Sentinel lymph node biopsy before and after neoadjuvant chemotherapy in cN0 breast cancer patients: impact on axillary morbidity and survival-a propensity score cohort study

PURPOSE

In patients with clinically lymph node-negative (cN0) breast cancer, performing sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NACT) has been preferentially embraced in comparison to before NACT. However, survival outcomes associated with both strategies remain understudied. We aimed to compare the axillary lymphadenectomy (ALND) rate, disease-free survival (DFS), and overall survival (OS), between two strategies.

METHODS

We included 310 patients in a retrospective observational study. SNLB was performed before NACT from December 2006 to April 2014 (107 cases) and after NACT from May 2014 to May 2020 (203 patients). An inverse probability of treatment weighting (IPTW) method was applied to homogenize both groups. Hazard ratios (HR) and odd ratios (OR) are reported with 95% confidence intervals (95%CI).

RESULTS

The lymphadenectomy rate was 29.9% before NACT and 7.4% after NACT (p < 0.001), with an OR of 5.35 95%CI (2.7-10.4); p = .002. After 4 years of follow-up, SLNB after NACT was associated with lower risk for DFS, HR 0.42 95%CI (0.17-1.06); p = 0.066 and better OS, HR 0.21 CI 95% (0.07-0.67); p = 0.009 than SLNB before NACT. After multivariate analysis, independent adverse prognostic factors for OS included SLNB before NACT, HR 3.095 95%CI (2.323-4.123), clinical nonresponse to NACT, HR 1.702 95% CI (1.012-2.861), and small tumors (cT1) with high proliferation index, HR 1.889 95% (1.195-2.985).

CONCLUSION

Performing SLNB before NACT results in more ALND and has no benefit for patient survival. These findings support discontinuing the practice of SLNB before NACT in patients with cN0 breast cancer.

Axillary lymph node dissection versus radiotherapy in breast cancer with positive sentinel nodes after neoadjuvant therapy (ADARNAT trial)

Introduction

Breast cancer surgery currently focuses on de-escalating treatment without compromising patient survival. Axillary radiotherapy (ART) now replaces axillary lymph node dissection (ALND) in patients with limited sentinel lymph node (SLN) involvement during the primary surgery, and this has significantly reduced the incidence of lymphedema without worsening the prognosis. However, patients treated with neoadjuvant systemic treatment (NST) cannot benefit from this option despite the low incidence of residual disease in the armpit in most cases. Data regarding the use of radiotherapy instead of ALND in this population are lacking. This study will assess whether ART is non-inferior to ALND in terms of recurrence and overall survival in patients with positive SLN after NST, including whether it reduces surgery-related adverse effects.

Methods and analyses

This multicenter, randomized, open-label, phase 3 trial will enroll 1660 patients with breast cancer and positive SLNs following NST in approximately 50 Spanish centers over 3 years. Patients will be stratified by NST regimen and nodal involvement (isolated tumoral cells or micrometastasis versus macrometastasis) and randomly assigned 1:1 to ART without ALND (study arm) or ALND alone (control arm). Level 3 and supraclavicular radiotherapy will be added in both arms. The primary outcome is the 5-year axillary recurrence determined by clinical and radiological examination. The secondary outcomes include lymphedema or arm dysfunction, quality of life based (EORTC QLQ-C30 and QLQ-BR23 questionnaires), disease-free survival, and overall survival.

Discussion

This study aims to provide data to confirm the efficacy and safety of ART over ALND in patients with a positive SLN after NST, together with the impact on morbidity.

Ethics and dissemination

The Research Ethics Committee of Bellvitge University Hospital approved this trial (Protocol Record PR148/21, version 3, 1/2/2022) and all patients must provide written informed consent. The involvement of around 50 centers across Spain will facilitate the dissemination of our results.

Trial registration

ClinicalTrials.gov, identifier number NCT04889924.

Management of the axilla in postmenopausal patients with cN0 hormone receptor-positive/HER2-negative breast cancer treated with neoadjuvant endocrine therapy and its prognostic impact

PURPOSE

To evaluate the differences in nodal positivity if the sentinel lymph node biopsy (SLNB) is performed before or after neoadjuvant endocrine therapy (NET) in breast cancer patients, and its impact on prognosis.

