p53 Mutations in Deep Tissues Are More Strongly Associated with Recurrence than Mutation-Positive Mucosal Margins

Molecular margins in head and neck cancer: Current techniques and future directions

Complete tumor extirpation with clear surgical margins remains a central tenet of oncologic head and neck surgery. Rates of locoregional recurrence and survival are both significantly worse when clear margins are unable to be obtained. Current clinical practice relies on the use of frozen sections intra-operatively, followed by traditional histopathologic analysis post-operatively to assess the surgical margin. However, with improved understanding of tumor biology and advances in technology, new techniques have emerged to analyze margins at a molecular level. Such molecular margin analysis interrogates tissue for genetic, epigenetic, or proteomic changes that may belie tumor presence or aggressive features not captured by standard histopathologic techniques. Intra-operatively, this information may be used to guide resection, while post-operatively, it may help to stratify patients for adjuvant treatment. In this review, we summarize the current state of molecular margin analysis and describe directions for future research.

Epi-drugs as triple-negative breast cancer treatment

Triple-negative breast cancer (TNBC) types with poor prognosis are due to the absence of estrogen receptors, progesterone receptors and HEGFR-2. The lack of suitable therapy for TNBC has led the research community to turn toward epigenetic regulation and its protagonists that can modulate certain oncogenes and tumor suppressors. This has opened an important new field of therapy using epi-drugs, in preclinical and clinical trials. The epi-drugs are natural or synthetic molecules capable of inhibiting or modulating the activity of epigenetic proteins such as DNA methyltransferases, modulating the expression of interferon microRNAs, as well as histone methyltransferases, demethylases, acetyltransferases and deacetylases. This review investigated the epi-drugs used in the treatment of TNBC.

p53-positive expression in dysplastic surgical margins is a predictor of tumor recurrence in patients with early oral squamous cell carcinoma

Purpose

This was a retrospective analysis of the impact of the expression of p53 in the dys-plastic surgical margins of early oral squamous cell carcinoma (OSCC) (pT1-2, N0).

Patients and methods

Seventy-two patients with early oral squamous cell carcinoma (OSCC) were recruited. Margin characteristics were abstracted from the pathology report. Expression of p53 in dysplastic surgical margins was examined with the immunohistochemical method and was correlated with clinicopathological parameters and clinical outcomes.

Results

Patients with moderate/severe dysplasia had poor local relapse-free survival (RFS) compared to those with mild dysplasia. Thirty-two (44.4%) had at least one p53-positive margin, and there was a significant association between the expression of p53 and tumor recurrence (P<0.001). p53-positive expression was correlated with RFS in patients with dysplastic margins, and its expression in moderate/severe dysplastic groups had a worse RFS than mild dysplastic groups. We also found that the grade of the dysplasia margin was not correlated with RFS in p53-negative groups. Multivariable analysis validated p53 expression in dysplastic surgical margins as an independent risk factor for recurrence.

Conclusion

Our results validated that p53 expression was an independent risk factor for early OSCC with dysplastic surgical margins. Additional therapy and close follow-up are needed for these patients.

Surgical margins in head and neck cancer: Intra- and postoperative considerations

OBJECTIVE

To provide a perspective on the significance of recent reports for optimizing cancer free surgical margins that have challenged standard practices.

METHODS

We conducted a review of the recent literature (2012-2018) using the keywords surgical margin analysis, frozen and paraffin section techniques, head and neck cancer, spectroscopy and molecular markers.

RESULTS

Of significance are the reports indicating superiority of tumor specimen directed sampling of margins compared to patient directed (tumor bed) sampling for frozen section control of oral cancers. With reference to optimal distance between tumor and the surgical margin, recent reports recommended cutoffs less than 5mm. Employment of new technologies such as light spectroscopy and molecular analysis of tissues, provide opportunities for a "real time" assessment of surgical margins.

CONCLUSIONS

The commonly practiced method of patient directed margin sampling involving previous studies raises concern over conclusions made regarding the efficacy of frozen section margin control. The recent studies that challenge the optimal distance for clear surgical margins are retrospective and address patient cohorts with inherently confounding factors. The use of novel ancillary techniques require further refinements, clinical trial validation, and justification based on the additional resources.

