HER2 positive gastric cancer is recently focused well because the Herceptin was approved in Japan.
Before chemotherapy, the diagnosis of HER2 status is needed at the gastric cancer tissue.
Usually, it is used immunohistochemical analysis and fluorescent in situ hybridization.
About the breast cancer, the relation of HER2 status between the primary tumor and the metastatic tumor is well analyzed, but it wasn't known about the gastric cancer.
This presentation revealed that the HER2 status of gastric cancer between the primary tumor and the metastatic tumor was well correlated, and the possibility that the HER2 test would be sufficient at the primary tumor was shown.
Of course, if it is possible, it will be better to test HER2 at the both tumor.
胃癌の原発巣、転移巣におけるHER2発現の相違は5％程度で、HER2検査は原発巣診断のみで容認できることが示された。ただし、可能な限り転移巣の検索は必要である。4月12日から千葉県幕張市で開催されている第112回日本外科学会定期学術集会で、日本大学消化器外科の東風貢氏が発表した。
胃癌におけるHER2陽性の定義は、原発巣の免疫染色で3＋、または2＋の場合FISH法で陽性とされている。
乳癌におけるHER2発現については、原発巣と転移巣で発現が相関するかが解析されており、同時性リンパ節転移での相違例は6.7％、異時性リンパ節転移では0％、異時性局所再発では13.3％、異時性遠隔転移では28.6％であることが明らかになっている。
http://medical.nikkeibp.co.jp/leaf/all/gakkai/sp/jss2012/201204/524423.html
The gastric cancer is different from the breast cancer, it is difficult to test HER2 status before surgery.
Recently, the neoadjuvant chemotherapy is well focused for the breast cancer treatment, but this strategy might be difficult for the gastric cancer treatment.
