Flow cytometric analysis of squamous cell carcinomas of the oral cavity in relation to lymph node metastasis

Evaluation of histomorphological and immunohistochemical parameters as biomarkers of cervical lymph node metastasis in squamous cell carcinoma of oral cavity: A retrospective study

Introduction:

Oral squamous cell carcinoma (OSCC) is seen worldwide but is more common in India. Lymph node (LN) metastasis has been shown to be the strongest prognostic factor in OSCC. Many histopathological and immunohistochemical markers have been studied to predict the LN metastasis.

Aims:

To identify clinicopathological factors and immunohistochemical (IHC) biomarkers which predict cervical metastasis in OSCC patients.

Study and Design:

A total of 105 cases of OSCC were taken up for our study. Histopathological parameters such as tumor thickness, depth, degree of differentiation, pattern of invasion (POI), lymphovascular and neural invasion were assessed. IHC was done on all cases using antibodies against Ki-67, cyclin D, E-cadherin, p53, CD31 and each antibody was assessed according to the standard protocol.

Statistical Analysis:

To calculate the relation between clinical, histopathological parameter, IHC marker and the occurrence of LN metastasis, chi-square test was used. Variables were tested using multivariate logistic regression method to assess the predictive significance.

Results:

Out of 105 cases studied, 29 cases showed LN metastasis. Maximum numbers of cases affected were females with involvement of buccal mucosa. We found significant association of cervical LN metastasis with high grade of differentiation, lack of E-cadherin expression, high Ki-67 and cyclin D1 expression. In our study; tumor depth, thickness, extent of peritumoral lympho-plasmacytic infiltration, presence of eosinophils, tumor nest type, p53 and microvessel density (MVD) showed no significant correlation.

Conclusion:

Significant association of cervical LN metastasis with high grade of differentiation, lack of E-cadherin expression, high Ki-67 and cyclin D1 expression was seen.

Is there a correlation between 18F-FDG-PET standardized uptake value, T-classification, histological grading and the anatomic subsites in newly diagnosed squamous cell carcinoma of the head and neck?

(18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET)/CT imaging of squamous cell carcinoma of the head and neck (HNSCC) renders the possibility to study metabolic tumor activity by measuring FDG-uptake expressed as maximum standardized uptake value (SUV(max)). A correlation between SUV(max) and several factors including T-classification, histological tumor differentiation or different anatomic subsites is of potential interest in HNSCC. The aim of this study was to evaluate how metabolic tumor activity derived from FDG-PET correlates with prognostic clinical and pathological parameters including these factors. 262 patients with HNSCC undergoing PET/CT for initial staging were assessed separately for a potential correlation between SUV(max) and T-classification, histological grading, and anatomical subsites of the primary tumor. Nonparametric testing showed a significant correlation between SUV(max) and T-classification (P < 0.001). On the contrary, no statistically significant correlation was found between SUV(max) and histological tumor grading. Furthermore, no statistical significant correlation between the different anatomical subsites and SUV(max) were found. There was no significant correlation of SUV(max) and tumor grading after adjustment for T-stage and anatomical localization of the tumor, neither.

CONCLUSION

Metabolic tumor activity correlates with T-stage of HNSCC. However, histological tumor grading does not correlate with SUV(max). The role of primary tumor SUV(max) as a predictor of outcome or survival remains unclear. Clinicians should therefore exercise caution in attributing any clinical importance to SUV(max) obtained from a single PET/CT exam.

Relationship between vascular endothelial growth factor and Notch1 expression and lymphatic metastasis in tongue cancer

Objective: To determine the role of angiogenesis in lymph node metastasis and the depth of invasion in early tongue cancer.

Study Design: Retrospective analysis.

Subjects and Methods: The study included 51 subjects with tongue cancer. Immunohistochemical staining for vascular endothelial growth factor, Notch1, and Notch3 was performed. Microvessel density was evaluated by counting the number of CD34-stained microvessels in each pathologic specimen.

Results: Significant correlations were found between vascular endothelial growth factor and Notch1 expression and cervical lymph node metastasis ( P = 0.020 and P < 0.009, respectively), tumor depth of invasion ( P = 0.001 and P < 0.001, respectively), and microvessel density indicated by CD34 staining ( P = 0.001 and P < 0.001, respectively). Nodal metastasis ( P = 0.022), T stage ( P = 0.002), and positive VEGF expression ( P = 0.044) were statistically significant prognostic factors for disease-specific survival.

Conclusion: Vascular endothelial growth factor and Notch1 expression are significantly related to cervical lymph node metastasis and depth of invasion in tongue cancer patients.

