Prospective trial on cryosurgery for early breast cancers without subsequent tumour excision (Poster Presentation)

Abstract

<p><strong>Introduction:</strong> Cryosurgery is a minimally invasive percutaneous ablative breast cancer treatment. Early pilot studies have shown its effectiveness in treating selected early breast cancers.</p><p><strong>Methods:</strong> This is a single arm prospective trial on cryosurgery on early breast cancers with ethical approval. Inclusion criteria include In-situ or invasive ductal carcinoma with size <=1.5 cm in the largest dimension. Patients were screened pre-operatively with PET/MRI scans for size eligibility. Eligible patients were treated by cryosurgery by a breast specialist. Axillary surgery such as sentinel lymph node biopsy were performed in the same setting.</p><p>PET/MRI scans were repeated at 6-week post-cryosurgery, and systematic image-guided core needle biopsy were performed at 8-weeks post-cryosurgery, for documentation of any residual breast cancers. Tissues from anterior, posterior, superior, inferior, medial, lateral and central areas were biopsied by one single breast surgical specialist for post-cryosurgery evaluation of tumor viability by specialist pathologist.</p><p><strong>Results:</strong> 43 patients were recruited into the study. 16 patients were excluded after multifocality/multicentricity found by MRI or MRI size fallen outside inclusion criteria. 27 patients received cryosurgery.</p><p>The median size of the tumor was 11 mm (Range 5–15 mm). Tumor histology include one ductal carcinoma in situ and 26 invasive ductal carcinoma. All patients had positive hormonal receptor (ER and PR) status. None of them were HER-2 enriched. Median cryosurgery procedure time was 45.5 minutes (Range 20–141 minutes). 6-week Post-cryosurgery PET scan of all 27 patients showed metabolically quiescent post-ablation lesion. 6-week Post-cryosurgery MRI scan of all 27 patients showed residual post-treatment cavity with median size of 42 mm (Range 28–54 mm). Post-cryosurgery surgery systematic biopsy at 6 weeks showed no evidence of residual viable tumor in all patients, which correlates with the post-cryosurgery PET/MRI findings. None of the 27 patients developed surgical complications. All patients had at least 12 weeks of follow-up and remained well.</p><p><strong>Conclusion:</strong> Cryosurgery resulted in complete ablation of all early breast cancers treated in this cohort. This cohort showed significantly better ablative results when compared to previously published retrospective studies where cryosurgery on larger tumors tend to be associated with increased risk of residual tumors. The authors believe strict size inclusion criteria in this study plays an important role in this. Pre-cryosurgery PET and MRI also allowed much more accurate estimation of the tumor size which is reflected by the large number of patient exclusion after PET and MRI in this cohort.</p><p><strong>Conflict of interest:</strong></p><p>Other Substantive Relationships: Cryoprobes and ProSense system were donated by WKK Medical Equipment Company Ltd.</p>