title: Predictive values of different forms of human chorionic gonadotropin in postmolar gestational trophoblastic neoplasia.
abstract: OBJECTIVE
  The aim of this study was to reach a publicly applicable marker, using the increasing or decreasing trend of different forms of β-human chorionic gonadotropin (β-hCG) during the first 28 days after molar pregnancy evacuation.
  
  
  METHODS
  The present retrospective cohort study investigated all of the documents of patients with hydatidiform mole according to their pathological results during their admission and follow-up in the past 10 years (2003-2013). The type of the relationship was determined using locally weighted scatterplot smoothing (Lowess Smoother) and fractional polynomial regression (Fracpoly), and then a model tailored to data processing was used for drawing the receiver operating characteristic curve. During the investigation of gestational trophoblastic neoplasia (GTN) risk factors, the multiple logistic regression method was used to control the confounding variables.
  
  
  RESULTS
  Among individuals with high-risk molar pregnancy, 11 (18%) had GTN, and the prevalence of GTN in individuals with low-risk molar pregnancy was 13.4%. The slope of the β-hCG line slightly decreases with a rate of change close to zero in individuals with GTN, but the decrease is not statistically significant (P > 0.05). The receiver operating characteristics curve for serum β-hCG measurement after 21 days of molar pregnancy evacuation showed 83% sensitivity at 89% specificity (area under the curve, 0.9), which indicates that this variable has an optimal performance for discrimination between the GTN cases and patients who had spontaneous disease remission. The mean times of reaching the first negative titer in those without neoplasia and reaching a definitive GTN diagnosis were 8.1 (SD, 2) and 6.2 (SD, 1.5), respectively. The most effective remaining variable in the logistic model was uterine size larger than gestational age (95% confidence interval, 0.99-1.31; odds ratio, 1.14) with a slight increase in the risk and borderline significance (P = 0.07).
  
  
  CONCLUSIONS
  The serum β-hCG measurement after 21 days of molar pregnancy evacuation and slope of the linear regression line of β-hCG showed to be a good test to discriminate between patients who will get spontaneous disease remission and patients developing GTN.
authors.affiliation: *Department of Gynecologic and Obstetrics, Mahdiyeh Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; †Mahdiyeh Hospital, Shahid Beheshti University of Medical Sciences; ‡Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences; §Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran; and ∥Prevention of Psychosocial Injuries Research Centre, Ilam University of Medical Sciences, Ilam, Iran.
authors.forename: Parichehr
authors.initials: P
authors.lastname: Kimiaee
authors.forename: Sepideh
authors.initials: S
authors.lastname: Ashrafi-vand
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Mansournia
authors.forename: Mahmood
authors.initials: M
authors.lastname: Bakhtiyari
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Mirzamoradi
authors.forename: Zaynab
authors.initials: Z
authors.lastname: Bakhtiyari
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016022:Case-Control Studies; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000473:pathology; D009367:Neoplasm Staging; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate