A Phase II Trial Exploring the Success of Cryoablation Therapy in the Treatment of Invasive Breast Carcinoma: Results from ACOSOG (Alliance) Z1072

Glycolysis inhibition induces anti-tumor central memory CD8+T cell differentiation upon combination with microwave ablation therapy

Minimally invasive thermal therapy is a successful alternative treatment to surgery in solid tumors with high complete ablation rates, however, tumor recurrence remains a concern. Central memory CD8+ T cells (TCM) play important roles in protection from chronic infection and cancer. Here we find, by single-cell RNA analysis of human breast cancer samples, that although the memory phenotype of peripheral CD8+ T cells increases slightly after microwave ablation (MWA), the metabolism of peripheral CD8+ T cells remains unfavorable for memory phenotype. In mouse models, glycolysis inhibition by 2-deoxy-D-glucose (2DG) in combination with MWA results in long-term anti-tumor effect via enhancing differentiation of tumor-specific CD44hiCD62L+CD8+ TCM cells. Enhancement of CD8+ TCM cell differentiation determined by Stat-1, is dependent on the tumor-draining lymph nodes (TDLN) but takes place in peripheral blood, with metabolic remodeling of CD8+ T cells lasting the entire course of the the combination therapy. Importantly, in-vitro glycolysis inhibition in peripheral CD8+ T cells of patients with breast or liver tumors having been treated with MWA thrice leads to their differentiation into CD8+ TCM cells. Our work thus offers a potential strategy to avoid tumor recurrence following MWA therapy and lays down the proof-of-principle for future clinical trials.

Minimally invasive treatment of early, good prognosis breast cancer-is this feasible?

Breast cancer screening programmes frequently detect early, good prognosis breast cancers with significant treatment burden for patients, and associated health-cost implications. Emerging evidence suggests a role for minimally invasive techniques in the management of these patients enabling many women to avoid surgical intervention. Minimally invasive techniques include vacuum-assisted excision, cryoablation, and radiofrequency ablation. We review published evidence in relation to the risks and benefits of each technique and discuss ongoing trials. Data to date are promising, and we predict a trend towards minimally invasive treatment for early, good-prognosis breast cancer as technical skills, suitability criteria, and follow-up protocols are established.

Percutaneous ultrasound-guided cryoablation for early-stage primary breast cancer: a follow-up study in Japan

BACKGROUND

Ultrasound-guided percutaneous cryoablation (PCA) for early-stage breast cancer (ESBC) can be performed under local anesthesia in an outpatient clinic. This study continues a pilot stage to examine local control, safety, patient quality of life (QoL), satisfaction and cosmetic outcomes of cryoablation for ESBC.

METHODS

PCA was performed under local anesthesia for patients with primary ESBC, followed by radiation and endocrine therapies. Oncologic outcomes were examined by imaging (mammography, ultrasound, MRI) at baseline and 1, 6, 12, 24, 36, and 60 months post-cryoablation. EQ-VAS, EQ-5D-5L, subjective satisfaction and Moiré topography were used to measure health-related QoL outcomes.

RESULTS

Eighteen patients, mean aged 59.0 ± 9.0 years, mean tumor size 9.8 ± 2.3 mm, ER + , PR + (17/18), HER2-, Ki67 < 20% (15/18), underwent PCA and were followed for a mean of 44.3 months. No serious adverse events were reported, and no patients had local recurrence or distant metastasis in the 5-year follow-up. Cosmetic outcomes, satisfaction level, and QoL all improved post-cryoablation. Five-year average reduction rates of the cryolesion long, short, and depth diameters, on US, were 61.3%, 42.3%, and 22.8%, respectively, compared to the 86.2% volume reduction rate on MRI. The correlation coefficient between MRI and US measurement criteria was highest for the long diameter. During follow-up, calcification of the treated area was observed in 13/18 cases.

CONCLUSION

Cryoablation for ESBC is an effective and safe procedure with excellent cosmetic outcomes and improved QoL. This study contributes to the growing evidence supporting cryoablation as a potential standard treatment for ESBC, given compliance to pre-defined patient selection criteria.

Breast Cryoablation, From the AJR "How We Do It" Special Series

Breast cryoablation is a minimally invasive image-guided percutaneous procedure to treat fibroadenomas and early-stage breast cancer utilizing liquid nitrogen or argon gas to create extremely cold temperatures that devitalize targeted tissue. Although more long term data are needed, this outpatient procedure is well tolerated and carries minimal risks, including non-target thermal injury that can be mitigated by careful planning and proper technique. Building a sustainable breast cryoablation service in a radiology practice poses several practical considerations, such as training proceduralists, purchasing equipment, recruiting patients, and understanding the revenue cycle. This article describes aspects of the radiologist's role in this procedure, including implementation of a breast ablation program, patient selection, technical details related to intervention, and expected postprocedural outcomes.

Treatment Options for Early Stage Inoperable Breast Cancer: Cryoablation or Radiotherapy?

Background

Surgical removal of the tumour is the gold standard treatment for early stage invasive breast cancer. However, with a global ageing population, a larger number of diagnoses are occurring in women with comorbidities that render them unsuitable for surgery. Hence, it is of interest to explore alternative treatment strategies for this group of women.

Summary

Our narrative review aims to explore two such techniques, cryoablation and external beam radiotherapy, providing a brief summary of the evidence behind each technique. Following this, we discuss which groups of patients would gain the most benefit from each technique. Factors favouring the use of radiotherapy include patients with larger tumours, more superficial tumours, and those with less well-demarcated tumours where there is uncertainty regarding tumour extent. Meanwhile, patients who may benefit more from cryoablation include those who desire a smaller number of treatment sessions, have concerns regarding cosmesis and skin pigmentation, or who have relative contraindications to radiotherapy such as scleroderma, systemic lupus erythematosus, reduced lung function, or cardiac comorbidities.

Key Messages

Continued advancements in both cryoablation and radiotherapy technologies are taking place, in tandem with imaging technologies enabling greater certainty in tumour detection and delineation. These factors will help increase local control rates in this group of non-operable early stage breast cancer patients. Through this review, we hope to aid in the clinical decision-making process regarding the selection and referral of patients for each treatment.

Non-surgical ablation for breast cancer: an emerging therapeutic option

Non-surgical ablation is emerging as an alternative local therapy option for patients with early-stage breast cancer and encompasses two main types of percutaneous therapeutic procedures: radiofrequency ablation and cryoablation. Both techniques involve obliteration of a spherical lesion and feasibility studies have shown that complete tumour ablation is achievable with good or excellent cosmetic results. Although few clinical studies have directly compared non-surgical ablation with conventional surgical resection, observational studies indicate that clinical outcomes are favourable with acceptable rates of local control and no detriment to long-term survival. There remain outstanding issues with these percutaneous ablative techniques that require resolution before they could be incorporated into routine clinical practice. Hence, a consensus meeting was convened to discuss the challenges of non-surgical ablation and clarify indications for its use alongside clinical management pathways. In this Policy Review we will address some of the broader biological aspects of non-surgical ablation, including immune-modulatory effects and potential novel applications for the future.