METHODS

A retrospective cohort study was performed in a single center including 91 postmenopausal cases with clinically node-negative and hormone receptor-positive/HER2-negative (HR + /HER2-) breast cancer, treated with NET and SLNB. SLNB was done pre-NET until 2014, and post-NET thereafter. Axillary lymph node dissection (ALND) was indicated only in SLNB macrometastasis, although in selected elderly patients, it was omitted. Kaplan-Meier survival curves were estimated in relation to the status of the axilla, and the differences assessed using the log-rank test.

RESULTS

Between December 2006 and March 2022, SLNB was performed pre-NET in 14 cases and post-NET in 77. Both groups were similar in baseline tumor and patient characteristics. SLNB positivity was similar regardless of whether SLNB was performed before (5/14, 35.7%) or after NET (27/77, 37%), with 2/14 SLN macrometastases in the pre-NET cohort and 17/77 in the post-NET cohort. Only three patients (18.7%) with SLN macrometastasis had > 3 positive nodes following ALND. The 5-year overall survival and distant disease-free survival were 92.4% and 94.8%, respectively, with no significant differences according to SLNB status (p 0.5 and 0.8, respectively).

CONCLUSION

SLN positivity did not differ according to its timing (before or after NET). Therefore, NET has no effect on lymph node clearance. Furthermore, the prognosis is good regardless of the axillary involvement. Therefore, factors other than axillary involvement may affect the prognosis in these patients.

Ten-year experience of bone SBRT in breast cancer: analysis of predictive factors of effectiveness

PURPOSE

Data on the benefit of stereotactic body radiation therapy (SBRT) in patients with breast cancer (BC) and bone metastases remain limited. The purpose of this study is to report our 10-year experience of bone SBRT, analyzing toxicity and prognostic factors for local control (LC); progression-free survival, and overall survival (OS).

METHODS/PATIENTS

We analyzed all spine and non-spine bone SBRT performed in patients with BC during the 2012-2022 period at our institution. Treatments carried out with ablative intent in stereotactic conditions with dose/fraction ≥ 5 Gy in 5 or fewer sessions were considered. Demographic, treatment, and toxicity data were recorded according to CTCAEv4. Risk factors were assessed through univariate and multivariate analysis by Cox regression.

RESULTS

60 bone SBRT treatments were performed during the study period. 75% were spine SBRT and 25% were non-spine SBRT (median BED₄Gy was 80 Gy₄). The median age was 52.5 years (34-79). The median tumor volume was 2.9 cm³ (0.5-39.4). The median follow-up was 32.4 months (1.2-101.7). 1 and 2 years LC were 92.9 and 86.6%, respectively. 1 and 2 years OS were 100 and 90.6%, respectively. Multivariate analysis (MVA) associated volume of the treated lesion ≥ 13 cm³ with worse LC (p = 0.046; HR 12.1, 95%CI = 1.1-140.3). In addition, deferring SBRT > 3 months after lesion diagnosis to prioritize systemic treatment showed a significant benefit, improving the 2 years LC up to 96.8% vs. 67.5% for SBRT performed before this period (p = 0.031; HR 0.1, 95%CI = 0.01-0.8). Hormonal receptors, the total number of metastases, and CA15-3 value were significantly associated with OS in MVA. During follow-up, three non-spine fractures (5%) were observed.

CONCLUSIONS

According to our data, bone SBRT is a safe and effective technique for BC. Upfront systemic treatment before SBRT offers a benefit in LC. Therefore, SBRT should be considered after prior systemic treatment in this population.

