Homozygous deletion of p16 gene in primary bladder and breast carcinomas in Egyptian cancer patients

Abstract EN

Bladder and breast cancers are the most common types of cancer affecting males and females in Egypt.

Bladder cancer in Egypt is different from Western countries due to its association with the presence of bilharzias is.

Genetic changes in bladder and breast cancers in Egypt are still not clearly understood.

In the present study, tissues from 170 primary bladder cancer patients (bilharzia and non-bilharzia) and 42 primary invasive ductal carcinoma of breast with different grades and stages were examined for homo-zygous deletion at P16 tumor suppressor gene, the gene that controls cell cycle growth, using comparative multiplex PCR technique.

Our results showed high frequency of deletion in bladder and breast carcinomas (41 % and 43 %, respectively).

Homozygous deletion at P16 observed in different histopathologically types of bladder cancer were slightly higher in squamous cell carcinoma (40.4 %) than in the transitional type (33.9 %).

Both bilharzia and non-bilharzia bladder carcinomas showed almost the same percentage of deletion at P16 gene (40.5 % and 40.7 %).

Also, homozygous deletion at P16 gene was detected in both positive and negative lymph node metastasis of bladder cancer (47.6 % and 39.6 %).

In breast carcinoma, P16 deletion detected in grade 3 was slightly higher (53.9 %) than in grade 2 (37.9 %) and was much higher in positive lymph node metastasis (48.6%) than in negative lymph nodes (14.8%).

This study showed that (1) P16 gene may be involved in the initiation and progression of bladder carcinoma, (2) Bilharzias is has no role in the inactivation of P16 gene, and finally (3) P16 gene may be involved in the progression and metastasis of breast carcinoma.