ESMO expert consensus statements (ECS) on the definition, diagnosis, and management of HER2-low breast cancer.

Human epidermal growth factor receptor 2 (HER2)-low breast cancer has recently emerged as a targetable subset of breast tumors, based on the evidence from clinical trials of novel anti-HER2 antibody-drug conjugates. This evolution has raised several biological and clinical questions, warranting the establishment of consensus to optimally treat patients with HER2-low breast tumors. Between 2022 and 2023, the European Society for Medical Oncology (ESMO) held a virtual consensus-building process focused on HER2-low breast cancer. The consensus included a multidisciplinary panel of 32 leading experts in the management of breast cancer from nine different countries. The aim of the consensus was to develop statements on topics that are not covered in detail in the current ESMO Clinical Practice Guideline. The main topics identified for discussion were (i) biology of HER2-low breast cancer; (ii) pathologic diagnosis of HER2-low breast cancer; (iii) clinical management of HER2-low metastatic breast cancer; and (iv) clinical trial design for HER2-low breast cancer. The expert panel was divided into four working groups to address questions relating to one of the four topics outlined above. A review of the relevant scientific literature was conducted in advance. Consensus statements were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This article presents the developed statements, including findings from the expert panel discussions, expert opinion, and a summary of evidence supporting each statement.

Current and future diagnostic and treatment strategies for patients with invasive lobular breast cancer.

BACKGROUND: Invasive lobular breast cancer (ILC) is the second most common type of breast cancer after invasive breast cancer of no special type (NST), representing up to 15% of all breast cancers. DESIGN: Latest data on ILC are presented, focusing on diagnosis, molecular make-up according to the European Society for Medical Oncology Scale for Clinical Actionability of molecular Targets (ESCAT) guidelines, treatment in the early and metastatic setting and ILC-focused clinical trials. RESULTS: At the imaging level, magnetic resonance imaging-based and novel positron emission tomography/computed tomography-based techniques can overcome the limitations of currently used imaging techniques for diagnosing ILC. At the pathology level, E-cadherin immunohistochemistry could help improving inter-pathologist agreement. The majority of patients with ILC do not seem to benefit as much from (neo-)adjuvant chemotherapy as patients with NST, although chemotherapy might be required in a subset of high-risk patients. No differences in treatment efficacy are seen for anti-human epidermal growth factor receptor 2 (HER2) therapies in the adjuvant setting and cyclin-dependent kinases 4 and 6 inhibitors in the metastatic setting. The clinical utility of the commercially available prognostic gene expression-based tests is unclear for patients with ILC. Several ESCAT alterations differ in frequency between ILC and NST. Germline BRCA1 and PALB2 alterations are less frequent in patients with ILC, while germline CDH1 (gene coding for E-cadherin) alterations are more frequent in patients with ILC. Somatic HER2 mutations are more frequent in ILC, especially in metastases (15% ILC versus 5% NST). A high tumour mutational burden, relevant for immune checkpoint inhibition, is more frequent in ILC metastases (16%) than in NST metastases (5%). Tumours with somatic inactivating CDH1 mutations may be vulnerable for treatment with ROS1 inhibitors, a concept currently investigated in early and metastatic ILC. CONCLUSION: ILC is a unique malignancy based on its pathological and biological features leading to differences in diagnosis as well as in treatment response, resistance and targets as compared to NST.

Prognostic value of tumor-infiltrating lymphocytes in patients with early-stage triple-negative breast cancers (TNBC) who did not receive adjuvant chemotherapy.

