p53 GENE ALTERATIONS AND p53 PROTEIN IN ORAL EPITHELIAL DYSPLASIA AND SQUAMOUS CELL CARCINOMA

To examine the expression of p53 protein and gene alterations in oral epithelial lesions including epithelial dysplasias and primary squamous cell carcinomas, immunohistochemical and temperature gradient gel electrophoresis (TGGE) methods were applied to formalin-fixed and paraffin-embedded tissues. Morphologically normal mucosal epithelium stained negatively for p53 protein. Three out of 11 (27·3 per cent) epithelial dysplasias and 19 out of 57 (33·3 per cent) primary squamous cell carcinomas stained positively for p53 protein. Although more than half of the cases were positive for p53 protein in stage I, the positive cancer cases were found at other stages with variable frequency. Immunoreactive products were localized in the nucleus, especially in the basal and suprabasal layers. The analysis by TGGE revealed gene alterations in exons 5–8 in 3 out of 3 epithelial dysplasias and 17 out of 19 (89·5 per cent) primary squamous cell carcinomas which were immunohistochemically positive for p53 protein. These results suggest that p53 gene mutation may be involved in carcinogenesis in the oral squamous epithelium even in the early stage of the dysplasia–carcinoma sequence.     

p21WAF1/Cip1 expression is associated with cell differentiation but not with p53 mutations in squamous cell carcinomas of the larynx

p21^WAF1/Cip1 is a recently identified gene involved in cell cycle regulation through cyclin-CDK-complex inhibition. The expression of this gene in several cell lines seems to be induced by wild-type, but not mutant, p53. p21^WAF1/Cip1 expression has been studied at both mRNA and protein levels in a series of 49 normal mucosae and squamous cell carcinomas of the larynx. A significant association was found between mRNA and protein expression in tumours (P<0·0001). p21^WAF1/Cip1 expression was strongly associated with squamous cell differentiation of carcinomas, because six of seven (86 per cent) undifferentiated carcinomas (grade 4) showed very low levels of p21^WAF1/Cip1 expression, whereas 41 out of 42 (98 per cent) carcinomas with squamous cell differentiation (grades 1–3) had normal or high levels of p21^WAF1/Cip1 expression (P<0·0001). In addition, p21^WAF1/Cip1 expression was topologically related to the squamous differentiation of tumour cells with a distribution similar to that seen in normal squamous epithelium. No correlation was found between p21^WAF1/Cip1 expression and the global S-phase of the carcinomas. p53 mutations (exons 5–9) were found in ten carcinomas with p21^WAF1/Cip1 expression, but no p53 mutations were detected in three p21^WAF1/Cip1-negative tumours. In conclusion, p21^WAF1/Cip1 expression is frequently upregulated in squamous cell carcinomas of the larynx and is associated with tumour cell differentiation. p21^WAF1/Cip1 expression in these tumours is independent of p53 gene mutations. © 1997 John Wiley & Sons, Ltd.     

p53 Immunoreactivity in inflammatory and neoplastic diseases of the uterine cervix

Immunoreactivity for the tumour suppressor gene product p53 is commonly found in many different human malignancies and few premalignant lesions. Data on cervical neoplasms, however, are still lacking. We retrospectively investigated p53 immunoreactivity in 92 lesions of the uterine cervix, including 44 cases of chronic cervicitis, 29 squamous intraepithelial lesions (SILs), and 19 invasive carcinomas. p53 immunoreactivity confined to the basal cell layer, was detected in 74 per cent of cases showing chronic cervicitis and in all cases with low-grade SILs. Conversely, suprabasal and/or diffuse p53 immunoreactivity was exclusively demonstrated in 25 per cent of high-grade SILs and in 74 per cent of invasive carcinomas. The results of this investigation document a high prevalence of p53-immunoreactive malignant tumours of the uterine cervix. In high-grade SILs, p53-immunoreactive cells paralleled the height of involvement by dysplastic changes within the squamous epithelium. A prolonged half-life of the protein is the most likely explanation for the occurrence of p53 immunoreactivity in neoplastic cells. The unexpected finding of p53-immunoreactive cells in inflammatory lesions, though possibly related to an increased proliferation rate of the basal cell compartment, requires further study and underlines the need for a careful approach to p53 immunocytochemistry.     

