"Different trend" in multiple primary lung cancer and intrapulmonary metastasis

Background: The distinguishing of intrapulmonary metastatic tumors from multiple primary lung cancers is difficult but of great importance for the therapeutic management and prognosis of these patients. Methods: We used genomic DNA analyzed by six microsatellites (D7S1824, D15S822, D2S1363, D10S1239, D6S1056, and D22S689) with PCR to identify discordant allelic variation from 12 patients. There are five patients with multiple primary lung cancers and seven patients who were diagnosed with intrapulmonary metastases from 850 patients with primary lung cancer in our hospital. The experiments were approved by the West China Hospital Ethics committee (No. 2013 ( 33)) and all patients agreed to participate in the study and signed an informed consent form. Results: In the group of metachronous lung tumor, three of five patients have different histological types and one of five patients have the same histological type which showed "contradictory trend". The other one showed "unique trend". In the second group ( intrapulmonary metastasis lung tumor), one patient showed "contradictory trend" and the others showed "unique trend". Conclusions: "Different trends" are useful in discrimination of intrapulmonary metastasis lung cancer and multiple primary lung cancer even diagnosed with the histopathological evaluation.