ARVO: Uveal Melanoma and Colon Cancer May Have Family Ties

May 9, 2007

FORT LAUDERDALE, Fla. -- Patients with melanoma of the uveal tract of the eye seem to be at an increased risk for colon cancer as well, suggesting a common genetic or molecular basis, reported investigators here.

FORT LAUDERDALE, Fla., May 9 -- Patients with melanoma of the uveal tract of the eye seem to be at an increased risk for colon cancer as well, suggesting a common genetic or molecular basis, reported investigators here.

Patients with uveal melanomas had a nearly threefold risk for colon cancer, and their first-degree relatives had a more than twofold risk, reported ophthalmologist Frederick H. Davidorf, M.D., of Ohio State in Columbus, and colleagues, at the Association for Research in Vision and Ophthalmology meeting.

"Ophthalmologists need to advise patients about the necessity of screening for colon cancer both for themselves and for their blood relatives," said Dr. Davidorf.

He and colleagues conducted a study to determine whether patients with uveal melanoma and their first-degree relatives might be at risk for other common malignancies, including breast, prostate, and colon cancer.

They took detailed histories spanning three generations of the families of all uveal melanoma patients seen in their department over the past three years, and conducted a retrospective review to identify the frequency of various cancers in the patients and their relatives.

The investigators then compared the actual cancer cases seen in uveal melanoma patients and their first-degree relatives with the expected number of cases in the general population. They used Surveillance, Epidemiology and End-Results (SEER) data to estimate rate ratios for the cancers.

They found that among the 130 patients for whom extended family histories were available, two (1.5%) had a first-degree relative who also had uveal melanoma, and 33 (25%) had a moderate to strong family history of cancer.

When they looked at the various cancers, they found that women with uveal melanoma showed a non-significant trend toward higher breast cancer incidence than the general population (rate ratio 1.67, P=0.076). The first-degree female relatives of uveal melanoma patients were not at higher risk of breast cancer (rate ratio 1.03, P=0.43).

Neither men with uveal melanoma nor their first-degree relatives were at increased risk for prostate cancer, the authors noted (rate ratio not shown).

But when they looked at colon cancer, they found that uveal melanoma patients had a significantly increased risk (rate ratio 2.84, P=0.006), and their first-degree relatives also had an increased frequency of colon cancer (rate ratio 2.26, P