Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Validation of a prediction model for post-chemotherapy fibrosis in nonseminoma patients

Gerdtsson, Axel LU ; Torisson, Gustav LU orcid ; Thor, Anna ; Grenabo Bergdahl, Anna ; Almås, Bjarte ; Håkansson, Ulf LU ; Törnblom, Magnus ; Negaard, Helene F.S. ; Glimelius, Ingrid and Halvorsen, Dag , et al. (2023) In BJU International 132(3). p.329-336
Abstract

Objective: To validate Vergouwe's prediction model using the Swedish and Norwegian Testicular Cancer Group (SWENOTECA) RETROP database and to define its clinical utility. Materials and methods: Vergouwe's prediction model for benign histopathology in post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) uses the following variables: presence of teratoma in orchiectomy specimen; pre-chemotherapy level of alpha-fetoprotein; β-Human chorionic gonadotropin and lactate dehydrogenase; and lymph node size pre- and post-chemotherapy. Our validation cohort consisted of patients included in RETROP, a prospective population-based database of patients in Sweden and Norway with metastatic nonseminoma, who underwent PC-RPLND in the... (More)

Objective: To validate Vergouwe's prediction model using the Swedish and Norwegian Testicular Cancer Group (SWENOTECA) RETROP database and to define its clinical utility. Materials and methods: Vergouwe's prediction model for benign histopathology in post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) uses the following variables: presence of teratoma in orchiectomy specimen; pre-chemotherapy level of alpha-fetoprotein; β-Human chorionic gonadotropin and lactate dehydrogenase; and lymph node size pre- and post-chemotherapy. Our validation cohort consisted of patients included in RETROP, a prospective population-based database of patients in Sweden and Norway with metastatic nonseminoma, who underwent PC-RPLND in the period 2007–2014. Discrimination and calibration analyses were used to validate Vergouwe's prediction model results. Calibration plots were created and a Hosmer–Lemeshow test was calculated. Clinical utility, expressed as opt-out net benefit (NBopt-out), was analysed using decision curve analysis. Results: Overall, 284 patients were included in the analysis, of whom 130 (46%) had benign histology after PC-RPLND. Discrimination analysis showed good reproducibility, with an area under the receiver-operating characteristic curve (AUC) of 0.82 (95% confidence interval 0.77–0.87) compared to Vergouwe's prediction model (AUC between 0.77 and 0.84). Calibration was acceptable with no recalibration. Using a prediction threshold of 70% for benign histopathology, NBopt-out was 0.098. Using the model and this threshold, 61 patients would have been spared surgery. However, only 51 of 61 were correctly classified as benign. Conclusions: The model was externally validated with good reproducibility. In a clinical setting, the model may identify patients with a high chance of benign histopathology, thereby sparing patients of surgery. However, meticulous follow-up is required.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
clinical decision rules, forecasting, germ cell and embryonal, lymph node excision, neoplasms, nonseminomatous germ cell tumour, testicular neoplasms
in
BJU International
volume
132
issue
3
pages
8 pages
publisher
Wiley-Blackwell
external identifiers
  • pmid:37129962
  • scopus:85159712336
ISSN
1464-4096
DOI
10.1111/bju.16040
language
English
LU publication?
yes
id
23f12119-a553-4abf-b19e-bc17dcac5542
date added to LUP
2023-09-22 14:42:19
date last changed
2024-04-19 01:19:52
@article{23f12119-a553-4abf-b19e-bc17dcac5542,
  abstract     = {{<p>Objective: To validate Vergouwe's prediction model using the Swedish and Norwegian Testicular Cancer Group (SWENOTECA) RETROP database and to define its clinical utility. Materials and methods: Vergouwe's prediction model for benign histopathology in post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) uses the following variables: presence of teratoma in orchiectomy specimen; pre-chemotherapy level of alpha-fetoprotein; β-Human chorionic gonadotropin and lactate dehydrogenase; and lymph node size pre- and post-chemotherapy. Our validation cohort consisted of patients included in RETROP, a prospective population-based database of patients in Sweden and Norway with metastatic nonseminoma, who underwent PC-RPLND in the period 2007–2014. Discrimination and calibration analyses were used to validate Vergouwe's prediction model results. Calibration plots were created and a Hosmer–Lemeshow test was calculated. Clinical utility, expressed as opt-out net benefit (NB<sup>opt-out</sup>), was analysed using decision curve analysis. Results: Overall, 284 patients were included in the analysis, of whom 130 (46%) had benign histology after PC-RPLND. Discrimination analysis showed good reproducibility, with an area under the receiver-operating characteristic curve (AUC) of 0.82 (95% confidence interval 0.77–0.87) compared to Vergouwe's prediction model (AUC between 0.77 and 0.84). Calibration was acceptable with no recalibration. Using a prediction threshold of 70% for benign histopathology, NB<sup>opt-out</sup> was 0.098. Using the model and this threshold, 61 patients would have been spared surgery. However, only 51 of 61 were correctly classified as benign. Conclusions: The model was externally validated with good reproducibility. In a clinical setting, the model may identify patients with a high chance of benign histopathology, thereby sparing patients of surgery. However, meticulous follow-up is required.</p>}},
  author       = {{Gerdtsson, Axel and Torisson, Gustav and Thor, Anna and Grenabo Bergdahl, Anna and Almås, Bjarte and Håkansson, Ulf and Törnblom, Magnus and Negaard, Helene F.S. and Glimelius, Ingrid and Halvorsen, Dag and Karlsdóttir, Ása and Haugnes, Hege Sagstuen and Larsen, Signe Melsen and Holmberg, Göran and Wahlqvist, Rolf and Tandstad, Torgrim and Cohn-Cedermark, Gabriella and Ståhl, Olof and Kjellman, Anders}},
  issn         = {{1464-4096}},
  keywords     = {{clinical decision rules; forecasting; germ cell and embryonal; lymph node excision; neoplasms; nonseminomatous germ cell tumour; testicular neoplasms}},
  language     = {{eng}},
  number       = {{3}},
  pages        = {{329--336}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{BJU International}},
  title        = {{Validation of a prediction model for post-chemotherapy fibrosis in nonseminoma patients}},
  url          = {{http://dx.doi.org/10.1111/bju.16040}},
  doi          = {{10.1111/bju.16040}},
  volume       = {{132}},
  year         = {{2023}},
}