P16INK4a as an adjunct marker in liquid-based cervical cytology

Cytological screening for cervical cancer is hampered by high false negative rates. Inter-observer reproducibility needs optimizing. The potential of p16(INK4a) as a biomarker for cervical lesions was examined in a study of liquid-based cytology (LBC), HPV DNA testing by MY09/MY11 consensus PCR and type-specific PCRs and p16(INK4a) immunocytochemistry on a series of 291 patients selected from routine screening. Comparison of the number of p16(INK4a) immunoreactive cells/1,000 cells exhibited a significantly higher mean count in HSIL (8.80 +/- 1.13) than other cytological groups. The mean count of LSIL (1.09 +/- 0.18) was significantly higher than that of the negative group (0.82 +/- 0.40). ASC-H and HSIL combined showed a significantly higher mean count (6.46 +/- 1.17) than negative, ASC, ASC-US and LSIL. The mean count of immunoreactive cells/1,000 cells was significantly higher in HPV16 positive samples (3.22 +/- 0.72) than in samples containing infections with types of unknown malignant potential (0.83 +/- 0.26) or HPV negative samples (1.17 +/- 0.41). The mean count in infections with other high-risk HPV types (2.55 +/- 0.52) was significantly higher than that in HPV negative samples. Receiver-operating characteristic curves yielded a test accuracy (area under curve) of 0.76, 0.79, 0.88 and 0.95 for ASCUS, LSIL, ASC-H/HSIL and HSIL, respectively. Thresholds for 95% sensitivity were at 0.005, 0.007, 0.098 and 0.445 immunopositive cells/1,000 cells for ASCUS, LSIL, ASC-H/HSIL and HSIL, respectively. The 95% specificity threshold for the detection of HSIL was at 1.87 immunopositive cells/1,000 cells. P16(INK4a) immunocytochemistry can be used as an adjunct to LBC in cervical screening, because it has a good diagnostic accuracy to discriminate HSIL and ASC-H from other lesions. It could be used as a surrogate marker of high-risk HPV infections.     

p16INK4a在宫颈液基细胞学辅助筛查中的标记意义

目的 评价p16INK4a在宫颈液基细胞学检查中的标记意义.方法 收集74例宫颈外口和颈管的脱落细胞标本,分别进行液基细胞学检测和p16INK4a免疫细胞化学染色,并应用杂交捕获二代法检测高危人乳头瘤病毒(HR-HPV)感染.结果 74例标本中,细胞学诊断未见癌细胞或癌前病变细胞(阴性)10例,意义不明的不典型鳞状细胞(ASC-US)15例,鳞状上皮内低度病变(LSIL)28例,不除外上皮内高度病变的不典型鳞状细胞(ASC-H)5例,鳞状上皮内高度病变(HSIL)11例,鳞状细胞癌(SCC)5例.各级别病变中,HR-HPV阳性者分别为1、4、3、9、7和5例,p16INK4a免疫细胞化学染色阳性者分别为2、5、3、8、9和5例.随着宫颈病变级别的上升,HR-HPV和p16INK4a免疫细胞化学染色阳性率均增高.结论 p16INK4a免疫细胞化学染色增强了对不典型细胞的区分能力,可以提高宫颈癌筛查的准确性.     

p16INK4a overexpression predicts translational active human papillomavirus infection in tonsillar cancer

The causal role of human papillomaviruses (HPV) in squamous cell carcinogenesis of tonsillar cancers (TSCC) depends on the activity of the viral oncoproteins E6 and E7, leading to inactivation of the cellular tumor suppressor p53 and the retinoblastoma gene product pRb. Because of the negative feedback mechanisms, the pRb inactivation causes an increase of the inhibitor of the cyclin‐dependent kinases p16^INK4a. In 39 TSCC specimens, genotyping based on the amplification of HPV DNA was carried out using PCR by applying HPV type‐specific oligonucleotides. Subsequently, amplicons were hybridised with fluorescence‐labeled complementary probes using the Southern blot technology. For HPV E6/E7 mRNA expression, Northern hybridization and RT‐PCR were performed, and for p16^INK4a detection, immunohistochemistry was performed. With 21/39 (53%) HPV‐positives, the detection rate is within the range that can be expected in TSCC. The E6/E7 oncogene mRNA was detectable in 11 cases, 10 of which showed positive signals after p16^INK4a staining. Albeit the small study group was investigated, the correlation of the HPV DNA status with the p16^INK4a expression was of statistical significance (p = 0.02). Kaplan‐Meier estimations revealed better survival outcome for patients with HPV‐positive tumors with detectable E6/E7 mRNA and p16^INK4a overexpression (p = 0.02, median observation time 29 months). As mRNA expression tests are not routinely available in many clinical diagnostic laboratories, and based on the high correlation of p16^INK4a staining with HPV E6/E7 mRNA expression, in conclusion we suggest for a deeper exploration for the use of p16^INK4a as a surrogate marker with the potential to impact the standard of care of HPV DNA‐positive head and neck carcinomas.     

