title: Associations between the standardized uptake value of (18)F-FDG PET/CT and the prognostic factors of invasive lobular carcinoma: in comparison with invasive ductal carcinoma.
abstract: BACKGROUND
  The aims of this study were to evaluate the associations between the maximum standardized uptake value (SUVmax) and prognostic factors in invasive lobular carcinoma (ILC) and to compare these results with those in invasive ductal carcinoma (IDC).
  
  
  METHODS
  The study included pathologically confirmed ILCs (n = 32) and IDCs (n = 73). We retrospectively evaluated the preoperative (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) and measured the SUVmax. The pathologic results were reviewed regarding the size, histological type, histological grade, estrogen receptor (ER) and progesterone receptor (PR) status, human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), and Ki-67 of the primary tumor. We also compared the associations between the SUVmax and prognostic factors.
  
  
  RESULTS
  The mean SUVmax of the ILCs was significantly lower compared with that of the IDCs (P = 0.032). The SUVmax increased with tumor grade (P < 0.001) and was higher with ER negativity compared with ER positivity (P = 0.007) in IDC. The SUVmax was higher with EGFR positivity compared with EGFR negativity (P = 0.013) in IDC and higher with Ki-67 positivity compared with Ki-67 negativity in IDC and ILC (P < 0.001 and P = 0.002, respectively). The SUVmax was not significantly different regarding PR or HER2 for both tumor groups. The correlation between the tumor size and the SUVmax was demonstrated for IDCs (r = 0.57), but not for ILCs (r = 0.25).
  
  
  CONCLUSIONS
  The SUVmax was significantly different according to the tumor grade, ER, EGFR, and Ki-67 for IDCs. The SUVmax exhibited a positive association with Ki-67 in ILC; however, it was not significantly different with other factors, which suggests that the role of (18)F-FDG PET/CT may be limited in ILC.
authors.affiliation: Department of Radiology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 327 Sosa-ro, Wonmi-gu, Bucheon-si, Gyeonggi-do, 420-717, Republic of Korea. healmind@catholic.ac.kr.
authors.forename: Na Young
authors.initials: NY
authors.lastname: Jung
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea. rad-ksh@catholic.ac.kr.
authors.forename: Sung Hun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Radiology, Chungnam National University Hospital, 282 Muhwha-ro Jung-gu, Daejeon, 301-721, Republic of Korea. med20@hanmail.net.
authors.forename: Bo Bae
authors.initials: BB
authors.lastname: Choi
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea. sghnk@catholic.ac.kr.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Radiology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 327 Sosa-ro, Wonmi-gu, Bucheon-si, Gyeonggi-do, 420-717, Republic of Korea. mssung99@catholic.ac.kr.
authors.forename: Mi Sook
authors.initials: MS
authors.lastname: Sung
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D018275:Carcinoma, Lobular / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor; D066246:ErbB Receptors; D019788:Fluorodeoxyglucose F18; D019275:Radiopharmaceuticals; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C512478:EGFR protein, human; C508053:ERBB2 protein, human