Predictive value of p53 and PCNA expression for occult neck metastases in patients with clinically node-negative oral tongue cancer

OBJECTIVE

In an attempt to identify molecular markers predictive of occult neck metastases, we investigated whether positive p53 or proliferating cell nuclear antigen (PCNA) immunoreactivities on deparaffinized sections of the primary tumor are correlated to the presence of occult neck node metastases in oral tongue cancer patients with clinically negative cervical nodes (N0).

STUDY DESIGN AND SETTING

Between 1986 and 1997, 37 clinically N0 patients who underwent neck dissection (25 male, 12 female; mean age 54 years) were selected for p53 and PCNA staining.

RESULTS

p53 and PCNA immunoreactivities were detected in 68% and 32%, respectively. There was no correlation between p53 or PCNA and other clinicopathological factors, such as tumor differentiation, tumor type, tumor size, and T-stage. Although tumor differentiation (P=0.03) and tumor size (P=0.03) were significantly correlated with occult neck metastases of oral tongue cancer by univariate analysis, no correlation was found between p53 or PCNA and the presence of occult neck metastasis.

CONCLUSION

p53 and/or PCNA expression are unsuitable as biological markers predictive of lymph node metastases of oral tongue cancer.

SIGNIFICANCE

p53- or PCNA-positive status are not a reliable parameter for selection of elective neck dissection in the management of N0 oral tongue cancer patients.

Endoreduplication in conjunction with tumor progression in an aneuploid laryngeal squamous cell carcinoma

We report the case of a 58-year-old man who presented with a squamous cell carcinoma pT1a G2 of the left vocal cord. Six months after histologically verified complete resection, the patient experienced an endolaryngeal and extralaryngeal local recurrence pT4 pN2b G2. We applied DNA flow cytometry (FCM) and comparative genomic hybridization (CGH) on both primary and recurrent tumor. The primary tumor and the endolaryngeal compartment of the relapse was an aneuploid cell clone with a FCM DNA index of 1.42 and 1.44, respectively. The extralaryngeal compartment showed a shift featuring a DNA index of 2.78. In the primary tumor and in both compartments of the recurrence there was an identical pattern of complex chromosomal imbalances as detected in CGH (CGH karyotype: rev ish enh [8q24.2-q24.3, 10q26.1-q26.3, 11q24-q25, 12q24.2-q23.33,X], dim [4q, 13q14.3-q31], amp[1p36.1-p36.2]). Hence, the recurrence was not associated with further gains and losses of chromosomal material. However, in the anterior part of the recurrence, the aneuploid tumor cell genome had completely doubled, obviously due to endoreduplication. Immunohistochemical analysis of several cell-cycle regulators revealed altered expression of checkpoint proteins, pointing to a complex disturbance in cell-cycle regulation.

Can flow cytometrically determined DNA ploidy and S-phase fraction predict regional metastasis in squamous cell carcinoma of the oral cavity?

BACKGROUND

The value of flow cytometric analysis of DNA ploidy and S-phase fraction (SPF) as an indicator of regional metastasis in oral cancer is currently being debated. Intratumoral heterogeneity makes this problem complex.

METHODS

Intratumoral DNA ploidy heterogeneity and intratumoral SPF variation were examined using multiple specimens from 31 surgically resected specimens taken from patients with oral cancer without preoperative therapy. Flow cytometric analysis of single biopsy specimens from 79 patients with oral cancer was also undertaken to ascertain their value as indicators of regional metastasis.

RESULTS

Forty-five percent (14 of 31) of tumors showed intratumoral ploidy heterogeneity. Intratumoral SPF variation in the 31 tumors ranged from 0.2% to 6.9% (mean, 3.3%). Multivariate analysis showed that a SPF greater than 27% was the most important parameter for predicting regional metastasis.

CONCLUSIONS

DNA ploidy is heterogeneous within a tumor, whereas SPF is relatively stable and can be correlated with regional metastasis in oral cancer.

Flow cytometric DNA ploidy analysis of oral cancer comparison with histologic grading

It has been reported that DNA content analysis provides prognostic information eliminating the subjective component involved in routine microscopic decision making. In an attempt to establish a relationship between pathological findings and flow cytometric analysis, 36 formalin-fixed, paraffin-embedded tumour tissue samples were prepared according to Hedley's method and analysed by means of an Epics Profile II flow cytometer. DNA aneuploidy was observed in 15 tumours (41%). A statistically significant correlation was identified between DNA index and mitoses, cellular response and degree of differentiation, but not the ploidy status. It was not possible to identify a significant association of sex, age, and site of the tumour to DNA index. We found a strong correlation between histologic malignancy and DNA index; an increase in DNA index as malignancy score increases was noted. It was concluded that DNA index shows a good correlation with the histologic features of oral cancer, being a complement of differentiation and histologic grading analysis. The use of DNA analysis as a complement to pathological studies would help to diminish the subjective component of assessment of head and neck cancers. Ploidy status was not statistically associated with the differentiation of tumours.

