Flow cytometric DNA analysis of primary and concurrent metastatic squamous cell carcinoma of the head and neck

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.

Effects of the anticancer drug cocktail "UFT" on metastatic potentials of squamous cell carcinoma (O-1N) in a hamster model

UFT, a mixture of 1-(2-tetrahydrofuryl)-5-fluorouracil (tegafur) and uracil, is one of the most widely used anticancer agents. The tissue localization and the efficacy of UFT in preventing lymph node metastasis were studied in hamsters transplanted with oral squamous cell carcinoma (termed "O-1N") which has high lymph node metastatic potency. After UFT administration for 14 consecutive days, the incidence of lymph node metastasis was significantly decreased (16% vs 58%). When UFT was administered orally for 3 consecutive days to hamsters bearing O-1N, and tissue concentrations of tegafur and 5-FU were measured by gas chromatography, the value of 5-FU was significantly higher in the primary transplant tumour, cervical lymph nodes with or without metastasis, and liver, than in the normal oral tissues. When 14C-UFT(14C-tegafur + uracil, a uracil/FT molar ratio of 4) was administered orally for 3 consecutive days to hamsters bearing O-1N, the 14C-tegafur level of tissue homogenates in the buccal and metastatic tumours was within the range of normal oral tissues, but the localization of silver grains was significantly higher in tumour cells than in the oral normal tissues. The results suggest that UFT would be useful for treatment and prevention of lymph node metastasis of oral carcinomas because of the high accumulation of active metabolites in metastatic and non-metastatic lymph nodes.

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.

DNA ploidy and protein synthesis in squamous cell carcinoma cell lines of the head and neck

Aneuploidy as abnormal nuclear DNA content, is considered almost positive evidence of malignancy. In this study three diploid and three aneuploid squamous cell carcinoma (SCC) cell lines were examined for DNA content by flow cytometry. The DNA indices of the SCC cell lines were found to range from 1.0 to 2.1. The mitotic activity of the diploid cell lines was 1.6 times higher and the cells were smaller than aneuploid cells. To find a molecular basis for these differences, the pattern of the de-novo synthesized proteins was analyzed by means of [35S]methionine incorporation, electrophoresis, and autoradiography. In all aneuploid SCC cell lines tested in this experiment, the increase of nuclear DNA content is associated with the synthesis of a novel protein with a molecular mass of approximate 55 kDa as well as with altered synthesis rates of two preexisting proteins (50 kDa and 100 kDa). For determination of the amino acid uptake in diploid and aneuploid cells, the accumulation of [35S]methionine was measured as a function of time by liquid scintillation counting. No significant difference was found in the uptake rate between diploid and aneuploid cells with the same protein content. However, discrepancies were revealed when equal numbers of cells with different DNA index were used, suggesting, that protein turnover is different in diploid and aneuploid SCC cells.

DNA ploidy as a predictor of cervical metastasis in advanced squamous carcinoma of the tongue

Flow cytometric analysis of nuclear DNA content was performed in 34 squamous cell carcinomas of oral cavity and base of tongue tumours using archived paraffin-embedded tissues. The DNA content was correlated with the presence of cervical metastasis. Ten and 24 patients were classified as early (I & II) and advanced (III & IV) clinical stages, respectively. The DNA index (DI) was grouped into diploid (DI 0.85-1.15) and non-diploid. Seven (70%) tumours were non-diploid in clinical stages I & II. Four out of 7 (57%) developed initial and late cervical lymph node metastasis (p > 0.05). There were 15 (62.5%) non-diploid tumours in clinical stages III & IV. Thirteen out of 15 (86.7%) had cervical lymph node metastases (p < 0.05). However, the survival period and the incidence of recurrent disease for the whole group did not show any association with DNA ploidy. Our results suggest that DNA content may be useful as a reliable predictor of regional metastasis in advanced stage carcinoma of the tongue.

