Optimal [18F]FDG PET/CT Cutoff for Pathologic Complete Response in HER2-Positive Early Breast Cancer Patients Treated with Neoadjuvant Trastuzumab and Pertuzumab in the PHERGain Trial.

The PHERGain trial investigated the potential of metabolic imaging to identify candidates for chemotherapy deescalation in human epidermal growth factor receptor 2 (HER2)-positive, invasive, operable breast cancer with at least 1 breast lesion evaluable by [18F]FDG PET/CT. [18F]FDG PET/CT responders were defined as patients with an SUVmax reduction (ΔSUVmax) of at least 40% in all of their target lesions after 2 cycles of trastuzumab and pertuzumab (HP) (with or without endocrine therapy). In total, 227 of 285 patients (80%) included in the HP arm showed a predefined metabolic response and received a total of 8 cycles of HP (with or without endocrine therapy). Pathologic complete response (pCR), defined as ypT0/isN0, was achieved in 37.9% of the patients. Here, we describe the secondary preplanned analysis of the best cutoff of ΔSUVmax for pCR prediction. Methods: Receiver-operating-characteristic analysis was applied to look for the most appropriate ΔSUVmax cutoff in HER2-positive early breast cancer patients treated exclusively with neoadjuvant HP (with or without endocrine therapy). Results: The ΔSUVmax capability of predicting pCR in terms of the area under the receiver-operating-characteristic curve was 72.1% (95% CI, 65.1-79.2%). The optimal ΔSUVmax cutoff was found to be 77.0%, with a 51.2% sensitivity and a 78.7% specificity. With this cutoff, 74 of 285 patients (26%) would be classified as metabolic responders, increasing the pCR rate from 37.9% (cutoff ≥ 40%) to 59.5% (44/74 patients) (P < 0.01). With this optimized cutoff, 44 of 285 patients (15.4%) would avoid chemotherapy in either the neoadjuvant or the adjuvant setting compared with 86 of 285 patients (30.2%) using the original cutoff (P < 0.001). Conclusion: In the PHERGain trial, an increased SUVmax cutoff (≥77%) after 2 cycles of exclusive HP (with or without endocrine therapy) achieves a pCR in the range of the control arm with chemotherapy plus HP (59.5% vs. 57.7%, respectively), further identifying a subgroup of patients with HER2-addicted tumors. However, the original cutoff (≥40%) maximizes the number of patients who could avoid chemotherapy.

3-year invasive disease-free survival with chemotherapy de-escalation using an 18F-FDG-PET-based, pathological complete response-adapted strategy in HER2-positive early breast cancer (PHERGain): a randomised, open-label, phase 2 trial.

