Abstract P5-08-15: Reducing Rates of Chronic Breast Cancer Related Lymphedema with Screening & Early Intervention: An Update of Recent Data

Background: Breast cancer related lymphedema (BCRL) represents a dreaded complication of breast cancer treatment that can lead to morbidity, diminished quality of life, and psychosocial harm and is associated with increased costs. Increasingly, data has supported the concept of prospective BCRL surveillance coupled with early intervention to mitigate these effects. Methods: We performed a systematic review of the literature searching for published randomized and prospective data evaluating prospective BCRL surveillance with early intervention. Results: We identified 12 studies (2,907 patients) including 4 randomized trials (1,203 patients) and 8 prospective studies (1,704 patients). Randomized data consistently demonstrate that early intervention reduces rates of progression to chronic BCRL with multiple paradigms and diagnostic modalities utilized; the strongest data in the review comes from the randomized PREVENT trial which demonstrated early detection with bioimpedance spectroscopy (BIS), coupled with a compression garment applied for 12 hours a day over 4 weeks, significantly reduced the rate of chronic BCRL compared to tape measurement. Conclusions: Current data support the role of prospective BCRL surveillance with early detection and intervention to reduce rates of chronic BCRL. Breast cancer patients at risk for BCRL should undergo prospective surveillance as part of survivorship. Given the level 1 data demonstrating that BIS is superior to conventional tape measure, it should be included as the standard BCRL diagnostic modality unless an equally effective modality is employed.

Citation Format: Pat Whitworth, Frank Vicini, Stephanie Valente, Kirstyn Brownson, Beth Dupree, Manpreet Kohli, Laura Lawson, Chirag Shah. Reducing Rates of Chronic Breast Cancer Related Lymphedema with Screening & Early Intervention: An Update of Recent Data [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-08-15.

Bioimpedance spectroscopy for breast cancer-related lymphedema assessment: clinical practice guidelines

PURPOSE

Breast cancer-related lymphedema (BCRL) represents a significant concern for patients following breast cancer treatment, and assessment for BCRL represents a key component of survivorship efforts. Growing data has demonstrated the benefits of early detection and treatment of BCRL. Traditional diagnostic modalities are less able to detect reversible subclinical BCRL while newer techniques such as bioimpedance spectroscopy (BIS) have shown the ability to detect subclinical BCRL, allowing for early intervention and low rates of chronic BCRL with level I evidence. We present updated clinical practice guidelines for BIS utilization to assess for BCRL.

METHODS AND RESULTS

Review of the literature identified a randomized controlled trial and other published data which form the basis for the recommendations made. The final results of the PREVENT trial, with 3-year follow-up, demonstrated an absolute reduction of 11.3% and relative reduction of 59% in chronic BCRL (through utilization of compression garment therapy) with BIS as compared to tape measurement. This is in keeping with real-world data demonstrating the effectiveness of BIS in a prospective surveillance model. For optimal outcomes patients should receive an initial pre-treatment measurement and subsequently be followed at a minimum quarterly for first 3 years then biannually for years 4-5, then annually as appropriate, consistent with previous guidelines; the target for intervention has been changed from a change in L-Dex of 10 to 6.5. The lack of pre-operative measure does not preclude inclusion in the prospective surveillance model of care.

CONCLUSION

The updated clinical practice guidelines present a standardized approach for a prospective model of care using BIS for BCRL assessment and supported by evidence from a randomized controlled trial as well as real-world data.

Age-Independent Preoperative Chemosensitivity and 5-Year Outcome Determined by Combined 70- and 80-Gene Signature in a Prospective Trial in Early-Stage Breast Cancer

BACKGROUND

The Neoadjuvant Breast Symphony Trial (NBRST) demonstrated the 70-gene risk of distant recurrence signature, MammaPrint, and the 80-gene molecular subtyping signature, BluePrint, precisely determined preoperative pathological complete response (pCR) in breast cancer patients. We report 5-year follow-up results in addition to an exploratory analysis by age and menopausal status.

METHODS

The observational, prospective NBRST (NCT01479101) included 954 early-stage breast cancer patients aged 18-90 years who received neoadjuvant chemotherapy and had clinical and genomic data available. Chemosensitivity and 5-year distant metastasis-free survival (DMFS) and overall survival (OS) were assessed. In a post hoc subanalysis, results were stratified by age (≤ 50 vs. > 50 years) and menopausal status in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) tumors.

