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

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.

Cryoablation: A promising non-operative therapy for low-risk breast cancer

BACKGROUND

The aim of this study was to evaluate the feasibility of cryoablation for early-stage low-risk breast cancer without tumor resection.

METHODS

Women diagnosed with ER+, PR+, and HER2-infiltrating ductal carcinomas ≤1.5 cm were treated with cryoablation. The non-surgical procedure used a Visica® 2 Treatment System with ultrasound guidance for ablation of the tumor with a 1 cm margin. Patients were monitored at 6-month intervals by MRI, mammogram, and ultrasound.

RESULTS

Twelve patients with unifocal breast cancer were treated with cryoablation for local control without follow-up tumor resection. All patients received adjuvant endocrine therapy, and none had radiation. The median follow-up was 28.5 (range = 4-41) months with 11 patients having at least one six-month follow-up. All imaging modalities showed complete ablation of target zone 11/11 (100%). Four patients (33.3%) have been followed up for ≥ 2 years with no local failure or residual disease.

CONCLUSION

Cryoablation of early-stage low-risk (ER+, PR+, and HER2-) breast cancer is a safe alternative to surgery.

Breast cancer care during a pandemic: an opportune time for cryoablation?

Purpose

Cryoablation is a minimally-invasive percutaneous procedure that is capable of reducing the psychosocial burden of surgical delay while also decreasing the morbidity of breast cancer therapy. The purpose of this editorial is to discuss the potential role of cryoablation for reducing the psychosocial burden of surgical delay during the COVID-19 pandemic by expediting the management of breast cancer while also lessening demand on limited healthcare resources.

Methods

This editorial critiques current expert opinion recommendations that aim to reduce viral transmission and preserve healthcare resources during the COVID-19 pandemic by advocating delay of elective breast cancer surgery.

Results

The editorial summarizes the current state of the evidence that supports the selective use of cryoablation as a definite or stopgap measure in the management of breast cancer during the COVID-19 pandemic or when healthcare resources are limited.

Conclusions

As an office-based procedure performed under local anesthesia, cryoablation eliminates the need for operating room personnel and equipment while also reducing the psychosocial impact of delayed breast cancer surgery. By reducing the number of patient and healthcare provider interactions, cryoablation not only decreases the risk of viral transmission but also the need for personal protective devices during resource-limited times.

A Case-Control Study Examining Disparities in Clinical Trial Participation Among Breast Surgical Oncology Patients

BACKGROUND

Clinical trial participation among racial and ethnic minorities remains low despite national efforts. We sought to determine how participation in clinical trials by breast surgical oncology patients has changed over time and what characteristics are associated with participation.

METHODS

Women with breast cancer enrolled in National Cancer Institute-sponsored, cooperative-group trials from 2000 to 2012 and who underwent oncologic surgery (n = 17 125) were compared with trial-eligible women in the National Cancer Database diagnosed in 2000-2012 (n = 792 719). Race-specific trial participation was plotted over time by income and reported as a proportion of the combined cohorts. Factors associated with trial participation were estimated using logistic regression; we report odds ratios (ORs) with 95% confidence intervals (CIs). A P value less than  .05 was considered statistically significant for all analyses. All tests were two-sided.

RESULTS

Participation declined across all groups over time because of a decrease in the scale and number of trials. In 2000-2003, Asian-Pacific Islander (7.17%), Hispanic (3.48%), and white (7.13%) patients from the highest income group had higher participation than their lower-income counterparts (Asian-Pacific Islander: 3.95%; Hispanic: 2.67%; white: 5.96%), but by 2008-2012, only high-income white patients participated more than lower-income whites (0.32% vs 0.25%, all P < .01). Black (OR = 0.80, 95% CI = 0.75 to 0.85) and Hispanic (OR = 0.84, 95% CI = 0.77 to 0.92) patients were less likely to participate than whites, but there were statistically significant interactions between income and race and ethnicity, with high-income black patients being approximately 50% less likely to participate than lower-income blacks (all P < .001).