BACKGROUND: Although stromal tumor-infiltrating lymphocytes (sTILs) have been considered an important prognostic factor in early-stage triple-negative breast cancer (TNBC), there have been limited data on their prognostic value in the absence of adjuvant chemotherapy. PATIENTS AND METHODS: A pooled analysis was carried out using four cohorts of TNBC patients not treated with chemotherapy. sTILs were evaluated in the most representative tumoral block of surgical specimens. Cox proportional hazards regression models were used for invasive disease-free survival (iDFS), distant disease-free survival (D-DFS), and overall survival (OS), fitting sTILs as a continuous variable adjusted for clinicopathologic factors. RESULTS: We analyzed individual data of 476 patients from 4 centers diagnosed between 1989 and 2015. Their median age was 64 years. The median tumor size was 1.6 cm and 83% were node-negative. The median level of sTILs was 10% (Q1-Q3, 4%-30%). Higher grade was associated with higher sTILs (P < 10-3). During follow-up, 107 deaths, and 173 and 118 events for iDFS and D-DFS were observed, respectively. In the multivariable analysis, sTILs obtained an independent prognostic value for all end points (likelihood ratio χ2 = 7.14 for iDFS; P < 10-2; χ2 = 9.63 for D-DFS, P < 10-2; χ2 = 5.96 for OS, P = 0.015). Each 10% increment in sTILs corresponded to a hazard ratio of 0.90 [95% confidence interval (CI) 0.82 - 0.97] for iDFS, 0.86 (95% CI 0.77 - 0.95) for D-DFS, and 0.88 (95% CI 0.79 - 0.98) for OS, respectively. In patients with pathological stage I tumors with sTILs ≥30% (n = 74), 5-year iDFS was 91% (95% CI 84% to 96%), D-DFS was 97% (95% CI 93% to 100%), and OS was 98% (95% CI 95% to 100%). CONCLUSION: sTILs add important prognostic information in systemically untreated early-stage TNBC patients. Notably, sTILs can identify a subset of stage I TNBC patients with an excellent prognosis without adjuvant chemotherapy.

Letrozole and palbociclib versus chemotherapy as neoadjuvant therapy of high-risk luminal breast cancer.

Background: Palbociclib is a CDK4/6 inhibitor with demonstrated efficacy and safety in combination with endocrine therapy in advanced luminal breast cancer (LBC). We evaluated the respective efficacy and safety of chemotherapy and letrozole-palbociclib (LETPAL) combination as neoadjuvant treatment in patients with high-risk LBC. Patients and methods: NeoPAL (UCBG10/4, NCT02400567) is a randomised, parallel, non-comparative phase II study. Patients with ER-positive, HER2-negative, Prosigna®-defined luminal B, or luminal A and node-positive, stage II-III breast cancer, not candidate for breast-conserving surgery, were randomly assigned to either letrozole (2.5 mg daily) and palbociclib (125 mg daily, 3 weeks/4) during 19 weeks, or to FEC100 (5FU 500 mg/m2, epirubicin 100 mg/m2, cyclophosphamide 500 mg/m2)×3 21-day courses followed by docetaxel 100 mg/m2×3 21-day courses. Primary end point was residual cancer burden (RCB 0-I rate). Secondary end points included clinical response, proliferation-based markers, and safety. Results: Overall, 106 patients were randomised [median Prosigna® ROR Score 71 (22-93)]. RCB 0-I was observed in four and eight patients in LETPAL [7.7% (95% CI 0.4-14.9)] and chemotherapy [15.7% (95% CI 5.7-25.7)] arms, respectively. Pathological complete response rates were 3.8% and 5.9%. Clinical response (75%) and breast-conserving surgery rates (69%) were similar in both arms. Preoperative Endocrine Prognostic Index 0 scores (breast cancer-specific survival) were observed in 17.6% and 8.0% of patients in LETPAL and chemotherapy arms, respectively. Safety profile was as expected, with 2 versus 17 serious adverse events (including 11 grade 4 serious AEs in the chemotherapy arm). Conclusion: LETPAL combination was associated with poor pathological response but encouraging clinical and biomarker responses in Prosigna®-defined high-risk LBC. Contemporary chemotherapy regimen was associated with poor pathological and biomarker responses, with a much less favourable safety profile. LETPAL combination might represent an alternative to chemotherapy in early high-risk LBC. Clinical Trial Number: NCT02400567.

Stromal lymphocyte infiltration after neoadjuvant chemotherapy is associated with aggressive residual disease and lower disease-free survival in HER2-positive breast cancer.

