Tumor determination method

A method for obtaining data for determining if a subject with a tumor has Lynch syndrome, comprising:

• (1) obtaining a tissue or cell sample from the tumor;
• (2) analyzing the tissue or cell sample to determine if:
• a. the tumor has no mutation in MLH1 in genetic examination and at least one of the properties selected from the group consisting of:
• i. MSI-H in an MSI examination;
• ii. no expression of MLH-1 in the tumor determined by immunohistochemical examination;
• and
• iii. a reduced expression of MLH-1 in the tumor determined by immunohistochemical examination;
• (3) treating genomic DNA prepared from the tissue sample having no mutation in MLH1 and at least one of the properties (2)(a)(i), (ii), and (iii) with bisulfite;
• (4) amplifying, by PCR, using at least one primer selected from the group consisting of primers consisting of the nucleotide sequences represented by SEQ ID Nos. 4 to 7 and 20 to 32, DNA comprising a portion or the whole of MLH1 promoter region from the bisulfate-treated DNA obtained in (3);
• (5) subjecting the PCR amplification product obtained in (4) to ion exchange chromatography to obtain a detection signal;
• and
• (6) determining whether the peak of the detection signal obtained in (5) is a peak indicating highly methylated DNA wherein a peak indicating highly methylated DNA indicates the tumor is a tumor derived from a subject without Lynch syndrome or a peak not indicating highly methylated DNA.