Molecular and biomarker analyses of salivary duct carcinomas: comparison with mammary duct carcinoma.

Salivary duct carcinoma (SDC) is a rare high-grade aggressive neoplasm that manifests close histologic features with invasive ductal carcinoma of the breast (IDC). In contrast to SDC, extensive molecular studies have been performed on IDC and led to the identification of certain biological markers. To investigate the underlying molecular and biologic characteristics of SDC, we performed molecular analyses using microsatellite markers on chromosomal arms 6q, 16q, 17p, and 17q, DNA flow cytometry and immunohistochemical staining for androgen receptor (AR) and p53 expression on 28 examples of these tumors in comparison to 24 IDC cases. Our results show that generally similar allelic alterations, elevated p53 and androgen receptor expressions, and high frequency of DNA aneuploidy are manifested in both SDCs and IDCs. Differences at certain markers on 6q, 17p and 17q chromosomal loci, however, were observed between the two entities. Certain loci on 6q were more frequently altered in SDC than IDC which loci on chromosomes 17p and q arms were more seen in IDCs than SDCs. The majority of SDCs had high AR expression while most of IDCs were AR negative. Our study indicates that: i) SDC may share some genetic alterations with IDC, ii) high AR expression in SDC may play a role in tumor progression, and iii) p53 overexpression and DNA aneuploidy in both entities reflect their aggressive behavior.

Schneiderian papillomas and carcinomas: a review.

The ectodermally derived Schneiderian mucosa gives rise to an extremely varied collection of benign and malignant neoplasms. Prototypical of these are the Schneiderian papillomas (inverted, fungiform, and cylindrical cell) and their malignant counterparts. Human papilloma virus (HPV) is currently the leading candidate as a cofactor in the pathogenesis of the papillomas. Carcinomas arise in association with the papillomas in about a 10% frequency. The carcinomas may be synchronous or metachronous. Recurrences of the papillomas are the bane of surgeons. The magnitude of the recurrences is directly proportional to the completeness of removal with the best results obtained by techniques that afford the best operative exposure. A comparison of results by different surgical procedures is presented. Histologic features sought to predict recurrences or malignant transformation have, by and large, not been helpful. Keratinization and hyperkeratosis in papillomas, however, are suggested to be sufficiently ominous as to warrant further study.

Sarcomatoid carcinomas of the upper aerodigestive tracts.

Sarcomatoid carcinoma of the upper aerodigestive tract continues to be one of the most difficult diagnostic challenges for surgical pathologists. Histogenesis has been settled in favor of a divergent (mesenchymal) differentiation of a carcinoma, most often a squamous cell carcinoma. Finding the carcinoma and/or its immunohistochemical marker in the metaplastic cells establishes the diagnosis. There are, however, lesions that can simulate sarcomatoid carcinomas to varying degrees, and in which neither a definable carcinoma nor immunohistochemical evidence of one can be found. Such lesions fall into several categories: 1. benign reactive lesions, 2. inflammatory myofibroblastic tumors, 3. sarcomas, usually low-grade, 4. atypical pseudosarcomatous proliferation. The clinicopathologic considerations of sarcomatoid carcinomas are presented in this context and include immunohistochemical findings, prognostic factors, and biologic course.

Papillary squamous cell carcinomas of the upper aerodigestive tract: a clinicopathologic and molecular study.

BACKGROUND: The limited studies and the small number of published cases of papillary squamous cell carcinoma have precluded accurate assessment of the biologic characteristics of this lesion. METHODS: Thirty-eight of the carcinomas were studied. In-situ hybridization and polymerase chain reaction were performed to detect human papilloma virus (HPV) and p53 expression. RESULTS: HPV was found in 4 of 14 assessable carcinomas by in-situ hybridization and in 5 of 14 by polymerase chain reaction. The most frequently identified HPVs were HPVs in 6/11 and 16/18 patients. In general, a reciprocal relationship was found between p53 and HPV prevalence. The most lethal site for this tumor was the sinonasal tract, whereas patients with papillary squamous cell carcinomas of the larynx had the best outlook. Eleven of 25 (44%) assessable patients died of disease (mean time interval, 2 year). CONCLUSIONS: Papillary squamous cell carcinoma of the upper aerodigestive tract is a distinct variant of squamous cell carcinoma. As such and because of its putative association with HPV, papillary squamous cell carcinoma could be an informative model for defining how viral oncogenes cooperate with other factors in genomic instability, carcinogenesis, and tumor development.

