Multidrug resistance-associated protein and mutant p53 protein expression in non-small cell lung cancer

Multidrug resistance-associated protein (MRP) is one of the major factors for non-P-glycoprotein (PGp)-mediated multidrug resistance. We reported previously that overexpression of the MRP gene was related to the prognosis of non-small cell lung cancer (NSCLC). It is unclear how MRP expression is regulated in NSCLC. In this study, we examined MRP and mutant p53 expression in 107 NSCLCs by immunohistochemical procedures. Forty-seven (43.9%) of these 107 NSCLCs were positive for MRP in the cytoplasm. Mutant p53-positive NSCLC showed a significant correlation with MRP overexpression (P=.011). Coexpression of MRP and p53 in the same cells of NSCLC was confirmed by double-staining procedures. Twenty-six patients with MRP-positive tumors who underwent postoperative chemotherapy with MRP-related anticancer drugs (vindesine and etoposide) had significantly poorer prognoses than did those with MRP-negative tumors (P=.017). This correlation between MRP expression and prognosis was also seen in Stage III patients (P=.022) and in patients with squamous cell carcinoma (P=.062). NSCLC patients with coexpression of MRP and p53 showed poorer prognoses than did those without MRP and p53 (P=.014). These results suggested that MRP overexpression affected by mutant p53 had a significant effect on prognosis through atypical non-PGp-mediated multidrug resistance in NSCLC.     

The results of treatment in 100 patients with limited-stage small cell lung cancer

Strain differences in midgut basal lamina thickness, assessed by measurement in transmission electron micrographs, and disseminated infection rates of dengue-1 virus were compared among three laboratory strains of Aedes albopictus (Skuse). Mean basal lamina thickness for the New Orleans and Houston strains were significantly greater than those for the Oahu strain, which exhibits a higher disseminated infection rate than the former two. Although basal lamina thickness among the F1 progeny of reciprocal crosses of the Oahu and Houston strains were intermediate between the parental strains, they were too variable to be useful as markers in genetic studies. Measurements of basal laminae among individuals of the New Orleans strain, with disseminated or nondisseminated infections, failed to demonstrate a role for basal lamina thickness as a modulator of dengue-1 virus dissemination across the midgut epithelium of Ae. albopictus.     

Altered retinoblastoma protein expression in nonsmall cell lung cancer: its synergistic effects with altered ras and p53 protein status on prognosis

BACKGROUND: Inactivation of the retinoblastoma (Rb) gene has been documented in various types of cancer, including lung cancer. Alterations of the p53 and ras genes are also common features in the molecular biology of lung carcinoma, and the authors of this article have reported previously on the prognostic significance of both of them. In the present study, the authors evaluated the prognostic significance of the loss of Rb protein expression alone, then performed a combined analysis of Rb protein and ras p21 status (Rb/ras) as well as an analysis of Rb and p53 protein status (Rb/p53) in patients with nonsmall cell lung cancer (NSCLC). METHODS: Ninety-one patients with NSCLC underwent potentially curative resection between 1977 and 1988, 65 of whom received postoperative combination chemotherapy. Tumor specimens were analyzed for Rb protein expression by immunohistochemistry. Univariate and multivariate analyses were performed to assess the association between Rb protein expression and survival. RESULTS: Nineteen (21%) of the 91 NSCLCs showed negative Rb protein expression. Positive or negative Rb protein expression (Rb+ or Rb-) as an individual factor was not statistically correlated with survival or prognosis in this cohort of NSCLC patients, although a tendency among Rb- patients to do worse was observed. The authors then combined the Rb protein status with previously studied results of ras p21 and p53 protein expression in the same tumor specimens, and compared the prognosis between the individuals with theoretically the best pattern of gene expression in their tumors and those with theoretically the worst pattern of expression, i.e., Rb+/ras- versus Rb-/ras+ and Rb+/p53- versus Rb-/p53+. In patients with adenocarcinoma, those with Rb-/ras+ tumors survived for a significantly shorter period after surgery (13% 5-year survival) than those with Rb+/ras- tumors (82% 5-year survival) (P = 0.01). Similarly, patients with Rb-/p53+ tumors survived for a significantly shorter period (20% 5-year survival) compared with those who had Rb+/p53- tumors (73% 5-year survival) (P = 0.008). Rb/ras status was a significant prognostic factor (P = 0.02 by univariate analysis, P = 0.048 by multivariate analysis), and Rb/p53 status tended to be significant as a prognostic factor (P = 0.04 by univariate analysis, P = 0.08 by multivariate analysis). In patients with squamous cell carcinoma, neither Rb/ras nor Rb/p53 status was a significant prognostic factor in this cohort. CONCLUSIONS: These results suggest that combined immunohistochemical analyses of Rb and ras p21 proteins and of Rb and p53 proteins may indicate their potentially synergistic effects on survival and prognosis. These analyses may also be useful for stratifying patients with adenocarcinoma of the lung into different prognostic groups and identifying populations with different risks of recurrence. Larger prospective studies with Stage I NSCLC patients are necessary to confirm the current findings.     

