p53 tumor suppressor gene as a clonal marker in head and neck squamous cell carcinoma: p53 mutations in primary tumor and matched lymph node metastases

Aneuploidy Landscape in Precursors of Ovarian Cancer

PURPOSE

Serous tubal intraepithelial carcinoma (STIC) is now recognized as the main precursor of ovarian high-grade serous carcinoma (HGSC). Other potential tubal lesions include p53 signatures and tubal intraepithelial lesions. We aimed to investigate the extent and pattern of aneuploidy in these epithelial lesions and HGSC to define the features that characterize stages of tumor initiation and progression.

EXPERIMENTAL DESIGN

We applied RealSeqS to compare genome-wide aneuploidy patterns among the precursors, HGSC (cases, n = 85), and histologically unremarkable fallopian tube epithelium (HU-FTE; control, n = 65). On the basis of a discovery set (n = 67), we developed an aneuploidy-based algorithm, REAL-FAST (Repetitive Element AneupLoidy Sequencing Fallopian Tube Aneuploidy in STIC), to correlate the molecular data with pathology diagnoses. We validated the result in an independent validation set (n = 83) to determine its performance. We correlated the molecularly defined precursor subgroups with proliferative activity and histology.

RESULTS

We found that nearly all p53 signatures lost the entire Chr17, offering a "two-hit" mechanism involving both TP53 and BRCA1 in BRCA1 germline mutation carriers. Proliferatively active STICs harbor gains of 19q12 (CCNE1), 19q13.2, 8q24 (MYC), or 8q arm, whereas proliferatively dormant STICs show 22q loss. REAL-FAST classified HU-FTE and STICs into 5 clusters and identified a STIC subgroup harboring unique aneuploidy that is associated with increased proliferation and discohesive growth. On the basis of a validation set, REAL-FAST showed 95.8% sensitivity and 97.1% specificity in detecting STIC/HGSC.

CONCLUSIONS

Morphologically similar STICs are molecularly distinct. The REAL-FAST assay identifies a potentially "aggressive" STIC subgroup harboring unique DNA aneuploidy that is associated with increased cellular proliferation and discohesive growth. REAL-FAST offers a highly reproducible adjunct technique to assist the diagnosis of STIC lesions.

TP53 Mutations in Head and Neck Squamous Cell Carcinoma and Their Impact on Disease Progression and Treatment Response

Recent studies describing the mutational landscape of head and neck squamous cell carcinoma (HNSCC) on a genomic scale by our group and others, including The Cancer Genome Atlas, have provided unprecedented perspective for understanding the molecular pathogenesis of HNSCC progression and response to treatment. These studies confirmed that mutations of the TP53 tumor suppressor gene were the most frequent of all somatic genomic alterations in HNSCC, alluding to the importance of the TP53 gene in suppressing the development and progression of this disease. Clinically, TP53 mutations are significantly associated with short survival time and tumor resistance to radiotherapy and chemotherapy in HNSCC patients, which makes the TP53 mutation status a potentially useful molecular factor for risk stratification and predictor of clinical response in these patients. In addition to loss of wild-type p53 function and the dominant-negative effect on the remaining wild-type p53, some p53 mutants often gain oncogenic functions to promote tumorigenesis and progression. Different p53 mutants may possess different gain-of-function properties. Herein, we review the most up-to-date information about TP53 mutations available via The Cancer Genome Atlas-based analysis of HNSCC and discuss our current understanding of the potential tumor-suppressive role of p53, focusing on gain-of-function activities of p53 mutations. We also summarize our knowledge regarding the use of the TP53 mutation status as a potential evaluation or stratification biomarker for prognosis and a predictor of clinical response to radiotherapy and chemotherapy in HNSCC patients. Finally, we discuss possible strategies for targeting HNSCCs bearing TP53 mutations. J. Cell. Biochem. 117: 2682-2692, 2016. © 2016 Wiley Periodicals, Inc.

