Background: Calcitonin, a tumor marker primarily used to diagnose medullary thyroid carcinoma (MTC), can also be elevated in other conditions, complicating diagnosis. This study aims to provide a clinical evaluation of the real-world consequences of unexplained calcitonin elevation. Methods: We conducted a retrospective cohort study of patients with elevated basal calcitonin levels who presented at the Department of General, Visceral, and Transplantation Surgery, University Medical Center Mainz, between January 2015 and March 2025. Additionally, we reviewed electronic health records from 2007 onward for patients with ICD codes indicating calcitonin hypersecretion. Patients with confirmed MTC or genetic syndromes were excluded. Results: Of 345 patients with elevated calcitonin levels, 167 (48%) met the inclusion criteria, and 29 additional patients with calcitonin hypersecretion were identified via ICD, resulting in 167 patients analyzed. More than half of the patients were female (52%), had an average age of 53.9 years and a high prevalence of goiter (86%). Calcitonin levels were slightly elevated (<20 pg/mL) in 81% of cases and were above 50 pg/mL in only 10 patients. Surgery was performed in 77% of patients, mainly to exclude malignancy. Postoperatively, calcitonin normalized in 86% of patients but remained elevated in eight patients. Two of these patients were found to have false-positive results due to assay interference. Follow-up data were incomplete for a substantial proportion of patients, with a median follow-up of 4.6 months. The mortality rate was 4%, with causes unrelated to calcitonin levels. Conclusions: Elevated basal calcitonin levels, especially slightly elevated levels (<20 pg/mL), are common in clinical practice and often do not appear to be related to malignant disease, so careful investigation is required. Persistently elevated calcitonin levels justify further examinations, especially if other explanations can be ruled out. Only a few patients attend follow-up appointments, which makes patient follow-up challenging.

Background/Objectives: To investigate the non-inferiority of preservative-free (PF) tafluprost eye drops (Taflotan sine^®) compared to latanoprost eye drops (Xalatan^®) in reducing mean 24 h intraocular pressure (IOP) on the second day of a diurnal IOP measurement. Methods: In this retrospective monocentric cohort study, patients suffering from primary open-angle glaucoma, ocular hypertension, normal tension glaucoma, pigment dispersion glaucoma, or pseudoexfoliation glaucoma who had undergone inpatient diurnal IOP measurement were included. Patients of cohort 1 used latanoprost eye drops as monotherapy; patients of cohort 2 used preservative-free tafluprost eye drops. Data from 7 January 2005 to 9 July 2019, inclusive, were analyzed. Results: Ninety-three eyes were included (n = 59 latanoprost group, n = 34 PF tafluprost group). Mean 24 h IOP on day 2 was 14.1 mmHg (SD 2.3) in the latanoprost group and 14.5 mmHg (SD 3.4) in the PF tafluprost group. The non-inferiority of PF tafluprost eye drops to latanoprost eye drops in efficacy on mean 24 h IOP could not be confirmed (95% CI −1.5, ∞, p = 0.235). The average difference in mean IOP at the individual measurement times between both cohorts was 0.24 mmHg (SD 0.17) on day 1 and 0.44 mmHg (SD 0.6) on day 2. The non-inferiority of PF tafluprost compared to latanoprost regarding fluctuation range could not be demonstrated for both days. Conclusions: The data suggests slight inferiority of PF tafluprost to latanoprost eye drops. There were similar mean 24 h IOP values in both cohorts. PF tafluprost eye drops remain a useful treatment option as long as the patient’s individual target pressure is achieved. Furthermore, according to the literature, it is also a treatment option for patients with symptoms of ocular surface disease and other side effects affecting the ocular surface while receiving preservative-containing topical therapy.