Abstract P1-08-26: Morphologic characterization of tumor-infiltrating lymphocytes and its relation with pathological response in a series of breast cancer patients treated with primary chemotherapy

Introduction: Tumor-Infiltrating Lymphocytes (TILS) is a well-known predictor of response to primary chemotherapy1,2 and a prognostic factor for improved survival in different breast cancer subtypes3. We present data on the association of the level of TILs and morphologic characteristics of such infiltrate with pCR. Material and methods: A series of 477 breast cancer patients (479 tumors) treated with primary chemotherapy at Catalan Institut of Oncolgy - H.U. Bellvitge between January 2009 and December 2016. Chemotherapy consisted on anthracyclines and taxanes (plus trastuzumab if Her-2 positive disease). Levels of percentage of TILs using hematoxylin-eosin-stained sections of diagnostic core-needle biopsy were evaluated according to international guidelines in a prospectively defined retrospective analysis. Characterization of TILS consisted on identification of plasma cells, intraepithelial infiltrate vs stromal infiltrate and homogeneous vs heterogeneous infiltrate. A sub-classification using levels of TILS and heterogeneity was done for statistical purposes. Levels of TILS and their morphological characteristics were examined for their associations with pCR adjusted for predictive clinic-pathological factors, by univariate and multivariate logistic regression, statistical significance set at 0.05. A ROC curve was performed to look for a cut-point of TILs to predict PCR. Results: The mean value of TILs was 23.79% (SD, 24%). TILs were significantly higher in ductal carcinomas (39.1% vs 0%, p=0.007), grade 3 (55.2 vs 17.7%p&lt;0.001), ki 67 &gt;30 (48.8% vs 24.5%, p&lt;0.001), HER2 (56.6%) and triple negative tumors (TNBC)(56.6%) vs luminal (20%), p&lt;0.001). The level of TILS was set in 20% to predict pCR by a ROC curve (S=62.3% E=71%). Characterization of TILs found plasma cells in 41.1% of the samples, intraepithelial infiltrate in 11.2% and homogeneous infiltrate in 60.1%. Homogeneously high infiltrate was found in 20% of the samples. In the univariate analysis pCR was higher in samples with TILs &gt; 20% (15.2% vs 41.5%, OR: 3.96 [95%CI, 2.57-6.10]; P &lt; 0.001); plasma cells (OR 6.61 [95%CI, 1.51-28.8]; P=0.01), intraepithelial TILS (OR: 10.34 [95%CI, 2.22-48.01]; P =0.003), homogeneous high infiltrate (OR: 13.6 [95%CI, 3.04-60.77]; P =0.001). In luminal tumors, TILs over 20% predicted pCR (OR 12.3 [95%CI, 4.0-37.7]; P &lt; 0.001) as well as in TNBC (OR 4.32 [95%CI, 1.77-10.53]; P=0 .001) but not in those cases with HER2 positive tumors (luminalB HER2 + HER2) (OR 1.65 [95%CI, 0.88-3.07]; P=0.118). In the multivariate analyses, levels of TILs &gt; 20% were associated with higher pCR rates (adjusted odds ratio, 2.44 [95%CI, 1.48-4.01]; P &lt; .001). Conclusions: The presence of TILs over 20% at diagnosis is an independent, positive, predictive marker of pCR in early breast cancer treated with neoadjuvant chemotherapy. Interestingly, the predictive information added by TILs &gt;20% was higher in luminal and triple negative tumors compared to HER2 positive cases. Careful morphological characterization of TILS may add valuable predictive information and can be done in current pathologic laboratories with a well-trained breast cancer pathologist. References: 1.J Clin Oncol 2009; 28:105-113. doi: 10.1200/JCO.2009.23.73702.JAMA Oncol. 2015;1(4):448-454. doi:10.1001/jamaoncol.2015.08303.Lancet Oncol 2018: 19: 40-50 http://dx.doi.org/10.1016/S1470-2045(17)30904-X.

N%Age years (mean, sd)Grade*I326.7II19540.7III15152.6Ki 67≤3020442.6&gt;3027557.4Molecular subtype*Luminal A469.6Luminal B HER2 -14329.9Luminal B HER2+9219.2HER+ enriched7615.9Triple negative12225.5Pathologic responseNon-pCR35874.7pCR12125.3

Citation Format: Catalina Falo, Juan Azcarate, Ana Petit, Andrea Vethencourt, Sergi Fernandez Gonzalez, Amparo Garcia-Tejedor, Silvia Vazquez, Hector Perez, Maria Laplana, Charo Taco, Esther Guerra, Anna Guma, Raul Ortega, Agostina Stradella, Sabela Recalde, Adela Fernandez-Ortega, Rafael Villanueva, F Javier Perez, M Jesus Pla, Miriam Campos, Diana Perez, Eulalia Fernandez-Montoliu, Veronica Obadia, Monica Cejuela, Miguel Gil-Gil, Sonia Pernas, Mar Varela, Teresa Soler-Monzo. Morphologic characterization of tumor-infiltrating lymphocytes and its relation with pathological response in a series of breast cancer patients treated with primary chemotherapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-08-26.