Flow cytometric analysis of primary and metastatic squamous cell carcinoma of the oral cavity and oropharynx

A retrospective analysis of formalin-fixed, paraffin-embedded tissue from patients with histologically confirmed metastatic squamous cell carcinoma was performed using flow cytometry. Ninety-eight sets of specimens from previously untreated patients with an oral cavity or oropharyngeal tumor and a simultaneous cervical metastatic deposit were analyzed. Normal mucosa and cervical lymph nodes were processed identically and run as controls. All patients underwent surgical resection at Wilford Hall USAF Medical Center or The Eye and Ear Hospital of Pittsburgh between 1980 and 1986. The specimens from 94 patients were technically adequate for interpretation. Diploid histograms in both the primary and metastatic tumors were present in 49 (52%) of 94 patients. Aneuploid histograms in either the primary and metastatic tumors were noted in 45 (47%) of 94 patients. In this group of 45 patients, the primary tumor and cervical metastasis were both aneuploid in 21 (46%), and aneuploid histograms occurred with equal incidence in either the primary or metastasis in the remaining 24 cases. No statistically significant prediction of survival could be made from any correlation with the histograms of either the primary or metastasis. The potential technical problems and limitations of flow cytometry in the determination of DNA content of formalin-fixed, paraffin-embedded tissue and the selection of patients with advanced disease warrant caution in the interpretation of results.

Computer-assisted image analysis of tumor sections for a new thrombospondin receptor

BACKGROUND

A cell surface receptor (50 kd) has been recently identified in malignant cells that recognizes the tumor cell adhesive domain (ie, cysteine-serine-valine-threonine-cysteine-glycine [CSVTCG]) of thrombospondin (TSP). This CSVTCG-specific TSP receptor can be considered as a new tumor marker, and its concentration on the cell surface may correlate directly with the capacity of tumor cells to invade and metastasize.

MATERIALS AND METHODS

Six patients with primary, stages III and IV squamous cell carcinomas of the head and neck were studied. Tumor sections were specifically stained for this receptor with immunohistochemical techniques. The stained specimens were then subjected to computer-assisted image analysis. The area of positive staining and the heterogeneity of the pattern of staining were compared to peritumoral angiogenesis and clinical outcome of the patients.

RESULTS

The results indicate that those patients with a high and homogenous positive stain score (mean +/- standard error [SE] 78 +/- 5%) for the CSVTCG-specific TSP receptor had high microvessel density and died from metastatic disease within 12 months of initial treatment (correlation coefficients = 0.95 and 1, respectively). Patients with a low and heterogenous positive stain score for receptor (mean +/- SE 8 +/- 2%; P < 0.001) had low microvessel counts and remained disease-free for at least 2 years. There was no relationship between receptor density and histologic classification of the primary tumors.

CONCLUSION

The CSVTCG-specific TSP receptor, quantified through image analysis of immunohistochemical stained tissue sections, is highly predictive of clinical outcome in patients with squamous cell carcinomas of the head and neck.

Flow cytometric analysis of primary and metastatic squamous cell carcinomas of the oral and maxillofacial region

OBJECTIVE

To elucidate characteristic changes in nuclear DNA content and cell kinetics in primary lesions and metastatic lymph nodes of squamous cell carcinomas of the oral and maxillofacial region.

MATERIALS AND METHODS

Materials used were paraffin-embedded tissue specimens obtained from 96 primary lesions of 96 patients and 85 metastatic lymph nodes of 41 patients with squamous cell carcinoma of the oral and maxillofacial region. Single cell suspensions for flow cytometry analysis were prepared, and cell cycle analysis was performed.

RESULTS

The incidence of aneuploidy in 41 carcinomas with metastasis was 39%, which was significantly higher than the 16% incidence in 55 carcinomas without metastasis. In terms of T classification and mode of invasion, the incidence of aneuploidy and metastasis increased with the increase in gradings. Forty-four of 46 metastatic lymph nodes associated with 25 diploid primary tumors remained diploid, whereas a shift down to diploidy was observed in 25 of 39 metastatic lymph nodes associated with 16 aneuploid primary tumors. The incidence of aneuploidy and S-phase fractions of 85 metastatic lymph nodes in 41 patients were 19% and 9.6%, respectively. The values were significantly lower than the 39% and 14.3% of the corresponding primary lesions.

