ABO Blood Group and Endometrial Carcinoma: A Preliminary Single-Center Experience from Saudi Arabia.

INTRODUCTION: Inherited ABO blood groups have been shown to play possible contributions in the pathogenesis of various gynecologic and non-gynecologic carcinomas. With regard to gynecologic carcinomas, there is a confined number of studies that explored the relationship between ABO blood group and endometrial carcinoma (EC) in the PubMed-indexed literature. To the best of our knowledge, no such study has ever been conducted in Saudi Arabia.

OBJECTIVES: Our study has two objectives: (I) to determine the prevalence of ABO blood groups among Saudi patients with EC, and (II) to explore the relationship between ABO blood group and several clinico-pathological prognostic parameters (namely: menopausal status [age], body mass index [BMI], tumor grade, FIGO [Fédération Internationale de Gynécologie et d'Obstétrique] stage and recurrence) in Saudi patients with EC.

MATERIALS AND METHODS: A retrospective cross-sectional study from 01-January-2010 to 31-July-2014 was conducted at King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia - a referral tertiary healthcare institute. One-hundred and fourteen patients (n=114) were included in the study. Clinico-pathological data were extrapolated from medical records, and their association with ABO blood groups were evaluated. Categorical data were presented as number of cases (n) and percentages (%). Two-tailed Chi-square test was used for univariate analysis. For all purposes, p values <0.05 were regarded as statistically significant.

RESULTS: The mean age and BMI were 59.5 ± 10.8 years (range: 31 - 90) and 36.6 ± 8.6 kg/m2 (range: 17 - 60), respectively. The vast majority of patients were post-menopausal (86%), had BMI >28 kg/m2 (84.2%), diagnosed with early FIGO stage I-II (76.3%) and developed no recurrence (86.8%). The frequencies of ABO blood group types A, B, AB, and O were 28.1%, 12.3%, 3.5% and 56.1%, respectively. When ABO blood groups were analyzed as four different types (A, B, AB and O), O-type was the most common ABO blood group in pre- and post-menopausal EC patients (43.8% and 58.2%, respectively; p=0.14). There were no statistically significant correlations between ABO blood groups and all the examined clinico-pathological factors. Moreover, when ABO blood groups were analyzed as two different types (O and non-O), similar results were obtained; no statistically significant correlations were found between ABO blood groups and all the examined clinico-pathological factors.

CONCLUSIONS:  O-type was the most prevalent ABO blood group among Saudi Arabian patients with EC, and our finding was different from the existing literature, probably highlighting an ethnic-related variance. Furthermore, no statistically significant correlations were identified between ABO blood groups and all the examined clinico-pathological factors. Also, routine ABO blood group may emerge as a clinically accessible, beneficial and economical biomarker for a possible EC vulnerability. A large-sized case-control study is needed to withdraw solid conclusions.