BACKGROUND: The role of tumor-infiltrating lymphocytes (TILs) in breast cancer has been extensively studied over the last decade. High TILs levels have been associated with pathological response rate in the neoadjuvant setting and with better outcomes in the adjuvant setting. However, little attention has been paid to changes in TILs and residual TIL levels after neoadjuvant chemotherapy (NAC). We investigated TIL levels before, after chemotherapy, and their dynamics during treatment; and we assessed the correlation of these levels with response to NAC and prognosis. MATERIALS AND METHODS: We identified 175 patients with primary HER2-positive breast cancers receiving NAC+/- trastuzumab between 2002 and 2011. Microbiopsy specimens and paired surgical samples were evaluated for stromal lymphocyte infiltration. Univariate and multivariate analyses were carried out to assess the association of clinical and pathological factors with pathological complete response (pCR) and disease-free survival. RESULTS: Baseline TIL levels were not significantly associated with pCR. TIL levels decreased during treatment in 78% of the patients. The magnitude of the decrease was strongly associated with pCR. After chemotherapy, TIL levels were high in tumors displaying aggressive patterns (high residual cancer burden score, mitotic index >22, tumor cellularity >5%). In the population with residual disease, TIL levels >25% at the end of NAC were significantly associated with an adverse outcome (TILs >25%, HR = 7.98, P = 0.009) after multivariate analyses including BMI, post-NAC mitotic index and tumor grade. CONCLUSION: A decrease in TIL levels during chemotherapy was positively associated with response to treatment. In tumor failing to achieve pCR, post-NAC lymphocytic infiltration was associated with higher residual tumor burden and adverse clinical outcome. Further studies are required to characterize immune infiltration in residual disease to identify candidates who could benefit from second-line therapy trials including immune checkpoint inhibitors.

Prognostic impact of discrepant Ki67 and mitotic index on hormone receptor-positive, HER2-negative breast carcinoma.

BACKGROUND: Inconsistencies between mitotic index (MI) and Ki67 measures have been identified in many breast tumour samples. The aim of this study was to describe the prognosis of hormone receptor-positive (HR+) HER2- tumours having discrepant MI and Ki67. METHODS: We included a cohort of breast cancer patients initially treated by surgery between 2001 and 2005 in the Institut Curie. Breast cancer-specific survival (BCSS) and disease-free survival (DFS) were analysed according to three proliferation groups: high MI/high Ki67 (MI=3, Ki67>20%), low MI/low Ki67 (MI<3, Ki67⩽20%) and discrepant (high MI/low Ki67 or low MI/high Ki67). RESULTS: Among the 1430 patients, 19.6% had discrepant Ki67 and MI, 11.6% had high markers and 68.8% had low markers. The 5-year BCSS was 95.8%, 95% CI (0.93-0.98) in the discrepant group, 99.3%, 95% CI (0.993-0.999) in the low-proliferation group and 91.8%, 95% CI (0.88-0.96) in the high-proliferation group. In multivariate analysis, the survival of the discrepant group was lower than that of the low-proliferation group: BCSS hazard ratio (HR)=3.01 (1.32-6.84; P=0.008) and DFS HR=2.07, 95% CI (1.31-3.26; P=0.002). Among grade 2 tumours in multivariate analysis, DFS of the discrepant group was lower than that of the low MI/low Ki67 group: HR=1.98, 95% CI (1.14-3.46), P=0.02. Regarding BCSS, the obtained results were similar. CONCLUSION: The prognosis of patients with discrepant MI and Ki67 appears intermediate between that of low MI/low Ki67 and high MI/high Ki67 groups. These markers should be jointly analysed to clarify prognosis.

Response to dual HER2 blockade in a patient with HER3-mutant metastatic breast cancer.

BACKGROUND: HER3 activating mutations have been shown in preclinical models to be oncogenic and ligand-independent, but to depend on kinase-active HER2. PATIENTS AND METHODS: Whole-exome sequencing of the primary HER2-negative breast cancer and its HER2-negative synchronous liver metastasis from a 46-year-old female revealed the presence of an activating and clonal HER3 G284R mutation. RESULTS: HER2 dual blockade with trastuzumab and lapatinib as third-line therapy led to complete metabolic response in 2 weeks and confirmed radiological partial response after 8 weeks. Following the resection of the liver metastasis, the patient remains disease-free 40 weeks after initiation of the HER2 dual blockade therapy. Immunohistochemical analysis demonstrated a substantial reduction of phospho-rpS6 and phospho-AKT in the post-therapy biopsy of the liver metastasis. DISCUSSION: This is the first-in-man evidence that anti-HER2 therapies are likely effective in breast cancers harboring HER3 activating mutations.

