根據癌第四屆症治療發展分子診斷學美國癌症研究學會國際會議上的數據，三陰性乳腺癌患者可能有唯一的可使他們接受更多靶向治療的生物標誌物，其中三陰性乳腺癌是最難治療的亞型。
三陰性乳腺癌是雌激素受體、孕酮受體和HER2檢測皆為陰性的乳腺癌。由於這種生物學特徵，這些癌症對內分泌療法或曲妥珠單抗治療無響應。
"在其他乳腺癌亞型中，你可以使用這些具有一定療效的藥物。但是，三陰性乳腺癌目前缺乏治療靶標，而且是用常規的化療進行治療"，美國費城託馬斯o傑弗遜大學醫院(Thomas Jefferson University Hospital) 病理學副教授Agnieszka K. Witkiewicz醫學博士說。
Witkiewicz檢查了97位三陰性乳腺癌患者，其中73人是白人，24人是非洲裔美國人。用免疫組織化學技術評估了胰島素樣生長因子1受體（IGF-1R）蛋白質表達，用顯色原位雜交技術評估了IGF-1R基因拷貝的數量。
他們發現在25%病例中IGF-1R過度表達。IGF-1R蛋白質過度表達與基因擴增有關聯。
此外，這種受體的表達較低與更高的淋巴結轉移風險有關，而較高的表達大致與更小的腫瘤尺寸有聯繫。在55歲以下的患者中間，IGF-1R過度表達與更長的存活期有聯繫。
由於阻滯IGF-1R已經是一種治療肉瘤的成功療法，Witkiewicz提出可能有潛力也在這種乳腺癌亞型中瞄準這種受體。
"眼下，我們知道它的存在而且我們知道這是一個更好的預後標記，" Witkiewicz說。"下一步將了解三陰性乳腺癌患者是否能從瞄準IGF-1R中受益。"（生物谷bioon.com)
ScienceDaily (Sep. 28, 2010) - Patients with triple-negative breast cancer, one of the hardest subtypes to treat, may have a unique biomarker that would enable them to receive more targeted therapy, according to data presented at the Fourth AACR International Conference on Molecular Diagnostics in Cancer Therapeutic Development.
Triple-negative breast cancers are breast cancers that have tested negative for estrogen receptors, progesterone receptors and HER2. Because of this biology, these cancers do not respond to endocrine therapies or trastuzumab.
"In other subsets of breast cancer, you can use these drugs with some success. However, triple-negative breast cancers currently lack therapeutic targets and are managed with conventional chemotherapy," said Agnieszka K. Witkiewicz, M.D., an associate professor of pathology at Thomas Jefferson University Hospital in Philadelphia.
Witkiewicz examined 97 patients with triple-negative breast cancer, of whom 73 were white and 24 were African-American. Insulin-like growth factor 1 receptor (IGF-1R) protein expression was evaluated by immunohistochemistry and IGF-1R gene copy number was assessed by chromogenic in situ hybridization.
They found that IGF-1R was overexpressed in 25 percent of the cases. The IGF-1R protein overexpression correlated with gene amplification.
Moreover, low expression of the receptor was associated with greater risk of lymph node metastasis and high expression showed borderline association with lower tumor size. Among patients younger than 55 years, IGF-1R overexpression was associated with longer survival.
Since IGF-1R blockade has been a successful therapeutic approach in sarcomas, Witkiewicz suggested that there may be potential to target this receptor in this breast cancer subtype as well.
"For now, we know that it is there and we know it is a marker of better prognosis," said Witkiewicz. "The next step is to learn if triple-negative breast cancer patients benefit from targeting IGF-1R."