gastric and colorectal carcinomas

The expression of p53 was immunohistochemically determined in sets of biopsies from primary and recurrent colorectal (12) and gastric (17) tumours that had progressed to more advanged stages in the following 6-54 months. At presentation 7 carcinomas overexpressed p53 protein in the cell nucleus and 22 tumours had normal, undetectable levels of p53. In most patients, the p53 phenotype was maintained during the process of tumour progression. In two gastric and two colorectal carcinomas p53 overexpression was subsequently detected in recurrent tumour growth at the primary site and was also associated with the development of metastases. These results suggests that in some cases p53 alterations may contribute to the conversion to malignancy and in others to tumour progression and metastatic capacity.

Prognostic significance of 5T4 oncofetal antigen expression in colorectal carcinoma

The 5T4 oncofetal antigen is a 72 kDa glycoprotein defined by a monoclonal antibody raised against human placental trophoblast and is expressed in many different carcinomas but detected only at low levels in some normal epithelia. Immunohistochemical analysis of the patterns of expression in colorectal carcinomas has indicated a significant association between the presence of the antigen in tumour cells and metastatic spread. The 5T4 antigen phenotype of 72 colorectal cancers has been compared with the clinical outcome of the patients in order to assess its relationship with prognosis. Forty per cent of tumours were 5T4 positive; the remainder were either unlabelled or exhibited stroma-associated labelling only. There was a significant correlation between 5T4 expression in the malignant cells and unfavourable course of disease (P < 0.001). The 5 year survival with 5T4-positive tumours was 22% compared with 75% for patients with 5T4-negative tumours; median survival was 24 versus > 90 months respectively. Stratified analysis showed that 5T4 antigen tumour positivity was acting independently of each of stage, site of tumour, age or sex. There were significant differences in survival for patients with Dukes' B and C stage carcinomas (P = 0.001 and P = 0.034). The results suggest that in colorectal cancer immunohistochemical assessment of 5T4 expression may be useful in identifying patients at high risk for tumour recurrence and for whom additional treatment strategies might be most appropriate.

p53 overexpression as a marker of malignancy in gastric biopsies

Inactivation of the p53 tumour-suppressor gene is the commonest genetic abnormality in human cancers. This results in a conformational change in the p53 protein, and a consequent prolongation in its half-life; thereby permitting the identification of p53 immunoreactivity in malignant cells. Such reactivity is observed in up to 57% of gastric carcinomas, and is a proven indicator of poor prognosis. We have investigated the use of p53 immunohistochemistry in the diagnosis of malignancy in pre-operative gastric biopsy specimens. Using a three-stage immunoperoxidase technique, p53 expression was examined in 117 gastric biopsies obtained during flexible upper gastrointestinal endoscopy: 80 of these biopsies were from known gastric carcinomas, 20 from benign gastric disorders and 17 from normal gastric mucosa. Of the gastric cancers 40% (n = 32) exhibited overexpression of p53. No reactivity was observed in any of the biopsies of gastric ulcers, polyps or normal mucosa. The expression of p53 by gastric carcinomas improved the diagnostic accuracy of conventional histopathology from 86% to 92.5%; with 5% of biopsies incorrectly diagnosed and 2.5% of an equivocal appearance. These results demonstrate that the detection of p53 is a highly specific marker of gastric malignancy, and that such a technique can easily be performed on biopsies obtained at endoscopy.

The expression of 5T4 antigen in colorectal and gastric carcinoma

The expression of 5T4, an oncotrophoblast cell surface antigen was examined in 72 colorectal and 27 gastric carcinomas, with immunoperoxidase technique, on frozen sections. Highly significant association was found between 5T4 expression in the malignant cells and metastatic spread. The results suggest that the appearance of 5T4 molecules in cancer cells reflects a change which may contribute to the development of metastatic potential.

Prognostic significance of p53 overexpression in gastric and colorectal carcinoma

p53 expression was examined in 55 gastric and 107 colorectal carcinomas with an immunoperoxidase technique, using the polyclonal antibody CM1 on routinely fixed, paraffin embedded tissue. p53 protein was detected in 47% gastric and in 46% colorectal carcinomas and found to correlate with stage of disease and unfavourable clinical outcome (P less than 0.001). Thus, the proportion of positively reacting neoplasms increased as the stage progressed, tumours which had invaded regional lymph-nodes overexpressed p53 more frequently than localised carcinomas and an elevated level of p53 was associated with early relapse and death. In colorectal carcinoma p53 positivity was also linked with site and macroscopic configuration of the primary tumour and was most frequently expressed in carcinomas from the rectum and in ulcerative tumours. p53 overexpression was irrespective of tumour grade. Uniform negative reactivity with anti-p53 antibody was seen in normal epithelium adjacent to carcinoma, intestinal metaplasia, atrophic gastritis and in colonic adenomas. There was a good correlation between immunohistochemical staining on paraffin and frozen sections. These studies suggest that in gastric and colorectal carcinoma, immunohistochemical detection of p53 protein in routinely fixed tissue can be used along with other established parameters to assess prognostic outcome, especially to identify patients with poor short-term prognosis.