Histological grade concordance between diagnostic core biopsy and corresponding surgical specimen in HR-positive/HER2-negative breast carcinoma.

BACKGROUND: The identification and validation of suitable predictive and prognostic factors are a challenge to improve the treatment scheme selection. Discordances in histological grade can be established between core biopsy and surgical specimens. This is important in HR-positive/HER2-negative subgroup where histological grade identifies patients at high risk and is a strong determinant for treatment scheme. METHODS: A total of 350 consecutive invasive breast carcinoma biopsies were assessed and compared with surgical specimens in Institut Curie, Paris, France. Clinical, radiological and pathological data were recorded. RESULTS: Histological grade concordance rate in the HR+/HER2- group was 75%. A grade underestimation was mainly due to mitotic index misgrading (23%). Large tumours (P<0.05), premenopausal patients (P=0.005) and non-ultrasound-guided biopsies (P=0.04) were risk factors for misgrading. The highest discordance was found in tumours that required chemotherapy (39%, P<0.05), and it was related to an underestimation of histological grade on core biopsies (94%). CONCLUSIONS: Histological grade in HR+/HER2- group is important to identify patients with poor prognosis and start a systemic therapy. Histological grade discordance was correlated with an underestimation of mitotic index and factors probably associated with intratumor heterogeneity (premenopausal status, tumour size and the type of core biopsy performed). But such discordance did not appear to modify the therapeutic decision, because systemic treatment decision-making also integrates other variables. Determining histological grade in core biopsy can be especially important in HR-positive/HER2-negative subgroup where it identifies patients at high risk and is a strong determinant of the treatment scheme.

Randomised proof-of-concept phase II trial comparing targeted therapy based on tumour molecular profiling vs conventional therapy in patients with refractory cancer: results of the feasibility part of the SHIVA trial.

BACKGROUND: The SHIVA trial is a multicentric randomised proof-of-concept phase II trial comparing molecularly targeted therapy based on tumour molecular profiling vs conventional therapy in patients with any type of refractory cancer. RESULTS of the feasibility study on the first 100 enrolled patients are presented. METHODS: Adult patients with any type of metastatic cancer who failed standard therapy were eligible for the study. The molecular profile was performed on a mandatory biopsy, and included mutations and gene copy number alteration analyses using high-throughput technologies, as well as the determination of oestrogen, progesterone, and androgen receptors by immunohistochemistry (IHC). RESULTS: Biopsy was safely performed in 95 of the first 100 included patients. Median time between the biopsy and the therapeutic decision taken during a weekly molecular biology board was 26 days. Mutations, gene copy number alterations, and IHC analyses were successful in 63 (66%), 65 (68%), and 87 (92%) patients, respectively. A druggable molecular abnormality was present in 38 patients (40%). CONCLUSIONS: The establishment of a comprehensive tumour molecular profile was safe, feasible, and compatible with clinical practice in refractory cancer patients.

Concurrent administration of trastuzumab with locoregional breast radiotherapy: long-term results of a prospective study.

This single-center prospective study aims to assess the outcomes and the toxicities related to the concurrent administration of trastuzumab (T) with adjuvant locoregional radiotherapy (RT) in localized breast cancer. Data of 308 patients were analyzed. T was delivered every 3 weeks (loading dose of 8 mg/kg, then 6 mg/kg) for 1 year. Left ventricular ejection fraction (LVEF), measured by echocardiography or myocardial scintigraphy, was considered as impaired when below 55%. Toxicities were assessed according to the Common Terminology Criteria for Adverse Events version 3.0. Univariate and multivariate analyses were carried out using the Cox model. Median follow-up was 50.2 months (13.0-126.0). Median age at diagnosis was 52 years (25-83). Internal mammary node (IMN) RT was performed in 227 patients (73.7%). After completion of RT, 26 patients (8.4%) presented an impaired LVEF: 17 (5.5%) of grade 1, 7 (2.3%) of grade 2, and 2 (0.6%) of grade 3. At 48 months, locoregional control rate was 95% [95% CI 92; 98], and overall survival rate was 98% [95% CI 96; 100]. In univariate analysis, neither the treated breast side (p = 0.655) nor IMN RT (p = 0.213) exposed patients to LVEF alteration. In multivariate analysis, clinical lymph node involvement was associated with an increased risk of locoregional and distant recurrence (p = 0.016 and p = 0.007, respectively). In this prospective study, the toxicities of concurrent T with locoregional breast RT were acceptable and the outcomes favorable. Longer follow-up is warranted to confirm these results.