Surgical Margins: The Perspective of Pathology

Neoplasms of the head and neck constitute a broad spectrum of benign and malignant entities. When treatment involves resection, assessment of the surgical margins represents an important component of the pathologic examination. Margin status is an important indicator of a complete surgical resection. The ability to generalize conclusions such as 'safe distance' measurements from work performed mSCCa or cutaneous malignancy to other types of neoplasms in the head and neck region seems limited. This article reviews conditions and considerations for reliable margin assessment and interpretation.

Paired box 5 methylation detection by droplet digital PCR for ultra-sensitive deep surgical margins analysis of head and neck squamous cell carcinoma

Molecular deep surgical margin analysis has been shown to predict locoregional recurrences of head and neck squamous cell carcinoma (HNSCC). To improve the accuracy and versatility of the analysis, we used a highly tumor-specific methylation marker and highly sensitive detection technology to test DNA from surgical margins. Histologically cancer-negative deep surgical margin samples were prospectively collected from 82 eligible HNSCC surgeries by an imprinting procedure (n = 75) and primary tissue collection (n = 70). Bisulfite-treated DNA from each sample was analyzed by both conventional quantitative methylation-specific PCR (QMSP) and QMSP by droplet digital PCR (ddQMSP) targeting Paired box 5 (PAX5) gene promoter methylation. The association between the presence of PAX5 methylation and locoregional recurrence-free survival (LRFS) was evaluated. PAX5 methylation was found in 68.0% (51 of 75) of tumors in the imprint samples and 71.4% (50 of 70) in the primary tissue samples. Among cases that did not have postoperative radiation (n = 31 in imprint samples, n = 29 in tissue samples), both conventional QMSP and ddQMSP revealed that PAX5 methylation-positive margins was significantly associated with poor LRFS by univariate analysis. In particular, ddQMSP increased detection of the PAX5 marker from 29% to 71% in the nonradiated imprint cases. Also, PAX5 methylated imprint margins were an excellent predictor of poor LRFS [HR, 3.89; 95% confidence interval (CI), 1.19-17.52; P = 0.023] by multivariate analysis. PAX5 methylation appears to be an excellent tumor-specific marker for molecular deep surgical margin analysis of HNSCC. Moreover, the ddQMSP assay displays increased sensitivity for methylation marker detection.

Correlation of gene methylation in surgical margin imprints with locoregional recurrence in head and neck squamous cell carcinoma

BACKGROUND

Securing negative surgical margins is a critical goal for head and neck surgery. Local recurrence develops even in some patients who have histologically negative surgical margins. Minimal residual tumor cells may lead to locoregional recurrence despite clear histologic margins reported at the time of resection of head and neck squamous cell carcinoma (HNSCC). To identify subclinical residual disease, the authors analyzed deep margin imprint samples collected on 1-layer nitrocellulose sheets.

METHODS

Bisulfite-treated DNA samples from 73 eligible patients were amplified by quantitative methylation-specific polymerase chain reaction (QMSP) targeting 6 genes (deleted in colorectal cancer [DCC], endothelin receptor type B [EDNRB], homeobox protein A9 [HOXA9], kinesin family member 1A [KIF1A], nidogen-2 [NID2], and N-methyl D-aspartate receptor subtype 2B [NR2B]). QMSP values were dichotomized as positive or negative. Associations between the QMSP status of deep margin samples and clinical outcomes were evaluated.

RESULTS

Two-gene methylation combinations among the genes DCC, EDNRB, and HOXA9 were associated with decreased locoregional recurrence-free survival, recurrence-free survival, and overall survival. The methylated gene combination of EDNRB and HOXA9 in margin imprints was the most powerful predictor of poor locoregional recurrence-free survival (hazard ratio [HR], 3.31; 95% confidence interval [CI], 1.30-8.46; P = .012) independent of standard histologic factors. In addition, methylation of both EDNRB and HOXA9 indicated a trend toward reduced recurrence-free survival (HR, 2.74; 95% CI, 0.90-8.33; P = .075) and reduced OS (HR, 5.78; 95% CI, 0.75-44.7; P = .093) in multivariable analysis.

CONCLUSIONS

A panel of gene methylation targets in deep surgical margin imprints provides a potential predictive marker of postoperative locoregional recurrence. Intraoperative use of molecular margin imprint analysis may assist surgeons in obtaining rigorously negative surgical margins and improve the outcome of head and neck surgery.

