Circulating tumor DNA validity and potential uses in metastatic breast cancer

Following the first characterization of circulating tumor DNA (ctDNA) in the 1990s, recent advances led to its introduction in the clinics. At present, the European Society Of Medical Oncology (ESMO) recommendations endorse ctDNA testing in routine clinical practice for tumor genotyping to direct molecularly targeted therapies in patients with metastatic cancer. In studies on metastatic breast cancer, ctDNA has been utilized for treatment tailoring, tracking mechanisms of drug resistance, and for predicting disease response before imaging. We review the available evidence regarding ctDNA applications in metastatic breast cancer.

Epidemiology trends and progress in breast cancer survival: earlier diagnosis, new therapeutics

PURPOSE OF REVIEW

In this review we will critically appraise the latest evidence on breast cancer (BC) survival trends and discuss how these may reflect breakthroughs in early diagnosis and treatment approaches. We will address the wide global inequalities in BC survival and review the ongoing initiatives aimed at improving cancer control worldwide.

RECENT FINDINGS

BC outcomes have improved in high-income countries during the last decades, following the implementation of strategies for early detection and optimal multimodality treatment. Novel therapeutics, such as anti-HER2 targeted treatments, have also contributed to the progress in BC survival. However, BC mortality is still high in low-income countries, due to the lack of optimal healthcare infrastructures. In the context of marked inequities in BC management across world regions, international collaborations such as the Global Breast Cancer Initiative and the Global Initiative for Cancer Registry Development work to foster capacity-building in developing countries, tackle the burden of BC and deliver the Sustainable Development Goals by 2030.

SUMMARY

Collection of robust, high-quality data from population-based cancer registries is crucial to drive and refine public health interventions. Population-based data are also the litmus paper to evaluate the real-world impact of clinical advances and monitor progress.

Association of body mass index with clinicopathological features and survival in patients with primary invasive lobular breast cancer

PURPOSE

Invasive lobular carcinoma (ILC) represents up to 15% of all breast carcinomas. While the proportion of women with overweight and obesity increases globally, the impact of body mass index (BMI) at primary diagnosis on clinicopathological features of ILC and the prognosis of the patients has not been investigated yet.

PATIENTS AND METHODS

We performed a multicentric retrospective study including patients diagnosed with non-metastatic pure ILC. The association of BMI at diagnosis with clinicopathological variables was assessed using linear or multinomial logistic regression. Univariable and multivariable survival analyses were performed to evaluate the association of BMI with disease-free survival (DFS), distant recurrence-free survival (DRFS), and overall survival (OS).

RESULTS

The data of 2856 patients with ILC and available BMI at diagnosis were collected, of which 2570/2856 (90.0%) had oestrogen receptor (ER)-positive and human epidermal growth factor receptor (HER2) not amplified/overexpressed (ER+/HER2-) ILC. Of these 2570 patients, 80 were underweight (3.1%), 1410 were lean (54.9%), 712 were overweight (27.7%), and 368 were obese (14.3%). Older age at diagnosis, a higher tumour grade, a larger tumour size, a nodal involvement, and multifocality were associated with a higher BMI. In univariable models, higher BMI was associated with worse outcomes for all end-points (DFS: hazard ratio (HR) 1.21, 95CI 1.12-1.31, p value<0.01; DRFS: HR 1.25, 95CI 1.12-1.40, p value<0.01; OS: HR 1.25, 95CI 1.13-1.37, p value<0.01). This association was not statistically significant in multivariable analyses (DFS: HR 1.09, 95CI 0.99-1.20, p value 0.08; DRFS: HR 1.03, 95CI 0.89-1.20, p value 0.67; OS: HR 1.11, 95CI 0.99-1.24, p value 0.08), whereas grade, tumour size, and nodal involvement were still prognostic for all end-points.

CONCLUSION

Worse prognostic factors such as higher grade, larger tumour size, and nodal involvement are associated with higher BMI in ER+/HER2- ILC, while there was no statistical evidence for an independent prognostic role for BMI. Therefore, we hypothesise that the effect of BMI on survival could be mediated through its association with these clinicopathological variables.

