title: Alpha-fetoprotein normalization as a prognostic surrogate in small hepatocellular carcinoma after stereotactic body radiotherapy: a propensity score matching analysis.
abstract: BACKGROUND
  To assess the significance of alpha-fetoprotein (AFP) normalization as a prognostic surrogate after stereotactic body radiotherapy (SBRT) for patients with small hepatocellular carcinoma (HCC).
  
  
  METHODS
  Patients who underwent SBRT for primary or recurrent HCC were registered and a database thereof was retrospectively reviewed. Among 165 total registered patients, 77 patients were selected who satisfied the following criteria: (1) their AFP levels were > 20 ng/mL before SBRT, and (2) their AFP levels were checked within three months after SBRT. Propensity score based matching analysis was performed to minimize potential confounding bias. AFP normalization was defined as a reduction of AFP level to ≤ 20 ng/mL. Overall survival (OS) and progression-free survival (PFS) curves were estimated by the Kaplan-Meier method.
  
  
  RESULTS
  Thirty-seven (48.1 %) patients displayed AFP normalization (normalized group), while 40 (51.9 %) patients comprised the non-normalized group. The OS rates at 3-year were 62.0 % and 44.0 % (p = 0.023), and the PFS rates at 3-year were 27.9 % and 12.0 % (p = 0.019), in the normalized and non-normalized groups, respectively. Local control rates were 97.2 % in the normalized group and 94.7 % in the non-normalized group at three years (p = 0.579). In the propensity score matching cohort (25 pairs), OS and PFS were significantly longer in the normalized group than in the non-normalized group (p = 0.017 and 0.049, respectively). The local control rates were 100 % in both matched groups.
  
  
  CONCLUSIONS
  AFP normalization within three months after SBRT is a prognostic surrogate for OS and PFS in patients with small HCC. AFP monitoring should be considered a useful tool for HCC patients with an elevated AFP level before SBRT.
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. jreign79@naver.com.|Present address: Department of Radiation Oncology, Kyung Hee University Medical Center, Kyung Hee University School of Medicine, Songpa-gu, Seoul, Republic of Korea. jreign79@naver.com.
authors.forename: Jinhong
authors.initials: J
authors.lastname: Jung
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. drsmyoon@amc.seoul.kr.|Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. drsmyoon@amc.seoul.kr.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Yoon
authors.affiliation: Department of Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. hanseungbone@gmail.com.
authors.forename: Seungbong
authors.initials: S
authors.lastname: Han
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. s5854@amc.seoul.kr.|Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. s5854@amc.seoul.kr.
authors.forename: Ju Hyun
authors.initials: JH
authors.lastname: Shim
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. kimkm70@amc.seoul.kr.|Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. kimkm70@amc.seoul.kr.
authors.forename: Kang Mo
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. limys@amc.seoul.kr.|Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. limys@amc.seoul.kr.
authors.forename: Young-Suk
authors.initials: YS
authors.lastname: Lim
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. hch@amc.seoul.kr.|Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. hch@amc.seoul.kr.
authors.forename: Han Chu
authors.initials: HC
authors.lastname: Lee
authors.affiliation: Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. sykim.radiology@gmail.com.|Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. sykim.radiology@gmail.com.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. pjhynwie@hanmail.net.
authors.forename: Jin-Hong
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. jhkim2@amc.seoul.kr.|Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. jhkim2@amc.seoul.kr.
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000097:blood* / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D057216:Propensity Score; D016634:Radiosurgery; D016019:Survival Analysis; D016896:Treatment Outcome; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: C097353:AFP protein, human; D000509:alpha-Fetoproteins