PIK3CA mutation and histological type in breast carcinoma: high frequency of mutations in lobular carcinoma.

摘要: Mutations in the PIK3CA gene have recently been reported different human neoplasms, including breast cancer. This paper reports results of a systematic analysis mutations histological types carcinoma. One hundred and eighty invasive carcinomas, comprising 74 ductal, 56 lobular, 22 mucinous, 20 medullary, eight papillary, were selected on basis their type consecutive series 780 cancers. Exons 1-20 subjected to SSCP followed by direct sequencing. observed 46 (26%) 180 tumours examined: 23 (50%) located exon 9, 20. frequent lobular (46%), less ductal (22%), uncommon medullary (10%), mucinous (5%), papillary (12%) (p = 0.0002). 9 more carcinomas (30% cases) than other (less 5% 0.00014). No significant differences distribution There was no correlation between clinicopathological biological variables, age, tumour size, lymph node metastases, oestrogen receptor (ER) status, progesterone (PgR) p53 mutations, protein expression. The findings indicate that alterations are mainly present tumours, whereas types, known be associated with favourable prognosis, show very low incidence mutations.