Loss of Maspin Expression in Bladder Cancer: Its Relationship with p53 and Clinicopathological Parameters.

Background And Purpose: Maspin (mammary serine protease inhibitor) is a member of the serpin superfamily of protease inhibitors and is known to have tumorsuppressor function in breast and prostate cancers, acting at the level of tumor invasion and metastasis. However, there have been no published data regarding the role of Maspin in squamous cell carcinoma (SCC) and transitional cell carcinoma (TCC) of urinary bladder.

Patients And Methods: We have evaluated the immunohistochemical expression of Maspin and p53 in a series of 134 bladder cancer patients (56 SCC and 78 TCC) and the interrelationship between clinicopathological features and Maspin and p53 expression.

Results: There was positive Maspin expression in 53.7% in all cases. In TCC, expression was found in 48/78 cases (61.5%). High Maspin expression was found in low grade (p<0.001) and advanced stage (p=0.02). In SCC, expression was found in 24/56 (42.8%). There was a statistically significant association between lost Maspin expression and grading (p=0.001). No correlation was found between Maspin expression and other clinicopathological parameters including gender, clinical stage and Bilharzial infestation. These results indicated that Maspin expression might predict a better prognosis for bladder carcinoma. Also Maspin probably could play a role in tumor progression. p53 was positive in 70 cases (52.2%) of all patients evaluated. In TCC, it was positive in 36/78 cases (46.1%) and correlated with high grade (p=0.01) and advanced stage (p=0.01). In SCC, it was positive in 34/56 cases (60.7%). There was a statistically significant association between p53 expression and high grade (p=0.01) and advanced stage (p=0.01). There was an inverse correlation between the Maspin and p53 expression in TCC and SCC of bladder cancer. We found no significant association between both Maspin and p53 expression and bilharziasis in TCC and SCC; this indicated that Maspin and p53 expression could be prognostic factors in both bilharzial and non-bilharzial bladder cancer.

Conclusions: The present study showed that no significant differences were seen regarding Maspin and p53 expression in TCC and SCC. Expression of both markers was not related to presence or absence of Bilharzial infestation. Therefore, it can be concluded that both markers do not seem to play a role in the pathogenesis of either types of Egyptian bladder cancer. However, both Maspin and p53 may have some prognostic value in bladder cancer that needs to be confirmed in further larger scale studies.

Key Words: Maspin - p53 - bladder cancer - Bilharziasis.