Does tumour biology determine surgical success in the treatment of epithelial ovarian cancer? A systematic literature review

BACKGROUND: Ovarian cancer is the most lethal gynaecological cancer. Progression-free and overall survival is significantly related to surgical success and residual disease volume. It is unclear whether this survival advantage is due to an intrinsic biological element of the tumour cells which enables successful surgery and improved prognosis, or alternatively the number of tumour sustaining cells remaining irrespective of differences in biology. METHODS: A systematic review of the literature was performed identifying studies that have investigated the association between biomarkers and surgical outcomes. We attempted validation of these results using The Cancer Genome Atlas ovarian cancer data sets. RESULTS: Thirty studies were identified of which sixteen determined protein expression, eight gene expression and one DNA methylation in association with surgical debulking. Individualised linear models adjusting for batch, stage and age identified only expression of the genes MTDH and insulin-like growth factor-1 receptor (IGF1R) to be significantly associated with debulking surgery (P<0.05, false discovery rate (FDR)<5%), although in the case of IGF1R this was in the opposite direction to previous findings. CONCLUSION: The majority of studies are limited by design, include heterogeneous samples and lack adjustment for major confounding factors. High quality detailed clinical annotations should be routinely collected in future to more accurately evaluate biomarkers of surgical outcome.