The Role of Contrast-Enhanced Mammography After Cryoablation of Breast Cancer

Image-guided cryoablation is an emerging therapeutic technique for the treatment of breast cancer and is a treatment strategy that is an effective alternate to surgery in select patients. Tumor features impacting the efficacy of cryoablation include size, location in relation to skin, and histology (e.g., extent of intraductal component), underscoring the importance of imaging for staging and workup in this patient population. Contrast-enhanced mammography (CEM) utilization is increasing in both the screening and diagnostic settings and may be useful for follow-up imaging after breast cancer cryoablation, given its high sensitivity for cancer detection and its advantages in terms of PPV, time, cost, eligibility, and accessibility compared with contrast-enhanced MRI. This Clinical Perspective describes the novel use of CEM after breast cancer cryoablation, highlighting the advantages and disadvantages of CEM compared with alternate imaging modalities, expected benign postablation CEM findings, and CEM findings suggestive of residual or recurrent tumor.

Cryoablation for the treatment of breast cancer: immunological implications and future perspectives. Utopia or reality?

Cryoablation is a minimally invasive technique currently employed in breast cancer care, that uses freeze and thaw cycles to treat benign breast lesions, small breast cancers or focal sites of metastatic disease in patients not eligible for surgery. The final goal of this procedure is to destroy breast cancer cells using extreme cold. In addition, several studies have shown that this technique seems to have an enhancing effect on the immune response, especially by increasing the expression of tumor neoantigens specific to tumor cells, which are then attacked and destroyed. Exploiting this effect, cryoablation in combination with immunotherapy could be the key to treating early-stage breast cancers or patients who are unsuitable for surgery. According to some recent studies, there are other potential tools that could be used to enhance the therapeutic effect of cryoablation, such as FE3O4 nanoparticles or the manipulation of aquaporin expression. The aim of this narrative review is to summarize the current evidence regarding the use, indications, advantages and disadvantages of cryoablation in the treatment of breast cancer.

Locoregional Therapies for Primary and Metastatic Breast Cancer: AJR Expert Panel Narrative Review

Minimally invasive locoregional therapies have a growing role in the multidisciplinary treatment of primary and metastatic breast cancer. Factors contributing to the expanding role of ablation for primary breast cancer include earlier diagnosis, when tumors are small, and increased longevity of patients whose condition precludes surgery. Cryoablation has emerged as the leading ablative modality for primary breast cancer owing to its wide availability, the lack of need for sedation, and the ability to monitor the ablation zone. Emerging evidence suggests that in patients with oligometastatic breast cancer, use of locoregional therapies to eradicate all disease sites may confer a survival advantage. Evidence also suggests that transarterial therapies-including chemoembolization, chemoperfusion, and radioembolization-may be helpful to some patients with advanced liver metastases from breast cancer, such as those with hepatic oligoprogression or those who cannot tolerate systemic therapy. However, the optimal modalities for treatment of oligometastatic and advanced metastatic disease remain unknown. Finally, locoregional therapies may produce tumor antigens that in combination with immunotherapy drive anti-tumor immunity. Although key trials are ongoing, additional prospective studies are needed to establish the inclusion of interventional oncology in societal breast cancer guidelines to support further clinical adoption and improved patient outcomes.

Reducing the Risk of Needle Tract Seeding or Tumor Cell Dissemination during Needle Biopsy Procedures

PURPOSE

Many women fear that breast needle biopsies increase the risk of cancer spread. The purpose of this review article is to discuss the breast cancer literature regarding the risk of needle-biopsy-induced cancer cell displacement and its impact on local and regional recurrence and breast cancer survival.

METHODS

A literature review is performed to discuss the risks and mitigation of needle-biopsy-induced cancer cell displacement.

RESULTS

Needle-biopsy-induced cancer cell displacement is a common event. The risk is influenced by the biopsy technique and the breast cancer type. Evidence suggests that the risk of needle-biopsy-induced cancer cell displacement may potentially increase the odds of local recurrence but has no impact on regional recurrence and long-term survival.

CONCLUSIONS

Technical modifications of needle biopsy procedures can reduce the risk of breast needle-biopsy-induced cancer cell displacement and potentially reduce the risk of local recurrence, especially in patients for whom whole breast radiation is to be omitted.

Magnetic resonance imaging-guided radiofrequency ablation of breast cancer: a current state of the art review

With a gradual increase in breast cancer incidence and mortality rates and an urgent need to improve patient prognosis and cosmetology, magnetic resonance imaging (MRI)-guided radiofrequency ablation (RFA) therapy has attracted wide attention as a new treatment method for breast cancer. MRI-RFA results in a higher complete ablation rate and extremely low recurrence and complication rates. Thus, it may be used as an independent treatment for breast cancer or adjuvant to breast-conserving surgery to reduce the extent of breast resection. Furthermore, with MRI guidance, accurate control of RFA can be achieved, and breast cancer treatment can enter a new stage of minimally invasive, safe, and comprehensive therapy. With progress in MR thermometry technology, the applications of MRI are expected to broaden.

Cryogenic Media in Biomedical Applications: Current Advances, Challenges, and Future Perspectives

This paper explores the crucial role of cryogenic mediums in driving breakthroughs within the biomedical sector. The objective was to investigate, critically discuss, and present the current knowledge and state-of-the-art practices, along with the challenges and perspectives of the most common applications. Through an extensive literature review, this work aims to supplement existing research, offering a comprehensive and up-to-date understanding of the subject. Biomedical research involving cryogenic mediums is advancing on multiple fronts, including the development of advanced medical technologies, clinical treatments for life-threatening conditions, high-quality biospecimen preservation, and antimicrobial interventions in industrial food processing. These advances open new horizons and present cutting-edge opportunities for research and the medical community. While the current body of evidence showcases the impressive impact of cryogenic mediums, such as nitrogen, helium, argon, and oxygen, on revolutionary developments, reaching definitive conclusions on their efficiency and safety remains challenging due to process complexity and research scarcity with a moderate certainty of evidence. Knowledge gaps further underline the need for additional studies to facilitate cryogenic research in developing innovative technological processes in biomedicine. These advancements have the potential to reshape the modern world and significantly enhance the quality of life for people worldwide.

Cryoablation for the Treatment of Breast Cancer: A Review of the Current Landscape and Future Possibilities

Breast cancer is one of the most common malignancies worldwide. Traditional treatment options for breast cancer include surgery, radiation therapy, and chemotherapy. However, cryoablation, a minimally invasive technique, has emerged as a promising alternative for the treatment of early-stage breast cancer. This article aims to provide an overview of cryoablation, focusing on incorporation into practice, patient selection, procedural technique, imaging follow-up, post-treatment radiopathological findings, and current and ongoing research in the field. The current evidence suggests that cryoablation offers a safe and effective treatment option for selected patients, providing comparable oncological outcomes to traditional treatments while minimizing invasiveness and preserving breast aesthetics.