Clonality analysis in primary oral squamous cell carcinoma and related lymph-node metastasis revealed by TP53 and mitochondrial DNA next generation sequencing analysis

The chance of developing a neck nodal metastasis after initial treatment of oral squamous cell carcinoma varies from 12.4% to 62%. Despite being the main reason for cancer-related mortality, nodal metastases are still rarely subjected to molecular analyses, and our knowledge of the clonal heterogeneity of multiple lesions within the same patient is limited. The aim of the present study was to evaluate the relationship between primary oral cancer and lymph node metastasis in a series of patients with synchronous and metachronous metastases by 2 clonality tests: mt-DNA and TP53 sequence analysis. The study population consisted of 10 consecutive patients. Data identified in this study demonstrate that our assay based on next-generation analysis of TP53 and mt-DNA is simple, is reliable, allows high throughput, and may be applied to retrospective cases. The combination of mt-DNA and TP53 data analysis helped us to evaluate more precisely and consistently the genetic relationship among different tumor clones.

Survivin and pAkt as potential prognostic markers in squamous cell carcinoma of the head and neck

OBJECTIVE

The purpose of our study was to investigate the expression patterns of cell cycle regulatory proteins and members of the epidermal growth factor receptor (EGFR) signaling pathway in squamous cell carcinoma of the head and neck (HNSCC).

STUDY DESIGN

The expression levels of survivin, Bub1 B (budding uninhibited by benzimidazoles 1 homolog beta), PLK-1 (polo-like kinase 1), Ki-67, cyclin D1, p53, EGFR, pMAPK (phosphorylated mitogen-activated protein kinase), pAkt (phosphorylated protein kinase B), and PTEN (phosphatase and tensin homolog) were studied in a series of 180 tumor samples obtained from HNSCC surgical resections, 50 metastatic lymph node samples, and 72 corresponding noncancerous epithelium samples. Protein expression analysis was performed by immunohistochemical staining. The results were correlated with clinicopathologic features and survival data.

RESULTS

Prognostic significance could be found only for the markers survivin and pAkt. Only the marker combination of cyclin D1 and p53 had positive prognosis potential regarding overall survival.

CONCLUSIONS

Both pAkt and survivin show a positive correlation with distant metastases and may have utility as predictors of long-term outcomes for patients with HNSCC.

Biological resonance for cancer metastasis, a new hypothesis based on comparisons between primary cancers and metastases

Many hypotheses have been proposed to try to explain cancer metastasis. However, they seem to be contradictory and have some limitations. Comparisons of primary tumors and matched metastases provide new insight into metastasis. The results show high concordances and minor differences at multiple scales from organic level to molecular level. The concordances reflect the commonality between primary cancer and metastasis, and also mean that metastatic cancer cells derived from primary cancer are quite conservative in distant sites. The differences reflect variation that cancer cells must acquire new traits to adapt to foreign milieu during the course of evolving into a new tumor in second organs. These comparisons also provided new information on understanding mechanism of vascular metastasis, organ-specific metastasis, and tumor dormancy. The collective results suggest a new hypothesis, biological resonance (bio-resonance) model. The hypothesis has two aspects. One is that primary cancer and matched metastasis have a common progenitor. The other is that both ancestors of primary cancer cells and metastatic cancer cells are under similar microenvironments and receive similar or same signals. When their interactions reach a status similar to primary cancer, metastasis will occur. Compared with previous hypotheses, the bio-resonance hypothesis seems to be more applicable for cancer metastasis to explain how, when and where metastasis occurs. Thus, it has important implications for individual prediction, prevention and treatment of cancer metastasis.

