Reuters Health reports that from 1975 to 2001, a rapid and steady rise in the rate of ocular non-Hodgkin lymphoma (NHL) occurred, and there is still no evidence the disease has peaked, according to a new report.
The findings, which appear in the Journal of the National Cancer Institute for July 5 (J Natl Cancer Inst 2006;98:936-939), are based on analysis of data from the Surveillance, Epidemiology, and End Results (SEER) Program.
Asians/Pacific Islanders had the highest rates of ocular NHL, around 0.33 cases per 100,000 person-years, lead author Dr. Roxana Moslehi, from the National Cancer Institute in Rockville, Maryland, and colleagues state. Whites had the next highest rate, roughly 0.27 cases per 100,000 person-years. Blacks and American Indian/Alaska native had the lowest rates.
Advancing age was identified as a risk factor for ocular NHL. In contrast to other NHLs, which typically showed an increased risk for men, gender seemed to have no bearing on the risk of ocular NHL.
During the 27-year study period, the incidence of ocular NHL in men and women climbed by 6.2% and 6.5% each year, respectively. As noted, there were no signs that disease rates were now leveling off.
As to why the rapid increase in cases, the authors suggest that it may relate to infection with Chlamydia psittaci, a microbe that has been tied to ocular NHL in the past. Further studies are needed to explore this possibility, they add.