Cryoablation Allows the Ultimate De-escalation of Surgical Therapy for Select Breast Cancer Patients

BACKGROUND

Widespread use of screening mammography has allowed breast cancer to be detected at earlier stages. This allows for increased customization of treatment and less aggressive management. De-escalation of therapy plays an important role in decreasing treatment burden and improving patient quality of life. This report examines cryoablation as the next step in the surgical de-escalation of breast cancer.

METHODS

Women with a diagnosis of clinically node-negative, estrogen receptor-positive (ER +), progesterone receptor-positive (PR +), human epidermal growth factor receptor 2-negative (HER2 -) infiltrating ductal carcinomas 1.5 cm or smaller underwent ultrasound-guided cryoablation. Either the Visica 2 treatment system (before 2020) or the ProSense treatment system (since 2020) was used to perform the cryoablation. Patients received mammograms and ultrasounds at a 6 months follow-up visit, and magnetic resonance images at baseline, then at 1 year follow-up intervals. Adjuvant therapy decisions and disease status were recorded.

RESULTS

This study enrolled 32 patients who underwent 33 cryoablation procedures (1 patient had bilateral cancer). One patient had a sentinel node biopsy in addition to clinical staging of the axilla. For all the patients, adjuvant endocrine therapy was recommended, and six patients (18.75%) received adjuvant radiation. Of the 32 patients, 20 (60.6%) have been followed up for 2 years or longer, with no residual or recurrent disease at the site of ablation.

CONCLUSION

Cryoablation of the primary tumor foregoing sentinel node biopsy offers an oncologically safe and feasible minimally invasive office-based procedure option in lieu of surgery for patients with early-stage, low-risk breast cancer.

Cryoablation Therapy for Early-Stage Breast Cancer: Evidence and Rationale

Recent advances in breast cancer research and treatment propel a paradigm shift toward less aggressive and less invasive treatment for some early-stage breast cancer. Select patients with small, low-risk tumors may benefit from a less aggressive approach with de-escalated local therapy. Cryoablation of breast cancer is an emerging nonsurgical treatment alternative to breast-conserving surgery. Advantages of cryoablation over surgery include the use of local anesthesia, faster recovery, improved cosmesis, and cost savings. Proper patient selection and meticulous technique are keys to achieving successful clinical outcomes. The best candidates for cryoablation have unifocal invasive ductal carcinoma tumors that are low grade, hormone receptor positive, and ≤1.5 cm in size. In this review, we outline the current evidence, patient selection criteria, procedural technique, pre- and postablation imaging, and the advantages and limitations of cryoablation therapy.

Leveraging cryoablation and checkpoint inhibitors for high-risk triple negative breast cancer

Breast cancer is the second most common cancer among women in the United States in which the standard of care treatment is surgery with adjunctive therapy. Cryoablation, which destroys the tumor using extremely cold temperatures while preserving the potential tumor antigens, is a promising alternative to surgical resection. It is less invasive, cosmetically appeasing, cost-effective, and capable of contributing to the abscopal effect - the immune response targeting potential distant metastasis. However, to maximize the immunologic benefit of cryoablation in biologically high-risk breast cancers, combination with therapies that enhance immune activation, such as immune checkpoint inhibitors (ICIs) may be necessary. This mini review describes the fundamentals of cryoablation and treatment with ICIs, as well as discuss the caveats in both strategies and current clinical trials aimed to improve this approach to benefit patients.

New Frontiers in the Role of Locoregional Therapies in Breast Cancer: Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel

Emerging evidence regarding the effectiveness of locoregional therapies (LRTs) for breast cancer has prompted investigation of the potential role of interventional radiology (IR) in the care continuum of patients with breast cancer. The Society of Interventional Radiology Foundation invited 7 key opinion leaders to develop research priorities to delineate the role of LRTs in both primary and metastatic breast cancer. The objectives of the research consensus panel were to identify knowledge gaps and opportunities pertaining to the treatment of primary and metastatic breast cancer, establish priorities for future breast cancer LRT clinical trials, and highlight lead technologies that will improve breast cancer outcomes either alone or in combination with other therapies. Potential research focus areas were proposed by individual panel members and ranked by all participants according to each focus area's overall impact. The results of this research consensus panel present the current priorities for the IR research community related to the treatment of breast cancer to investigate the clinical impact of minimally invasive therapies in the current breast cancer treatment paradigm.

Clinical significance of tumor cell seeding associated with needle biopsy in patients with breast cancer

BACKGROUND/OBJECTIVE

The occurrence of iatrogenic tumor cell seeding (seeding) in needle tract scars formed by core needle biopsy (CNB) or vacuum-assisted biopsy (VAB) is well known. Some risk factors for seeding have been reported, but the clinicopathological risk factors and its prognosis have not been fully investigated. We evaluated the clinical features and prognosis of seeding.

METHODS

We included 4405 patients who had undergone surgery (lumpectomy or mastectomy) with a diagnosis of breast cancer by preoperative CNB or VAB at our hospital between January 2012 and February 2021. Data of patients with confirmed presence of seeding in resected specimens were collected from pathological records. We analyzed the risk factors of seeding using logistic regression analysis and compared the ipsilateral breast tumor recurrence (IBTR) rate between cases based on the presence or absence of seeding in the lumpectomy group.

RESULTS

Of the 4405 patients, 133 (3.0%) had confirmed seeding. Univariate analysis revealed the association of clinicopathological features of seeding with lower nuclear grade (NG1 vs NG2-3; p = 0.043), lower Ki-67 (<30 vs. ≥30; p = 0.049), estrogen receptor (ER) positivity (positive vs negative; p<0.01), and human epidermal growth factor receptor 2 (HER2) negativity (negative vs positive; p = 0.016). Multivariate analysis showed ER positivity (odds ratio, 5.23; p<0.05) as an independent risk factor of seeding. The IBTR rate was not significantly different between the seeding and non-seeding groups.

CONCLUSIONS

Seeding was more likely to occur in ER positive, HER2 negative carcinomas with less aggressive features, and may remain subclinical if adequate adjuvant treatments are administered.

The Evolving Role of Cryosurgery in Breast Cancer Management: A Comprehensive Review

Breast cancer is the most commonly diagnosed type of cancer, accounting for approximately one in eight cancer diagnoses worldwide. In 2020, there were approximately 2.3 million new cases of breast cancer globally, resulting in around 685,000 deaths. Consequently, there is an ongoing need to develop innovative therapeutic approaches that can improve both clinical outcomes and patient quality of life. The use of ultra-low cryogenic temperatures, facilitated by cryogenic media such as liquid nitrogen, has revolutionized the biomedical field and opened up new possibilities for advanced clinical treatments, including cryosurgery. Cryosurgery has demonstrated its feasibility as a minimally invasive technique for destroying breast tumors and eliciting a significant antitumor immune response in the host. This feature sets cryosurgery apart from other ablative techniques. It has been shown to be well tolerated and effective, offering several advantages such as simplicity, the avoidance of general anesthesia, minimal pain, low morbidity, short recovery time, cost-effectiveness, and notably, improved aesthetic outcomes. The reviewed studies indicate that cryosurgery holds promise in the management of early-stage breast cancer and metastatic disease, especially in triple-negative and Her2-positive molecular subtypes in conjunction with checkpoint inhibitors and anti-Her2 antibodies, respectively. Furthermore, the effectiveness of cryosurgery in the management of ductal carcinoma in situ should be investigated as an alternative modality to surgery or surveillance. The minimally invasive nature of cryosurgery has the potential to significantly enhance the quality of life for patients.

