Background:
Numbness and tingling secondary to chemotherapy-induced peripheral neuropathy (CIPN) are frequent side effects that limit chemotherapy treatment and quality of life. Successful treatments for CIPN are limited. This preliminary report shows the potential long-term effects of ozone treatment in the management of persistent numbness and tingling secondary to CIPN.

Methods:
Ozone treatment was administered by rectal insufflation in 15 patients (female/male: 8/7, age: 66 years old) suffering from persistent numbness and tingling secondary to grade-2 or grade-3 CIPN. Planned ozone treatment consisted of 40 sessions over 4 months. The initial concentration of 10 μg/mL was progressively increased to 30 μg/mL. The initial gas volume of 180 mL/session was progressively increased to 300 mL/session if tolerated. Before and after ozone treatment, and at 3- and 6- months after the end of treatment, they were assessed (i) the grade of CIPN-toxicity, and (ii) the self-reported decrease in numbness and tingling.

Results:
After ozone treatment, 47% of patients experienced a decrease in the grade of CIPN-toxicity (P = .016), and 67% of patients reported a decrease in numbness and tingling ≥50% (P = .002). These effects were maintained at 3- and 6- months after the end of O3T.

Conclusions:
In this retrospective report, patients with persistent numbness and tingling secondary to CIPN showed clinically relevant and long-term improvements after ozone treatment. The magnitude and duration of the observed effects merit further research and support our ongoing clinical trials.

Keywords:
numbness and tingling, paresthesias, chemotherapy-induced peripheral neuropathy, grade of toxicity, side effects, cancer survivors, ozone treatment, oxidative stress modulation, Nrf2