The rising prevalence of obesity has spurred significant research interest in understanding its implications for various aspects of health ( 1 ). The Body Mass Index (BMI) ( 2 ), as an indicator of adiposity, has been widely employed to categorize individuals into different weight status groups ( 3 ). These categories, ranging from overweight to severe obesity, provide insights into the potential health risks associated with differing degrees of adiposity ( 4 ). Given strongly increasing global prevalence of obesity, it is crucial to comprehensively explore its impact on various demographic and clinical characteristics and its potential influence on the medical intervention and the treatment outcomes ( 4 , 5 ).

Endometrial cancer, a prevalent gynecologic malignancy, poses a significant public health concern worldwide ( 6 ). It accounts for a substantial proportion of cancer-related morbidity and mortality among women ( 7 ). While various risk factors have been identified for endometrial cancer, BMI, an established measure of adiposity, has emerged as a critical player in its aetiology ( 8 ). Obesity has reached epidemic proportions, and its association with endometrial cancer risk has garnered considerable attention due to its potential to contribute to the increasing incidence of this malignancy ( 9 ). Obesity, characterized by excess fatty tissue, disrupts hormonal balance, leading to chronic inflammation, insulin resistance, and altered sex hormone production ( 10 ). These metabolic perturbations have been implicated in the pathogenesis of endometrial cancer, particularly in postmenopausal women ( 11 ). As a result, investigating the relationship between BMI and endometrial cancer has become a focal point in clinical and epidemiological research ( 7 , 11 , 12 ).

The complexity of endometrial cancer management extends beyond its initial diagnosis, encompassing surgical, medical, and radiotherapeutic interventions ( 13 ). The effectiveness of these treatments can be influenced by BMI ( 14 ). An in-depth analysis of how BMI affects the choice of treatment modalities and its impact on treatment response and prognosis is essential for tailoring therapeutic approaches to the unique needs of individual patients ( 15 ). By investigating the influence of BMI, we aim to contribute valuable insights that can inform evidence-based clinical decision-making. This study aims to evaluate the relationship between BMI and endometrial cancer treatment outcomes.

This retrospective cohort study investigates the intricate interplay between BMI subgroups and a range of demographic and clinical variables in a cohort of individuals diagnosed with endometrial cancer who underwent gynaecological surgical interventions. We analysed clinical characteristics of individuals across different BMI subgroups.

This retrospective analysis was conducted following the Declaration of Helsinki and approved by the Hospital's Institutional Review Board (Date: 03/11/2022 – Approval: 10-01). All patient data were anonymized to ensure privacy and confidentiality.

As seen in Table-1, there are no differences among the subgroups concerning age and height (p=0.718 and p=0.061, respectively). Examining reproductive history, parity did not differ across the subgroups (p=0.879). Additionally, the mode of delivery did not significantly differ among the subgroups (p=0.268). In terms of menopausal status, our analysis reveals a difference across the subgroups (p=0.013), with a higher percentage of premenopausal women in the obesity class 3 subgroup compared to other subgroups. We observed no marital and employment status differences among the subgroups (p=0.738 and p=0.312, respectively). There were no differences in monthly income and smoking habits across the subgroups (p=0.559 and p=0.455, respectively). We noted that diabetes mellitus was more prevalent in the obesity class 3 (p=0.044).However, there were no differences in the prevalence of comorbidity and ECOG (p=0.236). Education levels among the subgroups did not differ either (p=0.079).

As seen in Table-2, the usage of radiotherapy was higher in the obesity class 3 compared to others, but the difference was not significant (p=0.155). The proportion of patients receiving brachytherapy was slightly lower in the obesity class 2, with no difference among subgroups (p=0.194). The application of chemotherapy and radiochemotherapy were similar among the subgroups, with no distinctions (p=0.982 and p=0.481, respectively). Relapse rates were similar across the BMI subgroups, with only the overweight and obesity class 2 having any relapses (p=0.322). Regarding grading, the obesity class 2 had a higher proportion of grade 3 patients. However, the differences were not significant (p=0.093).

