Introduction/Background Primary Mucinous Epithelial Ovarian Cancer (PMEOC) is a rare disease representing 3–4% of all ovarian cancers. PMEOC often presents early (65–80%) and has a good overall prognosis. Poor prognostic factors include infiltrative histological subtype, capsule rupture, and advanced stage. The Pan-Birmingham Gynaecological Cancer Centre (PBGCC) serves a large multi-ethnic population of 2 million people; 82.8% white ethnicity, 10.8% South-Asian ethnicity, 3.3% Black ethnicity, 2.4% Mixed ethnicity, 0.9% other ethnicity. We investigated whether ethnicity was a risk factor for differential outcomes in patients diagnosed with PMEOC.

Methodology Case notes of patients diagnosed with PMEOC at PBGCC between December 2005- February 2022 were retrospectively analysed. Data analysis was performed using Microsoft Excel.

Results All pathology was reviewed of the 160 cases identified to confirm PMEOC, 39 were excluded leaving 121 for data analysis. Patient ethnicities were: 17 (14%) South Asian, 85 (70%) white, 4 (3%) other, and 16 (13%) unknown. Age at diagnosis for the whole population was normally distributed with mean of 53.8 (±3) years. Age for non South Asian remained normally distributed with a mean of 55.7 (±3.1) years. However, a bimodal age distribution was noted in South Asian patients with two distinct groups- >40 and ≤ 40 years old with mean age at diagnosis being 55.4 (±4.1) and 25.1 (±8) years respectively. South Asian patients were more likely to be diagnosed with PMEOC ≤40 years old (p=0.01), stage 1C at diagnosis (p=0.03) and in women ≤40 more likely to have infiltrative histology (p=0.025).

Conclusion We have demonstrated that South Asian women under 40 appear to have a distinct high risk phenotype for PMEOC. Larger studies are required to confirm this as a novel risk factor and if confirmed work to elucidate biological causes is urgently needed.