| Novel biomarker can be used at
time of initial diagnosis to predict which patients with renal cell carcinoma
are at high risk to develop metastatic disease The RNA-binding protein IMP3 can be used when renal cell carcinoma is diagnosed to predict which patients are at high risk to develop metastatic disease and thus might benefit from systemic therapy, according to an article published online June 14 by Lancet Oncology. In an effort to identify biomarkers for renal cell carcinoma, the US team chose to study IMP3, a protein that was already demonstrated to be highly expressed in primary tumors from other cancers, including lung and pancreatic cancers. Examining the tissue samples and clinical information from 406 patients with primary renal cell carcinomas who underwent radical or partial kidney removal at three different medical centers, the scientists found that expression of IMP3 was significantly increased in metastatic renal cell carcinomas. They further demonstrated that elevated expression of IMP3 in primary renal cell carcinomas can predict tumor metastasis. Their data shows that expression of IMP3 was significantly increased not only in metastastic renal cell carcinomas but, most importantly, in patients with primary renal cell cancers who later developed metastatic disease compared with levels in patients whose renal cell cancers did not metastasize. Remarkably, 80 percent of patients with IMP3-positive localized renal cell carcinoma later developed metastasis, whereas only 13 percent of patients whose tumors did not express IMP3 developed metastases. Because patients whose tumors express IMP3 have a high potential to develop metastasis, IMP3 provides a marker that can help identify patients who might benefit from a different follow-up approach after partial or complete kidney removal. The researchers propose that IMP3 be used at initial diagnosis, the optimal time for considering early systemic therapy for patients whose cancer has a high likelihood of metastasizing. “IMP3 testing is a simple, inexpensive and reliable assay that can be easily applied in routine clinical practice,” explained Zhong Jiang, MD, lead author. “If we can identify in those patients with early-stage disease the high potential to develop metastasis after surgery, we may be able to alter the course of therapy to improve outcomes and survival.” Jiang and colleagues look forward to clinical studies to further evaluate IMP3 testing in other cancers and correlation with patient outcomes. |