Overview of cancer for the healthcare team: aetiopathogenesis and early diagnosis

Much cancer presents late, at a stage when not only is more radical treatment necessary, but the prognosis is also less favourable. This paper attempts to provide an overview of the aetiopathogenesis of cancer (carcinoma) for the healthcare team, a broad understanding of which is crucial for coping with issues related to prevention, diagnosis and management. Prevention of cancer involves lifestyle decisions which afford protection not only against cancers in many sites, but also against a wide range of other conditions, many of which are equally life-threatening. The paper also highlights areas of controversy in the early diagnosis of oral cancer. Earlier diagnosis is likely to be achieved reliably only with the introduction of molecular studies.

CDKN2A but not TP53 mutations nor HPV presence predict poor outcome in metastatic squamous cell carcinoma of the skin

Genetic alterations in metastatic cutaneous squamous cell carcinoma (CSCC) which might serve as prognostic biomarkers are not well investigated. We investigated the mutation status and protein expression of the CDKN2A (INK4a-ARF) and TP53 genes in metastatic CSCCs and correlated this with clinicopathological variables, HPV presence, and survival data. Sequence analysis was performed on formalin-fixed and paraffin-embedded tissue of 35 metastases and their primary tumors, and was correlated with immunohistochemical stainings for p53, p16 and p14. Beta-PV and alpha-PV DNA was detected using PCR-based assays. Kaplan-Meier and Cox regression methods were used for survival assessment. CDKN2A was mutated in 31% of the metastases and their primary tumors, while the TP53 gene was mutated in 51% of the metastases. P53 protein expression was significantly associated with missense type of mutations (p = 0.002). No persistent HPV types were detected. CDKN2A mutations were significantly associated with disease-specific death (p = 0.001). A significant difference was observed in disease-specific survival between patients with or without a CDKN2A mutation (p = 0.010), while this was not the case for TP53. At univariate Cox's regression analysis tumor size (p = 0.010), invasion depth (p = 0.030) and CDKN2A mutations (p = 0.040) were significantly related to shorter disease-specific survival. At multivariate Cox's regression only tumor size had an adverse effect on survival (p = 0.002). In conclusion, our study indicates that the CDKN2A mutation status might be of prognostic value in metastatic CSCCs. In most cases, CDKN2A and TP53 mutations are early genetic events in CSCC tumorigenesis. The possible role of HPV in metastatic CSCC needs further exploration.

Late (> 5 years) regional lymph node metastasis of oral squamous cell carcinoma (SCC), proven by p53 mutation analysis

BACKGROUND

A late (> 5 years) neck nodal metastasis of oral cancer, poses a problem to the clinician: is it a late metastasis or a metastasis of a (unknown) second primary tumour?

METHODS

A 50-year-old male was seen with a contralateral lymph node metastasis, 5 1/2 years after treatment of a pT2N1M0 carcinoma in the floor of the mouth. Both the late metastasis and the original tumour specimen were analysed for p53 mutations.

RESULTS

Both specimens showed an identical p53 mutation, thereby confirming the lymph node to be a late metastasis.

CONCLUSIONS

A lymph node metastasis can occur more than 5 years after treatment of an oral squamous cell carcinoma. p53 mutation analysis is of help to discriminate it from a second primary tumour.

Prognostic significance of p53 and p63 immunolocalisation in primary and matched lymph node metastasis in oral squamous cell carcinoma

This study evaluates the prognostic significance of p53 and p63 immunolocalisation in oral squamous cell carcinoma samples from 45 matched primary tumors (PT) and lymph node metastases (LNM). Data regarding patient age, gender, primary site, histological differentiation, metastasis, disease-free survival (DFS) and overall survival (OS) were available. p53 and p63 immunolabeling was detected in 17 (37.8%) and 23 (51.1%) of the PT, respectively. For LNM, there was p53 and p63 labeling in 23 (51.1%) and 26 (57.8%) cases, respectively. Most cases showed similar labeling in PT and the corresponding LNM (73.3% for p53 and 53.3% for p63, respectively). No statistically significant associations were found between p53 and p63 immunolabeling and histological differentiation; p63 positive tumors showed higher DFS (p=0.006) and OS (p=0.049); and p53-negative tumors had a higher DFS interval (p=0.009). Our findings suggest that initially p53-negative tumors and initially p63-positive tumors that retain this labeling pattern may follow less aggressive biological courses and present better prognoses.