PI3K/PTEN/mTOR pathway dynamic tracking and prognostic value in HR+/HER2- BC patients with residual disease after neoadjuvant chemotherapy: a cohort study

AIMS

Hormone receptor-positive (HR)+/HER2- breast cancer (BC) is highly heterogeneous, with PI3K/PTEN/mTOR pathway alterations emerging as possible players within this complexity. We longitudinally tracked PI3K/PTEN/mTOR pathway dynamics from baseline biopsy to residual disease (RD)-and to metastases in case of relapse-in HR+/HER2- BC patients receiving neoadjuvant chemotherapy (NACT).

METHODS

HR+/HER2- BC patients with RD after NACT were identified. We assessed PIK3CA mutational, Pten-loss and phosphorylation levels of mTOR and its substrates (p70S6K and 4EBP1) on baseline biopsies and matched RD samples; in case of disease relapse, we also assessed PIK3CA mutational status on metastatic samples. Recurrence-free survival (RFS) was adopted as endpoint.

RESULTS

92 patient were included. The conversion rate of PIK3CA mutational status was 12.8%; 1 patient acquired PIK3CA mutation at relapse; the rate of Pten conversion was 33.3%; mTOR phosphorylation levels significantly increased from baseline biopsy to RD, while its substrates significantly decreased. Baseline phosphorylated-mTOR significantly predicted poorer RFS in patients with PIK3CA wild-type status; baseline phosphorylated-70S6K was positively associated with RFS.

CONCLUSIONS

We observed that PI3K/PTEN/mTOR pathway is highly dynamic under NACT exposure and the assessment of PIK3CA mutations may capture only a small fraction of such complexity. In this context, mTOR activation trough alternative pathways with respect to PIK3CA signalling may have a crucial role in shaping the molecular landscape of HR+/HER2- BC with RD after NACT. It is imperative to further elucidate the role of PIK3CA and mTOR-dependent pathways in shaping chemoresistance and endocrine resistance in high-risk HR+/HER2- early/locally advanced BC patients.

PIK3CA copy number gain and inhibitors of the PI3K/AKT/mTOR pathway in triple-negative breast cancer

As wider insights are gained on the molecular landscape of triple-negative breast cancer (TNBC), novel targeted therapeutic strategies might become an option in this setting as well. Activating mutations of PIK3CA represent the second most common alteration in TNBC after the TP53 mutation, with a prevalence of about 10-15%. Considering the well-established predictive role of PIK3CA mutations for response to agents targeting the PI3K/AKT/mTOR pathway, several clinical trials are currently evaluating these drugs in patients with advanced TNBC. However, much less is known regarding the actionability of PIK3CA copy number gains, which represent a thoroughly common molecular alteration in TNBC, with a prevalence estimated at 6-20%, and are listed as "likely gain-of-function" alterations in the OncoKB database. In the present paper we describe two clinical cases in which patients harboring PIK3CA-amplified TNBC received a targeted treatment with the mTOR-inhibitor everolimus and the PI3K-inhibitor alpelisib, respectively, with evidence of disease response on 18F-FDG Positron-emission tomography (PET) imaging. Hence, we discuss the evidence presently available regarding a possible predictive value of PIK3CA amplification for response to targeted treatment strategies, suggesting that this molecular alteration might represent an intriguing biomarker in this sense. Considering that few of the currently active clinical trials assessing agents targeting the PI3K/AKT/mTOR pathway in TNBC select patients based on tumor molecular characterization, and none of these based on PIK3CA copy number status, we urge for the introduction of PIK3CA amplification as a criterion for patient selection in future clinical trials in this setting.

Abstract P3-05-40: Association of body mass index with clinicopathological features and survival in patients with primary ER+/HER2- invasive lobular breast cancer

Background: Invasive lobular carcinoma (ILC) represents up to 15% of all breast carcinomas. The majority of ILC express the estrogen receptor (ER) and have no amplification/overexpression of the human epidermal growth factor receptor 2 (HER2). A high body mass index (BMI) has been associated with an increased risk of developing ILC in postmenopausal women, similar to what is seen for breast cancer of no special type (NST). It is however unknown if BMI impacts the clinicopathological features and the prognosis of ILC.

