Adapting CryoPen, a Non-Gas Based Cryotherapy System for Use in Low- and Middle-Income Countries

Abstract

Listen

Translate article

Abstract 45 Background: Cervical cancer is a leading cause of cancer-related mortality among women in low- and middle-income countries (LMICs). Two point-of-care technologies that address the treatment gap are the LMIC-adapted CryoPen, with a core temperature of approximately −95°C, and the thermocoagulator, with a probe temperature of 100-120°C. Since there is scant data on the extent of CIN involvement in an underscreened population, determining mean cervical intraepithelial neoplasia (CIN) depth in an underscreened population will establish the depth of necrosis (DON) that ablative techniques need to achieve. The study aimed to establish the maximum depth of involvement of CIN3 and test whether the LMIC-adapted CryoPen and thermocoagulator reach the DON established as necessary for eradicating CIN3. Methods: A convenience sample of 107 CIN3 cases were reviewed by a pathologist at the National Cancer Institute (INEN, Peru) and a U.S. pathologist. Ten women had ablative procedures before non-cervical pathology indicated hysterectomy: a five-minute freeze with the CryoPen (n=5), or a 60-second, 100°C application of the thermocoagulator (n=5). The pathologists measured mean depth of involvement in the CIN3 cases and the local pathologist, blinded to ablative technique, measured maximum DON in both lips. Results: Mean depth of CIN3 involvement was 2.0mm among 107 cases. Mean depth was ≤3.0mm among 79.4%; ≤3.5mm among 89.7%; ≤4.0mm among 93.5%; and ≥5.0mm among 6.5%. The maximum DON achieved by the LMIC-adapted CryoPen was ≥3.0 in 80% of cases; ≥3.5mm in 80%; ≥4.0mm in 80%; ≥4.5mm in 40%; and ≥5.0mm in 20%. The maximum DON achieved by the thermocoagulator was ≥3.0mm in 80% of cases; ≥3.5mm in 80%; ≥4.0mm in 20%; and ≥4.5mm in 20%. Conclusion: The pathology review of CIN3 cases showed that 90% of CIN3 would be eradicated if DON reached at least 3.5mm. The mean DON of both the LMIC-adapted CryoPen and thermocoagulator exceeded 3.5mm. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST: Miriam Cremer No relationship to disclose Mauricio Maza No relationship to disclose Albert Zevallos No relationship to disclose Manuel Alvarez No relationship to disclose Luis Taxa No relationship to disclose Philip E. Castle Honoraria: Roche Cepheid Consulting or Advisory Role: Cepheid, GE Healthcare, Guided Therapeutics, ClearPath, Merck, Genticel, Teva, Inovio Pharmaceuticals, Hologic Todd Alonzo No relationship to disclose Juan Felix No relationship to disclose