Ki-67 expression in non-tumour epithelium adjacent to oral cancer as risk marker for multiple oral tumours.

摘要

We have read with great interest and would like to take the opportunity to comment on the recently published article 'Ki-67 expression in non-tumour epithelium adjacent to oral cancer as risk marker for multiple oral tumours' (Gonzalez-Moles et al, 2010). There is a lack of consensus on the duration on which the lesion would be classified as synchronous or metachronous e.g. 6 or more months (Hong et al, 1990), 1 month (Liao et al, 2007) and 2 months (Van der Haring et al, 2009). Such classification appears irrelevant as the treatment and prognosis depend ultimately on clinical and histopath-ological prognosticators. The criteria for secondary primary tumours (SPTs) were erroneously attributed to Billroth (1889), but it was revealed that he did not state such unrealistically rigid criteria (Moertel et al, 1961). The established criteria which are widely used include (i) each of the tumours must present a definite picture of malignancy; (ii) each must be distinct; and (iii) the probability that one was a metastatic lesion from the other must be excluded (Warren and Gates, 1931). Histopathological examination often solves the issue of whether the tumour is malignant, but the other two criteria remain confusing and debatable.