p53 codon 72 polymorphism in Taiwanese lung cancer patients: association with lung cancer susceptibility and prognosis

Previous studies have indicated that milrinone, a specific type III phosphodiesterase inhibitor, may be able to induce chloride secretion in cystic fibrosis (CF) tissues. We have now assessed the effect of this agent in vivo on the nasal epithelium of CF mutant mice and also in the nose and lungs of human subjects with CF. Wild-type mice showed a small hyperpolarization of the nasal potential difference (PD) in response to milrinone (100 microM, 1.6 +/- 0.6 mV, n = 8, P < 0.05). In contrast, CF mice carrying either the most common human mutation of the gene for the CF transmembrane regulator (CFTR), DeltaF508 (protein mislocalized), or the G551D mutation (protein normally localized) failed to demonstrate this response. Milrinone perfused alone had no significant effect on the baseline nasal PD of human subjects without CF (14.7 +/- 4.0 mV preperfusion; 15.3 +/- 4.6 mV postperfusion), but significantly (P < 0.05) augmented the hyperpolarization induced by a subsequently perfused low-chloride solution (with milrinone, 36.8 +/- 3.0 mV, n = 6; without milrinone, 18.1 +/- 2.2 mV, n = 19). In contrast, in human subjects with CF (n = 6), milrinone alone significantly (P < 0. 05) altered the nasal baseline PD (52.2 +/- 3.3 mV preperfusion; 57. 4 +/- 4.2 mV, postperfusion) but not the subsequent responses to the low-chloride solution (with milrinone, 1.1 +/- 2.2 mV, n = 4; without milrinone, 0.6 +/- 0.5 mV, n = 28) or to isoproterenol (100 microM). In a separate study in subjects (n = 6) with the DeltaF508 mutation, nasal coadministration of milrinone with isoproterenol produced no effect in the presence of amiloride and a low-chloride solution (-0.8 +/- 0.5 mV). This was also the case in the nasal epithelium of CF subjects (n = 4) carrying at least one G551D allele (-0.3 +/- 0.8 mV). Similarly, milrinone did not hyperpolarize the PD of either the tracheal (n = 6) or segmental (n = 6) airways of CF subjects (DeltaF508) when applied topically in vivo in the presence of amiloride, isoproterenol, or adenosine triphosphate (all 100 microM) in a low-chloride solution. These data do not support the use of milrinone to induce chloride secretion in CF airways in vivo.     