Breast Cancer Cryoablation in the Multidisciplinary Setting: Practical Guidelines for Patients and Physicians

Breast cancer cryoablation has emerged as a minimally invasive alternative to lumpectomy for treating early-stage breast cancer. However, no consensus exists on what should be considered the standard of care for the multidisciplinary management of patients treated with breast cancer cryoablation. In lieu of national guidelines, this review of the literature provides a multidisciplinary framework and an evidence-based discussion of the integration of "standard of care practices" in the comprehensive management of breast cancer cryoablation patients.

Percutaneous microwave ablation combined with endocrine therapy versus standard therapy for elderly patients with HR-positive and HER2-negative invasive breast cancer: a propensity score-matched analysis of a multi-center, prospective cohort study

Background

There is a growing trend to apply minimally invasive local treatments for elderly patients with early-stage breast cancer. As a minimally invasive thermal therapy, microwave ablation (MWA) has been attempted to treat breast cancer of small lesions, but its long-term local efficacy on elderly patients has seldom been reported. In this study, we aimed to compare outcomes of MWA combined with endocrine therapy to standard surgery combined with adjuvant therapy in the treatment of hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative invasive breast cancer for elderly patients.

Methods

This prospective multi-center cohort study enrolled patients over 70 years old diagnosed with HR-positive and HER2-negative early-stage invasive breast cancer between January 2016 and July 2021. Patients chose either non-randomized to undergo MWA combined with endocrine therapy (MWA group) or standard surgery combined with adjuvant therapy (surgery group). Endpoints for the comparisons were disease-free survival (DFS), overall survival (OS) and length of hospital stay (LOS) after adjusting for previously reported risk factors using propensity score matching (1:3).

Results

Of the enrolled 132 patients, 33 were in the MWA group and 99 were in the surgery group. MWA was successfully performed in all cases, and technical effectiveness was achieved in all cases. With a median follow-up of 31 months, only one case had local recurrence 23 months after MWA. MWA combined with endocrine therapy and standard surgery combined adjuvant therapy for elderly patients with breast cancer achieved similar DFS [hazard ratio, 0.536; 95% confidence interval (CI): 0.128-2.249] and OS (hazard ratio, 0.537; 95% CI: 0.089-3.235). Besides, MWA had much shorter LOS than standard surgery (7.1 versus 13.0 days, P<0.001).

Conclusions

MWA combined with endocrine therapy and standard surgery combined with adjuvant therapy for elderly breast cancer patients achieved similar outcomes. MWA combined with endocrine may be a feasible treatment strategy for elderly patients with HR-positive and HER2-negative invasive breast cancer.

Imaging of breast cancer-beyond the basics

Imaging of breast cancer is the backbone of breast cancer screening, diagnosis, preoperative/treatment assessment and follow-up. The main modalities are mammography, ultrasound and magnetic resonance imaging, each with its own advantages and disadvantages. New emerging technologies have also enabled each modality to improve on their weaknesses. Imaging-guided biopsies have allowed for accurate diagnosis of breast cancer, with low complication rates. The purpose of this article is to review the common modalities for breast cancer imaging in current practice with emphasis on the strengths and potential weaknesses, discuss the selection of the best imaging modality for the specific clinical question or patient population, and explore new technologies / future directions of breast cancer imaging.

Non-Surgical Definitive Treatment for Operable Breast Cancer: Current Status and Future Prospects

This article reviews the results of various non-surgical curative treatments for operable breast cancer. Radiotherapy is considered the most important among such treatments, but conventional radiotherapy alone and concurrent chemoradiotherapy do not achieve high cure rates. As a radiosensitization strategy, intratumoral injection of hydrogen peroxide before radiation has been investigated, and high local control rates (75-97%) were reported. The authors treated 45 patients with whole-breast radiotherapy, followed by stereotactic or intensity-modulated radiotherapy boost, with or without a radiosensitization strategy employing either hydrogen peroxide injection or hyperthermia plus oral tegafur-gimeracil-oteracil potassium. Stages were 0-I in 23 patients, II in 19, and III in 3. Clinical and cosmetic outcomes were good, with 5-year overall, progression-free, and local recurrence-free survival rates of 97, 86, and 88%, respectively. Trials of carbon ion radiotherapy are ongoing, with promising interim results. Radiofrequency ablation, focused ultrasound, and other image-guided ablation treatments yielded complete ablation rates of 20-100% (mostly ≥70%), but long-term cure rates remain unclear. In these treatments, combination with radiotherapy seems necessary to treat the extensive intraductal components. Non-surgical treatment of breast cancer is evolving steadily, with radiotherapy playing a major role. In the future, proton therapy with the ultra-high-dose-rate FLASH mode is expected to further improve outcomes.

Efficacy of ultrasound-guided cryoablation in treating low-risk breast cancer

OBJECTIVES

The primary objective of this study to determine whether infiltrating carcinoma is present in surgical specimens obtained after ultrasound-guided cryoablation from patients with HER2-negative luminal breast cancer without positive axillary lymph nodes at ultrasound. The secondary objective is to demonstrate that placing the presurgical seed-marker immediately before cryoablation does not interfere with the disappearance of tumor cells from freezing or in the surgeon's ability to locate the tumor.

METHODS

We treated 20 patients diagnosed with unifocal HR-positive HER2-negative infiltrating ductal carcinoma measuring <2cm by means of ultrasound-guided cryoablation (ICEfx Galil, Boston Scientific) using a triple-phase (freezing‒passive thawing‒freezing; 10min each phase) protocol. All patients later underwent tumorectomy according to the routine operating-room agenda.

RESULTS

No infiltrating carcinoma cells were detected in the post-cryoablation surgical specimen in 19 patients; a focus of infiltrating carcinoma cells measuring <1mm was detected in the remaining patient.

CONCLUSION

In the near future, if confirmed in larger studies with longer follow-up, cryoablation might constitute a safe and efficacious technique for the treatment of early, low-risk infiltrating ductal carcinoma. In our series, marking with ferromagnetic seeds did not interfere with the efficacy of the procedure or of the subsequent surgical intervention.

The Role of Cryoablation in Breast Cancer Beyond the Oncologic Control: COST and Breast-Q Patient-Reported Outcomes

BACKGROUND

Cryoablation has been established as a minimally invasive alternative to resection of early-stage breast cancer; however, there are no data on the cost and impact on patients' financial, psychosocial, sexual, physical, and cosmetic outcomes utilizing this approach. This study compares cost-effectiveness and patient-reported quality-of-life factors in cryoablation versus resection.

METHODS

Women with early-stage, low-risk infiltrating ductal carcinomas ≤ 1.5 cm underwent cryoablation or resection. Adjuvant therapy was provided according to tumor board recommendations. Direct and indirect costs were tracked for both groups. Financial toxicity and well-being outcome were measured by administering the Comprehensive Score of Financial Toxicity (COST) and BREAST-Q surveys, respectively, at 6-month follow-up.

