This study aims to determine the feasibility and efficacy of modulated electro-hyperthermia (mEHT) as a second-line therapy in progressive ovarian cancer. The power of mEHT was gradually increased from 135 W to 150 W based on the patient’s actual tolerance.
The mEHT treatment was feasible in patients with recurrent or progressive ovarian cancer without any complication and optimal dose of mEHT treatment was up to 150 W for 1 hour/day.
19 patients ages 18-85 years old with relapsed, refractory or progressive ovarian cancer. All had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. Initial stage of most patients (73.7%) was stage III and IV (n = 8 and 6, respectively). Patients had adequate bone marrow, liver and renal function.
Patients were placed in a supine position on a couch and received mEHT treatment using an EHY 2000 plus device (Oncotherm), 30 cm diameter circular electrode was lightly coupled to the abdominal area, for dose escalation during the first cycle (Part 1). This cycle of mEHT treatment comprised two sessions per week for 3 weeks. The dose of mEHT treatment was increased from 60 W to 80 W and then 100 W for 20 min each session, so that one session was one hour total. If the patient did not exhibit any dose limiting toxicity (DLT) in the first 1-hour session, higher doses were used at the second session (70 W, 90 W and 110 W, 20 minutes each).
MTD was defined as one dose level below the dose at which the dose escalation was terminated. MTD was determined in the first cycle. When the MTD at a specific dose was determined, additional cycles consisting of six sessions were carried out with the same dose level (Part 2). Pretreatment evaluation was repeated every 3 weeks. Diagnostic imaging for response evaluation was repeated every three cycles.
The mEHT was administered as 60 min/session, 3 times a week, for 8 weeks, for a total of 25 sessions from 2010 to 2014. The power of mEHT was gradually increased from 135 W to 150 W based on the patient’s actual tolerance. The applicator used was 7.1 dm2. The applied energy range in one session was between 486 KJ and 540 KJ.
In the first cycle, all patients were well tolerated the dose escalation to MTD of mEHT treatment (110 W, 130 W and 150 W) and there was no DLT. No one developed adverse reactions to the mEHT treatment, such as, grade ≥2 skin burns or inability to endure the hyperthermic state of the study. T
Among 17 evaluable patients after three cycles of mEHT treatment, stable disease was observed in seven patients (41.2%). Two patients who were treated less than two cycles failed to performfirst response assessment. Among nine evaluable patients after six cycles of mEHT treatment, an objective response was observed in only one patient (12.5%). After a median follow-up of 4.0 months (range 2–17 months), 18 patients demonstrated disease progression. The time to progression ranged from 2.5 to 5.0 months. At the time of analysis, 18 patients had died with a median follow-up of 8.0 months (range 2–32 months). The time to death ranged from 2.5 to 32.0 months.
Antitumor activity of mEHT treatment
The oncologic effectiveness of mEHT treatment was evaluated in patients with relapsed, refractory or progressive heavily pretreated ovarian cancer. The median overall survival was 8.0 months, and the RR was just 12.5% (1/7). Because all patients included in this study had metastatic tumors in the whole abdominal cavity, to measure antitumor activity by mEHT treatment alone which was a locoregional treatment might be unreasonable. Nevertheless, the present findings bolster the view that mEHT treatment might be efficacious in the treatment of ovarian malignancies.
The mEHT treatment was feasible in patients with recurrent or progressive ovarian cancer without any complication and optimal dose of mEHT treatment was up to 150 W for 1 hour/ day.