CONCLUSIONS

Multifaceted interventions addressing the intersectionality of race, ethnicity, and other patient characteristics are needed to address persistent disparities in trial participation among breast surgical oncology patients.

Implementing Breast Cryoablation in Practice

Breast cryoablation is becoming more commonplace as a minimally invasive percutaneous procedure that utilizes extreme cold to destroy targeted tissue and has been used to treat symptomatic fibroadenomas and early-stage breast cancer for over a decade with promising results. The practical considerations for implementing a breast cryoablation service include developing and communicating strategic and operational plans, training and privileging the proceduralist, selecting equipment, collaborating with referring clinicians, recruiting and navigating patients, and understanding billing considerations.

Safety and Efficacy of Ultrasound-Guided Cryoablation for Benign Breast Fibroepithelial Lesions

OBJECTIVE

The purpose of this study is to evaluate the safety and efficacy of cryoablation for benign breast fibroepithelial lesions (FELs) that otherwise warrant surgical excision, including symptomatic fibroadenomas, growing fibroadenomas, and cellular FELs.

METHODS

All patients from 2016-2018 who had ultrasound-guided cryoablation of a symptomatic and/or growing fibroadenoma or cellular fibroepithelial lesion were reviewed. The electronic medical record was reviewed for any procedure-related complications and reduction in mass volume by ultrasound and was recorded to assess for efficacy. Patients were surveyed using a seven-point Likert scale to assess satisfaction with the procedure and a ten-point visual analog pain scale to assess level of discomfort.

RESULTS

Twenty-four women (average age 37.1 years, range 19-57 years) with 26 FELs were treated with no adverse events and 100% technical success. Thirteen cellular FELs and 13 symptomatic and/or growing fibroadenomas were ablated. Twenty-two patients had an average imaging follow-up of 11.7 months (range 5-23 months), and 18 patients completed the follow-up survey. There was 92% (22/24) clinical success, defined as a greater-than-50% reduction in mass volume. Average reduction in mass volume was 86% overall. Eighty-five percent (17/20) would recommend the procedure to others and reported pain during the procedure to be minimal (average 2.4 out of 10) with overall satisfaction rating of 6.2 out of 7. Twelve symptomatic masses demonstrated a significant reduction in pain after cryoablation (P = 0.01).

CONCLUSION

Cryoablation is a safe and efficacious minimally invasive nonsurgical alternative for the treatment of benign breast FELs.

Cryoablation In The Management Of Breast Cancer: Evidence To Date

Cryoablation has been successfully used to treat various type of solid tumors, including breast carcinomas. This ablation method has the advantage of being a minimally invasive procedure useful in various clinical situations, including early breast cancer and metastatic breast cancer, when co-morbidities preclude the use of surgical treatment. However, due to the small sample size of the available studies, reliable and definitive conclusions on the usefulness of cryoablation in patients with breast cancer could not be drawn. In fact, many aspects necessitate to be elucidated, regarding technical issues, indications, efficacy, imaging follow-up, and possible advantages over other percutaneous ablative methods. This review article has the aim to clarify the current evidence supporting cryoablation of breast cancer, and discuss the future perspectives, including those arising from the new studies on immunological effects related to cryoablation.

Cryoablation and immunotherapy: an overview of evidence on its synergy

Cancer cells can escape the immune system by different mechanisms. The evasion of cancer cells from immune surveillance is prevented by immune checkpoint inhibitors, allowing the patient’s own immune system to attack their cancer. Immune checkpoint inhibitors have shown improvement in overall survival for melanoma, lung cancer and renal cell carcinoma in clinical trials. Unfortunately, not all patients respond to this therapy.