RESULTS

Of the 34 eligible patients, 14 (41.1%) consented for cryoablation and 20 (58.8%) underwent resection. The median (centile) (range) follow-up was 35.0 (21.3) (15-50) months for cryoablation vs. 25 (20.8) (17-50) months for resection [p = 0.6479]. Mean (standard deviation) cost of care for cryoablation versus resection was $2221.70 (615.70) versus $16,896.50 (1332.40) [p < 0.0001], and median financial well-being scores for the cryoablation versus resection groups were 38.0 (34.5, 40.0) versus 10 (5.3, 14.0) [p < 0.0001]. Poor financial well-being was directly correlated with the cost of care [p < 0.0001]. Median psychosocial well-being scores were similar across both groups, however the cryoablation group had higher scores for physical [100 (100, 100) vs. 89 (79, 100); p = 0.0141], sexual [100 (91, 100) vs. 91 (87.5, 91); p = 0.0079], and cosmetic [100 (100, 100) vs. 88 (88, 100); p = 0.0171] outcomes.

CONCLUSION

Cryoablation offers a cost-effective and quality-of-life advantage compared with resection for early-stage, low-risk breast cancer.

Prospective Clinical Trial on Expanding Indications for Cryosurgery for Early Breast Cancers

INTRODUCTION

This is a prospective single arm clinical trial on cryosurgery for early breast cancers, to evaluate the expanded criteria to tumors larger than 1.5 cm and non-luminal breast cancers.

METHODS

Inclusion criteria include Solitary T1 breast cancers of any immunohistotypes. Cryosurgery was performed using the IceCure ProSense Cryoablation System. Lumpectomy of the cryoablated tumor was then performed 8 weeks after cryosurgery.

RESULTS

Fifteen patients underwent cryosurgery followed by lumpectomy (BCS). Median age was 53 years old 5 (33.3%) patients had ductal carcinoma in situ (DCIS), while 10 (66.7%) patients had invasive ductal carcinoma (IDC), of which 5 (50%) patients had luminal type cancers of which 3 (60%) were luminal A and 2 (40%) luminal B, 3 (30%) patients had HER2 enriched invasive carcinoma and 2 (20%) patients had triple negative IDC. Median tumor size was 13mm (Range 8.6-18mm). Seven (46.7%) patients were found to have residual cancer in the post-cryosurgery lumpectomy specimen. All residual cancers were found at the periphery of the cryoablated breast tissue. All breast cancers were otherwise completely ablated centrally as confirmed by routine histopathology, immunochemistry and TUNEL assay for evaluation of cell viability. None of the tumor factors such as tumor biology, as well as surgical factors such as ablation time and iceball size, were associated with risk of residual cancer. None of the 15 patients developed post-operative complications.

CONCLUSION

Residual cancer occurs at the periphery of the cryoablation site, careful pre-operative planning and intra-operative monitoring is crucial to ensure complete cryoablation.

Ablative Therapies for Breast Cancer: State of Art

Breast cancer (BC) is the most frequently diagnosed malignancy among women. In the past two decades, new technologies and BC screening have led to the diagnosis of smaller and earlier-stage BC (ESBC). Therefore, percutaneous minimally invasive techniques (PMIT) were adopted to treat patients unfit for surgery, women who refuse it, or elderly patients with comorbidities that could make surgery a difficult and life-threatening treatment. The target of PMIT is small-size ESBC with the scope of obtaining similar efficacy as surgery. Minimally invasive treatments are convenient alternatives with promising effectiveness, lower morbidity, less cost, less scarring and pain, and more satisfying cosmetic results. Ablative techniques used in BC are cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused ultrasound (US), and laser ablation. The aim of our study is to discuss the current status of percutaneous management of BC, evaluate the clinical outcomes of PMIT in BC, and analyze future perspectives regarding ablation therapy in BC.

Breast cancer cryoablation with radiologic-pathologic correlation

Breast cryoablation has become a viable option for the treatment of breast cancer in properly selected patient populations. With the increase in the use of cryoablation, post-treatment follow-up imaging and pathology has also gained increased importance. By using the proper imaging combination of diagnostic mammography, ultrasound and MRI, physicians are able to detect residual or recurrent malignancy and differentiate it from expected post-treatment findings. If suspicious imaging findings are seen, prompt biopsy and pathological diagnosis are essential. The pathologist must also be able to differentiate the expected post-procedural histological findings from those of recurrent or residual malignancy. These imaging and pathological findings must also be compared in order to ensure concordance and appropriate patient treatment.

Percutaneous Management of Breast Cancer: a Systematic Review

PURPOSE OF REVIEW

Surgical treatment of breast cancer is becoming increasingly more minimally invasive. We review the development status of percutaneous management for primary breast cancer and the evidence relating to tumor size as a fundamental determinant of treatment clinical outcome.

RECENT FINDINGS

It is safe and feasible for percutaneous management to treat breast cancer. For tumor size ≤ 2 cm, percutaneous management is a promising alternative modality. For tumor size ≤ 3 cm, it is controversial whether percutaneous management can achieve similar effects to surgery, especially its long-term effects. For tumor size > 3 cm, it is still in the initial exploration stage and showed the potential in the treatment of unresectable cancer by benefitting the local control of primary cancer. Percutaneous management of breast cancer is a valuable method for breast cancer treatment in selected patients. However, it will be necessary to provide the high level of evidence for widespread clinical application.

An update on the use of cryoablation and immunotherapy for breast cancer

The use of cryoablation, a minimally-invasive image-guided technique to target and kill cancer cells, continues to gain traction within the medical field and with patients. This includes the use of cryoablation for the treatment of small breast cancers and focal sites of metastatic disease. In comparison to open surgical approaches, length of hospital stay and recovery time are decreased with the use of cryoablation. Research studies have also found that cryoablation may actually enhance tumor susceptibility to immunotherapy agents. Immunotherapy enhances a person's own immune system to identify and attack cancer cells. It is proposed that after cryoablation there is increased expression of tumor specific antigens which the body can recognize as foreign invaders and with the combination of immunotherapy, result in an even more robust and efficient attack on the cancer cells. In this review we aim to highlight some of the recent advances in cryoablation which support the potential for cryoablation to induce these tumor-specific immune responses and thus supporting the use of combining cryoablation and immunotherapy for the treatment of breast cancer.

Role of Fluorodeoxyglucose-PET in Interventional Radiology

Fluorodeoxyglucose (FDG)-PET has expanding applications in the field of interventional radiology. FDG-PET provides both qualitative and quantitative assessments of malignancy, infection, and inflammation. These assessments can assist interventional radiologists in selecting the most appropriate treatment options for their oncology patients. FDG-PET is also useful for evaluating the response to interventional treatments and in predicting the prognosis of oncology patients. Finally, FDG-PET can assist the interventional radiologist in diagnosing and monitoring response to treatment of infection and inflammation. Nevertheless, there is a need for additional prospective studies to further establish the role of FDG-PET in these applications.