Detection of protein p53 in the stool of patients with colorectal cancer

BACKGROUND AND AIMS: Mutations of TP53, a tumor suppressor gene, are found in 60% to 70% of colorectal cancers. These mutations usually induce an overexpression caused by modification of the p53 protein conformation. The aim of this study was to investigate whether stool specimens of patients with colorectal cancer contain increased amounts of p53 protein. METHODS: p53 protein was measured using a sandwich enzyme immunoassay in the stool specimens of 52 patients: 25 with colorectal cancer, 4 with colorectal adenomas and 23 apparently free of gastrointestinal disease. Results were expressed as pg/mg of total protein. The presence of fecal occult-blood was searched using Hemoccult II and Hemolex (an immunochemical assay for human hemoglobin). RESULTS: Median concentrations of stool p53 protein were 16.6 pg/mg (range: 0-591 pg/mg) in patients with colorectal cancers, 39.1 pg/mg (range: 5-72 pg/mg) in patients with adenomas and 5.9 pg/mg (range: 0-65 pg/mg) in control subjects. Resection of colorectal cancers caused a marked decrease of stool p53 protein concentrations. When the cut-off value for stool p53 protein was set at 60 pg/mg of fecal protein (concentrations over the 95th percentile), the positivity of the assay was independent of tumor size and Astler-Coller stage, but weakly associated with rectal location of cancer. The sensitivity of stool p53 protein for colorectal cancer was 44%, and the specificity was 96%. In contrast, the sensitivity of Hemoccult II and Hemolex tests was 48% and 44%, whereas their specificity was 91% and 96%, respectively. CONCLUSION: The detection of p53 protein is achievable in stool, but this assay is not more efficient than fecal occult blood tests for detection of colorectal cancer.     

The significance of p53 autoantibodies in the serum of patients with breast cancer

Serum p53 autoantibodies were studied in 82 patients with Stage 1 or 2 breast cancer using an ELISA assay. Tissue expression of p53 in these patients was also examined. High levels of serum p53 autoantibodies were detected in 48% (39/82) patients, while 23% (19/82) were tissue positive. Patients with high serum p53 autoantibodies levels were not significantly different to those with low levels with respect to, tissue p53, tumour grade, size, stage or oestrogen receptor status. Tissue immunoreactivity for p53 was significantly associated with tumour grade and negative oestrogen receptor status. Patients in both groups were followed for a median of over five years but the presence of p53 autoantibodies in serum was not prognostic with respect to disease free interval or survival. In this study detection of p53 autoantibodies in serum does not correlate with any of the usual tumour related prognostic factors, nor does it correlate with clinical outcome.     

Expression of p53 protein in colorectal cancer and its relationship to cell proliferative activity and prognosis

The expression of p53 protein in 66 cases of colorectal cancer and its relationship to cell proliferative activity, lymph node metastasis as well as prognosis were investigated by means of AB-PAP immunohistochemical technique. The results showed that 62.1% of colorectal cancer was positive. The cell proliferative activity and the frequency of lymph node metastasis in p53-positive cases were significantly higher than those of p53-negative cases (P < 0.05). The survival rate in patients with p53-positive tumors was significantly shorter than those with p53-negative tumors (P < 0.05). Our results suggest that the abnormal expression of p53 and cell proliferation associated with mutations are involved in both human carcinogenesis and lymph node metastasis of colorectal cancer. Examination of p53 expression is of value in understanding the degree of malignancy, and evaluating prognosis of the disease.     

Mutations in exon 7 and 8 of p53 as poor prognostic factors in patients with non-small cell lung cancer