CONCLUSIONS

The chance of evolution of metastatic cell lines is higher in aneuploid carcinomas than diploid carcinomas, possibly because the former are more heterogenous; however, most cell lines responsible for causing lymph node metastasis are diploid.

DNA heterogeneity in metastasizing squamous cell head and neck cancer

This study was carried out to determine whether analysis of DNA content of tumour cells (expressed as DNA-index: DI) from patients with head and neck squamous cell cancer (HNSCC) and lung squamous cell cancer (LSCC) could be helpful in distinguishing HNSCC patients with LSCC as a second primary from those in which LSCC represents a distant metastasis. Based on the assumption that metastasizing tumours retain their original DNA content, the same DI at both locations would suggest LSCC to be a distant metastasis from HNSCC, whereas a difference in DI at both tumour locations makes LSCC to be a second primary more likely. The study comprised 21 cases with HNSCC as well as LSCC. However, the basic assumption that the identity of a tumour can be inferred from its DI proved to be false as 7 of the 21 cases were characterized by more than one DI signifying several tumour cell populations. This DNA heterogeneity was further substantiated by differences in DI between the primary tumour and cervical lymph node metastasis in a second series composed of 16 HNSCC patients. These data indicate that due to variation in DI within one and the same tumour, DNA-analysis does not offer reliable information when trying to differentiate between lung cancer as a second primary or a distant metastasis in HNSCC patients.

Flow cytometry and Zollinger-Ellison syndrome: relationship to clinical course

BACKGROUND

With successful means of controlling gastric acid secretion in patients with Zollinger-Ellison syndrome, the gastrinoma itself is becoming the major determinant of long-term survival. No methods have yet been described to predict which tumors will have more malignant courses thereby indicating which patients should undergo aggressive surgery or antitumor therapy. Because DNA analysis, using flow cytometry, has proved helpful in this regard in other tumors, the current study was designed to evaluate its utility in gastrinoma patients.

METHODS

Flow cytometry was performed on 81 paraffin-embedded gastrinoma specimens from 59 patients. Results were compared with preoperative patient characteristics, findings at surgery, and postoperative follow up.

RESULTS

Tumors were diploid in 54% of patients, near diploid in 15%, pure tetraploid in 0%, nontetraploid aneuploid in 25%, and multiple stem line aneuploid in 5%. All patients with multiple stem line aneuploid tumors had wide-spread metastases whereas all patients with nontetraploid aneuploid tumors had localized or regional disease. Median S phase percentage was 3.6. S phase percentages were higher in patients with widespread metastatic disease than in patients with localized or regional disease. Disease extent also correlated closely with fasting serum gastrin level. After removing this variable with logistic regression analysis, the significant correlation between disease extent and DNA analysis persisted.

CONCLUSIONS

DNA analysis of gastrinoma tissue specimens correlates independently with the extent of disease and may be useful in planning therapeutic strategies for patients with Zollinger-Ellison syndrome.

DNA content and histologic growth pattern correlate with prognosis in patients with advanced squamous cell carcinoma of the larynx. The Department of Veterans Affairs Cooperative Laryngeal Cancer Study Group

BACKGROUND

Alterations in DNA content, nuclear morphologic characteristics, and histologic grading have been associated with prognosis in several types of solid malignant neoplasms.

METHODS

To determine the potential usefulness of these factors in predicting tumor behavior in patients with laryngeal squamous cell carcinoma, tumor specimens from 88 previously untreated patients with Stage III or IV cancers were studied. The DNA content and nuclear area (NA) were measured for individual nuclei of each tumor with the use of Azure A-stained frozen sections. An adjusted DNA index (aDI) for each patient was calculated from the slope of the linear regression analysis of nuclear DNA index on NA. Hematoxylin and eosinstained sections were examined and graded systematically for histologic growth pattern. All patients were enrolled in a prospective clinical trial and had laryngectomy and postoperative radiation therapy.

RESULTS

The disease-free survival length was longer and the relapse rates were lower in patients with a low aDI (P less than 0.005) and with tumors exhibiting low-grade growth patterns (P less than 0.001).

CONCLUSIONS

These parameters were independent of staging variables and were better predictors of tumor relapse than traditional clinical staging classifications.