Human monoclonal antibodies as a tool for the detection of HLA class I allele-specific expression loss in head-and-neck squamous cell carcinoma and corresponding lymph node metastases

Human leukocyte antigen (HLA) expression is important for the elimination of tumor cells by the immune system and immunotherapy. Activated T cells directed against tumor-associated antigens are fully capable of recognizing and eradicating neoplastic cells. Therefore, HLA expression loss is considered to be a main factor in tumor development. We report for the first time HLA-A and HLA-B allele-specific expression analysis by immunohistochemical staining of fresh tumor tissue and 9 lymph node metastases of 15 patients with head-and-neck squamous cell carcinoma. Heterogeneous HLA expression and HLA expression loss was detected in 13 tumor patients. Approximately 50% of the tumors had allele-specific expression loss, which would have remained undetected using HLA monomorphic and locus-specific antibodies. In the majority of the patients with head-and-neck squamous cell carcinoma, HLA allele-specific expression loss differed between primary lesions and metastases. This is important for the efficacy of immunotherapy in these patients. It can be concluded that it is crucial to study HLA expression at the allele-specific level of primary lesions and metastases. It increases and refines our knowledge of HLA expression loss in tumorgenesis, which will improve the development of specific immunotherapy.

Clinical value of genetically diagnosed lymph node micrometastasis for patients with oral squamous cell carcinoma

BACKGROUND

The purpose of this study was to investigate the incidence and clinical significance of genetically diagnosed lymph node micrometastasis for patients with oral squamous cell carcinoma (SCC).

METHODS

A total of 495 lymph nodes obtained from 21 patients with primary oral SCCs that had p53 mutations were examined for corresponding p53 mutations in lymph nodes using mutant allele-specific amplification (MASA).

RESULTS

Among 476 histologically negative nodes, 44 were scored as positive for metastasis by MASA. All 19 histologically positive lymph nodes were genetically positive. Four of the 10 pN0 cases and nine of the 11 pN-positive cases had genetically positive micrometastases. Four patients who had five or more genetically positive lymph nodes located in three or more levels, three with disease staged as pN0 or pN1, died of cancer.

CONCLUSIONS

These results indicate that a high rate of micrometastasis in cervical lymph nodes of oral SCCs and patients with multiple or lower neck spread of micrometastases have a poor prognosis; they should be treated with postoperative adjuvant therapy.

TP53 and head and neck neoplasms

Head and neck cancer is an important health problem around the world, accounting for approximately 500,000 new cases each year of head and neck squamous cell carcinoma (HNSCC). Carcinogenesis of head and neck results from a dysregulation of cellular proliferation, differentiation, and cell death. The major etiologic agents are tobacco and alcohol consumption and for some cases, human papilloma virus (HPV) infection. All three factors are associated with the disruption of a cellular pathway essential for the maintenance of cellular integrity, the p53 pathway. The objective of this review is to point out the specificity of p53 gene (TP53) alterations in head and neck cancer in relation with chemocarcinogenesis and to discuss whether or not the determination of p53 alterations will be of clinical relevance in the management of head and neck cancer in terms of prognosis and response to treatments.

Early metastatic progression of bladder carcinoma: molecular profile of primary tumor and sentinel lymph node

PURPOSE

We characterized early metastatic progression of bladder carcinoma from the primary tumor, separated in the central part and invasive front, to the first lymphatic metastasis.

MATERIALS AND METHODS

Included in this study were 8 patients undergoing sentinel lymph node detection for invasive bladder cancer, of whom 4 had metastasis in the sentinel lymph node and 4 were randomly chosen without metastases. After microdissection p53 genomic structure and immunohistochemical expression of p53, pRB, Ki67 and E-cadherin were analyzed. Microvessel density and apoptosis were also assessed.

