Can hematological and biochemical parameters clinically predict the diagnosis of deep infiltrating endometriosis?

To investigate whether preoperative laboratory biomarkers can differentiate deep infiltrative endometriosis (DIE) from other endometriosis (OE) phenotypes (ovarian, tubal, peritoneal) non-invasively. This retrospective case-control study analyzed data from patients operated for pathologically confirmed endometriosis at Kartal Dr. Lütfi Kırdar City Hospital between January 2015 and January 2025. Patients were divided into the DIE group (n = 286) and the OE group (n = 230). Demographic, clinical characteristics, and preoperative laboratory parameters, including complete blood count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), cancer antigen 125 (CA125), ferritin, serum iron, TIBC, albumin, and the hemoglobin-albumin-lymphocyte-platelet (HALP) index, were compared between the groups. Patients in the DIE group reported significantly higher rates and severity of dysmenorrhea, dyspareunia, and chronic pelvic pain compared to the OE group (p < 0.05). Preoperatively, the DIE group had significantly higher CA125 and NLR levels (p < 0.001 for both). Conversely, lymphocyte counts, hemoglobin levels, ferritin levels, and the HALP index were significantly lower in the DIE group (p = 0.003, p = 0.001, p < 0.001, and p < 0.001, respectively). No significant differences were found between the groups regarding age, BMI, WBC, neutrophil, platelet, MPV, PLR, serum iron, TIBC, or albumin levels (p > 0.05). Specific laboratory biomarkers, notably CA125, NLR, lymphocyte count, hemoglobin, ferritin, and the HALP index, show significant differences between patients with DIE and OE. While no single marker is sufficient for definitive diagnosis, these findings suggest that a combination of these parameters may hold potential for non-invasively assessing the risk of deep infiltrative disease, potentially aiding in preoperative planning and patient counseling. Further prospective validation studies are warranted. These combined biomarkers could assist clinicians in triaging patients for advanced imaging or referral to tertiary endometriosis centers before surgery.