This study was performed to clarify the different effects of each mutant exon of p53 as indicators of a poor prognosis in patients with non-small cell lung cancer (NSCLC). Tumor tissues of 204 patients with NSCLC were analysed; 96 tumors were stage I, 22 stage II, and 86 stage III. DNA was extracted from frozen specimens and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and direct sequencing were performed to investigate mutations of p53 from exon 5 to exon 8. Seventy-five patients with NSCLC (36.8%) had mutations in p53 which included 72 cases of missense mutations and three cases of non-missense mutations. The overall survival rate of patients with mutant p53 adenocarcinomas was strikingly worse than that of patients whose tumors had wild-type p53 (35.7% vs 53.8%; P=0.041), but no significant difference in survival was found in the patients with NSCLC and squamous cell carcinoma. Mutations in exon 5 of p53 occurred in 33 cases (16.2%), mutation in exon 6 was detected in only one case (0.5%), mutations in exon 7 in 20 cases (9.8%), and mutations in exon 8 in 18 cases (8.8%). The overall survival rate of patients with mutations in exon 7 was worse than that of patients with wild-type p53 in NSCLCs and adenocarcinomas (42.9% vs 56.0%; P=0.025 and 33.3% vs 53.8%; P=0.048, respectively), whereas the overall survival of patients with mutations in exon 5 was almost the same as that of patients with wild-type p53. In addition, the overall survival rate of patients with mutations in exon 8 was strikingly worse than that of patients with wild-type p53 in NSCLCs, adenocarcinomas and squamous cell carcinomas (22.9% vs 56.0%; P<0.001, 19.0% vs 53.8%; P=0.004 and 33.3% vs 62.5%; P=0.042, respectively). Multivariate analysis with the Cox regression model of patients with NSCLC, adenocarcinoma and squamous cell carcinoma indicated that mutations in exon 8 were best correlated with the overall survival rate, followed by lymph node status (P<0.001, P=0.015 and P=0.006, respectively), and mutations in exon 7 of NSCLC were also revealed to have good correlation, followed by lymph node status and mutations in exon 8 (P=0.031). Mutation of p53 was a poor prognostic factor for adenocarcinoma as described previously. Moreover, mutations in exon 8 were more useful indicators of prognosis not only for adenocarcinoma but also for NSCLC. Worse overall survival of the patients with mutations in exon 8 of p53 was suggested to be associated with codon 273 mutations as well as mutations between codon 280 and 285 included into the H2 alpha helix corresponding to residues 278-286. These results suggested that abnormal conformation of H2 alpha helix might play an important role not only in the loss of normal function but also in the acquisition of tumorigenesis. Investigation of mutations in exon 8, especially codon 273 mutation and mutant H2 alpha helix was considered to be a clinically useful approach for determining the prognosis of patients with NSCLC.     

Analysis of p53 serum antibodies in patients with head and neck squamous cell carcinoma

BACKGROUND: Mutation of the p53 tumor suppressor gene (also known as TP53) often leads to the synthesis of p53 protein that has a longer than normal half-life. Mutant p53 protein that accumulates in tumor cell nuclei can be detected by means of immunohistochemical staining techniques. Serum antibodies directed against p53 protein (p53-Abs) have been detected in some cancer patients. PURPOSE: We assayed serum samples from 80 patients with head and neck squamous cell carcinoma (HNSCC) for the presence of p53-Abs, and we evaluated potential associations between the presence of these antibodies and other histopathologic and clinical features. METHODS: Serum was collected from each patient at the time of diagnosis. In addition, tumor biopsy specimens were obtained before the initiation of treatment. An enzyme-linked immunosorbent assay was used to detect p53-Abs. The accumulation of p53 protein in tumor cell nuclei was assessed immunohistochemically by use of the anti-p53 monoclonal antibody DO7. Patient treatment consisted of radiotherapy alone, primary chemotherapy followed by radiotherapy, or surgery and postoperative radiotherapy. Relapse-free and overall survival from the beginning of treatment were estimated by use of the Kaplan-Meier method; survival comparisons were made by use of the logrank statistic. Univariate and multivariate analyses were conducted to identify factors associated with survival. Reported P values are two-sided. RESULTS: Fifteen (18.8%) of the 80 patients had p53-Abs. Tumor cell nuclei in 43 (58.9%) of 73 assessable biopsy specimens exhibited strong p53 immunostaining. Patient treatment method and the accumulation of p53 protein in tumor cell nuclei were not associated with increased risks of relapse or death. In univariate analyses, advanced tumor stage (> T1 [TNM classification]) and the presence of p53-Abs were significantly associated with an increased risk of death (P for trend = .007 and P = .002, respectively), whereas advanced tumor stage, substantial regional lymph node involvement (> N1), and the presence of p53-Abs were associated with an increased risk of relapse (P for trend = .002, P = .02, and P < .0001, respectively). In multivariate analyses, advanced tumor stage and the presence of p53-Abs were significantly associated with increased risks of relapse (p for trend = .04 and P = .003, respectively) and death (P for trend = .04 and P = .03, respectively). At 2 years of follow-up, the overall survival proportion was 63% (95% confidence interval [CI] = 47%-80%) when no p53-Abs were detected compared with 29% (95% CI = 4%-54%) when p53-Abs were detected. Relapse-free survival at 2 years was 62% (95% CI = 49%-76%) if no p53-Abs were detected compared with 13% (95% CI = 0%-31%) if p53-Abs were detected. CONCLUSIONS AND IMPLICATIONS: The proportion of patients with HNSCC who have serum p53-Abs is smaller than that of patients exhibiting tumor cell accumulation of p53 protein. The presence of p53-Abs is significantly associated with increased risks of relapse and death.     

