title: Nadir CA-125 level as prognosis indicator of high-grade serous ovarian cancer.
abstract: OBJECTIVE
  The capacity of nadir CA-125 levels to predict the prognosis of epithelial ovarian cancer remains controversial. This study aimed to explore whether the nadir CA-125 serum levels could predict the durations of overall survival (OS) and progression free survival (PFS) in patients with high-grade serous ovarian cancer (HG-SOC) from the USA and PRC.
  
  
  METHODS
  A total of 616 HG-SOC patients from the MD Anderson Cancer Center (MDACC, USA) between 1990 and 2011 were retrospectively analyzed. The results of 262 cases from the Jiangsu Institute of Cancer Research (JICR, PRC) between 1992 and 2011 were used to validate the MDACC data. The CA-125 immunohistochemistry assay was performed on 280 tissue specimens. The Cox proportional hazards model and the log-rank test were used to assess the associations between the clinicopathological characteristics and duration of survival.
  
  
  RESULTS
  The nadir CA-125 level was an independent predictor of OS and PFS (p < 0.01 for both) in the MDACC patients. Lower nadir CA-125 levels (≤10 U/mL) were associated with longer OS and PFS (median: 61.2 and 16.8 months with 95% CI: 52.0-72.4 and 14.0-19.6 months, respectively) than their counterparts with shorter OS and PFS (median: 49.2 and 10.5 months with 95% CI: 41.7-56.7 and 6.9-14.1 months, respectively). The nadir CA-125 levels in JICR patients were similarly independent when predicting the OS and PFS (p < 0.01 for both). Nadir CA-125 levels less than or equal to 10 U/mL were associated with longer OS and PFS (median: 59.9 and 15.5 months with 95% CI: 49.7-70.1 and 10.6-20.4 months, respectively), as compared with those more than 10 U/mL (median: 42.0 and 9.0 months with 95% CI: 34.4-49.7 and 6.6-11.2 months, respectively). Baseline serum CA-125 levels, but not the CA-125 expression in tissues, were associated with the OS and PFS of HG-SOC patients in the MDACC and JICR groups. However, these values were not independent. Nadir CA-125 levels were not associated with the tumor burden based on second-look surgery (p = 0.09). Patients who achieved a pathologic complete response had longer OS and PFS (median: 73.7 and 20.7 months with 95% CI: 63.7-83.7 and 9.5-31.9 months, respectively) than those with residual tumors (median: 34.6 and 10.6 months with 95% CI: 6.9-62.3 and 4.9-16.3 months, respectively).
  
  
  CONCLUSIONS
  The nadir CA-125 level was an independent predictor of OS and PFS in HG-SOC patients. Further prospective studies are required to clinically optimize the chances for a complete clinical response of HG-SOC cases with higher CA-125 levels (>10 U/mL) at the end of primary treatment.
authors.affiliation: Department of Chemotherapy, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Xia
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Pathology, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, Jiangsu 210028, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA ; Research Institute of Obstetrics and Gynecology, The third Affiliated Hospital of Guangzhou Medical College, Guangzhou, Guangdong 510150, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Lizhou
authors.initials: L
authors.lastname: Jia
authors.affiliation: Department of Radiotherapy, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Yiqin
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Gynecologic Oncology, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Deng
authors.affiliation: Department of Gynecologic Oncology, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Junwei
authors.initials: J
authors.lastname: Qu
authors.affiliation: Department of Gynecologic Oncology, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Bifang
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Department of Nursing, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Aifeng
authors.initials: A
authors.lastname: Meng
authors.affiliation: Department of Gynecologic Oncology, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China ; Department of Nursing, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Bole
authors.initials: B
authors.lastname: Fu
authors.affiliation: Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA ; Department of Gynecologic Oncology, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China ; State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096, PR China.
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Chemotherapy, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Zhiying
authors.initials: Z
authors.lastname: Qian
authors.affiliation: Department of Gynecologic Oncology, Jiangsu Cancer Hospital, Nanjing, Jiangsu 210009, PR China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Wang
keywords: CA-125; Epithelial ovarian cancer; HG-SOC; Prognosis