Treatment of early-stage breast cancer with percutaneous thermal ablation, an open-label randomised phase 2 screening trial: rationale and design of the THERMAC trial

INTRODUCTION

Breast cancer is the most frequently diagnosed malignancy worldwide but almost half of the patients have an excellent prognosis with a 5-year survival rate of 98%-99%. These patients could potentially be treated with thermal ablation to avoid surgical excision, reduce treatment-related morbidity and increase patients' quality of life without jeopardising treatment effectiveness. Previous studies showed highest complete ablation rates for radiofrequency, microwave and cryoablation. However, due to heterogeneity among studies, it is unknown which of these three techniques should be selected for a phase 3 comparative study.

METHODS AND ANALYSIS

The aim of this phase 2 screening trial is to determine the efficacy rate of radiofrequency, microwave and cryoablation with the intention to select one treatment for further testing in a phase 3 trial. Additionally, exploratory data are obtained for the phase 3 trial. The design is a multicentre open-label randomised phase 2 screening trial. Patients with unifocal, invasive breast cancer with a maximum diameter of 2 cm without lymph node or distant metastases are included. Triple negative, Bloom-Richardson grade 3 tumours and patients with an indication for neoadjuvant chemotherapy will be excluded. Included patients will be allocated to receive one of the three thermal ablation techniques. Three months later surgical excision will be performed to determine the efficacy of thermal ablation. Treatment efficacy in terms of complete ablation rate will be assessed with CK 8/18 and H&E staining. Secondary outcomes include feasibility of the techniques in an outpatient setting, accuracy of MRI for complete ablation, patient satisfaction, adverse events, side effects, cosmetic outcome, system usability and immune response.

ETHICS AND DISSEMINATION

This study protocol was approved by Medical Research Ethics Committee of the Erasmus Medical Center, Rotterdam, the Netherlands. Study results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NL9205 (www.trialregister.nl); Pre-results.

Cryoablation Without Excision for Low-Risk Early-Stage Breast Cancer: 3-Year Interim Analysis of Ipsilateral Breast Tumor Recurrence in the ICE3 Trial

BACKGROUND

The ICE3 trial is designed to evaluate the safety and efficacy of breast cryoablation, enabling women older than 60 years with low-risk early-stage breast cancers to benefit from a nonsurgical treatment and to avoid the associated surgical risks.

METHODS

The ICE3 trial is a prospective, multi-center, single-arm, non-randomized trial including women age 60 years or older with unifocal, ultrasound-visible invasive ductal carcinoma size 1.5 cm or smaller and classified as low to intermediate grade, hormone receptor (HR)-positive, and human epidermal growth factor receptor 2 (HER2)-negative. Ipsilateral breast tumor recurrence (IBTR) at 5 years was the primary outcome. A 3-year interim analysis of IBTR was performed, and the IBTR probability was estimated using the Kaplan-Meier method.

RESULTS

Full eligibility for the study was met by 194 patients, who received successful cryoablation per protocol. The mean age was 75 years (range, 55-94 years). The mean tumor length was 8.1 mm (range, 8-14.9 mm), and the mean tumor width was 7.4 mm (range, 2.8-14 mm). During a mean follow-up period of 34.83 months, the IBTR rate was 2.06% (4/194 patients). Device-related adverse events were reported as mild in 18.4% and moderate in 2.4% of the patients. No severe device-related adverse events were reported. More than 95% of the patients and 98% of the physicians reported satisfaction with the cosmetic results at the clinical follow-up evaluation.

CONCLUSIONS

Breast cryoablation presents a promising alternative to surgery while offering the benefits of a minimally invasive procedure with minimal risks. Further study within a clinical trial or registry is needed to confirm cryoablation as a viable alternative to surgical excision for appropriately selected low-risk patients.

Image-guided Microinvasive Percutaneous Treatment of Breast Lesions: Where Do We Stand?

Treatment of breast lesions has evolved toward the use of less-invasive or minimally invasive techniques. Minimally invasive treatments destroy focal groups of cells without surgery; hence, less anesthesia is required, better cosmetic outcomes are achieved because of minimal (if any) scarring, and recovery times are shorter. These techniques include cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused US, laser therapy, vacuum-assisted excision, and irreversible electroporation. Each modality involves the use of different mechanisms and requires specific considerations for application. To date, only cryoablation and vacuum-assisted excision have received U.S. Food and Drug Administration approval for treatment of fibroadenomas and have been implemented as part of the treatment algorithm by the American Society of Breast Surgeons. Several clinical studies on this topic have been performed on outcomes in patients with breast cancer who were treated with these techniques. The results are promising, with more data for radiofrequency ablation and cryoablation available than for other minimally invasive methods for treatment of early-stage breast cancer. Clinical decisions should be made on a case-by-case basis, according to the availability of the technique. MRI is the most effective imaging modality for postprocedural follow-up, with the pattern of enhancement differentiating residual or recurrent disease from postprocedural changes. ^©RSNA, 2021.

Innovations for the future of breast surgery

BACKGROUND

Future innovations in science and technology with an impact on multimodal breast cancer management from a surgical perspective are discussed in this narrative review. The work was undertaken in response to the Commission on the Future of Surgery project initiated by the Royal College of Surgeons of England.

METHODS

Expert opinion was sought around themes of surgical de-escalation, reduction in treatment morbidities, and improving the accuracy of breast-conserving surgery in terms of margin status. There was emphasis on how the primacy of surgical excision in an era of oncoplastic and reconstructive surgery is increasingly being challenged, with more effective systemic therapies that target residual disease burden, and permit response-adapted approaches to both breast and axillary surgery.

RESULTS

Technologies for intraoperative margin assessment can potentially half re-excision rates after breast-conserving surgery, and sentinel lymph node biopsy will become a therapeutic procedure for many patients with node-positive disease treated either with surgery or chemotherapy as the primary modality. Genomic profiling of tumours can aid in the selection of patients for neoadjuvant and adjuvant therapies as well as prevention strategies. Molecular subtypes are predictive of response to induction therapies and reductive approaches to surgery in the breast or axilla.

CONCLUSION

Treatments are increasingly being tailored and based on improved understanding of tumour biology and relevant biomarkers to determine absolute benefit and permit delivery of cost-effective healthcare. Patient involvement is crucial for breast cancer studies to ensure relevance and outcome measures that are objective, meaningful, and patient-centred.

The Present and Future of Neoadjuvant Endocrine Therapy for Breast Cancer Treatment

Simple Summary

The treatment of breast cancer has evolved considerably over the last two decades, leading toward individualized disease management. Hormone-sensitive breast cancers constitute the vast majority of cases and endocrine therapy is the mainstay of their treatment. On the other hand, neoadjuvant or pre-surgical treatments provide a number of advantages for tumor management. In this review we will discuss the existing evidence on neoadjuvant endocrine therapy, as well as its possible future indications.