Frequent p16INK4a promoter hypermethylation in human papillomavirus-infected female lung cancer in Taiwan

Inactivation of p16INK4a gene through promoter hypermethylation has been frequently observed in non small cell lung cancer; however, various studies have shown a controversial correlation between p16INK4a hypermethylation and cigarette smoking. Our recent report showed that human papillomarvirus (HPV) 16/18 infections were associated with the development of nonsmoking female lung cancer in Taiwan and we further speculated that HPV infection may be linked with p16INK4a hypermethylation. To verify the influence of environmental exposure, including cigarette smoking, environmental carcinogen exposure and HPV infections on p16INK4a hypermethylation, tumors from 162 lung patients, including 67 smoking males, 41 nonsmoking males and 58 nonsmoking females, were subjected to p16INK4a hypermethylation analysis by methylation-specific PCR. As the results showed, p16INK4a hypermethylation was detected in 40 (59.7%) of 67 smoking male, 15 (36.6%) of 41 nonsmoking male and 35 (60.3%) of 58 nonsmoking female lung tumors. This result seemed to reveal that gender and cigarette smoking both possess an equal influence on p16INK4a hypermethylation. This result also led to a speculation that HPV infection may promote p16INK4a hypermethylation in nonsmoking female lung cancer patients. From our data, p16INK4a hypermethylation frequency in nonsmoking female lung tumors with HPV infection was as high as 70% (30 of 43) compared to those without HPV infection (33%; 5 of 15). In fact, the correlation between HPV infection and p16INK4a hypermethylation was only observed in nonsmoking female lung tumors (p = 0.017), but not in smoking male or nonsmoking male lung tumors. Moreover, the reverse correlation between p16INK4a immunostaining and p16INK4a promoter hypermethylation was also only observed in nonsmoking female lung tumors. These results strongly suggested that the involvement of HPV infection in lung tumorigenesis of nonsmoking female cancer patients in Taiwan may be mediated at least in part through the increase of hypermethylation to cause p16INK4a inactivation.     

p16INK4a protein expression is associated with poor survival of the breast cancer patients after CMF chemotherapy

Immunohistochemical assay for p16 protein expession was performed in 192 breast carcinoma patients treated with adjuvant chemotherapy. p16 expression was observed in 78 cases (40.6%). The frequency of p16 expression significantly decreased in moderately differentiated (histologic grade II) cancers, 20 (19.6%) of 102. In poorly differentiated cancers (histologic grade III), p16 expression was not observed in all 16 cases. p16 expression was significantly associated with histologic grade of the breast carcinomas (p<0.001). The proliferative index (PI: S + G2/M) of individual tumors was measured by DNA flow cytometry. In 114 tumors with PI less than 20%, p16 expression was observed in 59 tumors (49.1%). In the tumors with PI equal or more than 20%, p16 expression was observed in 22 (28.2%) of 78 cases. p16 expression was significantly decreased in the tumor with higher PI (p=0.003). For the other clinicopathologic variables, no significant association was found with p16 expression status. Immunohistochemical assay for p53 protein expression was performed on the same breast carcinomas. There was no significant association between p16 and p53 expression in breast carcinomas. During median follow-up period of 52 months (range: 40–72 months), 46 patients (25.8%) had recurrent disease and 32 patients (18.91%) died of recurrent disease. p16 expression was observed in 20 (43.5%) of 46 patients with recurrent disease, while its expression was observed in 58 patients (39.7%) of 146 patients who were free of recurrence during the study period. p16 expression had no significant impact on predicting recurrence of breast carcinoma. Fourteen patients (12.2%) of 114 patients whose tumors did not show p16 expression died of recurrent breast carcinoma, whereas 18 patients (23.1%) of 78 patients with p16 expressing tumor died during the follow-up period. There was a significant difference of patient survival according to p16 expression status (p=0.039). These results indicate that p16 expression is useful in predicting response to chemotherapy in breast cancer patients. p16 protein seems to have a role in tumor growth and differentiation of the breast carcinoma.     