A phase I study of adenovirus-mediated wild-type p53 gene transfer in patients with advanced non-small cell lung cancer

Mutations of the tumor suppressor gene p53 are the most common genetic alterations observed in human cancer. Loss of wild-type p53 function impairs cell cycle arrest as well as repair mechanisms involved in response to DNA damage. Further, apoptotic pathways as induced by radio- or chemotherapy are also abrogated. Gene transfer of wild-type p53 was shown to reverse these deficiencies and to induce apoptosis in vitro and in preclinical in vivo tumor models. A phase I dose escalation study of a single intratumoral injection of a replication-defective adenoviral expression vector encoding wild-type p53 was carried out in patients with incurable non-small cell lung cancer. All patients enrolled had p53 protein overexpression as a marker of mutant p53 status in pretreatment tumor biopsies. Treatment was performed either by bronchoscopic intratumoral injection or by CT-guided percutaneous intratumoral injection of the vector solution. Fifteen patients were enrolled in two centers, and were treated at four different dose levels ranging from 10(7) to 10(10) PFU (7.5 x 10(9) to 7.5 x 10(12) particles). No clinically significant toxicity was observed. Successful transfer of wild-type p53 was achieved only with higher vector doses. Vector-specific wild-type p53 RNA sequences could be demonstrated in posttreatment biopsies of six patients. Transient local disease control by a single intratumoral injection of the vector solution was observed in four of those six successfully transduced patients. There was no evidence of clinical responses at untreated tumor sites. Wild-type p53 gene therapy by intratumoral injection of a replication-defective adenoviral expression vector is safe, feasible, and biologically effective in patients with advanced non-small cell lung cancer.     

Increased serum p53 antibody levels indicate poor prognosis in patients with colorectal cancer

Serum p53 antibody levels were analysed using an enzyme-linked immunosorbent assay in serum samples obtained before surgery from 184 consecutive patients with primary colorectal cancer. Possible associations with tumour stage and tumour differentiation and the relation to patient survival time after a median follow-up of 6 years were studied. Analysis of serum p53 antibodies in the entire material demonstrated prognostic value in univariate analysis (P = 0.02); a finding that did not remain (P = 0.07) when the Dukes' stage was included in a multivariate analysis model. When the survival analysis was restricted to the potentially cured patients in Dukes' stages A-C, the serum p53 antibody levels retained independent prognostic value (P = 0.03). No clear association with tumour differentiation was found. We conclude that analysis of serum p53 antibodies may be of value for the identification of patients with different prognoses. This may be of relevance for selection of patients for adjuvant treatment.     

