Tailoring distant metastatic imaging for patients with clinically localized undifferentiated nasopharyngeal carcinoma.

Abstract

The 2000 practice guidelines of the National Comprehensive Cancer Network recommend World Health Organization Type 2-3 nasopharyngeal carcinoma (NPC) be staged for distant disease using chest X-ray and bone scan. Our aim was to evaluate these modalities plus liver ultrasonography for American Joint Committee on Cancer/International Union Against Cancer 1997 clinical Stage I-IVB NPC. Between February 1999 and May 2002, all patients with clinical (examination plus CT/MRI of head and neck) Stage I-IVB undifferentiated NPC were prospectively evaluated for distant disease with chest X-ray, liver ultrasonography, and bone scan. Suspicious lesions underwent confirmatory investigation, and patients were reevaluated at 4 months. In the 139 patients evaluated, the positive yield was 3.6% and prevalence was 5.8% (0.7% lung, 2.2% skeletal, and 2.9% liver metastases). The prevalence increased by N stage (p = 0.004) and overall stage (p = 0.05). Compared with N3 disease (odds ratio 1.0), the odds of metastases for N0, N1, and N2 disease was 0, 0.12, and 0.33, respectively. The positive yield was 0%, 1.8%, 4.8%, and 14.3% for N0, N1, N2, and N3 disease, respectively. This is the first study to evaluate the use of distant staging investigations for American Joint Committee on Cancer/International Union Against Cancer 1997 staged NPC. We recommend alterations to the 2000 National Comprehensive Cancer Network guidelines as follows: high-risk (N3) disease should be fully staged with chest X-ray, bone scan, and liver ultrasonography; intermediate risk (N1 and N2) disease may be staged using all three modalities on an institutional basis. No evidence supports distant imaging for low-risk (N0 or Stage I) disease.