TUMOR HETEROGENEITY - A PROBLEM IN BIOPSY ASSESSMENT OF THE PROLIFERATION INDEX OF ESOPHAGEAL ADENOCARCINOMAS

Tumour heterogeneity may pose a problem when biopsy specimens are take n to measure proliferation (for example, in assessing response to ther apy). Two ''biopsy specimens)) were taken from the centre and two from the edge of the luminal surface of 20 resected oesophageal adenocarci nomas. The proliferation index for each ''biopsy specimen'') was measu red by counting Ki67 labelled nuclei in histological sections. The pro liferation index was not associated with tumour differentiation or sta ge. There was site specific heterogeneity with a significant differenc e in proliferation index between the central (mean (SD) 36.4 (9.7)) an d edge ''biopsy specimens'' (39.3 (9.9)). There was, however, a wide r ange of differences between pairs of ''biopsy specimens'' from both si tes. In conclusion, if a tumour is to be sampled for measurement of th e proliferation index before and after treatment, then the sequential biopsy specimens (preferably duplicated on each occasion) should be ta ken consistently from a leading edge of the lesion.