Assessment of Tumor Cell Death After Percutaneous Ultrasound– Guided Radiofrequency Ablation of Breast Carcinoma: A Prospective Study

Background: Current trends in breast cancer treatment include the use of less aggressive surgeries to reduce morbidity, shorten hospital stays and improve cosmetic results. The aim of the study is to assess tumor cell viability after percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) for small breast cancer by a combination of staining techniques. Methods: A prospective study was conducted at a single institution from 2013 to 2017. Twenty women with invasive ductal carcinoma of the breast measuring ≤ 20 mm were treated with US-guided RFA followed immediately by surgical resection. Tumor viability pre- and post-RFA was assessed with Hematoxylin and Eosin (H&E), Nicotinamide adenine dinucleotide (NADH), Succinate dehydrogenase (SDH), Cytochrome c oxidase (COX), Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and Cytokeratin 18 and 19 (CK18/CK19) staining techniques. Outcomes and correlation with the different techniques were evaluated with principal component analysis Cronbach’s alpha. Results: Oxidative enzymes in frozen sections showed loss of SDH and NADH in 13 of the 16 tumors (81%) and COX in 11 of the 13 tumors (84%). In paraffin-embedded tissues, CK18 was negative or markedly reduced in 98% and CK19 in 100% of the cases. Lack of evidence of cell death was seen in 3 cases where the maximum temperature achieved at the center of the tumor was ≤ 70ºC. The reliability and internal consistency between the different staining techniques was high (Cronbach’s alpha, 0.8), with concordance between the staining results of the oxidative enzymes and of CK18/CK19. Conclusion: Loss of tumor viability in small breast tumors after US-guided percutaneous RFA could be assessed in our series with different staining methods. CK18 and CK19 could be used in paraffin-embedded tissues as surrogate markers of tumor cell viability after immediate RFA.

Comparing the effects of alcohol sclerotherapy with those of surgery on anti-Müllerian hormone and ovarian reserve after endometrioma treatment. A prospective multicenter pilot cohort study

STUDY OBJECTIVE

To compare the effects of ultrasound-guided aspiration and ethanol sclerotherapy with those of laparoscopic surgery on anti-Müllerian hormone (AMH) levels and ovarian reserve in benign-appearing ovarian endometrioma.

DESIGN

A prospective, cohort pilot study.

SETTING

Multiple centers, Spain.

PATIENTS

Forty patients with a suspected ovarian endometrioma with a maximum diameter of 35-100 mm. Serum hormonal concentrations were analyzed in 26 of these women.

INTERVENTIONS

Two groups: one that received US-guided aspiration plus alcohol sclerotherapy (n = 16) and the other that underwent laparoscopic cystectomy (n = 10).

MEASUREMENTS AND MAIN RESULTS

We studied serum hormonal concentrations (AMH, FSH and 17-β-estradiol) and antral follicle counts (AFC) in each patient at baseline, and after the procedures and pregnancies. No differences were found when comparing AMH and FSH concentrations before and after each procedure. 17-β-estradiol concentrations were significantly increased after alcohol sclerotherapy (p < 0.001). AFC recovery after 6 months seemed to be higher after sclerotherapy than after surgery. Three patients became pregnant in the sclerotherapy group.

CONCLUSION

This pilot study indicated that alcohol sclerotherapy preserves fertility in patients with endometriomas better than surgery, with significant increases in serum estradiol concentrations, possible AFC recovery and spontaneous pregnancies observed in the patients after sclerotherapy.

Can we avoid axillary lymph node dissection in N2 breast cancer patients with chemo-sensitive tumours such as HER2 and TNBC?

PURPOSE

To find a group of cN2 patients or patients with high axillary burden who become ypN0 after neoadjuvant chemotherapy (NACT) and who may benefit from avoiding a lymphadenectomy.