Methods: We performed a multicentric retrospective study in 5 European centers of patients diagnosed between January 2000 and December 2020 with ER+/HER2- non-metastatic pure (i.e., not mixed) ILC. Patient and tumor characteristics and event-related data were collected. BMI was categorized into underweight (≤18.5kg/m2), lean (&gt;18.5kg/m2 and &lt; 25kg/m2), overweight (≥25kg/m2 and &lt; 30kg/m2) and obese (≥30kg/m2). The association of BMI as either a continuous or a categorical variable with clinicopathological variables was assessed using linear regression or ordinal logistic regression, respectively. Median follow-up was calculated using the reverse Kaplan-Meier estimator. Survival analyses using univariable (stratified by center) and multivariable (adjusted for all included variables and stratified by center) Cox regression were performed to evaluate the association of BMI with disease free survival (DFS), distant recurrence free survival (DRFS) and overall survival (OS). DFS and DRFS were analyzed in the presence of death without event as the competing risk.

Results: The data of 2476 patients were collected and BMI was available for 2346 patients. In total, 1299 (55%) patients were lean, 638 (27%) overweight and 339 (14%) obese. Underweight patients only represented 3% of all patients and were thus excluded from further analyses. A higher age at diagnosis, higher grade, larger tumor size, nodal involvement and multifocality were significantly associated with higher BMI (Table 1). The median follow-up was 8,5 years (interquartile range 59.24 – 142.13 months). In univariable analysis, higher BMI was associated with worse survival outcomes (Table 2). However, this association was not seen in multivariable analysis while grade, tumor size and nodal involvement were still prognostic for all endpoints. Similar results were seen with BMI as a continuous variable.

Conclusion: Larger tumors and nodal involvement were more likely to be found in patients with ER+/HER2- ILC with higher BMI which might be explained by a delayed diagnosis in these patients. Higher grade also seemed to be associated with higher BMI. In multivariable analyses, BMI was not found to be an independent prognostic factor. Tumor grade, tumor size, and nodal status remained strongly prognostic for survival outcomes in multivariable survival analyses which is consistent with their known prognostic importance in luminal tumors. We hypothesize that the prognostic effect of BMI is mediated through these variables for patients with ER+/HER2- ILC.

Table 1. Association of clinicopathological features of ER+/HER2- ILC with categorical BMI.

Table 2. Association of categorical BMI and other clinicopathological features of ER+/HER2- ILC with survival.

Citation Format: Karen Van Baelen, Ha-Linh Nguyen, François Richard, Anne-Sophie Hamy, Aullène Toussaint, Fabien Reyal, Anne Salomon, Luc Dirix, Peter Vermeulen, Hilde Wuyts, Maria Karsten, Adam D. Dordevic, Guilherme Nader Marta, Evandro de Azambuja, Christos Sotiriou, Denis Larsimont, Ottavia Amato, Marion Maetens, Maxim De Schepper, Tatjana Geukens, Sileny Han, Thaïs Baert, Kevin Punie, Hans Wildiers, Chantal Remmerie, Ann Smeets, Ines Nevelsteen, Giuseppe Floris, Elia Biganzoli, Patrick Neven, Christine Desmedt. Association of body mass index with clinicopathological features and survival in patients with primary ER+/HER2- invasive lobular breast cancer [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 P3-05-40.

HER2-low-positive breast cancer: evolution from primary tumor to residual disease after neoadjuvant treatment

