Preferred Role in Health Care Decision Making Over Time in Patients With Heart Failure: My Decision or My Doctor's Decision?

BACKGROUND: Understanding patients' preferred role in decision making can improve patient-centered care. This study aimed to determine change and the predictors of change in preferred decision-making roles over time in patients with heart failure. METHODS AND RESULTS: During the CASA (Collaborative Care to Alleviate Symptoms and Adjust to Illness) trial, patients' preferred roles in decision making were measured using the Control Preferences Scale (range 1-5; higher = less active; n = 312) at 4 timepoints over 1 year. The effect of the CASA intervention on preferred decision-making roles was tested using generalized linear mixed models. Whether preferences changed over time in the whole population was determined using linear regression. Demographic and health-related factors were examined as predictors of change using multiple linear regression. At baseline, most participants preferred active (score 1-2, 37.2%) or collaborative (score 3, 44.9%) roles. The CASA intervention did not influence preferred decision-making roles (P > 0.1). Preferences significantly changed over 1 year (P < 0.01), becoming more active (82.1%, 84.2%, 89.0%, 90.1% active/collaborative at each timepoint). Among all models and covariates, there were no significant predictors of change (P > 0.1). CONCLUSIONS: Patients' preferred roles in decision making change over time, but changes are not well predicted. Clinicians should frequently and directly communicate with patients about their preferred decision-making roles.

Reliability, Validity, and Responsiveness of the DEG, a Three-Item Dyspnea Measure.

BACKGROUND: Dyspnea is a common and debilitating symptom that affects many different patient populations. Dyspnea measures should assess multiple domains. OBJECTIVE: To evaluate the reliability, validity, and responsiveness of an ultra-brief, multi-dimensional dyspnea measure. DESIGN: We adapted the DEG from the PEG, a valid 3-item pain measure, to assess average dyspnea intensity (D), interference with enjoyment of life (E), and dyspnea burden with general activity (G). PARTICIPANTS: We used data from a multi-site randomized clinical trial among outpatients with heart failure. MAIN MEASURES: We evaluated reliability (Cronbach's alpha), concurrent validity with the Memorial-Symptom-Assessment-Scale (MSAS) shortness-of-breath distress-orbothersome item and 7-item Generalized-Anxiety-Disorder (GAD-7) scale, knowngroups validity with New-York-Heart-Association-Functional-Classification (NYHA) 1-2 or 3-4 and presence or absence of comorbid chronic obstructive pulmonary disease (COPD), responsiveness with the MSAS item as an anchor, and calculated a minimal clinically important difference (MCID) using distribution methods. KEY RESULTS: Among 312 participants, the DEG was reliable (Cronbach's alpha 0.92). The mean (standard deviation) DEG score was 5.26 (2.36) (range 0-10) points. DEG scores correlated strongly with the MSAS shortness of breath distress-or-bothersome item (r=0.66) and moderately with GAD-7 categories (ρ=0.36). DEG scores were statistically significantly lower among patients with NYHA 1-2 compared to 3-4 [mean difference (standard error): 1.22 (0.27) points, p<0.01], and those without compared to with comorbid COPD [0.87 (0.27) points, p<0.01]. The DEG was highly sensitive to change, with MCID of 0.59-1.34 points, or 11-25% change. CONCLUSIONS: The novel, ultra-brief DEG measure is reliable, valid, and highly responsive. Future studies should evaluate the DEG's sensitivity to interventions, use anchor-based methods to triangulate MCID estimates, and determine its prognostic usefulness among patients with chronic cardiopulmonary and other diseases.

How Does Spiritual Well-Being Change Over Time Among US Patients with Heart Failure and What Predicts Change?

Few studies have examined how spiritual well-being changes over time in patients with heart failure. We conducted a secondary analysis of data from the Collaborative Care to Alleviate Symptoms and Adjust to Illness (CASA) trial (N = 314). Spiritual well-being was measured using the Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale (FACIT-Sp) at baseline and 12-month follow-up. Of the 165 patients with spiritual well-being data at follow-up, 65 (39%) experienced probable clinically meaningful changes (> 0.5 SD) in spiritual well-being (35 improved, 30 declined). Increased pain (p = 0.04), decreased dyspnea (p < 0.01), and increased life completion (p = 0.02) were associated with improvement in overall spiritual well-being. Exploratory analyses found different predictors for FACIT-Sp subscales.