Immunohistochemical analysis of p53 protein overexpression in normal,premalignant, and malignant tissues of the cervix uteri

Two hundred and thirty-eight cervical lesions ranging from normal to malignant were examined for overexpression of p53 protein. Whereas p53 protein was identified in 62 per cent of invasive squamous cell carcinomas, 11 per cent of invasive adenocarcinomas, and 7 per cent of squamous cell carcinomas in situ, no staining was found in adenocarcinoma in situ, dysplastic tissue, condyloma, and normal tissue. In 9 per cent of the positive cases of invasive squamous cell carcinomas. 5-50 per cent of the tumour ceiis were immunoreactive for p53 protein, whereas the other positive specimens were characterized by only rare p53-positive cells. We conclude that in invasive cervical carcinomas widespread overexpression of p53 protein is unusual, but occasional positive nuclei can be found frequently. Furthermore, our results indicate that altered expression of p53 protein may be involved in the progression of cervical carcinomas.     

Concurrent p53 expression in bronchial dysplasias and squamous cell lung carcinomas.

We analyzed the p53 protein immunohistochemically in bronchial dysplasias or squamous cell carcinomas in situ and in squamous cell lung carcinomas occurring in the same patients. The polyclonal antibody used (CM-1) is directed against the wild-type p53 protein, but also recognizes the mutated p53 in formalin-fixed and paraffin-embedded sections. To study the integrity of basement membranes (BMs) and the possible invasion of the dysplastic epithelium, immunostainings for the BM proteins laminin and type IV collagen were used. Nine of the 17 dysplasias showed p53 protein expression (53%); it was significantly more often seen in severe dysplasias and carcinomas in situ than in mild or moderate dysplasias (P = 0.04). The p53 antigenicity was generally located in the basal part of the epithelium. The BMs beneath mildly dysplastic epithelia were continuous. In contrast, those under moderately or severely dysplastic epithelia showed occasional disruptions. p53 protein expression was also found in dysplastic epithelium above a continuous BM suggesting an ominous process before signs of invasion. Twelve of the 17 squamous cell carcinomas showed p53 protein expression (71%). There was a significant concurrent p53 expression in bronchial dysplasias and their related squamous cell carcinomas (P = 0.009), so that all nine cases of p53 positive bronchial dysplasia also showed p53 positivity in the associated squamous cell carcinomas. These findings indicate that p53 protein expression is possible in premalignant bronchial lesions, and suggests that the p53 expression could, at least in some cases, be an early event in the development of a squamous cell carcinoma of the lung.     

NUCLEAR p53 OVEREXPRESSION IS AN INDEPENDENT PROGNOSTIC PARAMETER IN NODE-NEGATIVE NON-SMALL CELL LUNG CARCINOMA

The prognosis of operated patients with non-small cell lung cancer (NSCLC) is poor despite thorough pre-operative staging. An improved preselection is needed of patients likely to profit from surgery. This study was undertaken to evaluate the prognostic significance of nuclear p53 overexpression in a cohort of 247 surgically treated patients with NSCLC. It showed that the prevalence of immunohistochemically detectable p53 overexpression varied between different tumour types. p53 overexpression was equally frequent in large cell carcinoma (53 per cent) and in squamous cell carcinoma (54 per cent), but significantly less frequent in adenocarcinoma (34 per cent; P =0·009). p53 overexpression was particularly rare in bronchioloalveolar carcinoma (positivity in 1 of 17 cases). These variations may reflect aetiological differences between the histological subtypes. p53 overexpression was also associated with high tumour grade ( P =0·0157) and the presence of lymph node metastasis ( P =0·0259), but not with advanced tumour stage. Survival analysis showed no difference in clinical outcome between p53-positive and p53-negative tumours within 101 node-positive tumours. In contrast, survival time was significantly better in p53-negative tumours than in p53-positive tumours within the group of 113 node-negative tumours ( P =0·032). Stepwise regression analysis showed that p53 overexpression is an independent prognostic factor in node-negative NSCLC.     

