A57
T cell density and location can influence the prognosis of ovarian cancer
Ahmad Al-Attar1, Mohamed Shehata1, Lindy Durrant2, Stephen Chan1
1Nottingham University Hospitals NHS Trust, Nottingham, Nottinghamshire, UK, 2University of Nottingham, Nottingham, Nottinghamshire, UK
Background
The presence of immune-cells in the tumour microenvironment and its influence on prognosis remains controversial. The dogma that inflammation can be good or bad in terms of controlling and modifying the growth of cancer cells is central to the current immunoediting hypothesis. The aims of this study were to examine the significance of CD3+ cells in patients with epithelial ovarian cancer and to determine their influence on the disease in relation to their location within tumours.
Method
A 157-core tissue-microarray constructed from primary ovarian cancer patients treated at Nottingham-University-Hospitals (2000-2007) was stained for the T-cell marker CD3. The number of CD3+ cells in direct contact with tumour cells was counted per tumour area. These were considered as intra-tumoural T-cells (ITTC). Cores were divided into CD3 high or low density tumours. Stromal T-cells (STC) were assigned as positive or negative.
Results
The study population had a median follow-up time of 36-months (0-75). The number of ITTC counted in tumour cores ranged between 0 and 184/mm2. 90-tumours (57%) were found to be in the low-density rubric, while 56 (36%) were of a high-density T-cell population. STC were found in 118-cores-(75%) compared to 22-cores-(14%) negative cores. Higher number of ITTC correlated with lower grade (p=0.045), tumour type (p=0.034), and longer median survival times (57-versus 37-months for high-and low-ITTC densities, respectively, p=0.0379). This relationship was reversed when tumours were infiltrated by CD3+-cells in the stromal-compartment, predicting worse survival (Log-rank test,-p=0.028). Combining ITTC with STC produced an interesting pattern where the ITTC-high/STC-ve had the best prognosis, while those with ITTC-low/STC+ve fared worst (p=0.002).
Conclusion
Infiltration of ovarian cancer by T-cells can influence its prognosis depending on the location of these cells (intra-tumoural versus stromal). The former seems to control tumour growth improving survival, while the latter is probably contributing to tumour progression and, in-turn, worse survival.
