To Örebro University

Tissue microarrays (TMAs) are a cost-effective tool to study biomarkers in clinical research. Cervical cancer (CC) is one of the most prevalent in women worldwide, with the highest prevalence in low-middle-income countries due to a lack of organized screening. CC is associated with persistent high-risk human papillomavirus infection. Several biomarkers have been studied for diagnostic, therapeutic, and prognostic purposes. We aimed to evaluate and validate the effectiveness of TMA in CC compared to whole slide images (WSs). We selected and anonymized twenty cases of CC. P16, cytokeratin 5 (CK5), cytokeratin 7 (CK7), programmed death-ligand 1 (PD-L1), and CD8 expression were immunohistochemically investigated. All WS were scanned and 10 representative virtual TMA cores with 0.6 mm diameter per sample were selected. Ten random combinations of 1-5 cylinders per case were assessed for each biomarker. The agreement of scoring between TMA and WS was evaluated by kappa statistics. We found that three cores of 0.6 mm on TMA can accurately represent WS in our setting. The Kappa value between TMA and WS varied from 1 for p16 to 0.61 for PD-L1. Our study presents an approach to address TMA sampling that could be generalized to TMA-based research, regardless of the tissue and biomarkers of interest.

Cervical cancer (CC) is the fourth most frequent cancer and cause of death related to cancer in women worldwide. CC is mainly caused by a persistent infection with human papillomaviruses (HPV). Mozambique is one of the African countries with high prevalence of HPV and HIV. The development of CC may be different in HIV immuno-compromised patients. In this thesis we investigated both the pathogenetic perspective of HPV, and the expression of immunotherapeutic target concerning the possible impacts in an HIV endemic milieu. In paper I, virtual tissue microarrays (TMA) were used to validate the representativity to study biomarkers in CC compared to whole slide images. Our study presents an approach to address TMA sampling that could be generalized to TMA-based research. In paper II, the immunoregulatory programmed deathligand 1 (PD-L1) was immunohistochemically assessed in cervical squamous carcinomas (SCC) in TMA. 575 cases of SCC were included, HIV status was available in 46% cases. Our findings indicated that the immunotherapeutic target of PD-L1 is not influenced by HIV status. In paper III, 40 cases of endocervical adenocarcinomas (ECA) were included. HIV status was established, and HPV was detected in all cases. In paper IV, 260 cases of SCC with known HIV status, were assessed concerning HPV genotype differences between HIV positive and negative cases. With a combination of HPV detection methods, almost all cases of our series were HPV positive. Our results in paper III and IV indicate that the newly established vaccination scheme in Mozambique, using quadrivalent vaccine would have the same potential to prevent morbidity and reduce mortality of CC regardless of a concomitant HIV infection or not.

Programmed death-ligand 1 (PD-L1) is overexpressed in squamous cervical cancer (SCC) and can be used for targeted immunotherapy. The highest mortality rates of SCC are reported in sub-Saharan Africa, where Human immunodeficiency virus (HIV) prevalence is high. In Mozambique most SCC patients present at advanced stages. Thus, there is a need to introduce new treatment options. However, immunocompromised patients were frequently excluded in previous clinical trials. Our aim was to determine if PD-L1 expression in SCC is as prevalent among women living with HIV (WLWH) as among other patients. 575 SCC from Maputo Central Hospital were included. HIV status was available in 266 (46%) cases PD-L1 expression was scored through tumour proportion score (TPS) and combined positive score (CPS). PD-L1 was positive in 20.1% of the cases (n = 110), TPS (score ≥ 25%) and in 26.3% (n = 144), CPS (score ≥ 1). Stratifying according to the HIV status, WLWH were TPS positive in 16.7%, compared to 20.9%, p = 0.43, and concerning CPS 21.1% versus 28.7%, p = 0.19, respectively. PD-L1 status was not influenced by stage, Ki-67 or p16, CD8 expression influenced only CPS status. Our data indicates that the documented effect of PD-L1 therapy on SCC should be confirmed in randomized clinical trials in an HIV endemic milieu.