Approximately a half of breast tumors classified as HER2-negative exhibit HER2-low-positive expression. We recently described a high instability of HER2-low-positive expression from primary breast cancer (BC) to relapse. Previous studies reporting discordance in HER2 status between baseline biopsy and residual disease (RD) in patients undergoing neoadjuvant treatment did not include the HER2-low-positive category. The aim of this study is to track the evolution of HER2-low-positive expression from primary BC to RD after neoadjuvant treatment. Patients undergoing neoadjuvant treatment with available baseline tumor tissue and matched samples of RD (in case of no pCR) were included. HER2-negative cases were sub-classified as HER2-0 or HER2-low-positive (IHC 1+ or 2+ and ISH negative). Four-hundred forty-six patients were included. Primary BC phenotype was: HR-positive/HER2-negative 23.5%, triple-negative (TN) 35%, HER2-positive 41.5%. HER2-low-positive cases were 55.6% of the HER2-negative cohort and were significantly enriched in the HR-positive/HER2-negative vs. TN subgroup (68.6% vs. 46.8%, p = 0.001 χ2 test). In all, 35.3% of non-pCR patients (n = 291) had a HER2-low-positive expression on RD. The overall rate of HER2 expression discordance was 26.4%, mostly driven by HER2-negative cases converting either from (14.8%) or to (8.9%) HER2-low-positive phenotype. Among HR-positive/HER2-negative patients with HER2-low-positive expression on RD, 32.0% and 57.1% had an estimated high risk of relapse according to the residual proliferative cancer burden and CPS-EG score, respectively. In conclusion, HER2-low-positive expression showed high instability from primary BC to RD after neoadjuvant treatment. HER2-low-positive expression on RD may guide personalized adjuvant treatment for high-risk patients in the context of clinical trials with novel anti-HER2 antibody-drug conjugates.

Inoculation of mother's own milk could personalize pasteurized donor human milk used for feeding preterm infants

BACKGROUND

Human milk is a vehicle for bioactive compounds and beneficial bacteria which promote the establishment of a healthy gut microbiome of newborns, especially of preterm infants. Pasteurized donor human milk (PDHM) is the second-best option when preterm mother's own milk is unavailable. Since pasteurization affect the microbiological quality of donor milk, PDHM was inoculated with different preterm milk samples and then incubated, in order to evaluate the effect in terms of bacterial growth, human milk microbiome and proteolytic phenomena.

METHODS

In an in-vitro study PDHM was inoculated at 10% v/v using ten preterm milk samples. Microbiological, metataxonomic and peptidomic analyses, on preterm milk samples at the baseline (T0), on PDHM and on inoculated milk (IM) samples at T0, after 2 h (T1) and 4 h (T2) of incubation at 37 °C, were conducted.

RESULTS

IM samples at T2 showed a Total Bacterial Count not significantly different (p > 0.01) compared to preterm milk samples. At T2 lactic acid bacteria level was restored in all IM. After inoculation, metataxonomic analysis in IM samples showed that Proteobacteria remained the predominant phylum while Firmicutes moved from 3% at T1 to 9.4% at T2. Peptidomic profile of IM resembled that of PDHM, incubated for the same time, in terms of number and type of peptides.

CONCLUSION

The study demonstrated that inoculation of PDHM with mother's own milk could restore bacterial growth and personalize human milk microbiome in PDHM. This effect could be beneficial because of the presence of maternal probiotic bacteria which make PDHM more similar to mother's own milk.

To Transplant or Not to Transplant During the SARS-CoV-2 Pandemic? That Is the Question

The novel coronavirus disease 2019 has grown to be a global public health emergency. The rapid spread of the infection has raised many questions in the oncohematological scientific community regarding the appropriateness of high‐dose chemotherapy with autologous stem cell transplantation (ASCT). We here report two cases of patients who received ASCT at our Institute during the epidemic in Italy, affected with Hodgkin lymphoma and germ cell tumor, respectively. The two patients underwent a nasopharyngeal swab for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) on hospital admittance and during the period of bone marrow aplasia. They were attended to exclusively by dedicated health care staff who followed specifically implemented protocols for bedside nursing and care. They completed the procedure without unexpected side effect. Our experience demonstrates how ASCT can be performed safely if procedures are reorganized ad hoc to reduce the risk of SARS‐CoV‐2 infection.

The COVID‐19 pandemic has raised many questions in the oncohematological scientific community about risks associated with transplant procedures. This article reports two patient cases, focusing on the risks of performing high‐dose chemotherapy with autologous peripheral blood stem cell transplantation during the COVID‐19 pandemic weighed against the expected clinical benefit.