Mucosal melanomas: a review.

Mucosal melanomas, far fewer in number than melanomas of the skin, manifest a far more aggressive and more rapid life-consuming biologic course. This behavior attends melanomas at any mucosal site, upper aerodigestive tracts, anorectum, and male and female genital tracts. Prognostic factors for both groups of melanoma are similar, but most mucosal melanomas have reached the dangerous limits, e.g., depth of invasion or thickness of melanoma at the time of diagnosis. In general, the mucosal melanomas are also more refractory to therapeutic modalities. In part, this may be due to anatomic restrictions of site and the large size of tumor when first discovered. This review presents a contemporary assessment of melanomas at all of the major mucosal sites.

Molecular genetic alterations in carcinoma ex-pleomorphic adenoma: a putative progression model?

To determine the genetic changes associated with the development of carcinoma ex-pleomorphic adenoma (Ca Ex-PA), we analyzed 15 microsatellite loci at chromosome arms 8q, 12q, and 17p on DNA from 26 neoplasms (including 8 microdissected benign and malignant components), and 13 pleomorphic adenomas for comparison. Pleomorphic adenomas and the adenoma component of Ca Ex-PAs showed a higher incidence of loss of heterozygosity (LOH) at chromosome arms 8q (52%) and 12q (28%) than at 17p (14%) loci. In the carcinoma component, the combined LOH at chromosome arm 8q, 12q, and 17p regions was 69%, 50%, and 69%, respectively; within these chromosomal regions, 8q11.23-q12 (42%), 12q23-qter (39%), 17p13 (41%), and 17p11 (45%) loci manifested the highest incidence of LOH. Eight carcinomas (30.7%) showed loss at all three chromosomal arms tested. Of the eight microdissected Ca Ex-PAs analyzed, four adenoma and corresponding carcinoma components (50%) had the same LOH at 12q loci and additional LOH at 17p loci only in carcinomas. Chromosome arm 17p alterations correlated significantly with high disease stage and an increased proliferative rate in these tumors. Our results indicate that alterations at regions on chromosome arms 8q and/or 12q may constitute early events associated with pleomorphic adenomas; that LOH at 12q loci may identify a subset of adenoma with potential progression to carcinoma; that acquisition of additional alterations at chromosome arm 17p loci might represent an event preceding malignant transformation and progression; and that 8q, 12q, and 17p regions may harbor tumor suppressor genes involved in the genesis of PA and Ca Ex-PA. Genes Chromosomes Cancer 27:162-168, 2000.

Myoepithelium in salivary and mammary neoplasms is host-friendly.

This commentary relates to ameliorative effects of myoepithelial cells in carcinomas of salivary glands and the breast as viewed not only by proliferative characteristics, but also by laboratory experiments and clinicopathologic evidence. The tumor suppressor action of myoepithelium is, in part, associated with its matrix-synthesizing and proteinase inhibitor properties. Loss of the myoepithelial phenotype yields a more aggressive carcinoma with enhanced invasive and metastatic capability.

Surgical excision margins: a pathologist's perspective.

The histopathologic status of excisional margins of malignant neoplasms has long been used as a potential indicator for recurrences and prognosis. The predictive ability of the margin, however, is far from satisfactory. Perhaps nowhere else in oncologic pathology has the significance of these margins been as intensively studied as in squamous cell carcinomas of the upper aerodigestive tracts. This review is, in part, a critique of current applications and the clinical implications of surgical margins for the removal of squamous cell carcinomas in these tracts. Specific points addressed in this article are: 1) postremoval (artifactual) changes in measurements; 2) the impact of margin status, as currently assessed, on recurrence and patient outcome; 3) margins and conservation surgery of the larynx; 4) margins and bone (mandible) invasion; and 5) molecular (p53 and eIF4E) margins.

Superimposed histologic and genetic mapping of chromosome 9 in progression of human urinary bladder neoplasia: implications for a genetic model of multistep urothelial carcinogenesis and early detection of urinary bladder cancer.