METHODS

A retrospective observational cohort study was conducted with 221 clinically staged N2 patients or patients with at least 3 suspicious lymph nodes found by ultrasound at diagnosis. The predictive factors for ypN0 analysed were age, MRI-determined tumour size, histological subtype, the Nottingham histologic grade, surrogate molecular subtype, ki-67 and vascular invasion when present. Clinical and radiological responses after NACT were also evaluated. Univariate and multivariate analyses by logistic regression were performed. Distant disease-free survival (DDFS) was calculated in relation to the status of the axillary lymph nodes after NACT.

RESULTS

After NACT, 89 patients (40.3%) had axillary pathologic complete response (pCR) (ypN0) and 132 (59.7%) had residual axillary disease (ypN+). Molecular surrogate subtype, Ki-67 expression, and the clinical and radiological responses to NACT were the only independent factors associated with ypN0. Axillary pCR was observed more often in HER2-positive and triple-negative tumours than in luminal ones (OR 7.5 and 3.6, respectively). DDFS was 88.7% (95% CI 80.7-96.7%) for ypN0 and 56.2% (95% CI 32.1-80.3%) for ypN+ (p = 0.09).

CONCLUSIONS

In HER2-positive and triple-negative breast cancer patients staged as cN2 or with high axillary burden before NACT, a sentinel lymph node biopsy after NACT could be recommended if there is a clinical and radiological response.

Ethanol Sclerotherapy versus Laparoscopic Surgery for Endometrioma Treatment: A Prospective, Multicenter, Cohort Pilot Study

STUDY OBJECTIVE

To compare the cost-effectiveness of ultrasound (US)-guided aspiration and ethanol sclerotherapy versus laparoscopic surgery for benign-appearing ovarian endometrioma.

DESIGN

Prospective, cohort pilot study.

SETTING

Multiple centers, Spain.

PATIENTS

Forty patients with suspected ovarian endometrioma identified by US, with a maximum diameter of 35 to 100 mm, of whom 33 met inclusion criteria.

INTERVENTIONS

The study group (n = 17) underwent US-guided aspiration plus sclerotherapy with ethanol, and the control group (n = 14) underwent laparoscopic cystectomy.

MEASUREMENTS AND MAIN RESULTS

Recurrence, complications, and direct costs were compared. One of 17 sclerotherapy patients recurred (5.9%) compared with 4 of 14 laparoscopic surgery patients (28.6%) (odds ratio 0.18, 0.01-1.53). No serious adverse effects (Clavien-Dindo ≥ III) were observed in the sclerotherapy group; 1 patient in the surgery group had a Clavien-Dindo IIIb complication. Median hospital direct costs were significantly lower in the sclerotherapy group than those in the surgery group-266 euros versus 2189 euros.

CONCLUSION

Ethanol sclerotherapy seems to be cost-effective for endometrioma and also appears to reduce complications. In this pilot study, recurrence was not higher than with conventional surgery.

Predictive factors for omitting lymphadenectomy in patients with node-positive breast cancer treated with neo-adjuvant systemic therapy

A pathologic complete response (pCR) in the axilla occurs in 30%-40% of patients with initially node-positive breast cancer after neo-adjuvant chemotherapy (NACT). Debate persists about whether to perform systematic axillary lymphadenectomy (ALND) in patients with initial node-positive disease and clinical complete response after NACT. We aimed to identify predictive factors of axillary pCR (ypN0) after NACT. This retrospective study analyzed data for all patients with initial biopsy-proven node-positive disease who underwent ALND after NACT between June 2008 and December 2016 at our institution. Clinical and pathologic features, recurrence and specific mortality rates were compared between patients who achieved an axillary pCR and those who did not (ypN0 vs ypN+, respectively). A total of 331 patients were included, of whom 128 (38.7%) became ypN0 after NACT. Among patients with >2 suspicious axillary lymph nodes before treatment, 54 (38%) achieved ypN0 status. The independent predictors of ypN0 were Ki-67 > 30 (OR 1.98; 95% CI, 1.146-3.381), HER2 positivity (OR 2.6; 95% CI, 1.354-5.108), nonluminal molecular-like subtype (OR 4.15; 95% CI, 2.068-5.108), and clinical complete response, defined as negative clinical and ultrasonographic findings (OR 2.8; 95% CI, 1.110-7.081). After a mean follow-up of 61 months, distant disease-free and overall survival rates were higher in patients with ypN0 disease (HR 4.14; 95% CI, 2.03-8.43) than ypN+ patients. Complete clinical response and the presence of nonluminal molecular-like subtypes independently predicted ypN0. Patients meeting these criteria might be suitable form omitting ALND and just performing targeted axillary procedures to patients meeting these criteria.