Machine learning with multiple modalities of brain magnetic resonance imaging data to identify the presence of bipolar disorder.

BACKGROUND: Bipolar disorder (BD) is a chronic psychiatric mood disorder that is solely diagnosed based on clinical symptoms. These symptoms often overlap with other psychiatric disorders. Efforts to use machine learning (ML) to create predictive models for BD based on data from brain imaging are expanding but have often been limited using only a single modality and the exclusion of the cerebellum, which may be relevant in BD. METHODS: In this study, we sought to improve ML classification of BD by combining information from structural, functional, and diffusion-weighted imaging. Participants (108 BD I, 78 control) with BD type I and matched controls were recruited into an imaging study. This dataset was randomly divided into training and testing sets. For each of the three modalities, a separate ML model was selected, trained, and then used to generate a prediction of the class of each test subject. Majority voting was used to combine results from the three models to make a final prediction of whether a subject had BD. An independent replication sample was used to evaluate the ability of the ML classification to generalize to data collected at other sites. RESULTS: Combining the three machine learning models through majority voting resulted in an accuracy of 89.5 % for classification of the test subjects as being in the BD or control group. Bootstrapping resulted in a 95 % confidence interval of 78.9 %-97.4 % for test accuracy. Performance was reduced when only using 2 of the 3 modalities. Analysis of feature importance revealed that the cerebellum and nodes of the emotional control network were among the most important regions for classification. The machine learning model performed at chance on the independent replication sample. CONCLUSION: BD I could be identified with high accuracy in our relatively small sample by combining structural, functional, and diffusion-weighted imaging data within a single site but not generalize well to an independent replication sample. Future studies using harmonized imaging protocols may facilitate generalization of ML models.

Serum p53 antibodies as early markers of lung cancer.

The p53 alteration is the most common alteration found in human cancer. It usually involves missense mutations that stabilize the p53 protein, which in turn accumulates, reaching levels detectable by immunohistochemistry. We and others have demonstrated that this overexpression of mutant p53 protein can induce a specific humoral response in cancer patients. This result was assessed by the presence of p53 antibodies in sera of patients with various types of cancers, whereas normal populations do not exhibit such antibodies. In lung cancer, the prevalence of p53 antibodies is high (30%) and is correlated with a very high rate of p53 mutations in this cancer (60-70%). We show that these antibodies are always present at the time of diagnosis, but never appear during tumour development, an observation strengthened by the fact that these antibodies are mostly IgG, corresponding to a secondary immune response. These results suggest that the humoral response is an early event and that p53 antibodies can be used as a precocious marker of p53 alteration before clinical manifestation of the disease.

Two Factor Structures Possible for the FACIT-Sp in Patients With Heart Failure.

CONTEXT: The Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale (FACIT-Sp) is a 12-item measure of spiritual well-being in chronic illness originally developed in patients with cancer. The overall scale, a two-factor model (meaning/peace, faith), and a three-factor model (meaning, peace, faith) have been proposed for the FACIT-Sp, and consensus on the best factor structure has not been reached. In addition, the factor structure of the FACIT-Sp has not been considered in patients with heart failure. OBJECTIVES: To examine the factor structure of the FACIT-Sp in heart failure patients. METHODS: A confirmatory factor analysis framework was used to test three competing models on 217 patients with heart failure using data from the CASA (Collaborative Care to Alleviate Symptoms and Adjust to Illness) trial. The overall scale (single factor), two-factor, and three-factor models were tested using baseline data, then confirmed with 12-month data. Model modifications were made based on empirical inspection of baseline data and replicated using 12-month data. Cronbach's alpha and correlations with measures of quality of life and psychological health were examined. RESULTS: All three models had strong factor loadings on all items except the negatively worded items. The two-factor and three-factor models fit reasonably well after modifications, but the single factor did not fit well (1/2/3-factor: RMSEA 0.14/0.09/0.06, CFI 0.85/0.93/0.97, SRMR 0.09/0.05/0.04). Internal consistency was sufficient for all factors. CONCLUSION: The two-factor and three-factor models were supported in heart failure patients. The three-factor model demonstrated better statistical fit but was not more interpretable. KEY MESSAGE: This study investigated the factor structure of the FACIT-Sp in patients with heart failure. The two-factor and three-factor models were supported, but the single factor model was not. Negatively worded items did not perform well.

