The p16INK4a gene, localized within chromosome 9p21, has been identified as a cyclin-dependent kinase inhibitor and may negatively regulate the cell cycle acting as a tumor suppressor. Genetic alterations involving the 9p21 region are common in human cancers. A consecutive series of 64 untreated patients (median of follow up 53 months) undergoing surgical resection for locally advanced laryngeal squamous-cell carcinomas (LSCCs) has been studied prospectively. Our purpose was to investigate p16 alterations (9p21 allelic loss, hypermethylation and point mutations) and their possible association with clinico-pathological data and flow cytometric variables (DNA-ploidy and S-phase fraction (SPF)), and to determine the possible prognostic role of this gene in these tumors. PCR-based techniques were used for investigating 9p21 loss of heterozygosity (LOH) and methylation promoter status of the p16 gene. p16 mutations were detected by PCR-SSCP (single strand conformation polymorphism) and sequencing. 9p21 LOH was detected in 16/62 (26%) informative tumors, point mutations in 5% (3/64) and hypermethylation in 9% (6/64) of the cases. p16 alterations were significantly associated with high SPF and DNA-aneuploidy. By univariate analysis, poor histologic differentiation, stage IV, DNA-aneuploidy and p16 point mutations proved to be significantly related to quicker relapse, whereas these same factors, and in addition high SPF, 9p21 LOH and any p16 alterations were significantly related to shorter overall survival. By Cox proportional hazards analysis only histologic grade (G3) and p16 point mutations were independently related to both disease relapse and death. Our study has identified p16 point mutations as important biomolecular indicators in LSCCs.
To prospectively evaluate the prognostic significance of TP53, H-, K-, and N-Ras mutations, DNA-ploidy and S-phase fraction (SPF) in patients affected by locally advanced laryngeal squamous cell carcinoma (LSCC). Eight-one patients (median follow-up was 71 months) who underwent resective surgery for primary operable locally advanced LSCC were analyzed. Tumor DNA was screened for mutational analysis by PCR/SSCP and sequencing. DNA-ploidy and SPF were performed by flow cytometric analyses. Thirty-six patients (44%) had, at least, a mutation in the TP53 gene. Of them, 22% (8/36) had double mutations and 3% (1/36) had triple mutations. In total, 46 TP53 mutations were observed. The majority (41%) of these occur in exon 5 (19/46), while the mutations in exons 6, 7, and 8 were represented in 14, 7, and 6 patients, respectively (31%, 15%, and 16%). Five LSCC patients (6%) showed a mutation in H-Ras gene. Sixty-three percent of the cases (51/81) were DNA aneuploidy, 14% of these (7/51) were multiclonal. Thirty-nine patients (48%) had an high SPF value. At Univariate analysis, the DNA aneuploidy, high SPF (>15.1%), TP53 mutations and, in particular, the mutations that occur in exons 5 and 8 were significantly related to quicker disease relapse and short OS. At Multivariate analysis, the major significant predictors for both disease relapse and death were high SPF and any TP53 mutations. While histological grade G3 was an independent factor only for relapse. In conclusions, any TP53 mutations and high SPF are important biological indicators to predict the outcome of LSCC patients.
Hairy polyp of the nasopharynx is an unusual but well-recognized entity, generally presenting as a single mass at birth or in the first year of life. We describe the clinico-pathological features of a previously unreported bilateral hairy polyp in an adult and briefly discuss the pathogenesis of this condition.
Background. The traditional factors of locally advanced laryngeal squamous cell carcinoma (LSCC) have limited predictive value for the identification of high risk patients. Therefore, it is extremely important to define prognostic factors that identify the more aggressive types. Reliable and reproducible prognostic indicators are being investigated to help clinicians identify high risk groups and address more rational treatment.
Methods. Flow cytometric DNA ploidy and S‐phase fraction (SPF) measurements were performed on frozen tumor tissues from a consecutive series of 71 patients with Stage III and IV LSCC. Lysosomal cathepsin B and L activity levels were determined biochemically in matched paired sets of tumor tissue and normal mucosa samples.
Results. By univariate analysis, lymph node positivity, poor histologic differentiation, DNA aneuploidy, high SPF, and high tumor/mucosa ratio of cathepsin B activity were significantly related to risk of relapse, whereas only DNA aneuploidy and high SPF proved to be significantly related to risk of death. Multivariate analysis showed that high histologic grade and high SPF values (>15.1%) were independent prognostic factors related to risk of relapse (relative risk [RR] = 3.54; 95% confidence limits [CL] = 1.05‐12.0; and RR = 4.22; CL = 1.54‐11.6, respectively), whereas only high SPF was related to risk of death (RR = 3.63; CL = 1.17‐11.3).
Conclusions. S‐phase fraction is an independent predictor of relapse free and overall survival in patients with locally advanced LSCC. On the basis of these findings, SPF should be used in addition to other established prognostic factors to refine the prognostic assessment of these patients further. More studies are needed for a better evaluation of the prognostic significance of DNA ploidy and that of lysosomal cysteine proteinases in these tumors. Cancer 1995; 76:1757–64.
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