Benefit of adjuvant trastuzumab-based chemotherapy in T1ab node-negative HER2-overexpressing breast carcinomas: a multicenter retrospective series.

BACKGROUND: Randomized clinical trials showed the benefit of adjuvant trastuzumab-based chemotherapy (ATBC) for node-positive and/or >1 cm HER2+ breast carcinomas. No efficacy data have been published on ATBC in large series of pT1abN0 HER2+ tumors. PATIENTS AND METHODS: This retrospective study evaluated 276 cases of pT1abN0 HER2+ breast tumors in eight French cancer centers. Factors associated with prognosis and ATBC prescription were analyzed. RESULTS: A total of 129 cases (47%) were treated with ATBC (ATBC+), 19 with chemotherapy alone, 5 with trastuzumab alone, and 123 (45%) with neither trastuzumab nor chemotherapy (ATBC-). ATBC use was associated with the date of diagnosis (before or after June 2005) and with poor prognostic features. At a median follow-up of 44 months, there were 13 recurrences in the ATBC- group and 2 in the ATBC+ group. ATBC was associated with a significant survival benefit (99% 40-month disease-free survival for ATBC+ versus 93% for ATBC- cases; P = 0.018). Lack of hormone receptors (HRs) and the presence of lymphovascular invasion (LVI) were significantly associated with a poor prognosis and a greater benefit of ATBC. CONCLUSIONS: ATBC was associated with a significantly reduced risk of recurrence in pT1abN0 HER2+ tumors, and was more beneficial in HR- and/or LVI+ tumors.

Prediction of axillary lymph node status in male breast carcinoma.

BACKGROUND: To evaluate whether predictive factors of axillary lymph node metastasis in female breast cancer (BC) are similar in male BC. PATIENTS AND METHODS: From January 1994 to May 2011, we recorded 80 non-metastatic male BC treated at Institut Curie (IC). We analysed the calibration and discrimination performance of two nomograms [IC, Memorian Sloan-Kettering Cancer Center (MSKCC)] originally designed to predict axillary lymph node metastases in female BC. RESULTS: About 55% and 24% of the tumours were pT1 and pT4, respectively. Nearly 46% demonstrated axillary lymph node metastasis. About 99% were oestrogen receptor positive and 94% HER2 negative. Lymph node status was the only significant prognostic factor of overall survival (P = 0.012). The area under curve (AUC) of IC and MSKCC nomograms were 0.66 (95% CI 0.54-0.79) and 0.64 (95% CI 0.52-0.76), respectively. The calibration of these two models was inadequate. CONCLUSIONS: Multi-variate models designed to predict axillary lymph node metastases for female BC were not effective in our male BC series. Our results may be explained by (i) small sample size (ii) different biological determinants influencing axillary metastasis in male BC compared with female BC.

Modeling of response to endocrine therapy in a panel of human luminal breast cancer xenografts.

Resistance to endocrine therapy is a major complication of luminal breast cancer and studies of the biological features of hormonal resistance are limited by the lack of adequate preclinical models. The aim of this study is to establish and characterize a panel of primary human luminal breast carcinoma xenografts, and to evaluate their response to endocrine therapies. Four hundred and twenty-three tumor fragments obtained directly from patients have been grafted in the interscapular fatpad of Swiss nude mice. After stable engraftment with estradiol supplementation, xenografted tumors have been validated by conventional pathology and immunohistochemistry examination, and additional molecular studies. In vivo tumor growth and response to different endocrine treatments were evaluated. We have engrafted 423 tumors including 314 ER+ tumors, and 8 new luminal breast cancer xenografts have been obtained (2.5%). Tumor take was much lower for luminal tumors than for non-luminal tumors (2.5 vs. 24.7%, P < 0.0001), and was associated with two independent criteria, i.e., ER status (P < 0.0001) and a high grade tumor (P = 0.05). Histological and immunohistochemical analyses performed on patient's tumors and xenografts showed striking similarities in the tumor morphology as well as in the expression level of ER, PR, and HER2. Response to hormone therapy, evaluated in 6 luminal models, showed different sensitivities, thus exhibiting heterogeneity similar to what is observed in the clinic. We have established a panel of primary human luminal breast cancer xenografts, recapitulating the biological and clinical behaviors of patient tumors, and therefore suitable for further preclinical experiments.

