The treatment of advanced-stage pancreatic cancers is limited. Previous studies have found that the use of modulated electro-hyperthermia (mEHT) is beneficial in this patient population. However, there is no data on the optimal treatment number and initiation period. Therefore, a retrospective study was conducted with the inclusion of 96 mEHT-treated and 86 age- and sex-matched control pancreatic cancer patients. 76, 57, 38 and 33 patient pairs were enrolled into propensity score matched cohorts, whether they received at least 10, 20, 30 and 40 mEHT treatments, respectively. The survival of patients with at least 30 (HR: 0.5011; p = 0.0041) and 40 (HR: 0.5048; p = 0.0085) mEHT treatments was significantly longer, median survival was almost twice as long (10 vs. 18 months). The introduction of mEHT had the greatest benefit in the first (HR: 0.5382; p = 0.0056) and second (HR: 0.7861; p = 0.0031) 6 months after diagnosis.