G. Viale et al., p21(WAF1/CIP1) expression in colorectal carcinoma correlates with advanceddisease stage and p53 mutations, J PATHOLOGY, 187(3), 1999, pp. 302-307
Citations number
43
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Medical Research Diagnosis & Treatment
Defects in the mechanisms controlling the cell cycle are crucial in cell tr
ansformation and/or tumour progression. p21(WAF1/CIP1) is an inhibitor of c
yclin-dependent kinases, induced by p53-dependent and p53-independent pathw
ays, which can block progression through the cell cycle, p21(WAF1/CIP1) exp
ression has been investigated immunohistochemically in a series of 191 pati
ents with colorectal cancer of known p53 status. The purpose of the study w
as two-fold: to assess the relationship between p21(WAF1/CIP1) immunoreacti
vity and p53 alterations, and to evaluate the prognostic significance of p2
1(WAF1/CIP1) expression, In 96 carcinomas (51 per cent), p21(WAF1/CIP1) was
expressed in over 10 per cent of tumour cells, whereas in 26, p21(WAF1/CIP
1) was detected in under 10 per cent of neoplastic cells; 69 tumours lacked
p21(WAF1/CIP1) expression. Immunoreactivity was more frequent in tumours o
f the right colon (p<0.003) and was inversely correlated with tumour stage
(p<0.03), p53 gene mutations (p<0.0007), p53 protein accumulation (p<0.019)
, and Bcl-2 expression (p<0.0005). In univariate analysis, down-regulation
of p21(WAF1/CIP1) expression was associated with poor overall (p=0.0022) an
d disease-free survival (p=0.0009). Multivariate analysis, however, did not
confirm any independent prognostic significance of p21(WAF1/CIP1) expressi
on. The results indicate that p21(WAF1/CIP1), associated with abnormal accu
mulation of p53 protein and the occurrence of p53 gene mutations in colorec
tal cancer and that lack of p21(WAF1/CIP1) expression is correlated with re
duced patient survival in univariate analysis. These data underline the cru
cial pathogenetic role of the p53-p21(WAF1/CIP1) pathway in carcinomas of t
he large bowel. Copyright (C) 1999 John Wiley & Sons, Ltd.