RESUMO
AIM: This study examined the impact of diabetes mellitus (DM) on survival in squamous cell carcinoma (SCC) patients, and the impact of SCC on glycemic control. MATERIALS & METHODS: Patients with newly diagnosed SCC with and without DM were matched 1:1 (2007-2017). Overall survival and recurrence-free survival were estimated using the Kaplan-Meier method. Hemoglobin A1c (HbA1c) and glucose level during the year following cancer diagnosis were compared using mixed models. RESULTS: HbA1c decreased over time in DM patients (p = 0.04). The 5-year overall survival was 61% in DM patients, compared with 78% in patients without DM (p = 0.004). CONCLUSION: The presence of co-existing DM adversely impacted survival in patients with SCC. SCC did not affect glycemic control.