Tumor microenvironment in head and neck squamous cell carcinoma

The tumor microenvironment (TME) of head and neck squamous cell carcinoma (HNSCC) is comprised of cancer-associated fibroblasts (CAFs), immune cells, and other supporting cells. Genetic changes in the carcinoma cells, such as alterations to TP53, NOTCH1, and specific gene expression profiles, contribute to derangements in cancer and microenvironment cells such as increased ROS, overproduction of cytokines, and epithelial to mesenchymal transition (EMT). CAFs are among the most critical elements of the TME contributing to proliferation, invasion, and metastasis. The adaptive immune response is suppressed in HNSCC through overexpression of cytokines, triggered apoptosis of T cells, and alterations in antigen processing machinery. Overexpression of critical cytokines, such as transforming growth factor-β (TGF-β), contributes to EMT, immune suppression, and evolution of CAFs. Inflammation and hypoxia are driving forces in angiogenesis and altered metabolism. HNSCC utilizes glycolytic and oxidative metabolism to fuel tumorigenesis via coupled mechanisms between cancer cell regions and cells of the TME. Increased understanding of the TME in HNSCC illustrates that the long-held notion of "condemned mucosa" reflects a process that extends beyond the epithelial cells to the entire tissue comprised of each of these elements.

Prognostic value of cyclin D1 expression in tumor-free surgical margins in head and neck squamous cell carcinomas

CONCLUSION

It was proved that cyclin D1-positive status in surgical margins was an independent prognostic indicator of local recurrence. The expression of cyclin D1 in tumor-free surgical margins may better predict local recurrence in patients with head and neck squamous cell carcinoma (HNSCC) after surgical treatment with curative intent.

OBJECTIVE

This retrospective study aimed to determine the prognostic indicators for local recurrence in HNSCC.

METHODS

A total of 116 HNSCC patients who underwent surgical treatment with curative intent and had histopathologically tumor-free margins were eligible for this study. The expression of p53 and cyclin D1 was assessed by immunohistochemical staining in surgical margins as well as in tumor specimens.

RESULTS

In all, 63 patients (54.3%) had p53-positive tumor specimens and 34 patients (29.3%) had p53-positive margins. Seventy-six patients (65.6%) had cyclin D1-positive tumor specimens and 54 patients (46.6%) had cyclin D1-positive margins. A significant difference in local control rates was observed between patients with cyclin D1-positive and -negative margins (77.2% vs 91.5%, log rank test, p = 0.0139). Multivariate Cox proportional hazards testing indicated that the hazard ratio of cyclin D1-positive margins for local recurrence was 4.58 (95% confidence interval 1.14-21.69, p = 0.0304).

p53: a molecular marker for the detection of cancer

BACKGROUND

The p53 gene is the most frequently mutated gene in cancer and accordingly has been the subject of intensive investigation for almost 30 years. Loss of p53 function due to mutations has been unequivocally demonstrated to promote cancer in both humans and in model systems. As a consequence, there exists an enormous body of information regarding the function of normal p53 in biology and the pathobiological consequences of p53 mutation. It has long been recognised that analysis of p53 has considerable potential as a tool for use in both diagnostic and, to a greater extent, prognostic settings and some significant progress has been made in both of these arenas.

OBJECTIVE

To provide an overview of the biology of p53, particularly in the context of uses of p53 as a diagnostic tool.

METHODS

A literature review focused upon the methods and uses of p53 analysis in the diagnosis of sporadic cancers, rare genetic disorders and in detection of residual disease.

CONCLUSION

p53 is currently an essential diagnostic for the rare inherited cancer prone syndrome (Li-Fraumeni) and is an important diagnostic in only a limited number of settings in sporadic disease. Research in specific cancers indicates that the uses of increasingly well informed p53 mutational analysis are likely to expand to other cancers.

The utility of molecular diagnostics to predict recurrence of head and neck carcinoma

BACKGROUND

Locoregional recurrence is the major cause of treatment failure after surgery for oral squamous cell carcinoma. Molecular diagnostics have the potential to improve on clinicopathological parameters to predict this recurrence and plan adjuvant treatment. The test most frequently applied is based on detecting TP53 mutations, but alternative methodology is required for cases that harbour the wild-type gene.