Expression of p53 protein has no independent prognostic value in breast cancer

A series of 392 female breast carcinomas was analysed immunohistochemically for expression of p53 protein with special emphasis on the role of p53 as an independent prognostic factor. Altogether, 54·8 per cent of the carcinomas expressed p53 protein, with the mean [standard error (SE)] fraction of positive nuclei being 17·1 per cent (1·2 per cent). Expression of p53 protein was independent of tumour metastasis at diagnosis, axillary lymph node status, tumour diameter, histological type, tubule formation, proportion of intraductal growth, margin formation, necrosis, DNA ploidy, and S-phase fraction. A high fraction of p53-positive nuclei was significantly related to patient age under 70 years, high grade, severe nuclear pleomorphism, dense infiltration of tumour by lymphocytes, high mitotic index, and high apoptotic index (for all, P<0·05). Impaired survival probability in the entire cohort (P=0·05) and in the axillary lymph node-positive (ANP) tumours (P=0·015) was associated with a fraction of p53-positive nuclei less than 25 per cent, while in the axillary lymph node-negative (ANN) tumours, expression of p53 had no prognostic value. In multivariate analysis, independent prognostic predictors included axillary lymph node status, tumour diameter, and mitotic index. In the ANN tumours, tumour diameter, fraction of p53-positive nuclei, and tumour grade were independent prognostic factors, whereas in the ANP tumours, diameter and mitotic index were the two independent prognostic factors. The results suggest that abnormal expression of p53 protein is only a weak independent prognostic factor in female breast cancer.     

PROGNOSTIC INFLUENCE OF p53 EXPRESSION IN GASTRIC CANCER

The presence of the nuclear phosphoprotein p53 was investigated in a series of 120 consecutive gastric carcinomas. This immunohistochemical study on formalin-fixed, paraffin-embedded material found p53 expression in 43 per cent ( n =51) of carcinomas using a monoclonal antibody (DO-1), whereas no immunoreactivity for p53 was present in tumour-associated non-neoplastic gastric mucosa or tumour stroma. There was no statistically significant correlation with known prognostic parameters such as extent of tumour growth (pT state), nodal involvement (pN state), or tumour grade. The same applied for association with patient age and sex or pathological parameters such as tumour size, localization, or growth pattern according to histological classification. Kaplan–Meier analysis revealed marginal statistically significant differences in survival times between patients with p53-positive tumours with more than 35 per cent of p53-positive tumour cells and those with less than 35 per cent of p53-positive tumour cells or p53-negative tumours ( P =0·04). However, by multivariate analysis, p53 immunoreactivity did not turn out as an independent prognostic parameter. p53 expression can easily be detected in a variety of human malignancies including gastric cancer by immunohistochemical methods, but its prognostic significance and possible role as an independent marker of poor prognosis still have to be confirmed by further studies.     

Expression of pS2 protein in transitional cell bladder tumours

A series of 201 bladder cancer biopsy specimens was analysed immunohistochemically for the expression of pS2 protein. Altogether, 61 per cent of the tumours were pS2-negative; in 16 per cent less than 1 per cent and in 23 per cent of cases more than 1 per cent of cells were pS2-positive. Normal transitional epithelium was negative for pS2. The fraction of positive cells was higher in poorly differentiated non-papillary tumours and in invasive tumours with pelvic lymph-node (P=0.05) and distant metastasis (P=0.10). pS2 expression was not related to sex, while patients aged 60–70 years had low fractions of pS2-positive cells (P=0.03). DNA ploidy, S-phase fraction, mitotic index, morphometric nuclear features, and expression of c-erbB-2, p53, and epidermal growth factor receptor were independent of expression of pS2. Tumours expressing pS2 in over 10 per cent of cells had a lower survival probability (P=0.0486). The results show that pS2 is expressed in 40 per cent of transitional cell bladder tumours, but that this marker has no clinical significance over established prognostic factors.     