In cancer management, percutaneous ablation techniques are well established for both cure and local control of many tumour types. Cryoablation of the tumour tissue results in cell destruction by freezing. Contrary to heat-based ablative modalities, cryoablation induces tumour cell death by osmosis and necrosis. It is hypothesised that with necrosis, the intracellular contents of the cancer cells stay intact allowing the immune system to induce an immune-specific reaction. This immune-specific reaction can, in theory, also affect cancer cells outside the ablated tissue, known as the abscopal effect. Unfortunately, this effect is rarely observed, but when cryoablation is combined with immunotherapy, the effect of both therapies may be enhanced. Although several preclinical studies demonstrated a synergistic effect between cryoablation and immunotherapy, prospective clinical trials are needed to prove this clinical benefit for patients. In this review, we will outline the current evidence for the combination of cryoablation with immunotherapy to treat cancer.

A Phase I clinical trial of carbon ion radiotherapy for Stage I breast cancer: clinical and pathological evaluation

Even with its high RBE and >20 years history, there had been no breast cancer clinical trial using carbon-ion radiotherapy. We started a Phase I trial of carbon ion radiotherapy for Stage I breast cancer in 2013. This article describes the clinical and pathological evaluation of this study. Patients with low-risk Stage I breast cancer were eligible. A dose escalation study was designed, with dose levels of 48.0, 52.8 or 60.0 Gy relative biological effectiveness (RBE) administered in four fractions within 1 week. Three months after radiotherapy, the patients underwent tumor excision for pathological evaluation. Between April 2013 and December 2014, three cases receiving 48 Gy (RBE), three cases receiving 52.8 Gy (RBE) and one case receiving 60 Gy (RBE) underwent this protocol. No adverse effects were observed except for Grade 1 acute skin reaction in four cases. Pathological evaluation revealed that all four cases with doses of 52.8 Gy (RBE) and 60.0 Gy (RBE) achieved Grade 2b or more, but only two cases reached Grade 3. At the end of 2017, all cases were alive without recurrence or late had not caused any late adverse reaction. Carbon ion radiotherapy for Stage I breast cancer seems to be safe, and we found that it did not reach enough treatment effect 3 months after the treatment.

Cryosurgery for primary breast cancers, its biological impact, and clinical outcomes

Recently, a number of new minimally invasive image-guided percutaneous ablation treatments, including cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused ultrasound, laser ablation, and irreversible electroporation have been developed. Several studies have shown the feasibility and safety of these cryoablation therapies for the treatment of benign breast tumors and small invasive breast cancer. Although the complete response rate of cryoablation for breast cancer is reported to be relatively good, most studies enrolled a small number of patients, and so reliable conclusions could not be drawn. In this review, we introduce the mechanisms of action of cryoablation, and summarize the current literature on the efficacy and safety of cryoablation for breast cancer. Cryoablation also induces an immunomodulatory effect, which is an interesting topic of research in the era of immune checkpoint inhibitors. Cryoablation for primary tumor may enhance the treatment effect of immune checkpoint inhibitors in patients with breast cancer. Further investigations of this new therapeutic strategy are needed.

Comparison of passive and scanning irradiation methods for carbon-ion radiotherapy for breast cancer

The dose distribution of passive and scanning irradiation for carbon-ion radiotherapy for breast cancer was compared in order to determine the preferred treatment method. Eleven Japanese patients who received carbon-ion radiotherapy for breast cancer were retrospectively analyzed. The original clinical plans were used for the passive irradiation method, while the plans for the scanning irradiation method were more recently made. Statistical analysis suggested that there was no significant difference in superiority in terms of dose distribution between the passive and scanning irradiation methods. The present study found that the scanning irradiation method was not always superior to the passive method, despite a previous study having reported the superiority of scanning irradiation. The present result is considered to arise from characteristics of breast cancer treatment, such as the simplicity of the organ at risk and the shallow depth point of the target from the skin. It is noteworthy that the present study suggests that the passive irradiation method can provide better dose distribution, depending on the case.