PAM50 Subtypes in Baseline and Residual Tumors Following Neoadjuvant Trastuzumab-Based Chemotherapy in HER2-Positive Breast Cancer: A Consecutive-Series From a Single Institution

Introduction: HER2-enriched subtype has been associated with higher response to neoadjuvant anti-HER2-based therapy across various clinical trials. However, limited data exist in real-world practice and regarding residual disease. Here, we evaluate the association of HER2-enriched with pathological response (pCR) and gene expression changes in pre- and post-treatment paired samples in HER2-positive breast cancer patients treated outside of a clinical trial.

Methods: We evaluated clinical-pathological data from a consecutive series of 150 patients with stage II-IIIC HER2-positive breast cancer treated from August 2004 to December 2012 with trastuzumab-based neoadjuvant chemotherapy. Expression of 105 breast cancer-related genes, including the PAM50 genes, was determined in available pre-and post-treatment formalin-fixed paraffin-embedded tumor samples using the nCounter platform. Intrinsic molecular subtypes were determined using the research-based PAM50 predictor. Association of genomic variables with total pCR was performed.

Results: The pCR rate was 53.3%, with higher pCR among hormonal receptor (HR)-negative tumors (70 vs. 39%; P < 0.001). A total of 89 baseline and 28 residual tumors were profiled, including pre- and post-treatment paired samples from 26 patients not achieving a pCR. HER2-enriched was the predominant baseline subtype not only in the overall and HR-negative cohorts (64 and 75%, respectively), but also in the HR-positive cohort (55%). HER2-enriched was associated with higher pCR rates compared to non-HER2-enriched subtypes (65 vs. 31%; OR = 4.07, 95% CI 1.65–10.61, P < 0.002) and this association was independent of HR status. In pre- and post-treatment paired samples from patients not achieving a pCR, a lower proportion of HER2-enriched and twice the number of luminal tumors were observed at baseline, and luminal A was the most frequent subtype in residual tumors. Interestingly, most (81.8%) HER2-enriched tumors changed to non-HER2-enriched, whereas most luminal A samples maintained the same subtype in residual tumors.

Conclusions: Outside of a clinical trial, PAM50 HER2-enriched subtype predicts pCR beyond HR status following trastuzumab-based chemotherapy in HER2-positive disease. The clinical value of intrinsic molecular subtype in residual disease warrants further investigation.

Abstract P3-13-07: Is radiofrequency ablation better than lumpectomy for margin status in breast cancer? Results of a randomized clinical trial

PURPOSE: To study the safety and efficacy of ultrasound-guided percutaneous radiofrequency ablation (RFA) as local treatment for breast cancer and to intraoperatively evaluate the margin status after RFA in comparison with lumpectomy.

MATERIAL and METHODS: Preliminary in vitro RF ablation experimentation with two mastectomy specimens was performed to test the electrode, practice the ultrasound technique and evaluate the macroscopic and microscopic effects of RF. Then, aprospective, randomized open-label phase II clinical trial (NCT02281812) was conducted in a single institution from 2013-2017. Forty subjects, mean age 64 (range 46-86), with ductal infiltrating carcinoma of the breast ≤2 cm were randomly assigned to RFA plus lumpectomy or lumpectomy alone. Margin status, tumor cell viability (TCV) after RFA (by nicotinamide adenine dinucleotide (NADH) and Cytokeratin 18 (CK18) staining), adverse events and local recurrences were evaluated by univariable and multivariable analyses (SPSS statistical software).

RESULTS: In the experimental design with mastectomies, the only procedural complication was a skin burn at the entrance site of the electrodes. We learned that the tip of the electrodes should cut cross the tumor by at least 10mm.

