Relatives of Patients With Carcinoma of Unknown Primary at Increased Risk

Relatives of patients with carcinoma of unknown primary (CUP) are at an increased risk of CUP and several other malignant neoplasms, according to a study published in JAMA Oncology.¹

In a nested case-control study of 4160 patients who received a CUP diagnosis between 1980 and 2010 through the Utah Cancer Registry, researchers led by N. Jewel Samadder, MD, Msc, FRCPC, of the University of Utah in Salt Lake City examined data about relatives from the Utah Population Database.

Patients were age- and sex-matched 10 to 1 to a general population control without CUP.

They found that first-degree relatives of patients who received a diagnosis of CUP were at an elevated risk of CUP themselves, as well as lung, pancreatic, myeloma, and non-Hodgkin lymphoma cancers compared to controls without CUP. 

When they restricted for relatives of cancer-free controls, they found that there was an additional increased risk for colon and bladder cancer.

Second-degree relatives were at a slightly increased risk of lung, pancreatic, breast, melanoma, and ovarian cancers.

“Relatives of patients with CUP should be aware of the elevated risks for lung, pancreatic, and colon cancer and encouraged to modify risk factors and adhere to site-specific population cancer screening,” the authors concluded.

Reference

1. Samadder NJ, Smith KR, Hanson H, et al. Familial risk in patients with carcinoma of unknown primary [published online ahead of print December 17, 2015]. JAMA Oncol. doi:10.1001/jamaoncol.2015.4265.