PHILADELPHIA (July 26, 2019) – In the current era of personalized medicine, researchers at Fox Chase Cancer Center are harnessing state-of-the-art technology to provide more accurate diagnosis of a rare form of kidney cancer: clear cell papillary renal cell carcinoma.
The two most common forms of renal cell carcinoma are the clear cell and papillary subtypes. However, some forms of renal cell carcinoma can have characteristics of both clear cell and papillary carcinoma, making accurate diagnosis difficult.
Diagnosis of the clear cell papillary renal cell carcinoma subtype is important because it could affect treatment, according to Shuanzeng Wei, MD, PhD, assistant professor in the Department of Pathology at Fox Chase. This type of disease does not metastasize.
“A lot of people think clear cell papillary renal cell carcinoma is a carcinoma, but we and other researchers are finding out that it may just be a benign lesion,” Wei said. “Patients diagnosed with clear cell papillary carcinoma won’t need surgery or treatment, just follow-up.”
Wei and colleagues recently used SNP-based chromosome microarrays to analyze 14 tumor samples taken from patients with low-grade renal cell carcinoma with both clear cell and papillary features. This technology allowed them to perform genome-wide screening and identify genetic copy number variations at a much higher resolution than that of standard or high-resolution chromosome analysis.
“We know that clear cell renal cell carcinoma has specific chromosome changes, such as 3p deletion,” Wei said. “On the other hand, if we find chromosome 7 or 17 gain or loss of chromosome Y, that is papillary renal cell carcinoma. If there are no changes, we can tell it is clear cell papillary renal cell carcinoma.”
Among the 14 samples with both clear cell and papillary characteristics, only seven cases were confirmed as clear cell papillary carcinoma. Among the remaining seven cases, two cases had loss of chromosome 3 and were diagnosed as clear cell renal cell carcinoma. One case had a gain of chromosome 7 and was diagnosed as papillary carcinoma. The remaining four cases had none of the common alterations. Three had monosomy 8, another unique subtype of kidney cancer, and one had no copy number alterations at all.
Wei noted that the technology used to classify these tumors is not widely available.
“Patients who come to Fox Chase will have an advantage over those who go to other institutions in our area because we have CLIA certified lab to do this testing,” Wei said. “We will be able to more accurately define the tumor type and decide the best treatment and management strategy for the patient.”
Wei and colleagues’ paper, “Application of Chromosome Microarray Analysis for the Differential Diagnosis of Low-Grade Renal Cell Carcinoma With Clear Cell and Papillary Features” was recently published in Applied Immunohistochemistry & Molecular Morphology. The other researchers involved in the project include Jianming Pei, Joseph R. Testa, PhD, and Jacqueline N. Talarchek from the Cancer Biology Program; and Robert G. Uzzo, MD, chief of Surgical Oncology, and Tahseen Al-Saleem, MD, and Essel Dulaimi, MD, from the Department of Pathology. This work was supported by NCI Grant P30 CA006927.