Exertional rhabdomyolysis leading to acute kidney injury: when genetic defects are diagnosed in adult life

Rhabdomyolysis is a common cause of acute kidney injury (AKI) that is usually triggered by trauma. However, less common causes of rhabdomyolysis may precipitate AKI as well, possibly representing a diagnostic challenge even for the experienced nephrologist. Genetic defects of muscle metabolism represent one of these causes and can be overlooked in adults, since these diseases usually become apparent in childhood. We present here a case in which an adult patient with severe exertional rhabdomyolysis leading to AKI was finally diagnosed with a genetic defect of lipid metabolism. A 41-year-old patient was brought to our attention because of AKI and pigmenturia after strenuous physical effort. At admission, the patient was over-hydrated with a weight increase of 3 kg in few days. Laboratory examination showed creatinine of 8.7 mg/dl, along with increased myoglobin and CPK. Urinalysis was positive for haemoglobin and proteins, while urinary sediment analysis did not demonstrate any red blood cell but rather "muddy-brown" casts and tubular cells. Urine output was forced and the patient completely recovered renal function. Genetic analysis later demonstrated the presence of a common mutation of Carnitine Palmitoyl-Transferase II (CPTII). When facing rhabdomyolysis of obscure origin, nephrologists must keep in mind the possibility that even adult patients may have a genetic defect of energy metabolism. In these cases, patients usually experience rhabdomyolysis during exertion, fasting, or infection. CPTII deficiency often has a subtle presentation and might be unrecognized until AKI develops. Therefore, it is important to consider a genetic defect of muscle metabolism even in adult patients when a history of rhabdomyolysis of unclear origin is present.

[Quality of post-discharge growth in small for gestational age preterm infants: an explorative study]

OBJECTIVES

The Preterm newborns, especially if born small for gestational age (SGA), appear to be at risk for developing post-natal growth failure and an altered body composition. Nutrition-related growth during a critical window in infancy may affect the development of metabolic syndrome in adult life. Aim of the present study was to test the hypothesis that the post-discharge period is critical for programming the catch up growth and the later development of metabolic syndrome in small for gestational-age infants fed either standard or enriched formula.

METHODS

A clinic randomized explorative study was conducted. Twenty-seven preterm SGA infants (gestational age < or = 33 weeks; birth weight < or = 1500 g) underwent assessment of growth and body composition by means of an air displacement system at 36 weeks, 15 days and 1 months adjusted age. SGA infants were randomized to receive standard formula (Kcal: 67/100 ml, proteins: 1,4 g/100 ml) or enriched formula (Kcal: 75/100 ml, proteins: 2 g/100 ml) after discharge.

RESULTS

No differences in weight, fat mass, length and head circumference were found in SGA infants fed standard formula as compared to those fed enriched formula at 15 day or 1 months adjusted age.

CONCLUSIONS

This explorative study suggests that in SGA infants growth, both in terms of quantity and quality, is not influenced by different nutritional management during the early post-discharge period.

[Quality of growth in preterm infants assessed at term equivalent age: a pilot study]

BACKGROUND

The American Academy of Pediatrics (AAP) recommends that preterm infants' growth duplicates fetal growth rates and that body composition replicates in utero body composition. Aim ofthe study was to compare the total body fat mass between preterm infants assessed at term and full-term newborns.

METHODS

A prospective observational study was conducted. Forty-five preterm infants (mean (SD) gestational age: 30,1 (2.3) weeks; birth weight: 1125 (280) g), and 40 full term (mean (SD) 38.5 (1.2) weeks, 3203 (385) g, breast fed infants underwent assessment of growth and body composition by means of an air displacement system at term adjusted-age and on day 3 of life, respectively. A T test was used to compare % fat mass between preterm and term infants.

RESULTS

Weight, length and head circumference were smaller in the preterm group assessed at term adjusted-age as compared to the term group. Mean (SD) percentage of fat mass in preterm infants was significantly higher as compared to term infants [14.5 (4.3) vs 7,6 (3.6), P < 0.0001].

CONCLUSIONS

Our data demonstrate that preterm infants are at risk of developing an increased adiposity in addition to postnatal growth retardation.