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.

Analysis of p53 antibodies in patients with various cancers define B-cell epitopes of human p53: distribution on primary structure and exposure on protein surface.

p53 antibodies have been found in sera of patients with breast and lung carcinomas and in children with B-lymphomas. We report here the presence of p53 antibodies in sera of patients with 11 different types of cancer. The frequency of seropositives for p53 varied among the different types of cancer, but a correlation with the frequency of p53 gene alteration was established. Using a powerful peptide enzyme-linked immunosorbent assay, we demonstrated that the immune response of patients with p53 antibodies was restricted to a small subset of peptides localized in the amino and carboxy termini of p53, whatever the type of cancer. Given the similarities of the patterns of immune responses in patients with p53 antibodies and animals hyperimmunized with human p53, we propose that the p53 humoral response is the result of a self-immunization process which is itself the consequence of p53 protein accumulation in tumor cells.

Detection of serum anti p53 antibodies and their correlation with p53 mutations in myelodysplastic syndromes and acute myeloid leukemia.

In solid tumors, p53 antibodies are found in 30% of the patients with p53 mutations, and their analysis is an interesting method for the detection of p53 mutations. We looked for circulating p53 antibodies in 83 patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML), by an ELISA technique. Detection of p53 mutations was made by single stranded conformation polymorphism (SSCP) analysis of exons 4 to 10 of the P53 gene and confirmed by direct sequencing. Circulating antibodies to p53 were seen in three of the 83 (3.5%) patients analyzed, and a p53 point mutation was found in ten cases. Two of the three patients with p53 antibodies had a p53 mutation, but the remaining case had no detectable mutation. The other eight mutated cases had no detectable p53 antibodies. Our findings show that serological analysis of p53 antibodies is rarely positive in MDS and AML. This could be due to the relatively low incidence of p53 mutations seen in those disorders, but also to the immune depression to which they are often associated.

p53 antibodies in patients with various types of cancer: assay, identification, and characterization.

Alteration of the p53 gene is the most frequent genetic alteration in human cancer and leads to the accumulation of mutant p53 in the nucleus of tumor cells. In addition, it has been shown that patients with various types of neoplasia have p53 antibodies in their sera which could be used as an indirect diagnostic procedure for p53 alteration. Using a new ELISA, we have analyzed the sera from more than 1000 patients with various types of cancer and from healthy blood donors. We demonstrate that p53 antibodies are detected mainly in cancer patients and are strictly proportional to the occurrence of p53 mutations. Using various immunological approaches, these antibodies were unambiguously demonstrated to be directed toward the human p53 protein. Isotyping analysis of these antibodies strongly suggested that they correspond to a humoral response to the p53 protein which accumulates in the tumor cell. This finding suggests that serological analysis, combined with histochemistry, is suitable for assessing the integrity of the p53 gene in cancer patients.

Monitoring of p53 autoantibodies in lung cancer during therapy: relationship to response to treatment.