Platinum-based chemotherapy in metastatic triple-negative breast cancer: the Institut Curie experience.

BACKGROUND: Although recent experimental data strongly suggest that platinum-based chemotherapy (PBCT) could improve the outcome of triple-negative breast cancer (TNBC), clinical data are lacking. Here, the authors reviewed clinical outcome in patients with metastatic TNBC treated with PBCT. PATIENTS AND METHODS: We conducted a retrospective analysis of all patients (N=143) treated for metastatic breast cancer with PBCT between 2000 and 2008, at Institut Curie, Paris, France. Ninety-three of them (63.7%) had TNBC. One-hundred twenty patients received cisplatin (CDDP). The main combination used was CDDP-ifosfamide, in 101 patients (70.2%). RESULTS: Median follow-up was 44 months. For the overall population (N=143), median overall survival (OS) and median progression-free survival (PFS) were 11 and 5 months, respectively. Objective response rate was 33.3% in the TNBC group versus 22% in non-TNBC, P=0.1. We observed no difference of OS, PFS and response duration. Other prognostic factors for poor OS were visceral metastasis sites (P<0.001). One patient died from sepsis during aplasia, 15 had to switch from CDDP to carboplatin because of CDDP-related toxicity. CONCLUSIONS: Metastatic TNBC patients treated with PBCT tended to have a higher response rate, without a significant improvement of PFS or OS, compared with other subtypes. Toxicity was acceptable. Longer observation and further analysis are warranted.

Necrosis in breast cancer patients with skin metastases receiving bevacizumab-based therapy.

OBJECTIVE: Bevacizumab has entered daily practice in advanced breast cancer patients, in whom skin metastases occurrence is a common event. Wound healing impairment has been described with bevacizumab, and this study looks at possible deleterious side effects of bevacizumab in patients with skin metastases. METHOD: We retrospectively reviewed a series of 12 patients with advanced breast cancer presenting extensive skin metastases, and who received bevacizumab based therapy. RESULTS: Nine patients who initially presented with erosive skin lesions developed extensive and durable skin necrosis, as well as delayed healing of surgical flaps, despite early discontinuation of bevacizumab therapy and intensive skin care in a specialised unit. Skin necrosis was usually associated with extensive tumoural involvement of the skin. CONCLUSION: Bevacizumab may be harmful in selected breast cancer patients with metastatic cutaneous involvement.

[Concurrent radiation therapy and dual HER2 blockade in breast cancer: Assessment of toxicity]. / Association du double blocage de HER2 et radiothérapie dans la prise en charge du cancer du sein exprimant HER2.