The Changing Paradigms for Breast Cancer Surgery: Performing Fewer and Less-Invasive Operations

Historically, through the conduct of prospective clinical trials, breast cancer surgeons have performed less radical breast and axillary surgeries with no survival decrement to our patients. Currently, other opportunities exist for the treating breast surgeon to do less. Possibilities include active surveillance for ductal carcinoma in situ, ablative therapy for small primary breast cancers, selective omission of a sentinel node biopsy, and selective elimination of breast surgery after neoadjuvant systemic therapy. Breast surgeons must be leaders in the development and testing of effective therapy with the least intervention possible.

Immunotherapy Plus Cryotherapy: Potential Augmented Abscopal Effect for Advanced Cancers

Since the 1920s the gold standard for treating cancer has been surgery, which is typically preceded or followed with chemotherapy and/or radiation, a process that perhaps contributes to the destruction of a patient’s immune defense system. Cryosurgery ablation of a solid tumor is mechanistically similar to a vaccination where hundreds of unique antigens from a heterogeneous population of tumor cells derived from the invading cancer are released. However, releasing tumor-derived self-antigens into circulation may not be sufficient enough to overcome the checkpoint escape mechanisms some cancers have evolved to avoid immune responses. The potentiated immune response caused by blocking tumor checkpoints designed to prevent programmed cell death may be the optimal treatment method for the immune system to recognize these new circulating cryoablated self-antigens. Preclinical and clinical evidence exists for the complementary roles for Cytotoxic T-lymphocyte-associated protein (CTLA-4) and PD-1 antagonists in regulating adaptive immunity, demonstrating that combination immunotherapy followed by cryosurgery provides a more targeted immune response to distant lesions, a phenomenon known as the abscopal effect. We propose that when the host’s immune system has been “primed” with combined anti-CTLA-4 and anti-PD-1 adjuvants prior to cryosurgery, the preserved cryoablated tumor antigens will be presented and processed by the host’s immune system resulting in a robust cytotoxic CD8⁺ T-cell response. Based on recent investigations and well-described biochemical mechanisms presented herein, a polyvalent autoinoculation of many tumor-specific antigens, derived from a heterogeneous population of tumor cancer cells, would present to an unhindered yet pre-sensitized immune system yielding a superior advantage in locating, recognizing, and destroying tumor cells throughout the body.

Successful cryoablation of breast cancer

The current standard of care for screen-detected breast cancers is surgical excision. Cryotherapy is a promising non- surgical alternative treatment for these cancers and is performed under local anesthesia as an outpatient, circumventing the risks that come with an operation. New research also shows promising results for the treatment of breast cancer when cryotherapy is combined with immune modulation as it may help prevent tumor recurrence. We herein report a case of breast cancer treated successfully with cryoablation. A brief literature review of cryoablation as a treatment for breast cancer is added.

Immunological Aspects of Cryoablation of Non-Small Cell Lung Cancer: A Comprehensive Review

In cryoimmunotherapy, target tumors are treated with cryoablation to generate antitumor immune responses. Because immune checkpoint inhibitors have demonstrated that lung cancer can be an immunotherapy-responsive disease, there has been renewed interest in the immunological aspects of cryoablation of lung cancer. Herein, we review preclinical and clinical trials of cryoablation of primary lung tumors. We examine the magnitude of cryoablation-induced antitumor immune responses and the synergy between cryoablation and either other immunotherapies or molecular targeted therapies to improve treatment responses in advanced lung cancer. We further discuss a rationale for the addition of cryoablation to immune checkpoint inhibitors for the treatment of advanced lung cancer, which is currently under clinical investigation.

Percutaneous cryoablation of breast tumours in patients with stable metastatic breast cancer: safety, feasibility and efficacy

PURPOSE

To evaluate safety, feasibility and efficacy of percutaneous cryoablation of breast tumours in patients with clinically stable metastatic breast cancer, and to compare the findings with reports on alternative procedures, namely surgery and local radiotherapy.

