Feasibility of percutaneous excision followed by ablation for local control in breast cancer

Cancer detection in excised breast tumors using terahertz imaging and spectroscopy

Terahertz imaging and spectroscopy has demonstrated a potential for differentiating tissue types of excised breast cancer tumors. Pulsed terahertz technology provides a broadband frequency range from 0.1 THz to 4 THz for detecting cancerous tissue. Tumor tissue types of interest include cancer typically manifested as infiltrating ductal or lobular carcinomas, fibro-glandular (healthy connective tissues) and fat. In this work, images of breast tumors excised from human and animal models are reviewed. In addition to alternate fresh tissues, breast cancer tissue phantoms are developed to further evaluate terahertz imaging and the potential use of contrast agents. Terahertz results are successfully validated with pathology images, showing strong differentiation between cancerous and healthy tissues for all freshly excised tissues and types. The advantages, challenges and limitations of THz imaging of breast cancer are discussed.

Current status of imaging-guided percutaneous ablation of breast cancer

OBJECTIVE

The purpose of this article is to briefly describe the various techniques used for percutaneous ablation of breast cancer, their preliminary results, and their limitations. The techniques include thermotherapy (radiofrequency ablation, laser irradiation, microwave irradiation, and insonation with high-intensity focused ultrasound waves), cryotherapy, and irreversible electroporation.

CONCLUSION

The techniques used for percutaneous ablation of breast cancer raise many questions and issues that must be addressed before percutaneous ablation can be adopted for the treatment of early breast cancer.

Close/positive margins after breast-conserving therapy: additional resection or no resection?

The primary goal of breast conserving surgery or mastectomy is the prevention of recurrent breast cancer. The distinguishing goal of breast conserving surgery is preservation of a breast as normal in appearance as possible. If the margins of the excised breast cancer extend to the border of the excised specimen one cannot determine the amount of gross tumor that was not excised. Retrospective analyses of surgical series show a 2-3 fold increase in local recurrence of the breast tumor if the margin is positive under the microscope, even when the surgeon believed it to be clear on gross examination. This fact has led to a variety of techniques attempting to ensure that the margins of the excised specimen are free of obvious tumor including pre-operative and specimen imaging and mapping, neo-adjuvant therapy to shrink the primary tumor, touch-prep and frozen section of the specimen margins during the procedure, shaving additional margins about the specimen at the closest aspects grossly or on all six surfaces, and examinations of the in situ walls of the remaining breast with new instrumentation. An obvious approach to diminishing the likelihood of positive specimen margins is taking a wider margin of normal tissue. As the volume of resected breast increases by the cube of the radius of excised tissue, this tracks all too well with diminishing cosmetic results and patient approval of the conserved breast. The question posed regards the finding of a positive or close margin after the surgical procedure. The finding of a positive margin can be parsed to a microscopic focus of tumor at the margin vs. the margin inking on a tumor surface. The latter demands re-excision despite the morbidity involved barring an extraordinary contra-indication or patient refusal. It represents the very real possibility of sufficient residual gross tumor in the breast that even with systemic therapy and breast irradiation the tumor will be un-controlled. A microscopic focus separated from the bulk of the primary tumor and adjacent to a margin has not been shown to carry such risk. The margin of normal tissue beyond the primary tumor that significantly reduces the risk of local recurrence remains undefined. Sufficient data are available to say that in the era of systemic therapy, excellent radiation therapy techniques, and boost doses when indicated, no margin of normal breast tissue beyond the tumor has been shown to be clearly superior to a layer of cells between the ink and the tumor. The larger the tumor and the more aggressive its biology is judged to be the lower the confidence that a single layer of cells at the point of histologic study accurately represents a clear margin. As in all medical decisions wise judgment must integrate all of the known factors to reach the best recommendation. There are few circumstances that would warrant a second surgical procedure for a close but clear margin today.

Nonsurgical ablation of breast cancer: future options for small breast tumors

The surgical management of breast cancer has evolved significantly, facilitated by advancements in technology and imaging and improvements in adjuvant therapy. The changes in surgical management have been characterized by equal or improved outcomes with significantly less morbidity. The next step in this evolution is the minimally invasive or noninvasive ablation of breast cancers as an alternative to lumpectomy. In this article, the various modalities for nonsurgical breast cancer ablation and the clinical experience are reviewed, and some of the next steps necessary for their clinical implementation are outlined.

[Minimally invasive breast surgery]

Due to the development in medical science and industrial technology, minimally invasive procedures have appeared in the surgery of benign and malignant breast diseases. In general , such interventions result in significantly reduced breast and chest wall scars, shorter hospitalization and less pain, but they require specific, expensive devices, longer surgical time compared to open surgery. Furthermore, indications or oncological safety have not been established yet. It is quite likely, that minimally invasive surgical procedures with high-tech devices - similar to other surgical subspecialties -, will gradually become popular and it may form part of routine breast surgery even. Vacuum-assisted core biopsy with a therapeutic indication is suitable for the removal of benign fibroadenomas leaving behind an almost invisible scar, while endoscopically assisted skin-sparing and nipple-sparing mastectomy, axillary staging and reconstruction with latissimus dorsi muscle flap are all feasible through the same short axillary incision. Endoscopic techniques are also suitable for the diagnostics and treatment of intracapsular complications of implant-based breast reconstructions (intracapsular fluid, implant rupture, capsular contracture) and for the biopsy of intracapsular lesions with uncertain pathology. Perception of the role of radiofrequency ablation of breast tumors requires further hands-on experience, but it is likely that it can serve as a replacement of surgical removal in a portion of primary tumors in the future due to the development in functional imaging and anticancer drugs. With the reduction of the price of ductoscopes routine examination of the ductal branch system, guided microdochectomy and targeted surgical removal of terminal ducto-lobular units or a "sick lobe" as an anatomical unit may become feasible. The paper presents the experience of the authors and provides a literature review, for the first time in Hungarian language on the subject. Orv. Hetil., 2014, 155(5), 162-169.

Long-term outcome of breast cancer patients treated with radiofrequency ablation

BACKGROUND

Radiofrequency ablation (RFA) is considered to be the most promising non-surgical ablation technique for the treatment of small breast cancer. However, few data are available regarding long-term follow-up of patients treated with this modality.

METHODS

Since 2005, we have performed RFA and sentinel lymph node (SLN) biopsy in 19 cases. Axillary lymph node dissection (ALND) was performed in patients with positive SLNs. From 24 to 202 days after RFA, the ablated tumour tissue was excised by mammotome biopsy and examined histologically or immunohistochemically with H&E staining, nicotinamide adenine dinucleotide (NADH)-diaphorase staining, and single-stranded (ss) DNA staining. All cases were followed-up after breast radiation and systemic therapies.

RESULTS

Although complete response was histologically confirmed in only 8 cases, NADH-diaphorase and ssDNA staining did not demonstrate any viable tumour cells in the ablated lesions. At a mean follow-up of 60 months (follow-up range, 37-82 months), there were no cases of in-breast recurrence, although one patient died due to hepatic metastases. Cosmesis of the conserved breast was excellent or good in all of the cases, but a hard lump was persistent after RFA in half of the cases.

CONCLUSIONS

The long-term outcome of patients treated with RFA is encouraging with regard to cosmesis and local control. Because a persisted lump may cause patient discomfort, anxiety and fear, however, further studies are needed to establish the optimal technique. Moreover, a prospective study will be required to determine the equivalency in local recurrence rates between the RFA therapy and conventional breast-conserving treatment.