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

The emerging links between chromosomal instability (CIN), metastasis, inflammation and tumour immunity

Many cancers possess an incorrect number of chromosomes, a state described as aneuploidy. Aneuploidy is often caused by Chromosomal Instability (CIN), a process of continuous chromosome mis-segregation. CIN is believed to endow tumours with enhanced evolutionary capabilities due to increased intratumour heterogeneity, and facilitating adaptive resistance to therapies. Recently, however, additional consequences and associations with CIN have been revealed, prompting the need to understand this universal hallmark of cancer in a multifaceted context. This review is focused on the investigation of possible links between CIN, metastasis and the host immune system in cancer development and treatment. We specifically focus on these links since most cancer deaths are due to the consequences of metastasis, and immunotherapy is a rapidly expanding novel avenue of cancer therapy.

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.

Factors in the pathogenesis of tumors of the sphenoid and maxillary sinuses: a comparative study

OBJECTIVES/HYPOTHESIS

To explain the processes that lead to the development of tumors in the maxillary and sphenoid sinuses.

STUDY DESIGN

A 32-year review of the world's literature on neoplasms of these two sinuses and a randomized case-controlled study comparing the normal mucosal architecture of the maxillary to the sphenoid sinus.

METHODS

Analysis of a 32-year world literature review reporting series of cases of maxillary and sphenoid sinus tumors. Tumors were classified by histological type and separated into subgroups if an individual incidence rate was reported. Histomorphometry of normal maxillary and sphenoid sinus mucosa was performed in 14 randomly selected patients (10 sphenoid and 4 maxillary specimens). Specimens were fixed in 10% formalin, embedded in paraffin, and stained with periodic acid-Schiff (PAS) and hematoxylin. Histomorphometric analysis was performed with a Zeiss Axioscope light microscope (Carl Zeiss Inc., Thornwood, NY) mounted with a Hamamatsu (Hamamatsu Photonics, Tokyo, Japan) color-chilled 3 charge coupled device digital camera. The images were captured on a 17-inch Sony (Sony Corp., Tokyo, Japan) multiscan monitor and analyzed with a Samba 4000 Image Analysis Program (Samba Corp., Los Angeles, CA). Five random areas were selected from strips of epithelium removed from each sinus, and goblet and basal cell measurements were made at magnifications x 100 and x 400.

RESULTS

The literature review revealed that the number and variety of tumors in the maxillary sinus are much greater than those in the sphenoid. The incidence of metastatic lesions to each sinus is approximately equal. No recognized pattern of spread from any particular organ system could be determined. On histomorphometric study there were no statistically significant differences between the sinuses in the concentration of goblet cells, basal cells, or seromucinous glands.

CONCLUSIONS

Factors involved in the pathogenesis of tumors of the maxillary and sphenoid sinuses include differences in nasal physiology, embryology, morphology, and topography. There are no significant histological differences in the epithelium and submucous glands between the two sinuses to explain the dissimilar formation of neoplasms.

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.

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.

DNA ploidy analysis of squamous cell carcinomas of the oral and maxillofacial region: clinical and pathologic correlations

DNA ploidy was investigated in 61 specimens obtained from 25 patients with squamous carcinoma of the oral and maxillofacial region. Biopsy specimens of normal tissue surrounding the tumor were also obtained in six patients. Single-cell suspensions for flow cytometric analysis were prepared. The DNA ploidy and histogram were calculated and compared with the histologic grade, presence of lymph node metastases, and course of the disease. The ploidy of the main stemline was peridiploid in 17 carcinomas, hyperdiploid in three, and aneuploid in five. Histologic grade but not nodal involvement was associated with the ploidy of the main stemline. Of 15 multisampled carcinomas 13 showed constant DNA ploidy and histogram classification. In the other two major changes in DNA ploidy (from peridiploid to hyperdiploid in the first and from peridiploid to aneuploid in the second) were found. Survival information was available for 24 patients. Ploidy values higher or lower than 2.5 c were strongly predictive of both overall (p < 0.001) and relapse-free survival (p < 0.001). The lymph node status proved a powerful prognostic indicator (p = 0.014) but was not related to the relapse-free time of survival. Multiparametric evaluation of survival revealed an independent role of both DNA ploidy and nodal involvement in the prognosis of squamous carcinoma of the oral and maxillofacial region.

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.