The evolution of alterations on chromosome 9, including the putative tumor suppressor genes mapped to the 9p21-22 region (the MTS genes), was studied in relation to the progression of human urinary bladder neoplasia by using whole organ superimposed histologic and genetic mapping in cystectomy specimens and was verified in urinary bladder tumors of various pathogenetic subsets with longterm follow-up. The applicability of chromosome 9 allelic losses as non-invasive markers of urothelial neoplasia was tested on voided urine and/or bladder washings of patients with urinary bladder cancer. Although sequential multiple hits in the MTS locus were documented in the development of intraurothelial precursor lesions, the MTS genes do not seem to represent a major target for p21-23 deletions in bladder cancer. Two additional tumor suppressor genes involved in bladder neoplasia located distally and proximally to the MTS locus within p22-23 and p11-13 regions respectively were identified. Several distinct putative tumor suppressor gene loci within the q12-13, q21-22, and q34 regions were identified on the q arm. In particular, the pericentromeric q12-13 area may contain the critical tumor suppressor gene or genes for the development of early urothelial neoplasia. Allelic losses of chromosome 9 were associated with expansion of the abnormal urothelial clone which frequently involved large areas of urinary bladder mucosa. These losses could be found in a high proportion of urothelial tumors and in voided urine or bladder washing samples of nearly all patients with urinary bladder carcinoma.

Genetic alterations in oral squamous cell carcinoma of young adults.

The underlying molecular abnormalities associated with head and neck squamous cell carcinoma in young adults (< 40 years) are unknown. We analyzed DNA extracted from paired microdissected samples of normal squamous epithelia and invasive oral squamous cell carcinomas from 36 young adults at microsatellite loci commonly found in older patients and correlated the results with clinicopathologic parameters and outcome. Our results showed that 30 of the 36 (83%) tumors manifest loss of heterozygosity (LOH) in at least one marker. Microsatellite instability was manifested in only six tumors (< 17%). The highest incidences of alterations were noted at markers D9S168 (9p23-22), TP53 (17p13), and D17S799 (17p11) on the short arms of chromosomes 9 and 17. In general, the incidences of LOH at 3, 9 and 17p regions in young adults were similar to those found in older patients. No correlation between LOH at chromosomes 3, 9, and 17p and clinicopathologic parameters was found. Our study indicates that chromosomal regions with frequent genetic alterations involved in young adult squamous tumorigenesis are similar to those reported in older patients. Further studies of other chromosomes in this population are underway to define the novel molecular features of these tumors.

Proliferative verrucous leukoplakia and its related lesions.

Proliferative verrucous leukoplakia (PVL) is a unique type of clinical oral leukoplakia. Enigmatic in etiology, PVL behaves in a far more aggressive fashion than other forms of leukoplakia. Its aggressiveness relates not only to a high recurrence rate, but more so to a very high level of and relentless progression from a localized simple keratosis to extensive oral disease and squamous carcinomas of verrucous, or conventional squamous cell type. Diagnosis is often late in the protracted course of PVL with the disease in an advanced stage when it is especially refractory to treatment. Within the histologic spectrum that is seen in PVL, usually as a function of time, are: (1) verrucous hyperplasia (VH), a histologically defined lesion; (2) varying degrees of dysplasia; and (3) three forms of squamous cell carcinoma: verrucous, conventional and, according to some, papillary squamous cell carcinoma. Each of these are discussed both within and outside the context of PVL. VH is a forerunner of verrucous carcinoma and the transition is so consistent that the hyperplasia, once diagnosed, should be treated like verrucous carcinoma. VH is not only an oral lesion; it can occur in the upper airway (sinonasal tract and larynx) where it is not usually found within a maternal soil of PVL. Papillary squamous cell carcinoma has been a loosely defined neoplasm, more often considered a verrucal type of malignancy. It nonetheless is a distinct clinicopathologic entity, separate from verrucous carcinoma and without a predilection for the oral cavity or an association with PVL.

Leukoplakia: still a gallimaufry or is progress being made?--A review.

Leukoplakia as a medical term has been encumbered by a hodgepodge of synonyms and interpretations. It also has been a term associated with strong emotions with respect to an implied malignant potential. It now is regarded as potentially malignant, with varying degrees of risk for transformation. Leukoplakia at its major anatomic site of occurrence, the oral cavity, recently has been redefined, classified, and staged as a preamble to a more rational approach to the clinicopathologic study of leukoplakia. These changes are presented, as are current assessments of proliferative verrucous leukoplakia, verrucous hyperplasia, palatal white lesions, effects of smokeless tobacco on the oral mucosa, hairy leukoplakia, and lichen planus.

Mucosal melanomas of the head and neck.