PURPOSE: The tolerance of the concurrent use of radiotherapy, pertuzumab and trastuzumab is unknown. The purpose of this study was to evaluate the toxicity of this association in patients treated for HER2 positive metastatic and/or locally recurrent unrespectable breast cancer. MATERIAL AND METHODS: A retrospective study was performed in our institution for all consecutive patients treated with concurrent irradiation, pertuzumab and trastuzumab. The radiotherapy was performed while pertuzumab and trastuzumab were administrated as a maintenance treatment at the dose of 420mg (total dose) and 6mg/kg respectively every 3 weeks without chemotherapy. Toxicity was assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Left ventricular ejection fraction (LVEF) was measured at baseline and then every 3-4 months. RESULTS: We studied 77 patients. treated in between 2013 and 2019 with median follow-up of 38 months (range 0-264 months). Median age was 53 years (33-86). There were 50 patients (64.9%) with metastatic and 27 patients (35.1%) with recurrent disease. All patients received docetaxel followed by P-T as first line treatment and they received 34 cycles (10-85) of pertuzumab and trastuzumab. All patients experienced partial or complete response according to RECIST criteria. Irradiation volumes were whole breast (41 patients, 53.2%) and chest wall (29 patients, 37.7%) at a dose of 50Gy with a median duration of 39 days. Radiotherapy of lymph nodes was performed in 53 patients (68.8%) as following: supraclavicular-infraclavicular and axillary lymph nodes in 52 patients (67.5%), and internal mammary nodes in 31 patients (40.3%). For 20 patients. (26.0%) radiotherapy was palliative: bone irradiation (12 patients, 15.6%), whole-brain radiotherapy (2 patients, 2.6%), cerebral metastasis irradiation (6 patients). As early toxicity we observed: radio dermatitis as following: 36 patients (46.8%) presented grade I, 17 patients (22.1%) presented grade II, and 3 patients (3.9%) presented grade III. One patient (1.3%) presented grade II esophagitis. One patient (1.3%) presented asymptomatic decrease of LVEF during treatment and 6 patients (7.7%) presented a decrease of LVEF. There was no radiation-induced pneumonitis. As late toxicity, we observed 1 (1.3%) case of grade I and 1 (1.3%) with grade II telangiectasia. There was 1 case (1.3%) of grade III cardiac toxicity, 8 months after the concurrent treatment. CONCLUSION: The concurrent use of radiotherapy, pertuzumab and trastuzumab is feasible with good tolerance. Larger prospective data with longer follow-up is needed to confirm these results.

Secondary orbital exenteration for conjunctival melanoma: A study of 25 cases.

INTRODUCTION: The treatment of conjunctival melanoma is most often conservative, but exenteration is sometimes necessary in order to achieve local control of the disease. It can be performed as a primary procedure in cases of locally advanced disease or as a secondary procedure after one or more recurrences. No benefit to secondary exenteration on patient survival has been demonstrated to date for conjunctival melanoma, and it is generally considered a palliative procedure. PATIENTS AND METHODS: Single-center retrospective study performed in the ocular oncology department of the Institut Curie (Paris, France). We included all patients who underwent secondary orbital exenteration for conjunctival melanoma between January 2008 and January 2016. RESULTS: Twenty-five patients underwent secondary exenteration for conjunctival melanoma. The maximum number of local recurrences prior to exenteration was six. Metastases occurred in 11 patients after exenteration and were more common when there was a greater tumor thickness on histology, if the tumor had not been treated initially in an ocular oncology center, or if there had been a greater number of local recurrences before the secondary exenteration was performed. Seventy-five percent of patients developed metastases when the exenteration was performed after 5 or 6 local recurrences. CONCLUSION: This study suggests that early secondary exenteration (i.e. after a number of local recurrences less than or equal to 4) may reduce the occurrence of metastases (and therefore improve patient survival) in conjunctival melanoma. Thus, secondary exenteration might be a curative surgery in some patients with recurrent disease.

Tumor BRCA testing can reveal a high tumor mutational burden related to POLE pathogenic variants.

OBJECTIVE: Tumors harboring a POLE pathogenic variant, associated with high tumor mutational burden, are good candidates for immunotherapy. However, POLE pathogenic variants are not currently screened in routine clinical practice. Can these tumors be identified by means of an already available test? METHODS: We describe seven tumors harboring a POLE pathogenic variant, among eight patients with tumors harboring multiple BRCA1/2 variants (from 4 to 20). All patients were managed at Institut Curie, Paris. Five patients were selected because of unexpected tumor BRCA testing results with multiple variants and another three patients were selected because of a POLE pathogenic variant detected by large tumor testing. We looked for other tumor variants by Next-Generation Sequencing in tumors harboring multiple BRCA1/2 variants, and for multiple BRCA1/2 variants in tumors harboring a POLE pathogenic variant. RESULTS: Four of the five tumors selected because of multiple BRCA1/2 variants exhibited a POLE pathogenic variant, and all three tumors selected for POLE pathogenic variants exhibited multiple BRCA1/2 variants. CONCLUSIONS: Tumor BRCA testing could be a way to detect tumors harboring a highly mutagenic POLE pathogenic variant.