Basaloid squamous carcinoma of the oesophagus: a distinct neoplasm with multipotential differentiation

AIMS: Basaloid squamous carcinoma (BSC) is an uncommon variant of squamous cell carcinoma, with its prevalent sites being the hypopharynx, tongue base and larynx. In the oesophagus, BSC is rarer than in the head and neck region. This study was aimed to document the clinicopathological features of BSCs of the oesophagus, and to present their relative incidence and immunohistochemical findings. METHODS AND RESULTS: Eighteen cases of BSC of the oesophagus, comprising 3.6% of 502 oesophageal carcinomas, were reviewed for their pathological and clinical features, and examined for the immunohistochemical expression of neuroendocrine markers, cytokeratins, p53, pRb and bcl-2. Oesophageal basaloid squamous carcinomas tended to be biphasic or multiphasic carcinomas, most commonly with basaloid and squamous components (eight cases), or with additional adenocarcinoma (three cases) or with small cell carcinoma (two cases). Each component was microscopically clearly distinguishable from the others, and metastasized separately, chiefly the basaloid component. The remaining five cases were apparently pure basaloid carcinomas, being characterized by lobules and nests of monotonous round undifferentiated cells with frequent comedo necrosis. They resembled, but were differentiated from, the small cell carcinoma on the basis of neuroendocrine markers and cytokeratin expression. p53, pRb and bcl-2 oncoprotein, which are known to normally present in the basal/parabasal cells of the oesophageal epithelium, were detected in 40-50% of cases, with a heterogeneous expression pattern. The patients were all male, with the age ranging 47-74 years (median 57) and presented at variable stages. The plotted 3 years survival rate was 51%, and the immunohistochemical expression of p53, pRb and bcl-2 was not related to the survival of the patients. CONCLUSION: Basaloid squamous carcinoma of the oesophagus is a peculiar neoplasm with a capacity of multidirectional differentiation, often with heterogeneous oncogene expression, probably reflecting the pluripotential stem cell origin.     

Expression of p53 protein in laryngeal squamous cell carcinoma and dysplasia: possible correlation with human papillomavirus infection and clinicopathological findings

In order to evaluate the expression of p53 protein in 28 premalignant and 40 malignant squamous cell proliferations of the larynx and its relationship to tobacco consumption, human papillomavirus infection and differentiation grade of the lesions, p53 expression was examined by means of a microwave post-fixation immunohistochemical method using the PAb 240 and PAb 1801 monoclonal antibodies. HPV infection was assessed by non-isotopic in situ hybridization (NISH) and polymerase chain reaction (PCR). A large proportion of carcinomas (77.5%) and dysplasias (61%) expressed p53. No difference was found between differentiation grades of the lesions regarding p53 detection (P>0.1), but moderate or intense p53 expression was more frequent in the carcinomas (P<0.05). A statistical correlation was found between cigarette consumption and both p53 detection and p53 staining intensity (P<0.05 in each case). HPV study revealed HPV 16 and 18 infection only in carcinomas. The frequency was 28% and the physical state of the virus as demonstrated by NISH was integration into the genome. We observed an inverse relationship between HPV infection and p53 expression (P=0.006). Our findings suggest that p53 overexpression is a common and early event which increases in frequency with progression of laryngeal squamous cell carcinoma. The expression of p53 is influenced by tobacco and high-risk types of HPV.     

