The discriminative properties of erythrocyte anisocytosis in patients with resectable malignant pancreatic masses compared with an age and gender matched control group.

Introduction: Red cell distribution width (RDW) is a parameter that reflects the heterogeneity in the size of the circulating erythrocytes. Elevated levels of RDW have been found related to various pathologic conditions including cancers. We hypothesized that elevated RDW levels might correspond to advanced stages of pancreatic cancer.

Methods: The medical files and pathology reports of patients who underwent Whipple procedure were evaluated in a retrospective casecontrol study. The relationship of RDW to age, gender, cancer antigen 19-9 (CA 19-9), blood hemoglobin levels, stage of the tumor, tumor size, tumor grade, number of lymph nodes with metastasis, the status of lymphovascular and perineural invasion were investigated. A oneto-two, age- and- gender matched group of seemingly healthy patients was used to compare the levels of RDW between the patients of pancreatic head malignancy and healthy people. ROC (receiver operating characteristics) curves analysis was conducted to define a threshold to discriminate malignant pancreatic head tumors from healthy control subjects. Then, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (+LR), and negative likelihood ratio (-LR) were calculated.

Results: The median age was 61 years (IRQ 54.75-69). The median RDWs were 15.20% (IQR 13.20-19.50) vs 13.00 (IQR 12.60-13.48) in the pancreas adenocancer and the control group, respectively, p=0.000). There was significant relationship between RDW and the grade of the tumor, p=0.026. An RDW level of 14% was obtained as a result of the ROC curves analysis and the positive predictivity about malignancy was 70.73% with a negative predictive rate of 89.95% compared with the healthy group of patients.

Conclusion: The elevated levels of RDW in patients with a pancreatic mass may point to a possible malignancy; however, an elevated RDW in a patient with a malignant pancreatic head mass is related to the grade of the disease, not the stage.