title: In vitro radiosensitivity of tumour cells and fibroblasts derived from head and neck carcinomas: mutual relationship and correlation with clinical data.
abstract: The aim was to characterize the variation in the cellular in vitro radiosensitivities in squamous cell carcinomas of the head and neck, and to test for a possible correlation between different measures of radiosensitivity and the clinical and histopathological data. Cellular in vitro radiosensitivities were assessed in tumour biopsies from 71 patients using the modified Courtenay-Mills soft agar clonogenic assay combined with an immunocytochemical analysis. Radiosensitivity was quantified as the surviving fraction after a radiation dose of 2 Gy irrespective of cell type (overall SF2), or based on identification of cell type (tumour cell SF2, fibroblast SF2). Sixty-three biopsies were from primary tumours, and eight were from recurrences. Overall plating efficiency ranged from 0.005 to 1.60% with a median of 0.052%. The majority of the colonies obtained from the biopsies were fibroblast marker-positive; the proportion of tumour marker-positive colonies ranged from 1 to 88% with a median of 15%. The median overall SF2 was 0.47 (range 0.24-0.96), the median tumour cell SF2 was 0.50 (range 0.11-1.0) and the median fibroblast SF2 was 0.49 (range 0.24-1.0). Comparing data from independent experiments, the overall SF2 was significantly correlated with the SF2 of fibroblasts (2P = 0.006) but not with the tumour cell SF2. The tumour cell and fibroblast radiosensitivities measured in the same individuals were not correlated (r= 0.06, 95% CI [-0.19, 0.30]):This finding seems to preclude a strong correlation between the radiosensitivity of tumour cells and fibroblasts. Concerning the clinical characteristics, neither of the measures of tumour radiosensitivity was correlated with T- and N-category, stage, tumour size, sex and age. However, the tumour cell radiosensitivity decreased with increasing grade of histopathological differentiation (2P = 0.012). The same tendency was found in two independent analyses of the same patient material. This correlation was not significant in case of the overall SF2 or the fibroblast SF2.
authors: Danish Cancer Society, Department of Experimental Clinical Oncology, Aarhus University Hospital.
authors: B
authors: B
authors: Stausbøl-Grøn
authors: S M
authors: SM
authors: Bentzen
authors: K E
authors: KE
authors: Jørgensen
authors: O S
authors: OS
authors: Nielsen
authors: T
authors: T
authors: Bundgaard
authors: J
authors: J
authors: Overgaard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D002452:Cell Count; D005260:Female; D005347:Fibroblasts / Q000528:radiation effects*; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007150:Immunohistochemistry; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011836:Radiation Tolerance; D015203:Reproducibility of Results; D014410:Tumor Stem Cell Assay