A Morphometric Study of the Vascularity of Oral Squamous Cell Carcinomas and its Relation to Outcome of Radiation Therapy.

In 26 patients the vascular morphology of pretreatment biopsies from oral squamous cell carcinomas (scc) was studied. Patients had been treated by radiation alone and followed up for 25-73 months. Vascular endothelial cells were identified using antifactor VIII staining. The distances from 700 randomly selected tumor cells to the closet blood vessel were measured in each tumor. Stepwise logistic regression analysis revealed that tumors with fewer than 21% of the morphologically intact tumour cells located within 48 microns of the closest blood vessel had a better control rate than tumors with a higher proportion of tumor cells within this distance. Using the analysis as a predictive assay, local tumor control was predicted from a single histological section with a sensitivity of 81% and a specificity of 60%. In correctly predicted cases of local control, the average median distance between tumor cells and blood vessels was 105 microns. These tumors formed well differentiated avascular tumor cell nests that were surrounded by stroma and blood vessels. Mitotic figures were observed only in the outer rim of cell nests while the center was often keratinizing or necrotic. In cases of correctly predicted treatment failures the average median distance from intact tumour cells to capillaries was 76 microns. These tumors showed varying degrees of organization and capillaries penetrating tumor cell areas. Clinical outcome of radiation therapy of oral scc appears to be correlated with different patterns of tumor architecture and blood supply

864 Combined radiation and surgery for malignant fibrous histiocytoma of subcutaneous tissue

The records of 21 patients treated with surgery and radiation for malignant fibrous histiocytoma (MFH) of subcutaneous tissue were identified. The majority of patients with subcutaneous MFH (83%) showed an extremely infiltrative growth pattern, defined as >0.2 cm from the main mass. These tumors frequently showed positive surgical margins (60%) after initial resection and frequently required reexcision and skin grafting. Two local failures were reported, one of these eventually developing distant failure. Two other patients eventually developed distant failure without evidence of local failure. Subcutaneous MFH show a highly infiltrative behavior, frequently showing positive margins after initial surgery. Contrary to prevailing opinion these tumors are locally aggressive and can display local and distant recurrence

Comparative Morphometric Study of Tumor Vasculature in Human Squamous Cell Carcinomas and Their Xenotransplants in Athymic Nude Mice.

When human tumor xenotransplants into nude mice are used as experimental models, it is important to know whether their microvascular anatomy is rather host or tumor specific. Therefore a morphometric comparison of the vascular network in human squamous cell carcinomas and their xenotransplants was carried out. Biopsies were taken from surgical specimens of three squamous cell carcinomas of the oral cavity. Part of the material was processed for histology and the rest was cut into 1-mm3 cubes and transplanted s.c. into the lateral thorax of athymic nude mice [NCr/Sed(nu/nu)]. The microvascular architecture of original tumors and of three first, one second, and one late generation xenografts was compared. Capillaries were identified in original human tumors by anti-factor VIII staining and in xenografts with antilaminin staining. The median distances between interphase tumor cells and blood vessels were determined and were found to be much longer in original human tumors than in xenografts, ranging from 81 microns to 99 microns and 53 microns to 65 microns, respectively. However, the characteristic qualitative histology of tumors appeared to be preserved in xenotransplants. Analysis of the topographic distribution of mitotic figures revealed that in both original tumors and xenotransplants proliferation of tumor cells was concentrated around blood vessels. Again, vascular distances in original tumors were significantly longer than in xenotransplants. In addition, xenotransplants into nude mice from a long passaged cell line from a human pharyngeal squamous cell carcinoma, FaDu, was investigated. FaDu showed a rare-fication of the capillary network with increasing tumor volume, but a constant median distance of mitotic figures from blood vessels. In conclusion, the pattern of spatial distribution of proliferating tumor cells as well as differentiation characteristics appear to be retained in xenograft tumors, but the density of the vascular system is host specific. This has to be taken into account when physiological parameters of blood supply are studied in xenotransplanted tumors