BACKGROUND: PHERGain was designed to assess the feasibility, safety, and efficacy of a chemotherapy-free treatment based on a dual human epidermal growth factor receptor 2 (HER2) blockade with trastuzumab and pertuzumab in patients with HER2-positive early breast cancer (EBC). It used an 18fluorine-fluorodeoxyglucose-PET-based, pathological complete response (pCR)-adapted strategy. METHODS: PHERGain was a randomised, open-label, phase 2 trial that took place in 45 hospitals in seven European countries. It randomly allocated patients in a 1:4 ratio with centrally confirmed, HER2-positive, stage I-IIIA invasive, operable breast cancer with at least one PET-evaluable lesion to either group A, where patients received docetaxel (75 mg/m2, intravenous), carboplatin (area under the curve 6 mg/mL per min, intravenous), trastuzumab (600 mg fixed dose, subcutaneous), and pertuzumab (840 mg loading dose followed by 420 mg maintenance doses, intravenous; TCHP), or group B, where patients received trastuzumab and pertuzumab with or without endocrine therapy, every 3 weeks. Random allocation was stratified by hormone receptor status. Centrally reviewed PET was conducted at baseline and after two treatment cycles. Patients in group B were treated according to on-treatment PET results. Patients in group B who were PET-responders continued with trastuzumab and pertuzumab with or without endocrine therapy for six cycles, while PET-non-responders were switched to receive six cycles of TCHP. After surgery, patients in group B who were PET-responders who did not achieve a pCR received six cycles of TCHP, and all patients completed up to 18 cycles of trastuzumab and pertuzumab. The primary endpoints were pCR in patients who were group B PET-responders after two treatment cycles (the results for which have been reported previously) and 3-year invasive disease-free survival (iDFS) in patients in group B. The study is registered with ClinicalTrials.gov (NCT03161353) and is ongoing. FINDINGS: Between June 26, 2017, and April 24, 2019, a total of 356 patients were randomly allocated (71 patients in group A and 285 patients in group B), and 63 (89%) and 267 (94%) patients proceeded to surgery in groups A and B, respectively. At this second analysis (data cutoff: Nov 4, 2022), the median duration of follow-up was 43·3 months (range 0·0-63·0). In group B, the 3-year iDFS rate was 94·8% (95% CI 91·4-97·1; p=0·001), meeting the primary endpoint. No new safety signals were identified. Treatment-related adverse events and serious adverse events (SAEs) were numerically higher in patients allocated to group A than to group B (grade ≥3 62% vs 33%; SAEs 28% vs 14%). Group B PET-responders with pCR presented the lowest incidence of treatment-related grade 3 or higher adverse events (1%) without any SAEs. INTERPRETATION: Among HER2-positive EBC patients, a PET-based, pCR-adapted strategy was associated with an excellent 3-year iDFS. This strategy identified about a third of patients who had HER2-positive EBC who could safely omit chemotherapy. FUNDING: F Hoffmann-La Roche.

Quality of life with palbociclib plus fulvestrant versus placebo plus fulvestrant in postmenopausal women with endocrine-sensitive hormone receptor-positive and HER2-negative advanced breast cancer: patient-reported outcomes from the FLIPPER trial.

Background: In the FLIPPER trial, palbociclib/fulvestrant significantly improved progression-free survival (PFS) compared with placebo/fulvestrant in postmenopausal women with HR+/HER2- advanced breast cancer (ABC). Objective: We assessed health-related quality of life (QoL) using patient-reported outcomes (PROs). Design and methods: In this phase II double-blinded study, PROs were assessed at baseline after every three cycles and at the end of the treatment using the European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23. Time to deterioration (TTD) in global health status (GHS)/QoL was defined as a decrease of ⩾10 points. Changes from baseline (CFB) and TTD were analysed using linear mixed-effect and Cox regression models, respectively. Results: Of the 189 randomised (1:1) patients, 178 (94%) completed ⩾1 post-baseline assessment; 50% received ⩾22 cycles of study treatment, with a questionnaire compliance >90%. Mean baseline scores were comparable between arms. GHS/QoL scores were maintained throughout the palbociclib/fulvestrant treatment. CFB showed significant differences for GHS/QoL, appetite loss, constipation and systemic therapy side effect scores favouring placebo/fulvestrant. TTD in GHS/QoL was delayed in placebo/fulvestrant versus palbociclib/fulvestrant [30.3 versus 11.1 months; adjusted hazard ratio (aHR): 1.57, 95% CI: 1.03-2.39, p = 0.036]; this difference was not significant in patients with progressive disease (aHR: 1.2, 95% CI: 0.6-2.2, p = 0.658). No statistically significant differences in TTD were found for the other QLQ-C30 and QLQ-BR23 scales. Conclusions: Although TTD in GHS/QoL was prolonged with placebo/fulvestrant, no differences were observed on other functional or symptom scales. This finding and the improvement in PFS support the combination of palbociclib/fulvestrant as a beneficial therapeutic option for HR+/HER2- ABC. Trial registration number: Sponsor Study Code: GEICAM/2014-12EudraCT Number: 2015-002437-21ClinTrials.gov reference: NCT02690480.

