Newly Defined Renal Neoplasm Has Low Risk of Metastasis, So Patients May Be Able to Avoid Surgery

Dr. Shuanzeng (Sam) Wei, investigator on the study and associate professor in the Department of Pathology and medical director of the Clinical Genomics Laboratory at Fox Chase.
Dr. Shuanzeng (Sam) Wei, associate professor in the Department of Pathology

PHILADELPHIA (March 31, 2022)—Researchers at Fox Chase Cancer Center have published a new study that identifies several characteristics of papillary renal neoplasm with reverse polarity (PRNRP), a neoplasm that may simply be monitored rather than removing it through surgery.

First described two years ago, PRNRP has a distinct histology from other papillary renal cell carcinoma, including low-grade pathologic features, according to Shuanzeng “Sam” Wei, MD, PhD, associate professor in the Department of Pathology.

“Prior to defining this new entity it was referred to as a carcinoma, but now we realize that it is not a carcinoma,” Wei said. “Looking at cases published to date, there have been no recurrences, metastasis, or tumor-related deaths.”

Wei and colleagues in Fox Chase’s Department of Surgical Oncology and the Cancer Signaling and Epigenetics research program recently published a report that detailed seven cases of PRNRP at Fox Chase and reviewed the 93 cases of PRNRP reported in the literature.

On average, these tumors are small, with the average size of the seven tumors reported at Fox Chase being about 3 centimeters. In addition, all seven tumors appeared to be at least partially cystic, Wei said.

“The observation that these tumors are cystic is very interesting because part of management of patients with a renal mass is to do an imaging study,” Wei added. “If the imaging reveals cystic lesions, the tumor may be PRNRP and it may be benign.”

Most patients diagnosed with renal cell carcinoma will undergo removal of part or all of the kidney. These surgeries may involve complications, Wei said. “We want to raise awareness about this new type of tumor because if a patient has it, the tumor may be able to remain in the body with close follow-up.”

The research team also performed chromosomal microarray and next-generation sequencing on samples of PRNRP. They found KRAS mutations in four of the seven cases. However, there were no chromosomal alterations found in any.

“This was surprising,” Wei said. “This tumor not having chromosomal changes is another indication that it is a low-grade tumor that is benign or has very low potential to become a malignant tumor.”

Taken together, these results are significant for patient management, he added. “If you are a local pathologist and are not sure if a sample is PRNRP, send it to us and we will be able to tell you.”

The paper, “Papillary Renal Neoplasm With Reverse Polarity Is Often Cystic,” was published in The American Journal of Surgical Pathology.

Fox Chase Cancer Center (Fox Chase), which includes the Institute for Cancer Research and the American Oncologic Hospital and is a part of Temple Health, is one of the leading comprehensive cancer centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase was also among the first institutions to be designated a National Cancer Institute Comprehensive Cancer Center in 1974. Fox Chase is also one of just 10 members of the Alliance of Dedicated Cancer Centers. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are also routinely recognized in national rankings, and the Center’s nursing program has received the Magnet recognition for excellence six consecutive times. Today, Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research, with special programs in cancer prevention, detection, survivorship, and community outreach. It is the policy of Fox Chase Cancer Center that there shall be no exclusion from, or participation in, and no one denied the benefits of, the delivery of quality medical care on the basis of race, ethnicity, religion, sexual orientation, gender, gender identity/expression, disability, age, ancestry, color, national origin, physical ability, level of education, or source of payment.

For more information, call 888-369-2427