p16INK4a immunocytochemistry versus human papillomavirus testing for triage of women with minor cytologic abnormalities

The best method for identifying women who have minor cervical lesions that require diagnostic workup remains unclear. The authors of this report performed a meta‐analysis to assess the accuracy of cyclin‐dependent kinase inhibitor 2A (p16^INK4a) immunocytochemistry compared with high‐risk human papillomavirus DNA testing with Hybrid Capture 2 (HC2) to detect grade 2 or greater cervical intraepithelial neoplasia (CIN2+) and CIN3+ among women who had cervical cytology indicating atypical squamous cells of undetermined significance (ASC‐US) or low‐grade cervical lesions (LSIL). A literature search was performed in 3 electronic databases to identify studies that were eligible for this meta‐analysis. Seventeen studies were included in the meta‐analysis. The pooled sensitivity of p16^INK4a to detect CIN2+ was 83.2% (95% confidence interval [CI], 76.8%‐88.2%) and 83.8% (95% CI, 73.5%‐90.6%) in ASC‐US and LSIL cervical cytology, respectively, and the pooled specificities were 71% (95% CI, 65%‐76.4%) and 65.7% (95% CI, 54.2%‐75.6%), respectively. Eight studies provided both HC2 and p16^INK4a triage data. p16^INK4a and HC2 had similar sensitivity, and p16^INK4a has significantly higher specificity in the triage of women with ASC‐US (relative sensitivity, 0.95 [95% CI, 0.89‐1.01]; relative specificity, 1.82 [95% CI, 1.57‐2.12]). In the triage of LSIL, p16^INK4a had significantly lower sensitivity but higher specificity compared with HC2 (relative sensitivity, 0.87 [95% CI, 0.81‐0.94]; relative specificity, 2.74 [95% CI, 1.99‐3.76]). The published literature indicated the improved accuracy of p16^INK4a compared with HC2 testing in the triage of women with ASC‐US. In LSIL triage, p16^INK4a was more specific but less sensitive. Cancer (Cancer Cytopathol) 2012. © 2012 American Cancer Society.     

Evaluation of p16INK4a expression in ThinPrep cervical specimens with the CINtec p16INK4a assay

BACKGROUND.

The aim of this study was to examine p16^INK4a protein expression in ThinPrep (Cytyc Corporation, Marlborough, Mass) cervical specimens by using the CINtec p16^INK4a Cytology Kit (Dako, Glostrup, Denmark). The ability of this assay to accurately identify underlying high‐grade lesions was assessed by using follow‐up biopsies and comparing these results with Hybrid Capture 2 (Digene, Gaithersburg, Md) high‐risk HPV (hc₂) results.

METHODS.

Three hundred ninety‐eight residual ThinPrep samples were collected, and histological follow‐up data were retrieved for abnormal cytology specimens. After preparation of a Papanicolaou‐stained slide, a second slide was processed in preparation for p16^INK4a immunostaining. High‐risk human papillomavirus testing (hc₂) was also performed.

RESULTS.

Of the 163 cytologically abnormal samples, 6‐month biopsy follow‐up data were available for 45% of the specimens. At initial blinded evaluation, 21 of the 26 cases with cervical intraepithelial neoplasia (CIN) II/III follow‐up were positive for p16^INK4a, yielding an overall diagnostic sensitivity of 81%; 29 of the 47 cases diagnosed as CIN I or less were p16^INK4a negative, yielding a diagnostic specificity of 62%. In comparison, the hc₂ test results indicated a diagnostic sensitivity of 100% with a diagnostic specificity of 15%. After review of selected cases with CIN II/III follow‐up, 25 of 26 slides were deemed to be positive for p16^INK4a, increasing the diagnostic sensitivity to 96%.

CONCLUSIONS.

The CINtec p16^INK4a Cytology Kit, in combination with ThinPrep cervical samples, allowed clear evaluation of p16^INK4a protein overexpression. Diagnostic specificity of the CINtec p16^INK4a assay was significantly improved relative to hc₂. To increase p16^INK4a immunostaining in abnormal cells, a modified kit version with improved staining performance has been developed and is currently being evaluated. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.     