Altered Serum Metabolic Profile Assessed by Advanced 1H-NMR in Breast Cancer Patients.

BACKGROUND: Altered lipid metabolism has been described in some types of cancer. To analyse in depth the metabolic modifications in breast cancer patients, advanced 1H-nuclear magnetic resonance was performed in these patients. The main objective of this paper was to define a specific lipidomic signature for these cancer patients. MATERIALS AND METHODS: Serum from 240 women (171 breast cancer patients and 69 control women) were studied and analysed by nuclear magnetic resonance. RESULTS: Triglyceride-enriched particles, specifically very low-density lipoprotein triglycerides, intermediate-density lipoprotein triglycerides, low-density lipoprotein triglycerides, and high-density lipoprotein triglycerides, were positively associated with breast cancer. Moreover, alanine, tyrosine, and branched amino acids were also associated with increased risk of breast cancer. CONCLUSIONS: Breast cancer patients showed a modified metabolome, giving a very interesting tool to draw different radar charts between control women and breast cancer patients. To our knowledge, this is the first time that advanced nuclear magnetic resonance profiling has been used to identify relevant and specifically altered lipid or amino acid metabolites in BC serum samples. The altered metabolic signature could be analysed for early and reliable BC patient diagnosis and prognosis.

Chemotherapy de-escalation using an 18F-FDG-PET-based pathological response-adapted strategy in patients with HER2-positive early breast cancer (PHERGain): a multicentre, randomised, open-label, non-comparative, phase 2 trial.

BACKGROUND: Several de-escalation approaches are under investigation in patients with HER2-positive, early-stage breast cancer. We assessed early metabolic responses to neoadjuvant trastuzumab and pertuzumab using 18F-fluorodeoxyglucose (18F-FDG)-PET (18F-FDG-PET) and the possibility of chemotherapy de-escalation using a pathological response-adapted strategy. METHODS: We did a multicentre, randomised, open-label, non-comparative, phase 2 trial in 45 hospitals in Spain, France, Belgium, Germany, the UK, Italy, and Portugal. Eligible participants were women aged 18 years or older with centrally confirmed, HER2-positive, stage I-IIIA, invasive, operable breast cancer (≥1·5 cm tumour size) with at least one breast lesion evaluable by 18F-FDG-PET, an Eastern Cooperative Oncology Group performance status of 0 or 1, and a baseline left ventricular ejection fraction of at least 55%. We randomly assigned participants (1:4), via an interactive response system using central block randomisation with block sizes of five, stratified by hormone receptor status, to either docetaxel (75 mg/m2 intravenous), carboplatin (area under the concentration-time curve 6 mg/mL per min intravenous), trastuzumab (subcutaneous 600 mg fixed dose), and pertuzumab (intravenous 840 mg loading dose, 420 mg maintenance doses; group A); or trastuzumab and pertuzumab (group B). Hormone receptor-positive patients allocated to group B were additionally given letrozole if postmenopausal (2·5 mg/day orally) or tamoxifen if premenopausal (20 mg/day orally). Centrally reviewed 18F-FDG-PET scans were done before randomisation and after two treatment cycles. Patients assigned to group A completed six cycles of treatment (every 3 weeks) regardless of 18F-FDG-PET results. All patients assigned to group B initially received two cycles of trastuzumab and pertuzumab. 18F-FDG-PET responders in group B continued this treatment for six further cycles; 18F-FDG-PET non-responders in this group were switched to six cycles of docetaxel, carboplatin, trastuzumab, and pertuzumab. Surgery was done 2-6 weeks after the last dose of study treatment. Adjuvant treatment was selected according to the neoadjuvant treatment administered, pathological response, hormone receptor status, and clinical stage at diagnosis. The coprimary endpoints were the proportion of 18F-FDG-PET responders in group B with a pathological complete response in the breast and axilla (ypT0/is ypN0) as determined by a local pathologist after surgery after eight cycles of treatment, and 3-year invasive disease-free survival of patients in group B, both assessed by intention to treat. The definitive assessment of pathological complete response was done at this primary analysis; follow-up to assess invasive disease-free survival is continuing, hence these data are not included in this Article. Safety was assessed in all participants who received at least one dose of study drug. Health-related quality-of-life was assessed with EORTC QLQ-C30 and QLQ-BR23 questionnaires at baseline, after two cycles of treatment, and before surgery. This trial is registered with EudraCT (2016-002676-27) and ClinicalTrials.gov (NCT03161353), and is ongoing. FINDINGS: Between June 26, 2017, and April 24, 2019, we randomly assigned 71 patients to group A and 285 to group B. Median follow-up was 5·7 months (IQR 5·3-6·0). 227 (80%) of 285 patients in group B were 18F-FDG-PET responders, of whom 86 (37·9%, 95% CI 31·6-44·5; p<0·0001 compared with the historical rate) of 227 had a pathological complete response. The most common haematological grade 3-4 adverse events were anaemia (six [9%] of 68 patients in group A vs four [1%] of 283 patients in group B), neutropenia (16 [24%] vs ten [4%]), and febrile neutropenia (14 [21%] vs 11 [4%]). Serious adverse events occurred in 20 (29%) of 68 patients in group A versus 13 (5%) of 283 patients in group B. No deaths were reported during neoadjuvant treatment. Global health status declined by at least 10% in 65·0% (95% CI 46·5-72·4) and 35·5% (29·7-41·7) of patients in groups A and B, respectively INTERPRETATION: 18F-FDG-PET identified patients with HER2-positive, early-stage breast cancer who were likely to benefit from chemotherapy-free dual HER2 blockade with trastuzumab and pertuzumab, and a reduced impact on global health status. Depending on the forthcoming results for the 3-year invasive disease-free survival endpoint, this strategy might be a valid approach to select patients not requiring chemotherapy. FUNDING: F Hoffmann-La Roche.