The clinical trial includes two groups: study group (n=20) and control group (n=20). NADH and CK18 staining demonstrated absence of TCV after RFA with at least one of the two techniques. The percentage of intraoperatively affected surgical margins was higher in the control group although local adverse effects after surgery was higher in the RFA treatment arm. Three study subjects presented local infection (two had partial irradiation of the breast) and none in the control group. Median follow up was 25 months (range 1–83). No recurrence or second surgery was required during the study period.

Outcomes RFA group (n = 20)Control group (n=20)p valueSpecimen weight (median, gr)42 (24-80)27 (11-60)0.004Specimen volume (median, ml)369 (259-847)201 (100-602)0.004Positive margin (intraoperative)4/20 (20%)11/20 (55%)0.022Pathological size (median, mm)11.5 (5-20)10.5 (6-16)0.07Local Adverse effect8/20 (40%)1/20 (5%)0.01Breast Inflammation5/20 (25%)1/20 (5%)0.182Breast Infection3/20 (15%)0/20 (0%)0.23RFA: radiofrequency ablation. n=number of subjects

CONCLUSION: RFA seems effective in the cases considered and could be more accurate than lumpectomy in terms of obtaining more free margins. Surgical excision associated with RFA leads to a higher amount of local adverse effects, especially if combined with partial irradiation of the breast. RFA could be considered as a less invasive treatment in tumors smaller than 20 mm; however, this warrants further investigation.

Citation Format: Garcia-Tejedor A, Guma A, Soler T, Valdivieso A, Petit A, Contreras N, Chappuis CG, Falo C, Pernas S, Anselem A, Fernandez-Montoli E, Pla MJ, Burdio F, Ponce J. Is radiofrequency ablation better than lumpectomy for margin status in breast cancer? Results of a randomized clinical trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-07.

Abstract P4-08-08: Biomarkers to predict distant recurrence free survival after neoadjuvant endocrine therapy in breast cancer. A long follow up retrospective study

Background:

Neoadjuvant endocrine therapy (NET) is gaining more acceptances for the management of estrogen receptor (ER) positive breast cancer (BC). Rate of patients achieving pathological complete response is very low and Ki67 suppression and PEPI score are the only prognostic factors associated with relapse free survival.

The aim of our study was to identify biomarkers of prediction of distant relapse risk that could help clinicians in the decision-making of systemic adjuvant treatment in patients previously treated with NET

Material & Methods:

Retrospective study of 119 postmenopausal women with ER or progesterone receptor (PR) positive BC treated with NET in ICO-HUB from 1997 to 2009. Clinical-pathological data and treatments administered were reviewed. IHC expression of ER, PR, Ki67, Androgen receptor (AR), BCL-2, Cyclin D1 (CD1), p16, p53, CD 44 and synaptophysin were analyzed in post-NET surgical formalin-fixed paraffin-embedded tumor samples through a tissue microarray. Survival was calculated by Kaplan-Meier method. Univariate and multivariate analysis of variables associated with distant relapse free survival (DRFS) was evaluated by Cox proportional hazard model.

Results:

Mean age was 74 (63-88). cT: T2 5%, T3 6.5%, T4 43.5%. cN: N0 59%, N1 25%, N2-3 16%. Stage: I 21%, II 49.5%, III 29.5%. Histological subtype: ductal 84%, lobular 6%, others 10%. Histological grade: G1 20%, G2 55%, G3 25%.

Vascular invasion 15%. NET: Aromatase Inhibitors 64%, SERM 36%. Median duration of NET 8.5 months. Clinical Response: Complete 4%, Partial 55%, Stable 37%, Progression 4%. Surgery: Lumpectomy 72%, Mastectomy 28%;Lymphadenectomy 70.5%, Sentinel lymph node biopsy 6%, No surgical approach of axilla 23.5%. Surgical specimen: ypT1 36%, ypT2 54%, ypT3 6%, ypT4 4%; ypN0 28%, ypN1 22%, ypN2 13.5%, ypN3 12% ypNx 23.5%. Surgical margins: Negative 89% Positive 11%. Median fibrosis rate 20% (0-95). PR and Ki67 showed a statistically significant decrease after NET(p&lt;0,05) but no ER (p=0,29).

