External validation and comparison of IPI, R-IPI, and NCCN-IPI in diffuse large B-cell lymphoma patients treated with R-CHOP to predict 2-year progression-free survival
Naree Warnnissorn,
Nonglak Kanitsap,
Pimjai Niparuck,
Paisarn Boonsakan,
Prapasri Kulalert,
Wasithep Limvorapitak,
Lantarima Bhoopat,
Supawee Saengboon,
Pichika Chantrathammachart,
Teeraya Puavilai,
Suporn Chuncharunee
Affiliations
Naree Warnnissorn
Department of Pathology, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Nonglak Kanitsap
Hematology Division, Department of Internal Medicine, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Pimjai Niparuck
Division of Hematology, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Paisarn Boonsakan
Department of Pathology, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Prapasri Kulalert
Department of Clinical Epidemiology, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Wasithep Limvorapitak
Hematology Division, Department of Internal Medicine, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Lantarima Bhoopat
Hematology Division, Department of Internal Medicine, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Supawee Saengboon
Hematology Division, Department of Internal Medicine, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Pichika Chantrathammachart
Division of Hematology, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Teeraya Puavilai
Division of Hematology, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Suporn Chuncharunee
Division of Hematology, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Background Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive lymphoma. The standard first-line therapy for DLBCL consists of rituximab cyclophosphamide doxorubicin vincristine and prednisone (R-CHOP). About 50–70% of patients may be cured by R-CHOP. There was no data on external validation and comparison of the international prognostic index, revised-IPI (R-IPI), and enhanced-IPI (NCCN-IPI) to predict treatment outcomes in the middle-income country with a resourced-limited setting.Objectives We aimed to externally validate and compare IPI, R-IPI, and NCCN-IPI in predicting 2-year progression-free survival (2-y PFS) of newly diagnosed DLBCL patients treated with R-CHOP.Methods This ambispective observational study recruited consecutive patients diagnosed between 1 January 2014 and 30 June 2020, with the last follow-up on 1 July 2022 from Thammasat University Hospital and Ramathibodi Hospital. We assessed discrimination by Harrell‘s concordance index (c-index), calibration by calibration plot, and absolute difference in survival (ADS) between the lowest-and the highest-risk groups.Results The cohort of 292 patients (median age 63 years and median follow-up 3.6 years) had 131 progressions and 96 deaths. The 2-y PFS was 63%. The c-indices were NCCN-IPI 0.6216, R-IPI 0.6004 (P = 0.215), and IPI 0.6104 (P = 0.463). The calibration plots of NCCN-IPI and R-IPI showed nearly perfect agreement (moderate strength), while IPI had miscalibrations. The ADSs were NCCN-IPI 52%, R-IPI 42%, and IPI 25%.Conclusion NCCN-IPI is the best prognostic index compared to IPI and R-IPI in prior studies. However, the prognostic model for DLBCL patients treated with R-CHOP requires updating or integrating biomarkers to improve discrimination to the acceptable level (c-index 0.7).
