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Jun 28, 2012 02:32 PM voraciousreader wrote:
Mucinous breast carcinomas lack PIK3CA and AKT1 mutations.
Kehr EL,et al. Show all
Kehr EL, Jorns JM, Ang D, Warrick A, Neff T, Degnin M, Lewis R, Beadling C, Corless CL, Troxell ML.
Hum Pathol. 2012 Jun 15. [Epub ahead of print]
Department of Pathology, Oregon Health & Science University, Portland, OR 97239, USA.
Activating point mutations in the phosphatidylinositol-3-kinase catalytic subunit (PIK3CA) are among the most common molecular defects in invasive breast cancer. Point mutations in the downstream kinase AKT1 are seen in a minority of carcinomas. These mutations are found preferentially in estrogen receptor-positive and Her2-positive breast carcinomas; however, special morphologic types of breast cancer have not been well studied. Twenty-nine cases of pure invasive mucinous carcinoma and 9 cases of ductal carcinoma with mucinous differentiation were screened for a panel of point mutations (>321 mutations in 30 genes) using a multiplex polymerase chain reaction panel with mass spectroscopy readout. In addition, associated ductal carcinoma in situ, hyperplasia, or columnar cell lesions were separately tested where available (25 lesions). In 3 invasive cases and 15 ductal carcinoma in situ/proliferative lesions, PIK3CA hotspot mutations were, instead, tested by direct sequencing. No point mutations were identified in invasive mucinous breast carcinoma. This contrasts with the 35% frequency of PIK3CA mutations in a comparative group of invasive ductal carcinomas of no special type. Interestingly, PIK3CA hotspot point mutations were identified in associated ductal carcinoma in situ (3/14) and hyperplasia (atypical ductal hyperplasia [2/3], usual ductal hyperplasia [2/3], columnar cell change [1/5]), suggesting that PIK3CA mutations may play a role in breast epithelial proliferation. This series represents the largest study, to date, of PIK3CA genotyping in mucinous carcinoma and supports the unique pathogenetics of invasive mucinous breast carcinoma.
Doctor told me regarding my prognosis that I WASN'T on the Titanic! Hmmm...Really?....Okay! 2/10 Pure Mucinous Breast Cancer, Oncotype DX 15, Stage 1, Grade 1, 1.8 cm, 0/2 nodes, ER+ 90% PR+ 70% HER2- (+1)