Adjuvant treatment: chemotherapy 7%, radiotherapy 76%, endocrine therapy 96%. Median follow-up: 104 months. Only 21 patients developed distance relapse. Median OS was 139 months [95% CI = 98-181]. Univariate analysis for DRFS showed statistically significant differences in cN (HR=3), histological grade 3 (HR=3.61), ypN (HR=3.62), p16 (HR=6.1) and p53 (HR=2.79). Multivariate analysis of post-NET biomarkers showed that negative nuclear p16 expression (HR=4.79)and positive p53 (HR=2.83)were independently associated with worse DRFS. In multivariate analysis of all clinico-pathological and molecular factors, histological grade 3 (HR=2.82) was the sole DRFS independent factor.

Conclusions:

Negative nuclear p16 expression and positive p53 post-NET were associated with worseDRFS. Whenall clinico-pathological and molecular factors were analysed, G3 was the sole DRFS independent factor. Patients with G3, negative p16 or positive p53 after NET could probably benefit from adjuvant chemotherapy or CDK 4-6 inhibitors treatment. In our series, we did not find usefulness in analysing ER, PR and Ki67 post-NET changes to predict DRFS.

Citation Format: Gil-Gil M, Morilla I, Petit A, Soler T, Perez-Martin X, Guma A, Pla MJ, Ortega R, Garcia-Tejedor A, Falo C, Montal R, Perez-Casanova L, Loayza C, Pernas S. Biomarkers to predict distant recurrence free survival after neoadjuvant endocrine therapy in breast cancer. A long follow up retrospective study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-08-08.

Risk factors for vertical transmission of hepatitis C virus: a single center experience with 710 HCV-infected mothers

OBJECTIVE

The aim of this study was to analyze the risk factors on the perinatal transmission of hepatitis C virus (HCV).

STUDY DESIGN

A retrospective cohort study with 711 infants born to 710 HCV-infected mothers was conducted at the Hospital La Fe, in Valencia, Spain, from 1986 to 2011. As potential risk factors for transmission we analyzed: maternal age, mode of acquisition of HCV infection, HIV co-infection, antiretroviral treatment against HIV, CD4 cell count, HIV and HCV viral load, liver enzyme levels during pregnancy, smoking habit, gestational age, intrapartum invasive procedures, length of rupture of membranes, length of labor, mode of delivery, episiotomy, birth weight, newborn gender and type of feeding.

RESULTS

Overall perinatal HCV transmission rate was 2.4%. The significant risk factors related with HCV transmission were maternal virus load >615copies/mL (OR 9.3 [95% CI 1.11-78.72]), intrapartum invasive procedures (OR 10.1 [95% CI 2.6-39.02]) and episiotomy (OR 4.2 [95% CI 1.2-14.16]). HIV co-infection and newborn female were near significance (p=0.081 and 0.075, respectively).

CONCLUSIONS

Invasive procedures as fetal scalp blood sampling or internal electrode and episiotomy increase vertical transmission of HCV, especially in patients with positive HCV RNA virus load at delivery.

Duration of ruptured membranes and extended labor are risk factors for HIV transmission

OBJECTIVES

To determine the effects of duration of ruptured membranes (DRM) and duration of labor in HIV transmission.

METHODS

A retrospective cohort study of 366 HIV-infected pregnant women and their infants analyzed the effects of these two variables; the cut-off point for transmission increase was estimated using a ROC curve. A multivariate analysis was performed with the most important risk factors according to the literature: maternal age, lymphocyte count, use of invasive procedures during gestation, antiretroviral treatment during pregnancy and labor, mode of delivery, newborn weight, DRM, labor duration, and the interaction of these last two factors.

RESULTS

The cut-off points were estimated at 6 h for DRM and at 5 h for labor duration. A lymphocyte count below 500 cells/ml, use of invasive procedures, use of antiretroviral treatment during pregnancy and interaction between DRM, and labor duration remained significant in perinatal HIV transmission (P<0.05).

CONCLUSIONS

An increased DRM increased perinatal HIV transmission when it was associated with prolonged labor.