Gender influences tumour growth in a model of human oral squamous cell carcinoma

The pattern of tumour growth was investigated using our unique syngeneic animal model of human oral squamous cell carcinoma of the head and neck (SCCHN). Gender-conditioned tumour fragments of near equal size were transplanted into recipient animals and the pattern of tumour growth was assessed by monitoring tumour size in vivo and/or the weight of tumour al termination of the experiment. Our results confirmed the epithelial nature of tumour cells on fresh tumour tissue sections using morphological and immunocytochemical examination. The mean weights of tumour per animal (n=10) after transplant from female (F) to F recipients, and across and between same gender showed differences if the animals were sexually mature. The results indicated an endocrine sensitive (sex hormone) component of tumour growth. In separate experiments, the recipient animals were immunised with a mechanically dissociated single cell suspension from fresh tumour after irradiation (500 cGys). The test,group (n=5) and control group (n=5, saline injected) animals received tumour fragments by grafting and following a Eur ther three weeks post immunisation, the tumours were removed and weighed. The test and control groups were different with a p-value of 0.001, suggesting an immune participation in the growth of this tumour. The results, taken together, thus suggest the participation of both the endocrine and the immune systems on the pattern of tumour growth in this animal model. The possible clinical relevance of these results is discussed.