Identification of germline pathogenic variants in DNA damage repair genes by a next-generation sequencing multigene panel in BRCAX patients.

BACKGROUND: Approximately 5-10% of breast carcinomas have been related to hereditary conditions and are attributable to pathogenic variants in the BRCA1 and BRCA2 genes, which is referred to as hereditary breast and ovarian cancer (HBOC) syndrome. The inclusion of additional genes that can be related to HBOC syndrome is under intense evaluation due to the high proportion of patients with HBOC criteria who do not present pathogenic mutations in BRCA genes, named BRCAX, despite having high clinical suspicion of hereditary cancer. The main aim is to identify new potentially pathogenic gene variants that may contribute to HBOC to improve the efficiency of routine diagnostic tests in this hereditary condition. METHODS: A retrospective cohort of 77 HBOC BRCAX patients was analyzed by next-generation sequencing using a targeted multigene panel composed of 25 genes related to hereditary cancer and deficiencies in DNA repair pathways. RESULTS: We found 9 variants in 7 different genes, which were confirmed by automated sequencing. Six variants were classified as pathogenic or likely pathogenic. Three of them were located in the PALB2 gene, one in the BRIP1 gene, one in the BARD1 gene and 1 in the RAD50 gene. In addition, three variants of uncertain significance (VUS) were detected in the TP53, CHEK2, and CDH1 genes. CONCLUSIONS: We identified that 8% of BRCAX patients were carriers of pathogenic variants in genes other than BRCA1 and BRCA2. Therefore, wide gene panels, including clinically actionable genes, should be routinely used in the screening of HBOC in our population. We observed differences from other studies in the prevalence of mutated genes, most likely due to differences in the selection criteria of the probands and in the population analyzed. The high incidence of deleterious variant detection in PALB2 supports its significant role in breast cancer susceptibility and reinforces its inclusion in the HBOC genetic diagnostic process.