Abstract

Endocrine therapy (ET) has established itself as an efficacious treatment for estrogen receptor-positive (ER+) breast cancers, with a reduction in recurrence rates and increased survival rates. The pre-surgical approach with chemotherapy (NCT) has become a common form of management for large, locally advanced, or high-risk tumors. However, a good response to NCT is not usually expected in ER+ tumors. Good results with primary ET, mainly in elderly women, have encouraged studies in other stages of life, and nowadays neoadjuvant endocrine treatment (NET) has become a useful approach to many ER+ breast cancers. The aim of this review is to provide an update on the current state of art regarding the present and the future role of NET.

Microwave ablation induces Th1-type immune response with activation of ICOS pathway in early-stage breast cancer

BACKGROUND

Despite great advances in the treatment of breast cancer, innovative approaches are still needed to reduce metastasis. As a minimally invasive local therapy (not standard therapy for breast cancer), microwave ablation (MWA) has been attempted to treat breast cancer, but the local effect and immune response induced by MWA have seldom been reported.

METHODS

The clinical study was performed to determine the complete ablation rate of MWA for early-stage breast cancer. Secondary endpoints included safety and antitumor immune response. 35 subjects from this clinical study were enrolled in the current report, and the local effect was determined by pathological examinations or follow-up. To investigate MWA-induced immune response, patients treated with surgery (n=13) were enrolled as control, and blood samples were collected before and after MWA or surgery. The immune cell populations, serum cytokines, secretory immune checkpoint molecules, and T-cell receptor sequencing were analyzed.

RESULTS

Of 35 enrolled patients, 32 (91.4%) showed complete ablation. Compared with surgery, MWA induced significantly increased levels of inducible co-stimulator (ICOS)+ activated CD4+ T cells and serum interferon gamma, indicating a shift in the Th1/Th2 balance toward Th1. The activated ICOS pathway was involved in the MWA-induced adaptive immune response. T-cell receptor sequencing revealed MWA of primary tumor activated T lymphocytes expansion and recognized some cancer-specific antigens. Moreover, CD4+ effector memory T-cell response was induced by MWA, and the immune response still existed after surgical resection of the ablated tumor.

CONCLUSIONS

MWA may not only be a promising local therapy but also a trigger of antitumor immunity for breast cancer, opening new avenues for the treatment of breast cancer. Combinatorial strategy using additional agents which boost MWA-induced immune response could be considered as potential treatment for clinical study for early breast cancer therapy.

Thermal Ablation as an Alternative for Surgical Resection of Small (≤ 2 cm) Breast Cancers: A Meta-Analysis

Women with early-stage breast cancer have an excellent prognosis with current therapy, but could presumably be treated less invasively, without the need for surgery. The primary goal of this meta-analysis was to examine whether thermal ablation is an effective method to treat early-stage breast cancer. Studies reporting on complete ablation rate after thermal ablation as a treatment of small breast cancers (≤ 2 cm) were included. Methodologic quality of included studies was assessed using MINORS criteria. Complete ablation rates are given as proportions, and meta-regression and subgroup analyses were performed. The overall complete ablation rate in 1266 patients was 86% and was highest after radiofrequency ablation (RFA) (92%). Local recurrence rates varied from 0% to 3%, with a median follow-up of 15 to 61 months. Overall, complication rates were low (5%-18% across techniques) and were highest after high-intensity focused ultrasound ablation and lowest after cryoablation. Cosmetic outcome was good to excellent in at least 85% of patients but was reported infrequently and long-term results of cosmetic outcome after thermal ablation and radiotherapy are still lacking. Thermal ablation techniques treating early-stage breast cancer (≤ 2 cm) are safe and effective based on complete ablation rate and short-term local recurrence rates. Especially, RFA, microwave ablation, and cryoablation are promising techniques as an alternative to surgical resection without jeopardizing current treatment effectiveness or safety. Owing to great heterogeneity in the included studies, a formal recommendation on the best technique is not possible. These findings warrant the design of large randomized controlled trials comparing thermal ablation and breast-conserving surgery in the treatment of T1 breast cancer.

Effects of Lean Thinking and Emerging Technologies on Breast Cancer Patients' Therapeutic Process During COVID-19 Pandemic: A Case-Control Matched Study

Introduction: The advent of the COVID-19 pandemic has led to the sudden disruption of routine medical care, and the subsequent reorganization of hospital structures and therapeutic algorithms, aiming at protecting patients and health professionals. This was inevitably bound to affect our Breast Unit, dilating both pre- and post-operative times. The aim of this study was to evaluate the effect on patients' flow of organizational and logistic changes (key interventions) based on lean thinking implemented after the COVID-19 outbreak.

Materials and Methods: Clinical and demographic data were retrospectively collected from patients undergoing sentinel lymph node biopsy for breast cancer at the Verona University Hospital from January 2018 to June 2020. Patients enrolled (n = 341) were divided into two groups according to date of admission: before (Group A; n = 294) and after (Group B; n = 47) the implementation of key interventions. Each case in Group B was subsequently matched 1:1 by means of case-control matching with cases from Group A for age, comorbidities, and type of surgery (Subgroup A1; N = 47). Pre-admission time (T0) and length of stay (T1) were compared between the three groups.

Results: Median T0 was 312 h, whereas median T1 was 24 h. Patients in Group B had a higher frequency of comorbidities (57.4 vs. 25.2%, p = 0.001) and underwent mastectomy more often than patients in Group A (61.7 vs. 36.7%, p = 0.001). Both median T0 and T1 were higher in group B than in group A (384 vs. 300 h, p = 0.001, 48 vs. 24 h, p = 0.001, respectively). Median T0 and T1 did not significantly differ between Group B and Subgroup A1 (all p > 0.05).

Conclusions: Lean thinking and new technologies could prove useful to the optimization of preoperative and postoperative times during the current pandemic, minimizing healthcare personnel and patients' exposure to SARS-CoV-2, and promoting a rational use of limited resources, while complying with oncological principles.

Cryoablation and Immunotherapy for Breast Cancer: Overview and Rationale for Combined Therapy

Cryoablation is a well-tolerated outpatient procedure that has been used to treat metastatic sites as well as small breast cancers in patients who are considered poor candidates for surgery. Recent studies suggest that cell disruption caused by cryoablation may increase the expression and immunogenicity of tumor neoantigens, which could enhance the ability of the immune system to recognize and attack cancer cells at both local and distant sites. Such an approach might broaden the role of immunotherapy for the treatment of breast cancer, which has previously demonstrated limited response to these agents, likely owing to the modest immunogenicity of most breast cancer subtypes. If cryoablation can induce a systemic tumor-specific response, it could enhance tumor susceptibility to immunotherapy agents. This review briefly summarizes the necessary components for generating an immune response against tumor cells, reviews the tumor microenvironment of breast cancer, describes the rationale for and limitations of immune checkpoint inhibition, highlights the potential for cryoablation to induce a systemic tumor-specific immune response, and describes the rationale for combining cryoablation and immune checkpoint inhibitors for the treatment of breast cancer. Keywords: Ablation Techniques, Breast, Neoplasms-Primary, Percutaneous, Tumor Microenvironment, Tumor Response, Ultrasonography © RSNA, 2021.