METHODS

17 female patients (average age of 54.8 years ± 10.8; range 37-72) with primary breast tumour not surgically treated because of metastatic disease were included. Patients were treated for their primary lesion by percutaneous cryotherapy in period of stable disease. This minimally intervention was performed using ultrasound or CT scan guidance. All patients had clinical and breast-MRI evaluation before and at 1, 3, 6 and 12 months after the procedure.

RESULTS

All procedures were performed under local anaesthesia and technically successful. The mean largest diameter of the primary lesions was 16 ± 12 mm (size range 5-45 mm). In 15 patients, we obtained a complete regression of the primary breast lesion without recurrence during the follow-up period. Two patients with lesions measured at 40 and 45 mm had recurrence in follow up period. A second session of cryotherapy was performed for these 2 patients, not included in this study. Five patients had painful masses before cryotherapy. All were immediately relieved after the intervention and durably during all follow-up.

CONCLUSION

These results show that the cryoablation of primary breast lesions seems to be well suited to the palliative care of metastatic patients, particularly because of its good tolerance, low complication rate and ability to provide local or analgesic control. Advances in knowledge: Therapies are limited for these symptomatic patients at metastatic state of primary breast tumour. This study shows that cryoablation in palliative care is achievable in common practice, is effective in local control of the tumour and can provide immediate and long-term analgesic control.

Cryoablation of Primary Breast Cancer in Patients with Metastatic Disease: Considerations Arising from a Single-Centre Data Analysis

Background

Patients presenting with stage IV breast cancer might benefit by removal of the primary tumor. We report our experience with CT-guided cryoablation of the primary tumor, with the aim of evaluating its role in this subgroup of patients.

Patients and Methods

Data of 35 patients with mean age of 58 years with breast cancer at stage IV submitted to CT-guided cryoablation of the primary tumor between 2010 and 2016 were prospectively evaluated. All patients, except three, were preoperatively and postoperatively evaluated with breast MRI to assess the extent of tumor necrosis. Retreatment was performed in case of incomplete ablation.

Results

Mean tumor size was 3.02 ± 1.4 cm. Six patients had multicentric disease. Complete tumor necrosis was 85.7% and 100% at 2-month and 6-month follow-up, respectively, as 5 patients with tumors > 3 cm required a redo cryoablation. No patient developed major complications. Minor side effects occurred in 30 patients (82%). All patients were discharged the same day of the procedure. During a mean follow-up of 46 months (range 3–84), 7 patients (20%) experienced local recurrences that were treated with redo cryoablation, and 7 (20%) died for disease progression.

Conclusions

Our results suggest that cryoablation of the primary tumor is safe and effective in the treatment of patients presenting with stage IV breast cancer.

Ablative techniques for the treatment of benign and malignant breast tumours

Minimally invasive techniques like high intensity focused ultrasound, radiofrequency ablation, cryo-ablation, laser ablation and microwave ablation have been used to treat both breast fibroadenomata and breast cancer as an alternative to surgical excision, potentially reducing the complications, improving cosmesis and reducing hospital stay. This review describes the most common minimally invasive techniques available, their history and some of the studies performed with these techniques in both benign and malignant lesions. In addition we described some of the difficulties of using these minimally invasive techniques such as optimization of anaesthesia, imaging and immobilisation in order to increase the complete histopathological ablation rates.

Development of a Searchable Database of Cryoablation Simulations for Use in Treatment Planning

PURPOSE

To create and validate a planning tool for multiple-probe cryoablation, using simulations of ice ball size and shape for various ablation probe configurations, ablation times, and types of tissue ablated.

MATERIALS AND METHODS

Ice ball size and shape was simulated using the Pennes bioheat equation. Five thousand six hundred and seventy different cryoablation procedures were simulated, using 1-6 cryoablation probes and 1-2 cm spacing between probes. The resulting ice ball was measured along three perpendicular axes and recorded in a database. Simulated ice ball sizes were compared to gel experiments (26 measurements) and clinical cryoablation cases (42 measurements). The clinical cryoablation measurements were obtained from a HIPAA-compliant retrospective review of kidney and liver cryoablation procedures between January 2015 and February 2016. Finally, we created a web-based cryoablation planning tool, which uses the cryoablation simulation database to look up the probe spacing and ablation time that produces the desired ice ball shape and dimensions.