RESULTS

MammaPrint and BluePrint further classified 23% of tumors to a different subtype compared with immunohistochemistry, with more precise correspondence to pCR rates. Five-year DMFS and OS were highest in MammaPrint Low Risk, Luminal A-type and HER2-type tumors, and lowest in MammaPrint High Risk, Luminal B-type and Basal-type tumors. There was no significant difference in chemosensitivity between younger and older patients with Low-Risk (2.2% vs. 3.8%; p = 0.64) or High-Risk tumors (14.5% vs. 11.5%; p = 0.42), or within each BluePrint subtype; this was similar when stratifying by menopausal status. The 5-year outcomes were comparable by age or menopausal status for each molecular subtype.

CONCLUSION

Intrinsic preoperative chemosensitivity and long-term outcomes were precisely determined by BluePrint and MammaPrint regardless of patient age, supporting the utility of these assays to inform treatment and surgical decisions in early-stage breast cancer.

Feasibility of testing core needle biopsies ex vivo in the ChemoFx assay

20073

Background: Multiple chemotherapy options exist for the treatment of primary breast cancer. While response rates are good, many patients are treated with unnecessary or ineffective chemotherapy. Inadequate treatments are partly due to the lack of accurate predictors of response in individual patients. To predict an individual’s response to therapy, ex vivo chemosensitivity and resistance assays (CSRAs) have long been evaluated, but have been limited by technical difficulties, including the need for large (1–2 gm) amounts of fresh tissue. However, these problems have largely been overcome with new technology. Novel methods used in Precision Therapeutics’ ChemoFx assay allow for testing smaller amounts of tissue (35 mg). The reduced tissue requirement is crucial in the breast cancer setting, as the diagnosis is often made by percutaneous biopsy. The goals of the study were to determine the growth success rate of culturing epithelial cells from breast tissue core needle biopsies and the feasibility of testing the cells in the assay. Methods: A prospective feasibility study involving women with invasive primary breast cancer. One to four core needle biopsy specimens were collected using a 14 gauge needle (est. per patient yield <50 mg) and submitted to Precision Therapeutics. A primary culture of each specimen was established and the ex vivo chemoresponse profiles of each culture were evaluated. Drugs tested included capecitabine, cisplatin, cyclophosphamide, docetaxel, doxorubicin, epirubicin, etoposide, 5-fluorouracil, gemcitabine, irinotecan, paclitaxel, and vinorelbine. Results: 21 of 25 (84%, 95% CI: 68% to 97%) specimens grew successfully; all 21 were tested for chemoresponsiveness with the assay. Of the 4 subjects with unsuccessful ex vivo cultures, 2 had no growth, 1 failed plating for culture, and 1 failed IHC testing due to overgrowth of non-epithelial cells. The average number of drugs tested for each specimen was 7 (range: 1–15). Conclusions: This study demonstrates that core needle biopsies from primary breast tumors can be successfully cultured and tested for chemoresponsiveness using the ChemoFx assay. The ability to perform ex vivo chemoresponse testing on core needle biopsies greatly increases the utility of the assay in adjuvant or neoadjuvant primary breast cancer settings.

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In situ hybridization analysis of Girk2 expression in the developing central nervous system in normal and weaver mice

A mutation in the gene Girk2 that encodes an inwardly rectifying potassium channel is the genetic defect causing the behavioral and pathologic abnormalities of the weaver mutant mouse. Of the pathologic abnormalities, the best studied is the neuronal degeneration that occurs in the cerebellar cortex and in the midbrain dopaminergic neurons. A detailed characterization of the topographic and temporal expression of Girk2 is fundamental to elucidate the mechanisms underlying neurodegeneration in these mutant mice. In this study we utilized in situ hybridization to determine the expression of Girk2 mRNA during prenatal and postnatal development in the murine central nervous system (CNS). Girk2 expression was seen in multiple regions of embryonic CNS including the cerebellum and midbrain. During postnatal development, the highest expression was seen in the cerebellum, midbrain and hippocampus. However, since the developing cerebellum undergoes significant neuronal loss due to the degeneration of granule cell precursors, Girk2 mRNA expression in this area decreases progressively.