Comparison of narrow-band imaging and conventional nasopharyngoscopy for the screening of unaffected members of families with nasopharyngeal carcinoma

Abstract

Familial aggregation of nasopharyngeal carcinoma (NPC) has been widely reported. The excess risk is about 4-8-fold among first-degree relatives of NPC patients compared with those without a family history of the disease. We used nasopharyngoscopy and a narrow-band image system (NBI) to screen NPC high-risk patients and identify a good tool for the early detection of NPC in these high-risk groups. We recruited all available, affected blood relations of the patients. When NPC patients were more distant relatives, such as cousins, we recruited their shared second-degree relatives, such as unaffected aunts and uncles, to genetically connect the NPC cases. We performed transnasal endoscopy, first in white-light mode, then under the NBI system. There were two NBI patterns in NPC: microvascular proliferation and engorged blood vessels. The NBI pattern in normal nasopharyngeal mucosa was a regular cobblestone pattern. A prospective study included 211 asymptomatic members from 154 NPC families. We found four cases of NPC, all with a tumor stage of T1. In one patient (1/4), MRI revealed a 2-cm-diameter neck lymphadenopathy (N1). The correlation between conventional nasopharyngoscopy and NBI was very high (κ = 0.798, P = 0.000). In conclusions, NBI is not superior to conventional nasopharyngoscopy for the early detection of NPC in unaffected members of families with NPC history. The long-term follow-up is necessary in high-risk NPC patients. Further studies will be needed to determine which screening tool-conventional nasopharyngoscopy, NBI, or EB virus titer-is most effective.