METHODS

One hundred and two cases with tumour-adjacent margins, considered to be clear margins by microscopy, were examined using carefully optimised molecular diagnostics based on detection of the TP53 and Ly-6D markers. The markers were also combined to provide a dual approach.

RESULTS

The dual molecular diagnostic identified cases with a significant increase in the probablility of developing locoregional recurrence when tumour-adjacent positive and clear margins were compared (P=0.0001). These tests were most useful when the clearance at the resection margins was 5 mm or less. The TP53-based diagnostic was a better predictor of locoregional recurrence than established clinicopathological parameters.

CONCLUSION

The optimised TP53-based diagnostic rapidly identifies an important subgroup of cases with close margins that will benefit from new treatment modalities to reduce the risk of recurrence.

Tissue imprint for molecular mapping of deep surgical margins in patients with head and neck squamous cell carcinoma

BACKGROUND

Tissue imprinting can generate molecular marker maps of tumor cells at deep surgical margins. The purpose of this study was to evaluate the feasibility of this method for detection of residual head and neck squamous cell carcinoma (HNSCC).

METHODS

Paired fresh tissue and nitrocellulose membrane imprints of tumor and deep margins were collected from 17 HNSCC resections. DNA was amplified using quantitative methylation-specific polymerase chain reaction (qMSP) for p16, DCC, KIF1A, and EDNRB. Levels of methylation in tumors and deep margins were compared.

RESULTS

DNA from imprints was adequate for qMSP. Hypermethylation of target genes was present in 12 of 17 tumors and in 8 deep margins. Methylation level was better from margin imprints than tissue. During follow-up (median, 13 months), local or regional recurrences occurred in 6 cases of which 5 had molecularly positive margins.

CONCLUSION

Tissue imprinting is feasible for molecular detection of residual tumor at deep surgical margins and may correlate with locoregional recurrence.

Loss of heterozygosity at 9p and p53 immunopositivity in surgical margins predict local relapse in head and neck squamous cell carcinoma

A major problem in head and neck cancer surgery is the high rate of local relapse (LR). In at least 25% of the surgically treated head and neck squamous cell carcinoma (HNSCC) patients, a genetically defined preneoplastic lesion, also known as "field," can be detected in the surgical margins. A remaining field may be an important cause for the development of LR. The aims of our study are (i) to investigate whether HNSCC patients with an unresected field are more likely to develop LR, and (ii) to identify molecular risk factors that predict malignant transformation of field. We retrospectively studied 35 HNSCC patients of whom 16 patients developed LR and 19 patients remained disease-free for at least 4 years. Loss of heterozygosity (LOH) at chromosomes 3p, 9p and 17p, p53 immunostaining, Ki-67 immunostaining and histopathological grading of all available paraffin-embedded surgical margins was performed, and related to LR. Significant associations were determined by Kaplan-Meier analysis and Cox-proportional hazard models. We show that presence of field is significantly associated with LR and that LOH at 9p and p53 immunostaining have the most predictive potential (hazard ratios 3.17 and 3.46, and p values 0.027 and 0.017, respectively). The combination of LOH at 9p and/or a large p53 positive field is most predictive (hazard ratio 7.06 and p = 0.01). Presence and grade of dysplasia was not associated with LR. These data may have major impact for future diagnostic workup of surgically treated HNSCC patients.

Molecular analysis of surgical margins in head and neck cancer: more than a marginal issue

The relatively modest survival of patients surgically treated for advanced HNSCC can partly be explained by the development of local relapse. It is important that surgeons are able to predict which patients are at high risk to develop local relapse, since clinical management can be tailored. Local relapse after resection of a primary HNSCC is easily explained, when tumour is detected in the surgical margins and thus residual tumour is likely to remain in the patient, but the pathobiology is more complex in cases where the margins are histologically tumour-free. Molecular studies indicate that there are two different mechanisms responsible in these cases. First, small clusters of residual tumour cells that are undetectable on routine histopathological examination (known as minimal residual cancer: MRC) proliferate and this forms the basis of recurring cancer. A second cause of relapse is a remaining field of preneoplastic cells that is struck by additional genetic hits leading to invasive cancer. It is likely that within this field, that can be over 7cm in diameter, the primary carcinoma has also emerged. Despite careful histopathological examination of the surgical margins of the primary carcinoma, it is at present not reliably possible to predict which patient will develop local relapse. Herein we focus on new developments regarding the analysis of margins, causes of local relapse, and how novel molecular techniques can be of help in a more accurate risk assessment. Critical analysis of the studies that have been published thus far shows that there is a list of promising markers, based on protein expression (immuno-histochemistry) and nucleic acid analysis. Further studies should be focused on validation and assessment of the clinical utility of these markers. Margin analysis should reveal whether one is dealing with residual cancer cells that might be treated by post-operative radiotherapy or with preneoplastic fields that remained behind. For this latter entity, there is no intervention available at present, except for a more intensive surveillance.