Alteration of the p53 gene is the most frequent genetic alteration in human cancer, and it leads to the accumulation of mutant p53 in the nucleus of tumor cells. In addition, it has been shown that patients with various types of neoplasias have p53 antibodies in their sera. ELISA was used to detect anti-p53 antibodies in their sera of 167 patients with lung cancer. Among these, 32 individuals (16 positive for p53 antibodies and 16 negative) were monitored over a period of 30 months for p53 antibodies. Twelve of 16 antibody positive patients had reduced titers during chemotherapy that led to partial or complete remissions of disease. The specificity of these antibodies was confirmed by two different ELISA procedures and by immunoprecipitation. The very rapid, specific decrease in these antibodies during therapy suggests that a constant level of tumoral cells with nuclear accumulating p53 protein is necessary for a detectable humoral anti-p53 response. The good correlation found between the specific evolution of the p53 antibody titer and the response to therapy suggests that p53 antibodies could represent a useful tool for checking the response to therapy and for monitoring some relapses before they are clinically detectable.

The EEG response to diffuse and patterned photic stimulation during acute untreated alcohol withdrawal.

We studied the responses to diffuse and patterned stroboscopic light stimulation prospectively in 49 individuals during acute alcohol withdrawal prior to pharmacologic treatment. Photomyogenic responses (PMR) occurred in only two (4%) of those tested, and photoparoxysmal responses (PPR) never occurred. These findings suggest that PMR occur far less often during alcohol withdrawal than previously thought and that PPR may not be a direct manifestation of alcohol withdrawal.

In vitro parameters and treatment outcome in head and neck cancers treated with surgery and/or radiation: cell characterization and correlations with local control and overall survival.

PURPOSE: To determine whether in vivo parameters (surviving fraction at 2 Gy, alpha values, and calculated cell growth fraction) were predictive of the treatment outcome. METHODS AND MATERIALS: Biopsies were obtained from patients with a head and neck tumor. In vitro parameters were determined using the CAM plate assay. Cell characterization by cytogenetic analysis was performed on 19 different cell cultures. In 25 additional cell cultures, cell clonogenicity was tested using the Courtenay Mills assay. RESULTS: Biopsies were obtained from 156 patients with a head and neck tumor and the oropharynx was the predominant primary site. In vitro parameters were obtained in 113 cases (72%) (SF2 in 93 cases and calculated cell growth fraction in 103 cases). Cell characterization showed that cells in CAM plates were diploid with no clonal chromosome abnormalities and gave colonies in soft agar with a mean cloning efficiency of 1.610(-3). Only patients treated with surgery and/or radiation (76), were considered eligible for in vitro parameters and treatment outcome correlation studies. The mean follow-up is over 2 years (range 9-47 months). The local control rate was significantly higher (p = 0.04) for patients with alpha values above the cut-off point of 0.07 Gy-1 (69% vs. 38% at 2 years). The local control rate was also significantly higher (p = 0.04) for patients with calculated cell growth fraction values about the cut-off point of 0.06% (70% vs. 48% at 2 years). Moreover for these latter patients the overall survival rate was also significantly higher (p = 0.004) (54% vs. 26% at 2 years). It is worth noting that alpha and calculated cell growth fraction values below the cut-off points identified a small group of patients (about 20%) who were at a significantly high risk of local failure. From a pragmatic point of view, as only radiosensitivity or calculated cell growth fraction values could be obtained in a certain number of experiments due to technical reasons, the treatment outcome of patients who had either alpha and/or calculated cell growth fraction values below the cut-off levels (about 30% of all patients) was analyzed. This group of patients fared significantly worse (p = 0.02) in terms of local control (50% vs. 68% at 2 years) and (p = 0.04) overall survival (36% vs. 50% at 2 years). CONCLUSION: These results suggest that in vitro parameters using the CAM plate assay, might be useful in predicting the treatment outcome of patients with a head and neck tumor treated with surgery and postoperative radiation, or radiation alone. However, they must be considered as preliminary because the cut offs used in the study were chosen for exploratory purposes. Only a multivariate analysis including all clinical and biologic factors will allow us to draw any firm conclusions.

Predictive value of in vitro radiosensitivity parameters in head and neck cancers and cervical carcinomas: preliminary correlations with local control and overall survival.

