Background Ovarian cancer is the second most common genital cancer worldwide, with poor prognosis and high mortality rates. The role of inflammation in cancer biology and markers of systemic inflammation such as neutrophils, lymphocytes and monocytes have been investigated. Cancer antigen 125 (CA-125) is currently in use as an adjunct to diagnosis, prognostication and monitoring of epithelial ovarian cancer (EOC). However, CA-125 test is not readily available in our sub-region, creating a need to search for alternative markers that are available and affordable. This study aims to determine the relationship between preoperative serum lymphocyte-monocyte ratio (LMR) and CA-125 in EOC.

Materials and Methods This was a retrospective cross-sectional study among 70 women, diagnosed with EOC. Data was extracted from the case notes. LMR was calculated as the absolute lymphocyte count divided by the absolute monocyte count. Data was analysed using SPSS version 25.0. The correlation between LMR and CA-125 was determined using the Spearman’s correlation coefficient.

Results The mean age of the patients was 48.57 ± 13.97 years. Serous adenocarcinoma was the most common subtype of ovarian cancer 66 (94.3%). The median serum CA-125 was 393.5 (215.00 – 765.67) U/mL. The median LMR was 6.77 (1.28–43.0) x109/L. There was a statistically significant negative correlation between CA-125 and LMR, r = - 0.28, p = 0.22.

Conclusion LMR was negatively associated with CA-125 in women with EOC. LMR may be considered as a simple, affordable alternative marker to CA-125 in the management of EOC.