The Ligamp TP53 Assay for Detection of Minimal Residual Disease in Head and Neck Squamous Cell Carcinoma Surgical Margins

PURPOSE: Detect tumor-related DNA using LigAmp in histologically clear margins and associate results with clinical outcome. EXPERIMENTAL DESIGN: Patients with head and neck cancer were registered for molecular analysis of surgical margins. Adequacy of resection was ensured using histologic margin analysis. Further margins were then harvested and DNA extracted. TP53 mutations in tumor were determined using Affymetrix p53 GeneChip. Margins were analyzed by Ligamp in comparison with standard curves for quantification of mutant DNA. Ligation used two oligonucleotides to isolate DNA targeting the mutation. Ligated DNA was amplified using real-time PCR. The quantity of mutation in the margin was determined as percent of mutant species relative to plasmid and relative to tumor. Cutpoints were identified and defined groups were evaluated for local failure-free, cancer-specific, and overall survival. Study margins were examined for presence of tumor by light microscopy. RESULTS: Tissue from 95 patients with common mutations was analyzed. Fifteen experienced local recurrence. Cutpoints of 0.15% for mutant species relative to plasmid and 0.5% for mutant species relative to tumor were chosen as most selective of recurrent cases. LigAmp had slightly better area under the receiver operator characteristic curve (P = 0.09) than light microscopy correctly predicting 9 of 15 recurrent tumors. There were 6 false negative cases and 26 false positive results. No statistically significant distinctions were observed in cancer-specific or overall survival in this limited cohort. CONCLUSIONS: Ligamp provides quantifiable, sensitive detection of mutant DNA in histologically normal margins. Detection of mutant species in margins may identify patients at risk of local recurrence. (Clin Cancer Res 2009;15(24):7658-65).

The antiangiogenic agent ZD4190 prevents tumour outgrowth in a model of minimal residual carcinoma in deep tissues

Background:

Tumour cells may persist at the operative site after seemingly adequate surgery. Radiotherapy is often given in an attempt to prevent repopulation, but this modality cannot be relied upon to prevent locoregional recurrence. An alternative strategy is to take advantage of the requirement of tumour cells to develop an independent blood supply and block this process to prevent recurrence.

Methods:

In this study, we evaluate the effect of the angiogenesis inhibitor, ZD4190, using a rodent model of residual carcinoma in deep tissues, mimicking the clinical scenario where low numbers of malignant cells persist at the operative site.

Results:

The tumour burden that could be eliminated was dependent on the site where the cells were implanted. Immediate treatment with ZD4190 prevented outgrowth of up to 2.5 × 10⁵ cells in the rectus muscle and 1 × 10⁵ in the gastrocnemius, whereas control animals developed large tumours. When more than 2.5 × 10⁶ cells were implanted into the rectus or 1 × 10⁶ into the gastrocnemius and treatment was maintained for 3 weeks, the carcinomas that developed in ZD4190-treated animals showed a reduced microvessel density and increased necrosis when compared with the vehicle-treated controls, but an infiltrative growth pattern was common.

Conclusion:

These findings suggest that antiangiogenic agents have a role to play in preventing outgrowth of residual carcinoma and are likely to be most effective when the tumour burden is minimal.

Determinants of outcome following surgery for oral squamous cell carcinoma

The recent changes in incidence and prevalence of oral squamous cell carcinoma in relation to gender and age mirror the changing patterns of exposure to tobacco and alcohol, the main etiological agents. Most cases of oral cancer are managed by surgery, often combined with radiotherapy. Histopathological assessment of the resection specimen provides information vital for postoperative management and prognosis. This review considers the full range of histological determinants of outcome in relation to the primary oral tumor and any metastatic involvement of the cervical lymphatic system, together with an outline of more general patient factors that may also impact on morbidity and mortality rates.