Cryotherapy mediates histopathological and microstructural changes during the treatment of skin and subcutaneous tumors in dogs

The therapeutic effects of cryotherapy on skin and subcutaneous tumors in dogs were retrospectively studied in 20 dogs with 37 tumor lesions, of which 30 were benign and seven were malignant. Our results showed that during follow-up, 94.5% of lesions were completely exfoliated, without relapse or metastasis (mean time = 245.7 days). To investigate the effects of cryotherapy, we compared histopathological observations and microstructural changes in healthy tissues and tumor tissues, before and after cryotherapy. After cryotherapy, both normal skin and tumor tissue exhibited edema and hyperemia, with inflammatory cell infiltration. The cell nuclei exhibited pyknosis, disintegration and necrosis, and tight junctions were decreased in size. Cell morphology was varied, along with fragmented cell nuclear envelopes, crenulated nuclei and indistinct and necrotic intracellular organelles. Vacuoles were apparent in the cytoplasm and intercellular desmosomes were absent. These observations suggested that cryosurgery inhibited skin and subcutaneous tumors via cold-induced injury to cells, and cellular microenvironment changes induced by apoptosis. The results suggested that cryosurgery prevented skin and subcutaneous tumors via cold-induced injury to cells, and cellular microenvironment changes induced by apoptosis. We believe these data will provide general cryotherapy guidance to scientists and veterinary surgeons.

Breast Cancer Cryoablation: Assessment of the Impact of Fundamental Procedural Variables in an In Vitro Human Breast Cancer Model

INTRODUCTION

Breast cancer is the most prominent form of cancer and the second leading cause of death in women behind lung cancer. The primary modes of treatment today include surgical excision (lumpectomy, mastectomy), radiation, chemoablation, anti-HER2/neu therapy, and/or hormone therapy. The severe side effects associated with these therapies suggest a minimally invasive therapy with fewer quality of life issues would be advantageous for treatment of this pervasive disease. Cryoablation has been used in the treatment of other cancers, including prostate, skin, and cervical, for decades and has been shown to be a successful minimally invasive therapeutic option. To this end, the use of cryotherapy for the treatment of breast cancer has increased over the last several years. Although successful, one of the challenges in cryoablation is management of cancer destruction in the periphery of the ice ball as the tissue within this outer margin may not experience ablative temperatures. In breast cancer, this is of concern due to the lobular nature of the tumors. As such, in this study, we investigated the level of cell death at various temperatures associated with the margin of a cryogenic lesion as well as the impact of repetitive freezing and thawing methods on overall efficacy.

METHODS

Human breast cancer cells, MCF-7, were exposed to temperatures of -5°C, -10°C, -15°C, -20°C, or -25°C for 5-minute freeze intervals in a single or repeat freeze-thaw cycle. Samples were thawed with either passive or active warming for 5 or 10 minutes. Samples were assessed at 1, 2, and 3 days post-freeze to assess cell survival and recovery. In addition, the modes of cell death associated with freezing were assessed over the initial 24-hour post-thaw recovery period.

RESULTS

Exposure of MCF-7 cells to -5°C and -10°C resulted in minimal cell death regardless of the freeze/thaw conditions. Freezing to a temperature of -25°C resulted in complete cell death 1 day post-thaw with no cell recovery in all freeze/thaw scenarios evaluated. Exposure to a single freeze event resulted in a gradual increase in cell death at -15°C and -20°C. Application of a repeat freeze-thaw cycle (dual 5-minute freeze) resulted in an increase in cell death with complete destruction at -20°C and near complete death at -15°C (day 1 survival: single -15°C freeze/thaw = 20%; repeated -15°C freeze/thaw = 4%). Analysis of thaw interval time (5 vs 10 minute) demonstrated that the shorter 5-minute thaw interval between freezes resulted in increased cell destruction. Furthermore, investigation of thaw rate (active vs passive thawing) demonstrated that active thawing resulted in increased cell survival thereby less effective ablation compared with passive thawing (eg, -15°C 5/10/5 procedure survival, passive thaw: 4% vs active thaw: 29%).

CONCLUSIONS

In summary, these in vitro findings suggest that freezing to temperatures of 25°C results in a high degree of breast cancer cell destruction. Furthermore, the data demonstrate that the application of a repeat freeze procedure with a passive 5-minute or 10-minute thaw interval between freeze cycles increases the minimal lethal temperature to the -15°C to -20°C range. The data also demonstrate that the use of an active thawing procedure between freezes reduces ablation efficacy at temperatures associated with the iceball periphery. These findings may be important to improving future clinical applications of cryoablation for the treatment of breast cancer.

Liquid Nitrogen-Based Cryoablation in In Vivo Porcine Tissue: A Pilot Study

Introduction:

Liquid nitrogen-based cryoablation induces freezing evenly throughout the probe tip surface, resulting in larger ablation volumes and faster treatment times. The purpose of this preliminary investigation is to determine the efficacy of the liquid nitrogen-based Visica2 Cryoablation System (Sanarus Technologies, Pleasanton, CA) in in vivo porcine kidney, liver, and fibro-fatty tissue.

Methods:

Ablations were performed under ultrasound guidance in 4 Yorkshire pigs. The target lesion cross-section width (W) and depth (D) were 1 cm for liver (n=8), kidney (n=4), and head-neck (n=5) and 2 cm for kidney (n=4). Expected axial length (L) of the resulting lesion is approximately 4 cm. After three-day survival, the ablated tissue was harvested and histologically analysed. The mean width and depth were compared with the target diameter using a one-sample t-test.

Results:

All animals survived the procedure. For the 1 cm target, mean dimensions (L x W x D) were 3.8±1.5 x 1.7±0.3 x 1.7±0.7 for liver, 3.0±0.5 x 2.0±0.4 x 1.7±0.6 for kidney, and 3.3±0.8 x 1.8±0.4 x 1.8±0.4 for head-neck. Mean width and depth were significantly greater than desired dimension. For the 2 cm target, mean dimensions were 3.2±0.5 x 3.1±0.8 x 1.9±0.7. Mean width and depth were not significantly different to desired target.

Conclusion:

Our preliminary results show that the Visica2 liquid nitrogen-based cryoablation system can efficiently and reproducibly create ablation volumes in liver, kidney, and fibro-fatty tissue within 4 minutes and 12 minutes for 1cm and 2cm targeted diameters, respectively. Further investigation is necessary to determine the optimal freeze-thaw-freeze protocol for larger ablation volumes.

Could ultrasound-guided cryoablation be used to manage "low-risk" DCIS?: a feasibility case report

Management of ductal carcinoma in-situ (DCIS) is controversial as there is concern that the majority of diagnoses will never become life threatening such that a subset of patients may be overtreated with surgery. Active surveillance is an alternative proposed management strategy; however, we cannot accurately predict which DCIS will never progress to invasive disease potentially undertreating a large proportion of women. We present a case of a 58-year-old female with DCIS successfully treated with only ultrasound-guided cryoablation without resection. A follow-up needle biopsy of the ablation zone was benign and imaging follow-up has demonstrated no evidence of disease at 14-months. Cryoablation of DCIS is feasible with appropriate patient selection and warrants further investigation as an alternative to surgical resection or active surveillance.