The validity of 5-aminorevrinic acid as a biomarker for risk screening and supportive diagnostic parameters in lung cancer patients.

Abstract

e21027 Background: Early detection and treatment of cancer is an important issue that affect the prognosis of cancer patients. Photodynamic screening with 5-aminorevrinic acid (ALA-PDS) is simple and non-invasive procedure for risk screening of cancer, and it is gradually recognized as the predictable biomarkers for cancer in Japan. In this study, we examined the predictability of lung cancer by ALA-PDS and its usefulness as a supportive parameter for preoperative diagnosis. Methods: Eighty-five lung cancer patients (48 males and 37 females) just before lung resection were enrolled. 5-aminolevulinic acid phosphate 150mg was taken at night and urine samples were collected in the next morning. The porphyrin metabolites in the urine samples were detected by solid phase extraction method, previously reported from our group. Afterwards, the data was adjusted depending renal function. The data was compared with that from healthy volunteer without any abnormal symptom and physical disorder. Results: The average age of 85 patients was 70 years (46-85). The number of patients in each pathological stage was 2 in Stage 0, 58 in Stage IA and IB, 15 in Stage IIA and IIB, 8 in Stage IIIA and IIIB, and 2 in Stage IV, respectively. The diagnosis was 61 cases of adenocarcinoma and 22 cases of squamous cell carcinoma. Urinary porphyrin metabolites in lung cancer patients increased significantly as compared to those of healthy volunteers (2,847nM/gCRE vs 1,668nM/gCRE, p < 0.001). Increase of urinary porphyrin metabolites was observed even in stage 0 or I patients, but the correlation with stage progression was not clear (Stage 0 and I vs Stage II vs Stage III and IV: 2,757nM/gCRE vs 3,099nM/gCRE vs 3,010nM/gCRE). Furthermore, urinary porphyrin metabolites were confirmed to be significantly increased even in PET-negative cancer patients, compared to healthy volunteers (p < 0.001). Conclusions: ALA-PDS was able to predict lung cancer in our cohort. Moreover, it was also suggested that it may be useful as a supportive parameter for diagnosis of early stage lung cancer or PET negative lung cancer.