Mucosal melanomas of the head and neck, as a group, are rapidly lethal neoplasms with site-specific differences in survival. They are preponderantly thick melanomas and as a consequence can present with cervical lymph node metastasis with or without distant spread. Long-term survival is unusual to rare; 5-year survival is poor, and 10-year survival, dismal. Whether this life-consuming nature is due to a biologic characteristic or related to late discovery is unknown. Because of the accelerated course and obvious differences in epidemiology, mucosal melanomas should be considered separate from melanomas of the skin.

Localization of chromosome 8p regions involved in early tumorigenesis of oral and laryngeal squamous carcinoma.

We analysed 30 primary invasive oral and laryngeal squamous carcinomas (SC), with concurrent dysplastic lesions, for genetic alterations at 15 microsatellite loci on the short arm of chromosome 8. Overall, loss of heterozygosity (LOH) was observed, in at least one informative locus, in 27% of the dysplastic lesions and in 67% of the invasive carcinomas. The highest frequency of allele losses in dysplasia (20% and 17%), and invasive carcinoma (40% and 48%) were detected in the same D8S298 and LPL-tet loci located on chromosomes 8p21 and 8p22 respectively. The minimal region with LOH was limited to 4.6 megaBases (mBs) at 8p22 and 7.1 mBs at 8p21. In addition, allelic losses in both dysplastic and corresponding invasive specimens were noted at the same loci in some tumors suggesting their emergence from a common preneoplastic clone. Allele losses correlated significantly with male gender, oral and laryngeal sites and high proliferative index. The data suggest that inactivation of tumor suppressor gene(s), within these loci, may constitute an early event in the evolution of oral and laryngeal SC.

The prognostic significance of the biomarkers p21WAF1/CIP1, p53, and bcl-2 in laryngeal squamous cell carcinoma.

BACKGROUND: The clinical course of laryngeal squamous cell carcinoma (LSCC) varies considerably among patients. New biologic markers are needed to facilitate the stratification of individual patients within the conventional clinicopathologic stages of LSCC. METHODS: Eighty-three LSCCs from an equal number of patients who received at least 10 years of follow-up were investigated for p53, p21WAF1/CIP1, and bcl-2 protein expression by immunohistochemical techniques. The results were correlated with various clinicopathologic parameters, DNA content, and patient outcome by univariate and multivariate statistical analyses. RESULTS: Stage IV disease, large tumor size (>3 cm), positive lymph node status, extranodal extension, and p53 overexpression (in > 75% of cells) correlated significantly with prognosis in univariate analysis. There was no correlation between patient outcome and age, gender, race, histologic differentiation, or expression of bcl-2 or p21WAF1/CIP1. In multivariate analysis, lymph node status and p53 overexpression were the only factors significantly associated with survival. CONCLUSIONS: High p53 expression and positive lymph node status were independent predictors of the outcomes of patients with LSCC. These factors may assist in prognostication and better classification of patients for treatment.

Genetic alterations in acinic cell carcinoma of the parotid gland determined by microsatellite analysis.

We investigated, for the first time, the genetic alterations at certain chromosomal loci in 25 primary parotid acinic cell carcinomas to define the most frequently altered chromosomal regions and their association with pathologic features and DNA content analysis. Our results showed that 21 (84.0%) of the tumors had alteration in at least one of the loci tested. In general, chromosomal regions at chromosomes 4p, 5q, 6p, and 17p were more frequently altered than those on chromosomes 1p and 1q, 4q, 5p, and 6q. Certain markers at 4p15-16, 6p25-qter, and 17p11 regions showed the highest incidence of LOH, suggesting the presence of tumor suppressor genes associated with the oncogenesis of these tumors. LOH was significantly associated only with tumor grade. No apparent correlation between LOH and other clinicopathologic and DNA content characteristics was identified. Our study broadly defined the chromosomal arms and loci that may be targeted for further localization of the minimally deleted regions involved in the tumorigenesis of these tumors.

Methylation, a major mechanism of p16/CDKN2 gene inactivation in head and neck squamous carcinoma.