RESULTS

Average absolute error between the simulated and experimentally measured ice balls was 1 mm in gel experiments and 4 mm in clinical cryoablation cases. The simulations accurately predicted the degree of synergy in multiple-probe ablations. The cryoablation simulation database covers a wide range of ice ball sizes and shapes up to 9.8 cm.

CONCLUSION

Cryoablation simulations accurately predict the ice ball size in multiple-probe ablations. The cryoablation database can be used to plan ablation procedures: given the desired ice ball size and shape, it will find the number and type of probes, probe configuration and spacing, and ablation time required.

Percutaneous image-guided cryoablation: current applications and results in the oncologic field

Percutaneous imaging-guided cryoablation (PICA) is a recently developed technique, which applies extreme hypothermia to destroy tumours under close imaging surveillance. It is minimally invasive, safe, repeatable, and does not interrupt or compromise other oncologic therapies. It presents several advantages over more established heat-based thermal ablation techniques (e.g. radiofrequency ablation; RFA) including intrinsic analgesic properties, superior monitoring capability on multi-modal imaging, ability to treat larger tumours, and preservation of tissue collagenous architecture. There has been a recent large increase in reports evaluating the utility of PICA in a wide range of patients and tumours, but systematic analysis of the literature is challenging due to the rapid pace of change and predominance of extensively heterogeneous level III studies. The precise onco-therapeutic role of PICA has not been established. This narrative review outlines the available evidence for PICA in a range of tumours. Current indications include curative therapy of small T1a renal tumours; curative/palliative therapy of small primary/secondary lung tumours where RFA is unsuitable; palliation of painful bone metastases; and urologic treatment of organ-confined prostate cancer. There is growing evidence to support its use for small hepatic tumours, and encouraging results have been obtained for breast tumours, extra-abdominal desmoid tumours, and management of higher-stage tumours and oligometastatic disease. However, the overall evidence base is weak, effectively restricting PICA to cases where standard therapy and RFA are unsuitable. As the technique and evidence continue to mature, the benefits of this emerging technique will hopefully become more widely available to cancer patients in the future.

Minimally invasive ablative techniques in the treatment of breast cancer: a systematic review and meta-analysis

PURPOSE

Breast-conserving surgery is effective for breast cancer treatment but is associated with morbidity in particular high re-excision rates. We performed a systematic review and meta-analysis to assess the current evidence for clinical outcomes with minimally invasive ablative techniques in the non-surgical treatment of breast cancer.

METHODS

A systematic search of the literature was performed using PubMed and Medline library databases to identify all studies published between 1994 and May 2016. Studies were considered eligible for inclusion if they evaluated the role of ablative techniques in the treatment of breast cancer and included ten patients or more. Studies that failed to fulfil the inclusion criteria were excluded.

RESULTS

We identified 63 studies including 1608 patients whose breast tumours were treated with radiofrequency (RFA), high intensity focussed ultrasound (HIFU), cryo-, laser or microwave ablation. Fifty studies reported on the number of patients with complete ablation as found on histopathology and the highest rate of complete ablation was achieved with RFA (87.1%, 491/564) and microwave ablation (83.2%, 89/107). Short-term complications were most often reported with microwave ablation (14.6%, 21/144). Recurrence was reported in 24 patients (4.2%, 24/570) and most often with laser ablation (10.7%, 11/103). The shortest treatment times were observed with RFA (15.6 ± 5.6 min) and the longest with HIFU (101.5 ± 46.6 min).

CONCLUSION

Minimally invasive ablative techniques are able to successfully induce coagulative necrosis in breast cancer with a low side effect profile. Adequately powered and prospectively conducted cohort trials are required to confirm complete pathological ablation in all patients.