Combined p16INK4a and human papillomavirus testing improves the prediction of cervical intraepithelial neoplasia (CIN II-III) in Thai patients with low-grade cytological abnormalities

Thailand is in the process of developing a national cervical screening program. This study examined p16INK4a staining and HPV prevalence in abnormal cervical samples with atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL), to evaluate the efficacy of combined HPV and p16INK4a detection to predict CIN II-III. Totals of 125 ASCUS and 87 LSIL cases were re-evaluated by Pap test and cervical cells of ASCUS and LSIL cases were prepared on slides for p16INK4a detection by immunocytochemistry. HPV genotyping of DNA extracts was performed by GP5+/6+ PCR and reverse line blot hybridization. Histopathologic tests were performed to identify cervical lesion. Total of 212 cases were diagnosed to normal (20), ASCUS (112), LSIL (78) and HSIL (2). HPV was detected in ASCUS (49/112, 43.8%), LSIL (60/78, 76.9%) and HSIL (2/2, 100%) cases. The majority of HPV positive samples typed for high-risk HPV. 55.7% (107/192) of abnormal cases (ASCUS, LSIL and HSIL) were positive p16INK4a. For the 111 HPV DNA positive cases, 34 of 49 (69.4%) ASCUS cases and 49 of 60 (81.7%) LSIL cases were p16INK4a positive. 140 biopsies were taken and histological classified: CIN negative (65 cases), CIN I (56 cases) and CIN II-III (19 cases). HPV DNA detection predicted CIN II-III with sensitivity and specificity of 84% and 49%, whereas p16INK4a staining showed higher sensitivity (89.5%) and specificity (56.2%). The prediction of CIN II-III was significantly better by combination of positive HPV DNA and p16INK4a with 93.8% sensitivity and 59.2% specificity. Detection of HPV DNA combined with p16INK4a in cervical cells can predict CIN II-III and may improve the screening diagnosis of Thai women at risk for CIN II-III or cancer.     

p14ARF, p15INK4b and p16INK4a methylation status in chronic myelogenous leukemia

The INK4 family of proteins p15^INK4b, p14^ARF and p16^INK4a function as cell cycle inhibitors where they are involved in the inhibition of G1 phase progression. Methylation of the p15^INK4b promoter never seems to occur in solid tumors but is a major gene silencing mechanism in hematological malignancies. p14^ARF and p16^INK4a promoter methylation often occurs in solid tumors but also in leukemias and lymphomas. In chronic myelogenous leukemia (CML), only a few reports have been published regarding INK4 methylation and the results of the literature are discordant. Thus clearly, more works on large series have to be performed independently.     

p16INK4a downregulation is involved in immortalization of primary human prostate epithelial cells induced by telomerase

Prostate cancer is a major cause of cancer death among male population. Therefore, development of appropriate model systems is critical for understanding the molecular basis of prostate cancer progression. In this study, introduction of human telomerase (hTERT) into normal human prostate epithelial cells (PrECs) renders them higher telomerase activity, elongated telomere length and an extended proliferative lifespan. The immortal mass culture of PrEC-hTERT cell line with stabilized telomere length has been established using hTERT transfection. However, activation of hTERT alone appears to be insufficient for immortalization of PrEC cells because methylation of p16(INK4a) promoter has been found to be involved in the immortalization process. p53 was functionally intact and no mutations of p53 gene were identified in the immortalized PrECs. In addition, the immortal PrECs show a near diploid complement of chromosomes albeit a few reciprocal and non-reciprocal translocations are identified. They are anchorage dependent and do not form tumors in immunosuppressed host animals. Therefore, premalignantly transformed human PrECs provide a valuable model for prostate cancer research.     

p19~(ARF)和p16~(INK4a)在人骨肉瘤中表达的比较研究

目的比较p16INK4a和p19ARF两种抑癌基因在可切除的人骨肉瘤组织中的表达形式,探讨其在人骨肉瘤的发生、发展中的意义。方法人骨肉瘤切除石蜡标本37例,用单克隆抗体间接免疫荧光法同时测定肿瘤组织的p16、p19蛋白的表达。结果p16INK4a表达率56.8%(21/37),p19ARF表达率40.5%(15/37);p16与p19表达无相关性;p16和p19与骨肉瘤的外科分期、病理分级、血管浸润和肺部转移均无显著相关。结论p16、p19的下调都很可能是骨肉瘤发生发展的重要原因之一,未发现这两种抑癌基因之间的表达有显著关系。     

p16INK4a is superior to high‐risk human papillomavirus testing in cervical cytology for the prediction of underlying high‐grade dysplasia