The utility of p53 immunostaining of transbronchial biopsy specimens of lung cancer: p53 overexpression predicts poor prognosis and chemoresistance in advanced non-small cell lung cancer

There are few reports on the p53 status of small cell lung cancer (SCLC) and advanced non-SCLC (NSCLC) because surgically resected specimens are generally not available. Therefore, we evaluated p53 immunostaining in 175 transbronchial biopsy (TBB) specimens obtained from patients with all stages of lung cancer and retrospectively evaluated the relationship between p53 status and clinical parameters. All of the specimens were obtained prior to therapy. Formalin-fixed, paraffin-embedded TBB specimens were immunostained using an anti-p53 antibody (DO-1). p53 protein was detected in 55% (61 of 111) of NSCLCs and 58% (37 of 64) of SCLCs. The rate of positivity increased significantly with increasing stage (stages I and II, 45%; stage III, 54%; stage IV, 66%), but not with other clinical parameters. Ninety-five patients were evaluated for their response to chemotherapy. Positive staining for p53 correlated significantly with unresponsiveness to chemotherapy in NSCLC (response rate of 13 versus 60%; P = 0.006), but not in SCLC (80 versus 57%; P = 0.22). p53 positivity was a statistically significant negative prognostic factor for stage III and stage IV NSCLC (P = 0.02), but not for stage I and stage II NSCLC (P = 0.79). There was no survival difference relative to p53 status in SCLC (P = 0.35). These results indicate that p53 overexpression in TBB specimens predicts poor prognosis and chemoresistance in advanced stage NSCLC.     

The prognostic significance of accumulation of p53 protein in stage III non-small cell lung cancer treated by radiotherapy

In the present study the prognostic significance of accumulation of nuclear p53 protein on survival and freedom from local progression was investigated. Formalin-fixed, paraffin-embedded sections obtained by bronchoscopy or mediastinoscopy were used to examine the expression of nuclear p53 protein using immunohistochemistry. In 37 cases (57%), overexpression of the p53 protein was detected. No relation was found between p53 expression and other pretreatment variables. Response to radiotherapy was found in 11 p53-negative cases (65%) versus 10 p53-positive cases (42%). Freedom from local progression was significantly better in the p53-negative cases as compared with the p53-positive cases. The p53-negative cases who responded to radiotherapy showed an excellent freedom from local progression rate after 2 years of 100%, whereas all p53-positive cases without response to radiotherapy showed local progression within 24 months. Overall survival between p53-negative and -positive cases did not differ, however the disease-specific survival was found to be worse in the p53-positive cases as compared to the negative cases (median survival 8.4 vs. 14.4 months (P < 0.05)). No correlation was found between p53 expression and the frequency of distant metastases. In conclusion, the results of this study suggest that p53 protein expression may be of prognostic value on freedom from local progression in non-small cell lung carcinoma.     

Clinical pharmacology of chronic oral etoposide in patients with small cell and non-small cell lung cancer

We aimed to evaluate the pharmacokinetics and pharmacodynamics of etoposide given chronically by the p.o. route to patients with small cell and non-small cell lung cancer. Single daily p.o. doses of 100 mg etoposide were given for 21 consecutive days every 4 weeks to 39 previously untreated patients with small cell lung cancer and 10 patients with non-small cell lung cancer. Bioavailability was studied after one i.v. and one p.o. dose of 100 mg etoposide given 48 h before and on day 1 of treatment, respectively. Etoposide plasma levels were measured using the HPLC method. Inter- and intrapatient variability of the area under the curve of the concentration versus time (AUC) during the first cycle were evaluated using a limited sampling model; the variability of etoposide plasma concentrations (Ecs) during the first cycle was assessed by weekly blood samples taken 24 h after dosing. The overall bioavailability of etoposide (mean +/- SD) was 67% +/- 22% and was not affected by fasting. A much higher inter- than intrapatient variability of both the AUC and 24-h Ec determined on days 8, 15, and 22 was found. Neutropenia was dose limiting and of varying degrees (mean +/- SD of absolute neutrophil count nadir at the first cycle: 1.5 +/- 1.2 x 10(3)/microliter). Neutropenia WHO grade >/=3 occurred in 38% of the patients after the first cycle. Pharmacodynamic analyses showed a significant relationship between the mean 24-h Ec and neutropenia, expressed as log- of absolute neutrophil count nadir or as a relative decrease of neutrophils. A correlation between a critical value of mean 24-h Ec (0.34 microgram/ml) and a high probability of achieving a greater than 80% decrease in absolute neutrophil count was found. Two pharmacodynamic models (one previously described and one developed in this study) were used to evaluate the possibility of predicting neutropenia on the basis of individual etoposide pharmacokinetics and baseline absolute neutrophil count. Pharmacokinetic studies have shown a high interpatient variability and a relatively low intrapatient variability of AUC and 24-h Ec. The application of the pharmacodynamic models and mean 24-h Ec cutoff values has proven statistically valid to predict the occurrence of severe neutropenia. However, it remains to be demonstrated in a prospective manner whether the application of pharmacokinetic/ pharmacodynamic knowledge can improve the overall therapeutic outcome of chronic p.o. treatment with etoposide.     