RESULTS

In 5 patients there were p53 gene mutations in the primary tumor, while 3 had the wild-type gene. The genotypes were identical in the central part and invasive front. All sentinel lymph node metastases harbored p53 mutations, in contrast to all nonmetastatic sentinel lymph nodes. Two patients had the same mutation as the primary tumor and 1 had an additional mutation. In a patient with a wild-type gene in each compartment of the primary tumor a mutation appeared in the corresponding sentinel lymph node metastasis. There was poor concordance of p53 mutation with protein status. The expression of p53, pRB, Ki67, E-cadherin, and the evaluation of apoptosis and angiogenesis showed in most cases only slight variations in tumor compartments and the sentinel lymph node.

CONCLUSIONS

In this study invasive bladder carcinoma involved monoclonal proliferations with a mainly homogenous biomarker profile. The first metastases in sentinel lymph nodes had a similar molecular profile but in half of the cases signs of clonal evolution appeared.

Discordance of genetic alterations between primary head and neck tumors and corresponding metastases associated with mutational status of the TP53 gene

Ample molecular data are available on the progression from normal mucosa to invasive head and neck squamous cell carcinoma (HNSCC), but information on further genetic progression to metastatic disease is scarce. To obtain insight into the metastatic process, we compared 23 primary HNSCCs with 25 corresponding lymph node metastases (LNMs) and 10 corresponding distant metastases (DMs) with respect to TP53 mutations and patterns of loss of heterozygosity (LOH) based on 26 microsatellite markers on six chromosome arms (3p, 9p, 17p, 13q, 8p, and 18q). In 18 of the 23 patients, a TP53 mutation was detected in the primary tumor, and in all cases the same TP53 mutation was present in the corresponding LNM or DM. In nine of 20 patients with LNMs and three of seven patients with DMs, the LOH pattern of metastasis differed from that of the corresponding primary tumor by at least one marker. Microsatellite markers located on chromosome arms 13q, 8p, and 18q were most frequently discordant, providing evidence that alterations at these chromosomes occur late in HNSCC carcinogenesis. Moreover, evidence was found that DMs had developed directly from the primary tumor and not from LNMs. Remarkably, we observed that the mutational status of the TP53 gene is associated significantly with the degree of genetic differences between primary HNSCCs and corresponding metastases. All patients with TP53 wild-type primary tumors showed significantly more discordant LOH patterns in the corresponding LNMs and DMs than patients with TP53-mutated tumors. The percentages were 100% versus 27% (LNMs) and 100% versus 0% (DMs), respectively (P = 0.008 and P = 0.029; two-sided Fisher exact test). This finding suggests that TP53-mutated tumors need fewer additional genetic alterations to develop metastases compared with TP53 wild-type primary tumors.

p53 mutation analysis for definite diagnosis of multiple primary lung carcinoma

BACKGROUND

The detection of a second tumor in patients with lung carcinoma raises the question whether this lesion is a metastasis or a second primary lung carcinoma. Patients cannot always be categorized satisfactorily according the criteria of multiple lung carcinoma proposed by Martini and Melamed. This may result in an inadequate treatment schedule in individual patients. Because p53 mutations can be used as clonal marker, the authors investigated whether p53 mutation analysis can differentiate between primary lung carcinomas and metastatic disease.

METHODS

Sixty-four tumors in 31 patients with synchronous and metachronous lung tumors were investigated by p53 mutation analysis.

RESULTS

In 21 patients, the tumors showed different p53 mutations, and therefore a definite diagnosis of multiple primary lung carcinoma was made. One of these patients did not meet the criteria of Martini and Melamed. In two other patients not matching these criteria, identical mutations were demonstrated in both tumors, indicating the presence of metastatic disease. In eight patients, analysis was not conclusive or possible.

