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Archive - May 6, 2009

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Marker in Surrounding Tissue Is Prognostic in Breast Cancer

Researchers have shown that a marker in tissue surrounding tumor cells is a new prognostic factor for patients with breast cancer. Absence of the market (caveolin-1) in stromal fibroblasts is associated with early disease recurrence, metastasis, and decreased patient survival. Stroma is non-cancerous connective tissue, which, in solid tumors, surrounds tumor cells. “The idea that a prognostic biomarker is present in the stroma rather than the epithelial cancer cell is paradigm-shifting," said Dr. Michael Lisanti, the senior of the study and editor-in-chief of the American Journal of Pathology. “Importantly, these findings could be developed into a diagnostic test that would not require DNA-based technologies. This inexpensive and cost-effective test would allow doctors to identify high-risk breast cancer patients at diagnosis and treat them more aggressively.” The absence of caveolin-1 in the stroma also appeared to be a marker for drug resistance in patients receiving the anti-cancer drug tamoxifen, the researchers said. “These are significant findings that do have to be validated in prospective breast cancer clinical trials,”said Dr. Richard Pestell, director of the Kimmel Cancer Center at Thomas Jefferson University, and an author of the study. “However, we should start taking the breast tumor stroma into our clinical considerations sooner, rather than later.” The study appears in the May 1 online edition of American Journal of Pathology, together with another group’s study on stromal expression of caveolin-1 in breast cancer. A related study was published online in Cancer Biology & Therapy.

Gold Nanorods May Permit Heat Treatment of Tumors

Scientists at MIT, together with collaborators, have developed gold nanorods that can home in on tumors and then, by absorbing energy from near-infrared light and emitting it as heat, destroy the tumors with minimal side effects. The light heats the nanorods, but passes harmlessly through tissue. Although it has long been known that heat can kill tumor cells, it has previously been difficult to heat the tumor cells specifically while leaving the surrounding tissue undamaged. In designing the nanorods, the researchers took advantage of the fact that blood vessels located near tumors have tiny pores just large enough for the nanorods to enter. The team developed a polymer coating for the particles that allows them to survive in the bloodstream longer than any other gold nanoparticles. In experiments in mice with tumors, the nanorods were injected into the bloodstream and accumulated in the tumors. With near-infrared laser treatment, the tumors disappeared in 15 days. The treated mice survived for three months with no evidence of recurrence, until the end of the study, while mice that received no treatment or only the nanorods or laser, did not. The researches noted that the gold nanorods also have potential in the detection and diagnosis of tumors, because the particles can be imaged by a technique known as Raman scattering. This work was reported in two recent papers, one in Cancer Research and the other in Advanced Materials. [MIT release]