Distinctive clinicopathological associations of amplification of the cortactin gene at 11q13 in head and neck squamous cell carcinomas

Amplification of the 11q13 region is a prevalent genetic alteration in head and neck squamous cell carcinoma (HNSCC). We investigated the clinical significance of cortactin (CTTN) and cyclin D1 (CCND1) amplification in both malignant transformation and tumour progression. CTTN and CCND1 amplification was analysed by differential and real-time PCR in a prospective series of laryngeal/pharyngeal carcinomas and archival premalignant tissues. CTTN mRNA and protein expression were respectively determined by real-time RT-PCR and immunohistochemistry, and correlated with gene status. Molecular alterations were associated with clinicopathological parameters and disease outcome. CTTN and CCND1 amplifications were respectively found in 75 (37%) and 90 (45%) tumours. Both correlated with advanced disease; however, only CTTN amplification was associated with recurrence and reduced disease-specific survival (p = 0.0022). Strikingly, CTTN amplification differentially influenced survival depending on tumour site (p = 0.0001 larynx versus p = 0.68 pharynx) and was an independent predictor of reduced survival in the larynx (p = 0.04). CCND1 amplification was detected in early tumourigenesis and increased with the severity of dysplasia. Importantly, CTTN amplification was only found in high-grade dysplasias that progressed to invasive carcinoma. CTTN gene status strongly correlated with mRNA and protein expression. Furthermore, CTTN overexpression correlated significantly with reduced disease-specific survival (p = 0.018). Taken together, these data indicate that CTTN may serve as a valuable biomarker to identify patients with laryngeal tumours at high risk of recurrence and poor outcome.     

p53 Protein,PCNA staining,and DNA content in follicular neoplasms of the thyroid gland

Forty-nine follicular adenomas and 11 follicular carcinomas of the thyroid were investigated by immuno-histochemistry for the expression of p53 protein and proliferating cell nuclear antigen (PCNA). The DNA ploidy and the S-phase fraction (SPF) of the neoplasms were analysed by flow cytometry. Twelve adenomas (24 per cent) and six carcinomas (55 per cent) were DNA non-diploid (P=0·07). The carcinomas had a higher proliferation rate than the adenomas when assessed either by SPF size (median 9·9 per cent vs. 2·9 per cent, P=0·0003) or by PCNA staining intensity (P<0·0001). Some scattered nuclei in two (4 per cent) adenomas and in three (27 per cent) carcinomas stained positively for p53 (P=0·04). The two adenomas with positive staining for p53 were subserially sectioned, but no signs of invasion were found; both patients are alive and well 6 and 7 years after surgery. One of the two adenomas showing positive p53 nuclear staining was DNA aneuploid, and both were positive in PCNA staining, but their SPFs were low (2·1 and 3·3 per cent). We conclude that p53 protein expression is not confined to follicular carcinomas; scattered p53-positive cells may also be present in histologically and clinically benign follicular adenomas. Because both follicular adenomas and carcinomas may be DNA aneuploid and their SPF and PCNA staining distributions overlap, the distinction between follicular adenoma and carcinoma should still be based on histological criteria.     

p53 OVEREXPRESSION AND HUMAN PAPILLOMAVIRUS INFECTION IN TRANSITIONAL CELL CARCINOMA OF THE URINARY BLADDER: CORRELATION WITH HISTOLOGICAL PARAMETERS