PURPOSE: To determine whether in vitro radiosensitivity parameters are predictive of treatment outcome. METHODS AND MATERIALS: Biopsies were obtained from patients with head and neck cancers (57) and cervical carcinomas (20) and in vitro radiosensitivity parameters were obtained using the CAM plate assay. RESULTS: In most cases (75%) patients were treated with radiation alone. The median follow up was 461 days. When the whole group of head and neck cancers and cervical carcinomas was considered, patients with a SF2 value below 0.36 had a higher 2-year local control rate (93% versus 68%) and a higher 2-year survival rate (71% vs. 62%) than those with SF2 values above that threshold, but differences were not significant. These trends persisted when head and neck cancers were considered alone with a higher local control rate (86% vs. 67%) and a higher survival rate (75% vs. 52.5%) obtained for patients with a SF2 value below 0.36. When the alpha value was evaluated for the whole group of patients a significantly higher local control rate (80.5% vs. 40.5%) and overall survival rate (71% versus 37.5%) at 2 years were obtained for patients with alpha values above 0.07 Gy-1. When only the group of head and neck cancers was considered, local control rate was significantly higher (79% vs. 33%) but overall survival rate (65.5% vs. 33%) was not significantly higher for alpha values above 0.07 Gy-1. CONCLUSION: These results are encouraging but need to be confirmed with a larger number of patients with a longer follow-up.

Validation of dietary assessment methods in the UK arm of EPIC using weighed records, and 24-hour urinary nitrogen and potassium and serum vitamin C and carotenoids as biomarkers.

BACKGROUND: In the UK EPIC validation studies, the accuracy of several methods was assessed by comparison with to-day weighed records and the biomarkers, 24-hour urine nitrogen (N) and potassium (K), plasma carotenoids and plasma vitamin C. METHODS: Comparisons between methods were made on 156 women, studied over 1 year at 3-monthly intervals at home. On each of four occasions, volunteers completed 4 days of weighed records and provided two 24-hour urine collections and a fasting blood sample. RESULTS: In comparison with the 16 days of weighed records, a food frequency questionnaire (FFQ) yielded higher values mainly due to greater reported consumption of milk and of vegetables. A 24-hour recall was as good as the FFQ in placing individuals in the distribution of habitual diet from weighed records. Results obtained from a 7-day estimated record were closest to those obtained from the weighed record. Correlations between 24-hour urine excretion and dietary N intake from weighed records were high (0.78-0.87) as were those with estimated food diaries (0.60-0.70). Correlations between urine N and the FFQ and 24-hour recall were lower (0.10 to 0.27), but improved by energy adjustment using residuals for N and K which are correlated with total energy intake. Comparisons between dietary estimates and urinary K and serum carotenoids and vitamin C showed broadly similar results. Limited biomarker information amongst 200 UK EPIC participants supported the findings of the validation study. CONCLUSIONS: UK EPIC uses three methods (the 7-day diary, an improved FFQ, and the 24-hour recall) to assess diet. 93% of first food diaries are returned completed by participants. Repeated diaries are the main dietary assessment method for nested case-control analyses.

Analysis of p53 antibody response in patients with squamous cell carcinoma of the head and neck.

p53 alterations are the most common alteration found in human cancer. Protein p53 was studied in 102 patients with early lesions or advanced squamous cell carcinoma of the head and neck (SCCHN). Biopsies and sera samples were collected before the initiation of treatment. Protein p53 expression was evaluated by immunohistochemistry using Pab 1801, Pab 240, DO7 and CM1 antibodies on paraffin-embedded sections. Antibodies specific for p53 protein were analysed in the sera of these patients by an ELISA procedure. We demonstrated that p53 protein overexpression (> or = 20% positive cells) was an early event in the carcinogenesis of SSCHN and correlated to the progression of carcinogenesis. Overexpression of protein p53 was frequent (56.5%) in advanced tumors. No correlation was found with clinical stage or the differentiation status of the tumor, but we demonstrated differences in protein p53 expression according to the initial localisation of the tumor, with high expression in hypopharynx (67%) and oropharynx (65%) versus larynx (12%). The prevalence of p53 antibodies was high (44%) and was correlated with the rate of p53 overexpression (> or = 30% positive cells) in tumors (p < 0.0001 chi square test). These results suggest that the humoral response is an indicator of the presence of squamous cell carcinoma with immunogenic mutant p53 protein. Therefore the detection of anti-p53 antibodies could be used as a precocuous marker of p53 alteration and a prognostic marker, in order to screen for patients with a better prognosis.

