Show simple item record

dc.contributor.advisorRakaee, Mehrdad
dc.contributor.advisorRichardsen, Elin
dc.contributor.advisorBerg, Thomas
dc.contributor.authorTekie, Kiniena
dc.date.accessioned2024-06-05T06:58:39Z
dc.date.available2024-06-05T06:58:39Z
dc.date.issued2022-05-31
dc.description.abstractIntroduction PD-L1 is a biomarker that is used to predict the response to immunotherapy of patients with lung cancer. A pathologist manually assesses the PD-L1 expression mainly on biopsy specimens. Even though PD-L1 is an established biomarkers in the routine practice, still some challenges remain. This thesis aims to address two issues: 1) whether an automated scoring system can objectively and reliably reproduce the manual scores, and 2) how the PD-L1 score on biopsy is comparable with surgically resected samples. Methods Paired biopsy and resection tumor tissues from 26 patients with adenocarcinoma of the non-small cell lung cancer (NSCLC) were included in this thesis. Immunohistochemistry was used to detect the expression of PD-L1. The slides were digitalized, and the clinical data was retrieved from the patient’s journals. A supervised machine learning model (ML) was developed to assess the tumor proportion score (TPS) of PD-L1 expression in the whole slide images. Sensitivity and specificity of ML-derived PD-L1 scores and the intra-class correlation coefficient (ICC) of biopsy vs resected PD-L1 scores were computed. Results There was a moderate correlation (r=0.59, P<0.001) between digital and manual scores using PD-L1 TPS as continuous variable. The ML model showed high performance in PD-L1 scoring with a sensitivity/specificity of 0.88/0.92 and 0.85/0.96 at both <1 vs ≥1 % and <50 vs ≥50 % TPS cutoffs, respectively. No correlation was observed between biopsy vs resected PD-L1 scores at 1% cutoff using either digital or manual scores. However, at 50% cutoff, both digital and manual scores show high level of consistency (manual TPS ICC, 0.82, P<0.001; digital TPS ICC: 0.7, P=0.01) across paired biopsy and resection tissues. Conclusion The biopsies were found to be equivalent to corresponding resected specimens for determining PD-L1 expression at 50% cutoff in adenocarcinoma of NSCLC. Our machine learning algorithm is found to be robust in detecting PD-L1 positive tumor cells with an accuracy like pathologists. Validation of the findings and algorithms is warranted in large-scale cohort.en_US
dc.identifier.urihttps://hdl.handle.net/10037/33729
dc.language.isoengen_US
dc.publisherUiT Norges arktiske universiteten_US
dc.publisherUiT The Arctic University of Norwayen_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2022 The Author(s)
dc.rights.urihttps://creativecommons.org/licenses/by-nc-sa/4.0en_US
dc.rightsAttribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)en_US
dc.subject.courseIDMED-3950
dc.subjectVDP::Medical disciplines: 700::Clinical medical disciplines: 750::Oncology: 762en_US
dc.subjectVDP::Medisinske Fag: 700::Klinisk medisinske fag: 750::Onkologi: 762en_US
dc.subjectVDP::Medical disciplines: 700::Clinical medical disciplines: 750::Lung diseases: 777en_US
dc.subjectVDP::Medisinske Fag: 700::Klinisk medisinske fag: 750::Lungesykdommer: 777en_US
dc.subjectVDP::Technology: 500::Biotechnology: 590en_US
dc.subjectVDP::Teknologi: 500::Bioteknologi: 590en_US
dc.titleHeterogeneity Assessment of PD-L1 Expression in Biopsy Versus Resected Specimens of Lung Adenocarcinoma - Machine Learning Approachen_US
dc.typeMaster thesisen_US
dc.typeMastergradsoppgaveen_US


File(s) in this item

Thumbnail
Thumbnail

This item appears in the following collection(s)

Show simple item record

Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)