Efficacy and safety of prophylactic cranial irradiation in patients with small cell lung cancer

In this review we examine the complex interactions between lipoprotein metabolism, immunosuppressive drug therapy, and inflammation and the potential benefits of lipid-lowering drug therapy after heart transplantation. The newer formulations of cyclosporine, Neoral (Novartis Pharmaceuticals; Basle, Switzerland), and other newer agents such as tacrolimus may have advantages in regard to lipid metabolism as compared with traditional triple-drug immunosuppression. Lipoprotein levels may influence both the toxicity and efficacy of cyclosporine. Dyslipidemia may adversely influence inflammation and rejection in the allograft. Two recent clinical trials have shown that lipid-lowering therapy with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor alone or in combination with low-density lipoprotein apheresis may confer significant benefits toward preventing transplant coronary artery disease.     

Clinical evaluation of autoantibodies to p53 protein in patients with chronic liver disease and hepatocellular carcinoma

In hepatocellular carcinoma (HCC) of patients from the Western hemisphere, mutations in the p53 tumour suppressor gene are present in up to 37% of cases. Conformational change and cellular accumulation can initiate an immune response with generation of circulating autoantibodies to p53 protein. In the present study, we investigated 711 consecutive patients with chronic liver disease to evaluate the sensitivity and specificity of autoantibodies to p53 protein as a serological marker for HCC. Detection of p53 autoantibodies was performed using an enzyme-linked immunosorbent assay with immobilised recombinant p53 protein. Liver cirrhosis was present in 259 patients (36.4%) and a HCC was diagnosed in 75 patients (10.6%). Autoantibodies to p53 protein were detectable in 15 of 377 patients with chronic liver disease (4.0%) and in 10 of 259 patients presenting with liver cirrhosis (3.9%). All 25 p53 autoantibody-positive/HCC-negative patients were carefully investigated and no underlying malignancy was clinically detected, suggesting that elevated p53 antibody levels may not exclusively be detectable in patients with malignant disease. In patients with clinically manifest HCC, p53 autoantibodies were detected in 17 of 75 cases, thus resulting in a sensitivity of 22.7% and a specificity of 96.1%. In contrast, assessment of serum alpha-fetoprotein (AFP) resulted in a sensitivity and specificity of 69.3 and 91.8% (AFP > 20 ng/ml) and 53.3 and 99.1% (AFP > 100 ng/ml) for the detection of HCC, respectively. The data of the present study reveal that the presence of p53 autoantibodies in patients with chronic liver disease is not completely specific for HCC. Moreover, we obtained no direct evidence that p53 autoantibody formation precedes the clinical diagnosis of HCC. However, serological screening for HCC might be improved by combining AFP and p53 autoantibody assays.     