BACKGROUND

The primary goal of this study was to compare the clinical performance of an optimized and rigorously controlled immunocytochemical (ICC) assay for p16^INK4a to high‐risk (HR) human papillomavirus (HPV) detection by polymerase chain reaction (PCR) as diagnostic adjuncts for cytology specimens from colposcopy patients.

METHODS:

The study included 403 cervical cytology specimens collected within 3 months of colposcopy. The colposcopic impression and cervical biopsy diagnosis served as the standards for correlation with cytological, p16^INK4a, and HPV data. p16^INK4a was evaluated using an immunoperoxidase‐based assay that was linear over 4 logs for the detection of HeLa‐spiked positive control cytology specimens, using a threshold for positive test results that was based on receiver operating characteristic curve analysis. HR‐HPV was detected by multiplex PCR using genotype‐specific primers.

RESULTS:

In all combined diagnostic categories (negative for intraepithelial lesion and malignancy, atypical glandular cells, atypical squamous cells of undetermined significance, atypical squamous cells cannot exclude high‐grade squamous intraepithelial lesion, low‐grade squamous intraepithelial lesion, and high‐grade squamous intraepithelial lesion), the p16^INK4a ICC and HR‐HPV assays, respectively, had sensitivity of 81.7% and 83.3% (P = .81) and specificity of 78.1% and 50.9% (P < .001) for the detection of underlying ≥grade 2 cervical intraepithelial neoplasia (CIN) lesions on biopsy. Furthermore, the positive predictive value of p16^INK4a ICC was greater than that of HR‐HPV for patients with biopsies ≥CIN‐2 (41.2% and 24.2%, respectively, P = .001).

CONCLUSIONS:

This p16^INK4a immunocytochemical assay has superior specificity but similar sensitivity to HR‐HPV testing to predict underlying high‐grade dysplastic lesions in patients who are referred for colposcopy. The determination of the overall performance characteristics of p16^INK4a immunocytochemistry, as an independent test or in combination with HPV testing in low‐risk screening populations, however, will require subsequent large‐scale prospective clinical trials. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.     

Immunohistochemical analysis of p16INK4a,p14ARF,p18INK4c,p21CIP1, p27KIP1 and p73 expression in 271 meningiomas correlation with tumor grade and clinical outcome

Routine pathological examination cannot distinctively predict the clinical course of meningiomas because even histologically benign tumors may recur after gross total resection. Numerous efforts have been made for the evaluation of different immunohistochemical assays in meningioma prognosis. We investigated the prognostic significance of p16INK4a, p14ARF, p18INK4c, p21CIP1, p27KIP1 and p73 expression by immunohistochemical analysis of 271 meningiomas. All tumors were additionally stained for the proliferation markers Ki-67 and DNA topoisomerase II alpha (TopoIIalpha). Significant differences between the number of p16INK4a-, p18INK4c- and p21CIP1-positive cases were noted among the 3 grades of meningiomas. p16INK4a- and p21CIP-positive tumors were found to prevail among benign meningiomas, whereas p18INK4c immunostaining was closely associated to anaplastic meningiomas. The number of p16INK4a- and p21CIP-positive cases was significantly lower in the cohort of recurrent meningiomas. In contrast, p18INK4c-positive cases were clustered among recurrent meningiomas regardless of tumor grade. Immunoreactivity of p14ARF, p27KIP1 and p73 did not show any differences between meningiomas of various histology and clinical outcomes. Multivariate analysis revealed that only tumor grade and TopoIIalpha index are independent criteria for predicting meningioma recurrence. Thus, the immunohistochemical assessment of p16INK4a, p14ARF, p18INK4c, p21CIP1, p27KIP1 and p73 expression in meningiomas does not appear to provide prognostically useful information. Further studies are needed to identify more reliable prognostic markers and to address in more detail the role of cell cycle aberrations in these tumors.     