Variations in characteristics and service needs of persons with autism.

Information concerning socio-demographics, disability characteristics, and services received and needed became available on approximately 900 autistic children and adults as a result of a statewide needs assessment and case-finding collection project conducted in New York. Analyses of the results confirmed other findings as to the predominance of males to females and a high concomitant occurrence of mental retardation. Results also showed a population having few problems with mobility, hearing or vision, but moderate deficits in most skills related to activities of daily living, and significant deficits in communication and basic independent functioning skills. Differences were observed between institutionalized and noninstitutionalized autistic persons in terms of level of retardation, functional skills, age, and use of medications. Implications of the findings are drawn for clinicians, administrators, and public policy makers.

Clinicopathological findings associated with agenesis of the corpus callosum.

Seven hundred five cases of agenesis of the corpus callosum (ACC) are reviewed from the literature (n = 660) and from our own observations (n = 45). The diagnosis was made or confirmed using neuroradiological techniques (n = 519) and necropsy or surgery (n = 231). Association with abnormalities often of chromosomes 8, 11, 13-15 and 18 suggests their involvement in abnormal corpus callosum (CC) morphogenesis. Four syndromes (e.g. Aicardi, acrocallosal, Andermann and Shapiro) are characterized by ACC, while others are only sporadically associated (e.g. fetal alcohol syndrome, Dandy-Walker syndrome, Leigh disease, Arnold-Chiari II syndrome). In non-Aicardi patients, the male-to-female ratio was 3:2 and X-linked recessive inheritance is postulated to play a role in some cases. Common abnormalities in acallosal patients included: mental retardation (MR), 73% [corrected]; seizures, 42%; ocular anomalies, 42%; gyral abnormalities, 32%; hydrocephalus, 23%; other central nervous system (CNS) lesions, 29%; costovertebral defects, 24%. Developmental disabilities are not attributable to absence of the CC per se, but due to other CNS malformation or dysfunction, which may be genetic or non-genetic. Future research using recombinant DNA techniques will enable isolation and identification of specific chromosomal defects in those cases with a genetic abnormality.

[The p53 gene and protein in bronchial carcinogenesis:from biological to clinical aspects]. / Le gène et la protéine p53 dans la carcinogenèse bronchique: de la biologie à la clinique.

The p53 gene codes for a nuclear phosphoprotein which is capable of modulating the expression of certain genes implicated in the regulation of cell division. The mutation of an allele on the p53 gene with loss of the healthy allele, in different tissues such as lung, larynx, bladder, liver, skin, colon and breast, which may or may not be exposed to chemical or physical carcinogens (tobacco, radon, ultraviolet, aflatoxin B1), is associated with the occurrence of cancer. Indeed, the mutated p53 protein loses its anti-proliferative properties favouring a de-regulation of cellular multiplication with the accumulation of genetic aberrations. The homozygous deletion of the p53 gene in germ cells in the members of certain family cancers (Li-Fraumeni syndrome) leads to an increased incidence of cancers in the child or young adult. The most frequent mutations of the p53 gene end in a stabilisation of the mutated protein with immuno-histochemical nuclear marking of the cells carrying such an alteration. In certain patients this stabilisation of the mutated protein ends in auto-immunisation with anti-p53 serum antibodies. Bronchial cancer is a cancer of which the mutations of p53 are the most frequent (45-65% of bronchial cancer) as result of the mutagenic effect of tobacco smoke. These mutations seem to be associated with a bad prognosis and indeed to chemo-and radiotherapeutic resistance. The early diagnosis of p53 alterations (in dysplastic lesions or tumours which are only slightly developed) would enable new therapeutic interventions in bronchial cancer such as gene therapy or radio-immunotherapy to either restore the p53 gene to normality or to eliminate the cells expressing the mutated p53 protein respectively.