We studied 11 head and neck squamous carcinoma (HNSC) cell lines and 46 primary tumors for p16 gene status by protein, mRNA, and DNA genetic/epigenetic analyses to determine the incidence, the mechanism(s), and the potential biological significance of its inactivation. Of the 11 cell lines, only 1 showed intact p16 and 10 lacked its protein and mRNA; DNA analysis of these 10 cell lines showed 2 homozygous deletions, 6 methylations at exon 1 and 2, and 2 with no detectable abnormalities. In primary tumors, 16 (34.7%) of the 46 showed detectable p16 protein and mRNA; of these, 12 had no DNA abnormalities and 4 had only exon 2 methylation. Loss of p16 expression was found in three tumors with concurrent mutation at exon 2 and methylation at exon 2 (two) and both 1 and 2 (one). Of the 30 tumors that lacked p16 protein, 27 also lacked mRNA, 1 had detectable p16 mRNA, and 2 failed RT-PCR amplification. Twenty-two of the thirty tumors showed DNA alterations and eight manifested no abnormalities; DNA alterations comprised 6 homozygous deletions, 2 concurrent mutations and methylation of exon 2, and 13 with methylation at exon 1 and exons 1 and 2 (12 with methylation only and 1 with mutation) at exon 1. Except for patients' gender (P = 0.02), no significant correlation between p16 and clinicopathological factors was observed. We conclude that in HNSC 1) intragenic p16 alterations are infrequent events, 2) methylation of exon 1 constitutes a common mechanism in silencing the p16 gene, 3) p16 inactivation may play an important role in the early development and progression of HNSC, and 4) no association between p16 alterations and conventional clinicopathological factors was noted in this cohort.

Microsatellite alterations at chromosome 8q loci in pleomorphic adenoma.

OBJECTIVE: To determine the extent, localization, and clinical significance of microsatellite loci alterations at sites of reported cytogenetic abnormalities in pleomorphic adenomas. BACKGROUND: Pleomorphic adenoma is a benign salivary gland tumor with a propensity for recurrence and potential for malignant conversion. Although its cause remains unclear, clonal cytogenetic abnormalities have been reported consistently. DESIGN: DNA extracted from paired normal and tumor tissue specimens from 1 patient with carcinoma ex pleomorphic adenoma and 17 patients with pleomorphic adenoma (3 contained foci of carcinoma ex pleomorphic adenoma) was evaluated for loss of heterozygosity at microsatellite loci with a multiplex polymerase chain reaction-based analysis. Correlation with clinical and pathologic features was performed. RESULTS: Overall 10 (56%) of 18 cases manifested loss of heterozygosity at the loci tested. The frequency of loss of heterozygosity noted on 3p, 6q, 8p, 8q, and 12q microsatellite loci was 17%, 12%, 8%, 47%, and 27% of informative cases, respectively. Specimens from patients with carcinoma ex pleomorphic adenoma showed a similar loss of heterozygosity incidence at these loci. No apparent association between molecular abnormalities and clinical-pathologic features was observed in this cohort. CONCLUSIONS: Loss of heterozygosity at microsatellite loci on 8q, a breakpoint at which translocations have been previously documented in pleomorphic adenoma, is a frequent event in this tumor. The incidence is not increased in patients with focal carcinoma ex pleomorphic adenoma, suggesting that loss of heterozygosity at 8q is an early event in tumorigenesis. Further evaluation at these loci is needed to identify potential tumor suppressor genes that may be associated with the initiation and progression of pleomorphic adenomas.

Chromosomal and DNA ploidy characterization of salivary gland neoplasms by combined FISH and flow cytometry.

Concurrent DNA ploidy by flow cytometry and interphase FISH analysis of chromosomes 6 through 12, 17, 18, X, and Y were prospectively performed on 22 salivary gland neoplasms (four benign and 18 malignant) to investigate the diagnostic and biological implications of their alterations in these neoplasms. Our results show that benign neoplasms lack DNA aneuploidy and numerical chromosomal abnormalities. Low-grade malignant neoplasms, except for two lesions, manifested small chromosomal gains and losses and were generally DNA diploid or near-diploid aneuploid, whereas all high-grade tumors showed marked polysomy and were DNA aneuploid. Marked intratumoral and intertumoral chromosomal heterogeneity also were noted in and between individual tumors. Although polysomy was the main finding in DNA aneuploid lesions, monosomy was more noted in DNA diploid neoplasms and was restricted to chromosomes 8, 11, and 17. Significant correlation between the DNA index, chromosomal aneusomy, histological grade, and tumor stage was noted. Our study indicates that (1) benign salivary gland neoplasms lack gross DNA content and numerical chromosomal abnormalities, (2) clonal chromosomal alterations are manifested in most DNA diploid and all DNA aneuploid malignant tumors, (3) chromosomal gain is the most common alteration; chromosomal loss is less frequent and restricted to certain chromosomes, and (4) DNA aneuploidy and chromosomal aneusomy characterize tumors with aggressive features.