Neuropathies in small cell lung cancer

A routine neurological examination, electromyography studies and conductance in sensory and motoric fibres of upper and lower extremity peripheral nerves, was carried out in 65 subjects with small cell lung cancer prior instituting chemotherapy. None of the patients demonstrated metabolic changes nor toxic injury to the neurological system. The results of the neurological examination led to suspicion of neuropathy in 22 (34%) which was later confirmed by the electromyographic studies. In 12 subjects only EMG abnormalities were found allowing to diagnose a subclinical phase of neuropathy. Altogether 52% of the subjects demonstrated injury of the peripheral nervous system. Sensory neuropathy was observed in 6 patients, motor-sensory in 7, motoric neuropathy in 12. In one of the subjects from the latter group a myasthenic syndrome of the Eaton-Lambert type was found. In 7 patients the EMG results suggested injury of the anterior horn cells, in two further patients the clinical and EMG data suggested injury of the peripheral and spinal column.     

K-ras and p53 mutations are an independent unfavourable prognostic indicator in patients with non-small-cell lung cancer

We examined 159 consecutive cases of non-small-cell lung cancer (NSCLC) for a mutation at codon 12 of the K-ras gene and for a mutation of the p53 gene occurring in exons 5-8. Eleven (6.9%) had mutations of the K-ras (ras+) and 57 (35.8%) had mutations of the p53 (p53+). There were 95 cases (59.7%) with ras- p53-, seven cases (4.4%) with ras+/p53-, 53 cases (33.3%) with ras-/p53+ and four cases (2.5%) with ras+/p53+. The ras+ group had a worse prognosis than the ras group in all cases and in 107 early-stage cases (stage I-II, P<0.05). The p53+ group had a worse prognosis in 107 early-stage cases (P<0.01), but there was no statistically significant difference when 52 advanced-stage cases (stage III-IV) or all patients were considered. Both ras and p53 mutations were unfavourable prognostic factors in 94 cases with adenocarcinoma, but there was no statistical significance in 57 cases with squamous cell carcinoma. According to Cox's model, the pathological stage, ras mutation and p53 mutation were found to be independent prognostic factors. Our results suggest that ras and p53 mutations were independent unfavourable prognostic markers especially in the early stage of NSCLC or in adenocarcinoma.     

Genetic analysis of second primary lung cancers in patients surviving small cell lung cancer

We performed genetic analysis on 12 second primary non-small cell lung cancers in patients surviving small cell lung cancer to assess the potential contribution of smoking to the development of these tumors. Mutations of TP53 were found in three (25%) tumors, KRAS2 in three (25%) tumors, and CDKN2 in two (18%) tumors. Four (50%) mutations (one each in TP53 and CDKN2 and two in KRAS2) were G:C to T:A transversions on the coding strand, a mutation accounting for approximately one-third of mutations in smoking-related tumors but uncommonly found in lung cancers not associated with smoking. The genetic changes in these second lung cancers are more representative of smoking-associated malignancies than lung cancers arising in patients occupationally exposed to irradiation and atomic bomb survivors.     

Incidence of beta HCG elevation in serum of patients with small cell lung neoplasms and their prognosis

HCG-like immunoreactivity has been found in many nontrophoblastic tumors, but the biological behaviour of HCG--producing cells has not been clarified yet. The aim of the study was to estimate the frequency of serum bHCG (sbHCG) elevation in SCLC patients and to assess its possible prognostic role in this type of tumor. 156 SCLC patients entered the study: 93 men, 63 women, median age 58 years. SbHCG activity was measured with immunoenzymassay (Abbott EIA bHCG 15-15) before treatment. ScHCG elevation (5 mIU/ml) was found in 21 of 156 patients (14%). Response to treatment after chemotherapy (CR + PR) was obtained in only 48% of those patients in whom elevated sbHCG was found, in comparison to 73% of response rate observed in the remaining patients. Only 5% of patients with elevated sbHCG survived 2 years, in comparison to 21% of 2-years survivors in the remaining patients. Thus sbHCG elevation in SCLC seems to be a marker of more resistant tumors and of poor prognosis.