CONCLUSIONS

p53 mutation analysis can be a useful tool to confirm or rule out multiple primary lung carcinoma, and the results confirm the criteria of Martini and Melamed. However, in patients not meeting these criteria, the diagnosis of multiple lung carcinoma still has to be considered, and metastatic disease has to be ruled out. P53 mutation analysis can be helpful for this purpose.

Molecular markers of metastasis in squamous carcinomas

The prognosis for patients with squamous carcinomas of the head and neck region is strongly influenced by the presence or absence of cervical lymph node metastases. Biological markers that indicated a high risk of metastasis would have a major role in determining the optimal therapeutic strategy for these patients. This editorial discusses recent studies of molecular and genetic markers of squamous carcinomas in relation to metastatic potential and highlights some of the issues that limit current progress in this field of study.

Expression of p53 tumor suppressor gene in adenoid cystic and mucoepidermoid carcinomas of the salivary glands

Seventeen adenoid cystic carcinomas (ACCs) and 27 mucoepidermoid carcinomas (MECs) occurring in the salivary glands were analyzed for p53 tumor suppressor gene alteration (exons 5-8) and protein expression. The cell proliferation activity was also examined by Ki-67 immunohistochemistry. The p53 alterations were detected in three samples (17.6%) of ACC and in four samples (14.8%) of MEC, and were only found in carcinomas arising in the minor salivary glands. The occurrence of the p53 gene alteration is less frequent in ACC and MEC than that in other kinds of tumors, and therefore does not seem to play a critical role in the course of the tumorigenesis in ACC and MEC. All ACC samples arising from the minor salivary glands exhibiting p53 gene alterations showed recurrence/metastasis, thus suggesting a poor outcome of these patients. All ACCs and three out of four MECs samples with p53 gene alterations showed the lowest degree of p53 immunostaining ratio, thus suggesting that no correlation exists between the p53 gene alterations and the p53 immunostaining in these salivary gland carcinomas. No significant relationship was demonstrated between the immunostaining ratio of either p53 or Ki-67 and the morphological growth pattern or patient clinical course in the ACC samples. The p53 immunopositivity in MEC correlated to the histological grade. The Ki-67 immunostaining ratio was also significantly related to the histological grade and the clinical course in MEC.

The origins of multiple squamous cell carcinomas in the aerodigestive tract

BACKGROUND

Chemoprevention and cessation of smoking and alcohol may prevent development of multiple tumors (MTs) in the aerodigestive tract if new MTs arise independently, but they are of no benefit if MTs are due to migration of an already transformed clone of tumor cells. This issue was addressed in this study by investigation of the clonality among MTs.

METHODS

Mutation analysis of the entire coding region of p53 and loss of heterozygosity (LOH) pattern analysis of microsatellite markers on chromosome arms 3p, 9p, and 17p are promising for the investigation of clonality. In the first part of this study, the authors established the variability and stability of these clonal markers by comparing primary head and neck squamous cell carcinomas (HNSCCs) with their metastases. In the second part of this study, the authors evaluated nine patients with multiple HNSCCs using these markers. In the final part, the authors illustrate the use of these clonal markers in 11 patients for whom there was diagnostic uncertainty as to whether their second squamous cell carcinoma was either a new primary tumor, a metastasis, or a recurrence.

RESULTS

Both p53 gene mutations and LOH patterns were stable during tumor progression. Furthermore, the variability of p53 gene mutations was high. More than 90% of the tumors contained a p53 mutation. A particular mutation never occurred more than twice in a total of 69 primary HNSCCs. Five of 69 cases presented a common mutation. In contrast, LOH patterns showed less variability; they were identical in 5 of 16 cases. The metachronous HNSCCs from nine patients all showed different p53 mutations, and in the three cases that were subjected to LOH analysis different patterns were observed. All 11 patients for whom there was diagnostic uncertainty about the origin of their second squamous cell carcinoma could be categorized as having multiple primary tumors, disseminated disease, or recurrent disease.

CONCLUSIONS

Metachronous HNSCCs at different locations are not clonally related and thus have not developed from the migration of tumor cells.