Change of flow cytometric DNA content in para-aortic lymph node showing recurrence after adjuvant chemotherapy for gastric cancer

A para-aortic lymph node showing recurrence was resected from a patient who had received adjuvant chemotherapy after curative resection of an advanced gastric cancer. A flow cytometric analysis of DNA content was carried out for the primary lesion, a metastatic lymph node and the resected lymph node. A peri-diploid cell population in addition to diploid cells appeared in the recurrent lesion, whereas a major diploid cell population and a minor aneuploid cell population were found in the primary lesion and the metastatic lymph node, indicating that a clone of chemo-resistant tumor cells selectively multiplied after the cytotoxic therapy. The characters of a recurrent lesion may be changed by clonal selection following chemotherapy.