Seventy-nine transitional cell carcinomas (TCCs) of the urinary bladder (25 grade 1, 22 grade 2, and 32 grade 3 tumours) were examined for p53 overexpression by immunohistochemistry with a monoclonal antibody and for human papillomavirus (HPV) infection by the polymerase chain reaction (PCR). Positive immunostaining for p53 was detected in 40·5 per cent of the cases; the percentage of positive cases was significantly lower in low-grade (G1 and G2) TCCs than in high-grade (G3) tumours (10·6 per cent vs. 84·4 per cent; P <0·0001). The overall rate of HPV infection was 32·9 per cent; 20·3 per cent of the cases were positive for HPV 16, 3·8 per cent for HPV 18, and 8·9 per cent for both. Consensus primers as well as type-specific primers for HPV types 6, 11, and 33 failed to detect any additional case with HPV infection. The prevalence of HPV 16 and/or HPV 18 infection was significantly higher in low-grade than in high-grade tumours (44·7 per cent vs. 15·6 per cent; P =0·0061). p53-positive cases were more common among papillary, deeply infiltrating tumours, and HPV-positive cases among papillary, non-infiltrating lesions. According to these data, p53 overexpression and HPV 16/18 infection are common findings in bladder TCC and there appears to be an inverse correlation of p53 overexpression and of HPV infection with tumour aggressiveness. The possibility of different molecular pathways in superficial low-grade and in invasive high-grade tumours is suggested.     

Oesophageal basaloid squamous cell carcinoma: a unique clinicopathological entity with telomerase activity as a prognostic indicator.

Oesophageal basaloid squamous cell carcinoma (BSCC) is uncommon and has been reported to have a worse prognosis than squamous cell carcinomas (SCCs), but this tumour has not been fully characterized. The aim of the present study was to analyse the clinicopathological features of a large cohort of patients with oesophageal BSCC treated at a single institution. The pathology of 756 primary oesophageal cancers treated between January 1989 and December 1998 was reviewed. Tumours that fulfilled the diagnostic criteria of BSCC were identified and were compared with SCC. Their expression of MIB-1, DNA ploidy, and telomerase activity were also studied. Thirty Chinese patients (25 men and five women) with BSCC were found, comprising 4% of patients with oesophageal cancer treated by surgical resection in the study period. Their median age was 67 years (range 40-78 years). Dysphagia was usually the main presenting symptom. Other concomitant malignant tumours were seen in three patients and paraneoplastic glomerulopathy in one. Five tumours were located in the upper third, 19 in the middle third, and six in the lower third. The median length was 5.8 cm (range 2-12 cm). The median MIB-1 score of BSCC was 750 (range 400-858) and was higher than that of SCC (p=0.003). The primary tumour and metastatic BSCC were aneuploid, as detected by flow cytometric analysis in nine patients. Telomerase activity was positive in 95% (19 out of 20) of the cases analysed. The 5-year survival of patients with BSCC was 12%. Distant metastases were seen in 53% (n=16); lung and liver were the most common sites. The median survival of patients with tumours which had a high level of telomerase activity was significantly shorter than those with low levels of telomerase activity (1 vs. 27 months) (p=0.001). The median survival of patients with BSCC and SCC was 26 and 16 months, respectively (p=0.3). In conclusion, BSCC has distinctive clinicopathological features and its long-term prognosis is no worse than SCC. The level of telomerase activity may have a prognostic role.     

p53蛋白表达与上颌窦鳞状细胞癌发生的关系

用免疫组化技术对８例上颌窦正常粘膜、１６例乳头状瘤及癌变、５０例鳞状细胞癌及１４例癌旁粘膜（包括癌旁正常粘膜、单纯增生及不典型增生）ｐ５３蛋白的表达进行了检测。结果显示，上颌窦癌ｐ５３阳性率为６２％（３１／５０）。ｐ５３表达与患者性别、年龄及肿瘤分化程度无关。上颌窦正常粘膜、单纯增生及乳头状瘤ｐ５３表达阴性。不典型增生ｐ５３表达为４／６，其表达与相应鳞癌存在一致性，不典型增生ｐ５３阳性者，相应癌组织亦为阳性，反之亦然。４例乳头状瘤癌变中，３例ｐ５３阳性。研究结果表明，ｐ５３表达是人上颌窦癌发生的早期事件，而与其恶性程度无关，ｐ５３表达发生于不典型增生或乳头状瘤癌变阶段，显示ｐ５３基因突变与上颌窦癌的发生密切相关。研究结果还表明，检测ｐ５３蛋白有助于上颌窦良，恶性病变的鉴别及早期发现上颌窦癌。     

p53 Protein expression in laryngeal squamous cell carcinomas bearing wild-type and mutated p53 gene