The most commonly performed surgery across all subgroups was TAH+BSO+PPLND, with the highest percentage observed in the obesity class 3 subgroup (68.4%). This surgery was chosen in more than half of the individuals in each subgroup, ranging from 55% in obesity class 1 to 68.4% in obesity class 3. Conversely, TAH+BSO was the least performed surgery among the subgroups, with the lowest percentage in the class 3 and overweight subgroups, at 10.5%. Similarly, TLH+BSO+ PLND and TLH+BSO+PPLND were infrequently performed across all subgroups. Interestingly, no individual in the obesity class 2 subgroup underwent TLH+BSO+PLND and no individuals in the overweight and class 3 experienced TLH+BSO+PLND. We found no difference when comparing the distribution of surgery types across the BMI subgroups (p=0.569).

Our retrospective comprehensive analysis of the relationship between BMI subgroups and endometrial cancer treatment outcomes offers several key insights into the intricate interplay between BMI, characteristics, and treatment strategies for endometrial cancer patients. This study underscores the importance of considering BMI as a critical factor in managing endometrial cancer, given its potential influence on characteristics and treatment outcomes. Novel studies have explored the connection between obesity and outcomes in treatment of endometrial cancer. In research by Kokts- Porietis et al. ( 16 ), obese endometrial cancer survivors faced higher recurrence risks. Ward et al. ( 17 ) found that cardiovascular diseases were the most common cause of death among women diagnosed with endometrial cancer. They observed a poorer preoperative health status with a BMI>30, indicative of existing chronic health issues. Onstad et al. ( 18 ) argued that performing surgery on obese patients with endometrial cancer could be more complex due to the technical aspects of the procedure. However, the choice of surgical procedures was not affected by obesity. This finding mirrors those of Gabala et al. ( 19 ) as well as Erkanli et al. ( 20 ). This is in contrast to findings by Bouwman et al. ( 21 ), who reported that obese patients undergoing laparotomy were at higher risk for postoperative complications. Factors such as patient characteristics, the surgeon's experience, and the equipment used might account for the discrepancies ( 15 ). Interestingly, our study found no differences among the BMI subgroups regarding age, height, parity, mode of delivery, marital and employment status, smoking habits, comorbidity, and ECOG.

Notably, diabetes mellitus was more prevalent in the obesity class 3, suggesting that higher BMI may be associated with an increased risk of comorbid conditions such as diabetes. This finding aligns with previous research that has established a link between obesity and type-2 diabetes mellitus. It highlights the importance of carefully managing diabetes in endometrial cancer, as it can affect treatment outcomes. Regarding menopausal status, our analysis revealed a higher proportion of premenopausal women in the obesity class 3 compared to other subgroups. Obesity can influence hormonal balance and contribute to alterations in sex hormone production, which may, in turn, affect menopausal status and reproductive history in endometrial cancer patients ( 4 , 20 , 22 ). Obesity-associated chronic inflammation and insulin resistance have been implicated in endometrial carcinogenesis, particularly in postmenopausal women ( 11 , 19 ). Thus, our finding underscores the potential influence of BMI on endometrial cancer risk and the importance of considering menopausal status in endometrial cancer management.

Regarding treatment modalities, we observed no differences in the use of radiotherapy, brachytherapy, chemotherapy, radio-chemo therapy, and relapse rates across the BMI subgroups. However, distribution of surgical procedures revealed that the most commonly performed surgery across all subgroups was TAH+BSO+PPLND, with the highest percent observed in the obesity class 3 subgroup. Notably, TAH+BSO was the least performed surgery among the subgroups, with the lowest rate in the obesity class 3 and overweight subgroups. This may suggest that individuals with higher BMI may be more likely to undergo more extensive surgical procedures, possibly due to the increased complexity of their cases. However, we found no differences in the surgery types across the BMI subgroups.

There are some limitations. The retrospective nature of our analysis may introduce selection bias, and the data may not be entirely representative of the broader population. Additionally, our study's sample size may limit our findings' generalizability. More extensive prospective studies are needed to validate our findings and further explore the impact of BMI on endometrial cancer treatment outcomes.

Our analysis offers valuable insights into the relationship between BMI and endometrial cancer treatment outcomes. While we observed no differences among the BMI subgroups regarding most demographic and clinical characteristics, our study highlights potential influence of BMI on menopausal status and surgical treatment strategies in endometrial cancer. Considering the increasing global prevalence of obesity, our findings underscore the importance of considering BMI as a critical factor in managing endometrial cancer. Further research is needed to elucidate the complex interplay between BMI, demographic and clinical characteristics, and treatment outcomes in endometrial cancer patients.