p16^INK4a和p14^ARF蛋白在宫颈癌和肺癌中的差异表达

[目的]研究宫颈癌和肺癌中p16INK4a和p14ARF蛋白表达水平的差异及意义。[方法]应用免疫组化方法检测50例宫颈癌和127例肺癌组织中p16INK4a和p14ARF蛋白表达。[结果]50例宫颈癌中,p16INK4a和p14ARF蛋白全部阳性表达;127例肺癌中,p16INK4a和p14ARF蛋白阳性表达率分别为61.42%和30.79%;宫颈癌和肺癌中p16INK4a和p14ARF蛋白表达差异均有显著性（P〈0.01）。[结论]p16INK4a和p14ARF蛋白在宫颈癌中过表达,而在肺癌中缺失表达。提示p16INK4a和p14ARF蛋白在宫颈癌和肺癌的发生发展中所起的作用和作用机制可能不同。     

Evaluation of a new p16(INK4A) ELISA test and a high-risk HPV DNA test for cervical cancer screening: results from proof-of-concept study

p16(INK4a), a cell cycle regulation protein, accumulates in abnormal epithelial cells infected with high-risk human papilloma virus (HPV). In immunostaining studies, p16(INK4a) has shown potential as a marker of high grade cervical intraepithelial neoplasia (CIN) and invasive cervical cancer. To evaluate its potential use in cervical cancer screening, we conducted a feasibility study to compare the performance of a new enzyme linked immunosorbant assay (ELISA) for p16(INK4a) (mtm laboratories, Heidelberg, Germany) to that of the Hybrid Capture 2 (hc2) test for high-risk HPV DNA for the detection of CIN3. Three hundred and nineteen women were referred from Western Washington Planned Parenthood clinics for colposcopy examination and cervical biopsy because of abnormal Pap test results. Cervical samples were obtained from study participants for p16(INK4a) ELISA, liquid-based cytology and hc2. The order (first and second) for obtaining samples for cervical cytology and p16(INK4a) ELISA changed with every other subject. Concentrations of p16(INK4a) protein were higher when the sample was taken before the cytology. The sensitivity of p16(INK4a) ELISA (concentration > or = 8 units/ml) taken as first sample was 90.0% for CIN3, and the sensitivity of HC2 taken as a second sample was 85%. In the same group, the specificity of p16(INK4a) ELISA (46.9%) was slightly better than hc2 (35.4%) Results from this proof-of-concept study suggest that p16(INK4a) ELISA has a similar sensitivity and slightly better specificity for CIN3 compared to hc2. These findings support proceeding with a larger study with samples from a population of women presenting for routine cytology screening.     

应用组织微阵列技术研究胃癌hMSH2和p16INK4a的表达意义

目的探讨错配修复基因hMSH2和抑癌基因p16INK4a在胃癌组织中表达的意义.方法构建胃癌组织微阵列(TMA),采用免疫组化法测定hMSH2和p16INK4a的表达.结果在胃癌组织中,hM-SH2和p16INK4a的过表达呈正相关(r=0.235,P=0.0134),与有无淋巴结转移及转移程度、生存时间无关.结论hMSH2和P16INK4a的过表达呈正相关,两者均不能作为预测有否淋巴结转移、转移程度和预后的分子标志物.     

非小细胞肺癌p14ARFp16INK4a蛋白共表达及其临床意义

目的:探讨p14ARF、p16INK4a蛋白在非小细胞肺癌(NSCLC)组织中的表达、意义及相关关系.方法:采用免疫组织化学SP方法对103例NSCLC组织中p14ARF和p16INK4a蛋白的表达进行检测.结果:103例NSCLC组织中p14ARF、p16INK4a蛋白表达阴性率分别为70.87%和43.69%,差异有显著性(P＜0.01).其中35例p14ARF、p16INK4a蛋白表达共阴性,共阴性率达33.98%(35/103),鳞癌中共阴性率明显高于其它组织类型(P＜0.01).p14ARF、p16INK4a蛋白表达阴性相互间无显著相关性(P＞0.05).临床Ⅲ Ⅳ期病例两种蛋白表达阴性率明显高于临床Ⅰ Ⅱ期(P＜0.05).结论:NSCLC组织p14ARF、p16INK4a蛋白表达共阴性具有明显的组织学类型特异性,两种蛋白阴性表达是各自独立的事件.