Heterogeneity of squamous cell carcinomas of the head and neck in relation to clinicopathological variables

We analysed 32 primary, 8 recurrent and 16 metastatic squamous cell carcinomas of the head and neck by flow cytometry to assess tumoural heterogeneity. Intratumoural heterogeneity was found in 9 of 30 primary tumours (30%). All heterogeneous tumours had diploid and aneuploid cell lines. DNA indices were different from those of the primary tumours in 3 of the 8 recurrent lesions (38%) and in 8 of the 12 metastatic lesions (67%). The results indicate that new cell lines evolve during the process of recurrence and metastasis. The incidence of recurrence, metastasis, and heterogeneity increased with the size of the tumour. Histologically, there were tumours in which the degree of differentiation and mode of invasion of primary lesions were not consistent with the results of flow cytometry in both homogeneous and heterogeneous tumours. In conclusion, multiple sampling for flow cytometric analysis is essential for better characterization of oral carcinomas.

The significance of DNA flow cytometry in predicting survival and delayed clinical manifestation of occult lymph node metastasis to the untreated neck in patients with oral squamous cell carcinoma

A total number of 116 clinically neck-negative patients with squamous cell carcinoma of the oral cavity who underwent radical primary tumour surgery without simultaneous neck treatment were entered into this prospective study. The 5 year overall survival rate was 87% for patients with flow cytometrically diploid tumours and 58% for the aneuploid group (P < 0.05). By multivariate survival analysis, tumour stage (P < 0.05) and DNA ploidy (P < 0.05) were significantly associated with the outcome. The cumulative 3 year rate of delayed clinical manifestation of lymph node metastasis to the previously untreated neck was 12.6% for patients with flow cytometrically diploid tumours and 41.3% for the aneuploid group (P < 0.01). By multivariate analysis, the DNA ploidy status of the primary tumour was the only factor among tumour stage, localization and degree of histological differentiation predictive of occult metastasis development (P < 0.05). Also, patients with T1 tumours who frequently are not considered to benefit from elective neck dissection were at high risk of subclinical lymph node involvement if the primary tumours were aneuploid (47%), whereas only 10% of the diploid T1 sample showed occult neck disease. Particularly in patients with less extensive oral carcinomas, DNA aneuploidy is therefore an important decisive factor in elective neck dissection.

Advances and new concepts in oral and maxillofacial pathology

New techniques in surgical pathology at the cellular and molecular levels offer the clinician help in determining modalities of treatment of specific diseases. In addition to routine staining, adjunctive tests such as immunohistochemical analysis, and the various methods of evaluating nucleic acid have helped make this possible. The efficacy of fine-needle aspiration biopsy has been enhanced by these diagnostic aids that enable the assessment of information from small amounts of tissue.

Representativity of incisional biopsies for the assessment of flow cytometric DNA content in head and neck squamous cell carcinoma

DNA flow cytometry studies of squamous cell carcinoma of the head and neck have shown that patients with diploid tumours have favourable prognoses, whereas the outcomes of those with DNA aneuploid tumours are poor. DNA flow cytometry is therefore increasingly used as an integral part of diagnostic procedures. To evaluate how representative biopsies predict the DNA ploidy of oral carcinomas, incisional biopsies taken pretherapeutically from 256 tumours were compared with the corresponding surgical resection specimens. Sixty-six tumours exclusively displayed cells with flow cytometrically diploid DNA content in both the biopsy and the subsequent resection specimen, while 182 carcinomas expressed DNA aneuploid tumour cell lines in matched samples. There were only 8 tumours (3.1%) with heterogeneity in the DNA ploidy status between the biopsy and the resection specimen. These results emphasise the usefulness of incisional biopsies to reliably prognosticate the DNA ploidy status of oral carcinomas.

Tumor DNA content as a prognostic indicator in squamous cell carcinoma of the oral cavity and tongue base

BACKGROUND

Nuclear deoxyribonucleic acid (DNA) content is a prognostic factor in several tumors, and decisions regarding treatment have been made using this parameter. Nevertheless, there is no agreement in head and neck cancer. The purpose of the present study was to ascertain whether tumor DNA content correlated with prognosis in cases of primary squamous cell carcinoma (SCC) of the oral cavity and tongue base.

