p53 gene mutation in 150 dissected lymph nodes in a patient with esophageal cancer

For thoracic esophageal cancer, we perform extended three field lymph node dissection, and have achieved nearly 50% of overall 5-year survival. However, patients sometimes develop lymph node recurrences in spite of having no lymph node metastases found by conventional histopathologic examination. In a patient with esophageal squamous cell carcinoma, we sequenced all the p53 cDNA translated regions (exon 2-10) of primary carcinoma, and confirmed one p53 nonsense mutation in exon 10. Then we extracted genomic DNA from 150 surgically dissected lymph nodes from that patient, and performed polymerase chain reaction analysis (PCR-RFLP) to detect the same p53 mutation in the lymph nodes. PCR-RFLP analysis showed the same p53 mutation in six lymph nodes. One node was located along the right recurrent laryngeal nerve, where no positive nodes was identified by conventional histopathologic examination. The p53 mutational diagnosis of metastatic cancer may be useful in detecting minimal residual disease.