Sant Antonio Breast Cancer Symposium(SABCS) is one of most authoritative clinical symposium in Breast Cancer, and SABCS2011 are held at Henry B. Gonzalez Convention Center from 12.6 to 12.10 this year.
In SABCS2011, Dr. Bring-he Xu suggested that two biomarker could be associated with the efficacy for the treatment using Lapatinib and paclitaxel.
One of them is PIK3CA. If the patients who is metastatic HER2 positive breast cancer have this gene's mutation, they could prolong the overall survival after treatment.
Another of them is PTEN gene expression. If this is not expressed in breast cancer cells, Lapatinib could work well to them.
Most remarkably, these biomarkers were found from the FFPE archives. The FFPE archives are usually utilized in a pathological test, so it is very useful to measure these gene's changes in the FFPE archives.
PIK3CA遺伝子変異とPTENの有無がHER2陽性転移性乳癌でのパクリタキセルとラパチニブ併用の有効性に関連【SABCS2011】：日経メディカル
- PIK3CA遺伝子変異型が、HER2陽性転移性乳癌患者の全生存期間（OS）の悪化と有意に関連していること、PIK3CA遺伝子変異型患者にパクリタキセルとラパチニブを併用投与すると無増悪生存期間（PFS）の改善傾向が見られることが明らかとなった。
- さらにPTEN遺伝子の発現のない患者はラパチニブを加えることでOSが有意に改善すること、PFSはPTEN遺伝子の有無に関わらず、ラパチニブとパクリタキセルの併用で有意に改善することが分かった。
These findings were reported from Chinese hospital, so the difference of races maybe remains. However, PIK3CA and PTEN are famous cancer related genes, so we could use them in Japan in the future.