METHODS

A retrospective study of formalin-fixed, paraffin-embedded tissue from patients with histologically confirmed SCC of the oral cavity and tongue base was performed using flow cytometry. Tumor DNA content was studied in 109 sets of specimens from previously untreated patients. All of them underwent surgical resection at the University "Hospital de La Princesa" between 1982 and 1992. Clinical parameters (age, sex, site of primary tumor, clinical stage, adjuvant therapy received, and disease-free and overall survival) and histologic parameters (histopathologic stage, tumor differentiation, type of inflammatory infiltration, presence of perineural invasion) were recorded in all cases. An exhaustive statistical analysis was applied.

RESULTS

Only the histograms of 93 patients were adequate for consideration. In flow cytometric analysis, DNA aneuploidy was observed in 51 tumors (55%). The proportion of aneuploid tumors was significantly higher in advanced-stage carcinomas (p < .05), tumors with perineural invasion (p < .05) and in men (p < .05). In the 24 patients with lymph node metastasis, the incidence of aneuploidy was 82% (19 of 24) (p < .05). The rate of metastasis and aneuploidy increased as the degree of differentiation decreased (p < .05 for both). Patients with aneuploid carcinomas in both early and advanced stages had shorter relapse-free and overall survival periods than did the patients with diploid tumors (p < .001 for both). A Cox regression analysis demonstrated that ploidy was the single most important prognostic factor in determining relapse and death (p < .001 for both).

CONCLUSIONS

The results indicate that tumor DNA analysis by flow cytometry appears to be useful as a supplement to clinical and histologic evaluation in predicting the tendency of SCC of the oral cavity and tongue base to metastasize to regional lymph nodes and to predict the outcome of the disease.

Comparison of DNA flow cytometry and fluorescence in situ hybridization with a set of 10 chromosome-specific DNA probes in four head and neck carcinomas

Four squamous cell carcinomas of the oral cavity were simultaneously analysed by DNA flow cytometry (FCM) and fluorescence in situ hybridization (FISH) with alpha-telomeric DNA probes specific for chromosomes 1, 2, 3, 6, 7, 8, 10, 12, 17, and X. Nuclei with 2 hybridization signals for most chromosomes were in agreement with flow cytometric DNA content in a diploid tumor, but a monosomy 8 for half of the cells indicated a tumor clone with an aberrant chromosome 8. Aberrations of virtually all chromosomes were found in 3 aneuploid tumors. Comparing the relative numbers of disomal and aneusomal nuclei with the corresponding proportions of DNA diploid and aneuploid sample cells provided evidence that the flow cytometrically diploid cell population of an aneuploid tumor consisted of both karyotypically normal and abnormal cells. Although there was a high degree of concordance between aberrant DNA content and magnitude of chromosomal aberration, discrepancies between both methods suggested a notable clonal heterogeneity in aneuploid tumor cell populations. These results demonstrate that a simultaneous application of DNA flow cytometry contributes to broaden the utility of interphase cytogenetics.

The value of DNA flow cytometry in predicting the development of lymph node metastasis and survival in patients with locally recurrent oral squamous cell carcinoma

BACKGROUND

DNA flow cytometry studies of squamous cell carcinoma of the head and neck have shown that patients with diploid tumors have favorable prognoses, whereas the outcomes of those with, aneuploid tumors are poor. This study was conducted to examine the importance of DNA ploidy in patients with locally recurrent oral carcinoma.

METHODS

DNA flow cytometry was performed on 93 primary oral carcinomas and their subsequent recurrences.

RESULTS

Eight patients with diploidy of both the primary tumor and the recurrence never developed lymph node metastasis. The 5-year overall survival rate of this group was 87%. For 80 aneuploid primary carcinomas, recurrences developed that were also aneuploid. Only 31% of these patients were 5-year survivors (P < 0.001). Lymph node metastasis at presentation was found in 55% of this group, whereas 13% of initially lymph node negative patients presented with regional disease at second surgery. Five of 13 diploid primary tumors recurred with aneuploid cell lines. Three of these five patients died, two with regional metastasis. The 5-year survival rate of patients with aneuploid recurrences who were never afflicted with lymph node involvement (41%) was better (P < 0.05) than the 5-year survival rate of those with metastasis at presentation or at second surgery (26%).

CONCLUSIONS

The excellent prognosis of patients with diploid primary tumors can be reestablished by treating local recurrences with radical surgery, if the surgery is performed before aneuploid cell lines have emerged. It appears that aneuploid tumor cell lines acquire unique properties that make them capable of invasion and metastasis.

