Ulcer Metastasis? Location of Recurrence for Patients in Diabetic Foot Remission

Background: The cancer analogy has proven effective for provisioning care to patients with diabetic foot ulcers (DFU). One potentially under-appreciated similarity between cancer and DFU is that both can recur at anatomical locations distinct from the primary occurrence. In the case of DFU, major risk factors affect the entirety of both extremities. Unfortunately, few studies have adequately characterized the location of DFU recidivism relative to prior wounds.

Purpose: We therefore analyzed existing data to better characterize the metastatic nature of DFU.

Methods: We report data from a multicenter longitudinal study (NCT02647346) of 129 participants in remission from DFU.  Each was followed for 34 weeks for recurrence.  At enrollment, investigators conducted chart reviews to characterize the locations of previous DFU.  During the trial, 37 participants suffered 53 DFU recurrences.

Results: Participants had prior DFU at 2.0±1.7 distinct locations before enrollment.  We observed high recurrence rates (48%) to the foot contralateral to the most recent DFU, with 35% occurring to a distinct ipsilateral location and 17% recurring at the previous location.  Heel and medial forefoot DFU were most likely to recur at the same location, while lateral forefoot DFU were most likely to recur elsewhere on the ipsilateral foot.  Risk of DFU to the contralateral limb was independent of primary DFU location.  Despite increased clinical attention, incidence remained high during periods of treatment for DFU.  Four DFU (two to the contralateral limb) occurred to participants undergoing treatment (0.41 DFU/ulcer-year, compared to a baseline rate of 0.63 DFU/patient-year in all participants).

Conclusion: These results suggest that recurrence for patients in diabetic foot remission frequently affects anatomy other than the site of previously healed DFU. This is particularly true for the contralateral foot.  Furthermore, patients undergoing treatment for unhealed wounds remain at high risk.  High quality preventive care is essential to increase ulcer-free days in this population.