The results of the present study showed that IGRT resulted in significantly lower levels of SCC-Ag, CEA, CA50, and CA724 versus conventional radiotherapy, which may be attributed to the fact that IGRT performs calibration of position and dose distribution to reduce positional errors, increases the irradiation dose to the tumor target area, and reduces the exposure of normal tissue, which kills cancer cells while effectively inhibiting DNA repair, thereby controlling cancer cell proliferation and suppressing the metastasis of tumor cells and lesion infiltration. The gene discussed is CEACAM5; the disease is cancer.