DNA analysis of squamous cell carcinoma in the oral cavity by image cytometry and its rating in the assessment of tumor prognosis

Image cytometric measurements on the DNA content of squamous cell carcinoma of the oral cavity were carried out to evaluate its relationship with clinicopathological features. In the prospective study 52 patients with operable oral cavity carcinoma in stage T1-4 and N0-3 were studied. The tumors were classified according to the TNM classification (UICC 1987) and graded histopathologically. A positive correlation between tumor size and ploidy status was observed. There was a significant correlation between ploidy status and histologically confirmed cervical lymph node metastases (P < 0.03). A relationship between histopathological grading and ploidy status was not found. The cumulative 5-year survival rate was significantly higher (P < 0.03) among patients with diploid DNA findings than among those with nondiploid findings. When assessing the prognosis of squamous cell carcinoma, DNA cytometry analysis should be used as an additional method. Particularly the primarily existing, significantly higher N stage, a higher frequency of metastases, and a significantly lower survival rate with nondiploid tumors underline the importance of this examination method.

Predicting factors for distant metastases in head and neck carcinomas: an analysis of 103 patients with locoregional control

PURPOSE

This study evaluated the ability of certain clinical and pathologic parameters to predict distant metastases (DMs) in patients with squamous cell carcinoma of the head and neck.

MATERIALS AND METHODS

A total of 103 patients with histologically proven squamous cell carcinoma of the head and neck were studied. None had persistent or recurrent disease above the clavicle. Of these patients, 48 (47%) had metastatic lymph nodes. The relationships of tumor stage, primary site, clinical growth pattern, tumor differentiation, regional node status, and extranodal spread (ENS) with DMs were evaluated.

RESULTS

Twenty-one (20%) of the 103 patients developed DMs as the initial treatment failure. The incidence of DMs was significantly higher in patients with neck metastases (40%) than in those without neck metastases (4%) (P < .001). The degree of histologic differentiation and the presence of ENS were also correlated with the subsequent occurrence of DMs. There was no statistical difference in the incidence of DMs based on sex, location, stage of the disease, and clinical growth pattern. On multivariate analysis, only pathologic nodal status and ENS proved to be independent cofactors of DMs. The most common site of DMs was the lungs (56%), followed by bone (16%) and skin (16%).

CONCLUSION

The presence of pathologically positive nodes is the most critical factor to influence the eventual development of DMs.

The implication of DNA content and S-phase fraction in oral carcinomas with and without metastasis

Flow cytometry DNA analysis was performed on fresh tissue samples of 90 primary lesions and 32 metastatic lymph nodes of squamous cell carcinomas of the oral cavity and related regions to elucidate the characteristics of tumors with metastatic potency. The incidence of aneuploidy for carcinomas with metastasis was 67%, which was significantly higher than the 44% of carcinomas without metastasis, and aneuploid carcinomas (39%) had a higher tendency to metastasis than diploid carcinomas (20%). The incidence of aneuploidy and metastasis was related to the T classification, the degree of differentiation, and the histologic grade of malignancy. The incidence of aneuploidy and mean DNA index of metastatic lesions were 31% and 1.12, respectively, and the values were significantly lower than the 67% and 1.30 of the corresponding primary lesions. The results indicate that the chance of evolution of metastatic cell lines is higher in aneuploid carcinomas than diploid carcinomas, possible because the former is more heterogeneous than the latter, but most of the cell lines causing lymph-node metastasis are diploid cell lines. Metastatic lesions had a lower S-phase fraction than primary lesions, indicating that a high S-phase fraction does not always reflect the presence of metastatic cell lines.

Feulgen hydrolysis profiles and acid-labile DNA in oral squamous cell carcinoma

The full Feulgen hydrolysis profiles of healthy and malignant oral epithelial cells were compared by measuring the staining density of nuclei using microdensitometry after varying hydrolysis times. Malignant nuclei contained significantly increased levels of acid-labile DNA. The relative amounts of the rapidly hydrolysable fraction were compared after 5 min hydrolysis for exfoliating epithelial cells from healthy oral mucosa, healing chronic ulcers and squamous cell carcinomas. Although the latter exhibited a wide range of values, analysis of variance showed significant differences (P < 0.05) between healthy control and ulcer groups compared to oral carcinoma. The relative proportion of highly acid-labile DNA in malignant nuclei showed a significant positive correlation with mitotic score (P < 0.01) but no significant correlation with nuclear area. It was concluded that since the susceptibility of DNA to acid hydrolysis probably reflects functional differences in nuclear activity between cells, estimation of the highly acid-labile fraction may have diagnostic and/or prognostic value.