Patent ID: 8053193

Claim:
A method for determining a presence of a cancer cell in a sample obtained from a patient, comprising: obtaining a sample suspected of containing a cancer cell from a patient; obtaining a value related to an expression level of a cancer marker gene and a value related to an expression level of a housekeeping gene; a first comparing step of comparing the value related to the expression level of the cancer marker gene with a first threshold value, wherein the first threshold value is a value equal to or less than a value related to an expression level of the cancer marker gene in a sample containing cancer cells and a value higher than a value related to an expression level of the cancer marker gene in a sample free of cancer cells; a normalizing step of normalizing the value related to the expression level of the cancer marker gene based on the value related to the expression level of the housekeeping gene; a second comparing step of comparing the normalized value obtained from the normalizing step with a second threshold value, wherein the second threshold value is a value equal to or less than a normalized value obtained by normalizing the value of the expression level of the cancer marker gene in the sample containing cancer cells based on the value related to the expression level of the housekeeping gene and a value higher than a normalized value obtained by normalizing the value of the expression level of the cancer marker gene in the sample free of cancer cells; and judging the cancer cell is present in the sample based on the result of the comparison of the first comparing step and the result of the second comparing step.