We performed an immunohistochemical analysis to investigate the expression of p53 protein in a panel of 18 laryngeal squamous cell carcinomas, 15 primary tumours and three in relapse, previously analysed by us for the presence of p53 gene mutations. Dysplastic and/or normal surrounding mucosa was evaluated in 15 different tumours. The results of our study are the following: (1) expression of p53 protein was observed in one out of five tumours positive for p53 gene mutations (20%) and in 10 out of 13 (80%) negative cases; (2), p53 protein over-expression was frequently observed in normal and/or dysplastic mucosa surrounding either wild-type (7/11) or mutated p53 tumours (2/4); (3), p53 immunoreactive cells showed a pattern of distribution in normal and mildly/moderately dysplastic mucosa (basal layers), different from that in severely dysplastic mucosa (whole thickness). These data further support the hypothesis that p53 protein over-expression may be a marker of the earliest phases of multistep tumorigenesis in laryngeal squamous cell carcinoma.     

The influence of p53 and associated factors on the outcome of patients with oral squamous cell carcinoma

 In several tumour entities the immunohistochemical detection of p53 has proved to be a predictive factor for the survival of the patients. In this study the effector waf1 and the regulator mdm2 responsible for the inactivation of p53 were also determined in 156 tissue samples of primary squamous cell carcinomas in the oral cavity and oropharynx, their lymph node metastases, and the epithelium outside the invasively growing tumour from 107 patients. In this latter epithelium there was a significant correlation between grade of dysplasia and staining for p53 (P<0.01). In the dysplastic epithelium a significant correlation between p53, waf1, and mdm2 was shown (P<0.05). Differences in the immunohistochemical staining between different blocks of the tumour tissue and also between primary tumours and their lymph node metastases were revealed in 11–44% of cases, but there was no correlation with other variables, such as formation of lymph node metastases. In contrast to the conventional tumour grading and staging, no influence of any of the variables determined on survival or recurrence-free survival could be detected. It seems that p53 and associated factors are important in the early stages of cancerogenesis but not in further tumour progression and metastatic spread. Received: 26 March 1998 / Accepted: 10 June 1998     

DNA Aneuploidy, S-phase fraction, nuclear p53 positivity, and survival in non-small-cell lung carcinoma

 Inactivation of the p53 gene plays a key role in tumour biology, probably through a disturbed cell cycle control and an increased genetic instability in p53-inactivated tumours. To learn more about the relationship between p53 alterations, proliferation and genetic instability (DNA aneuploidy) in lung cancer patients, specimens of 220 surgically resected lung carcinomas with clinical follow-up information were examined by immunohistochemistry (p53; CM1) and flow cytometry. Nuclear p53 positivity – found in 49.5% of the tumours – was associated with both high S-phase fraction (SPF) and DNA ploidy aberrations. SPF was higher in p53-positive tumours (15.9 ± 10.2) than in p53-negative tumours (10.3 ± 8.7; P = 0.03). The rate of p53 positivity was higher in 101 DNA-aneuploid and DNA-multiploid tumours (55%) than in 27 diploid and peridiploid carcinomas (33%; P = 0.0512). These results are consistent with an in vivo role of p53 inactivation for increased proliferative activity and development of genomic instability in lung cancer. There was no association between SPF and prognosis. Although prognosis was worse in DNA-aneuploid and multiploid tumours than in diploid, peridiploid and tetraploid carcinomas (P = 0.029), DNA ploidy was not an independent predictor of poor prognosis in multivariate analysis. These data show that DNA-flow cytometry has little prognostic value for patients with resected non-small-cell lung carcinoma. Received: 18 February 1997 / Accepted: 25 March 1997