Adaptive evolution of Salmonella Typhimurium LT2 exposed to carvacrol lacks a uniform pattern

Emergence of genetic variants with increased resistance/tolerance to natural antimicrobials, such as essential oils, has been previously evidenced; however, it is unknown whether mutagenesis follows a general or a specific pattern. For this purpose, we carried out four adaptive laboratory evolutions (ALE) in parallel of Salmonella enterica Typhimurium with carvacrol. After 10 evolution steps, we selected and characterized one colony from each lineage (SeCarA, SeCarB, SeCarC, and SeCarD). Phenotypic characterization of the four evolved strains revealed enhanced survival to lethal treatments; two of them (SeCarA and SeCarB) showed an increase of minimum inhibitory concentration of carvacrol and a better growth fitness in the presence of carvacrol compared to wild-type strain. Whole genome sequencing revealed 10 mutations, of which four (rrsH, sseG, wbaV, and flhA) were present in more than one strain, whereas six (nirC, fliH, lon, rob, upstream yfhP, and upstream argR) were unique to individual strains. Single-mutation genetic constructs in SeWT confirmed lon and rob as responsible for the increased resistance to carvacrol as well as to antibiotics (ampicillin, ciprofloxacin, chloramphenicol, nalidixic acid, rifampicin, tetracycline, and trimethoprim). wbaV played an important role in increased tolerance against carvacrol and chloramphenicol, and flhA in cross-tolerance to heat treatments. As a conclusion, no common phenotypical or genotypical pattern was observed in the isolated resistant variants of Salmonella Typhimurium emerged under carvacrol stress. Furthermore, the demonstration of cross-resistance against heat and antibiotics exhibited by resistant variants raises concerns regarding food safety. KEY POINTS: • Stable resistant variants of Salmonella Typhimurium emerged under carvacrol stress • No common pattern of mutagenesis after cyclic exposures to carvacrol was observed • Resistant variants to carvacrol showed cross-resistance to heat and to antibiotics.

Systematic review and meta-analysis of post-progression outcomes in ER+/HER2- metastatic breast cancer after CDK4/6 inhibitors within randomized clinical trials

Background

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors and endocrine therapy (ET) deeply transformed the treatment landscape of hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2−) advanced breast cancer. Randomized clinical trials suggest that second progression-free survival (PFS2) was not compromised and time to subsequent chemotherapy (TTC) may be delayed. We carried out a meta-analysis to assess the benefit on PFS2 and on delaying the TTC.

Methods

We conducted a systematic literature search of randomized clinical trials with CDK4/6 inhibitors and ET reporting PFS2 or TTC of HR+/HER2− pre- or postmenopausal metastatic breast cancer. We also reviewed abstracts and presentations from all major conference proceedings. We calculated the pooled hazard ratios (HR) for PFS2 and TTC using random-effects models with 95% confidence intervals (CI). I² was used to quantify heterogeneity between results of the studies.

Results

Eight studies (MONALEESA-2/3/7, MONARCH-2/3, PALOMA-1/2/3) were included in this analysis (N = 4580 patients). PFS2 benefit was observed in patients who received CDK4/6 inhibitors plus ET (pooled HR = 0.68, 95% CI = 0.62-0.74, I² = 0%) and also a delay in subsequent TTC (pooled HR = 0.65, 95% CI = 0.60-0.71, I² = 0%). A benefit in terms of PFS (pooled HR = 0.55, 95% CI = 0.51-0.59, I² = 0%) and overall survival (pooled HR = 0.76, 95% CI = 0.69-0.84, I² = 0%) was also observed.

Conclusions

CDK4/6 inhibitors plus ET compared with ET alone improve PFS2 and TTC. The delay of chemotherapy may postpone the start of a more toxic treatment option, delaying related toxicities and potentially maintaining a better quality of life for patients, for a longer time. The benefit in PFS2 may postpone the onset of endocrine resistance and help further validate this treatment approach.

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Eight RCTs (MONALEESA-2/3/7, MONARCH-2/3, PALOMA-1/2/3) were included in this analysis on pooled HR for PFS2 and TTC.

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Patients who received CDK4/6 inhibitors plus ET had a clear PFS2 benefit and a delay in subsequent TTC.

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CDK4/6 inhibitors plus ET compared with ET alone improve PFS2 and TTC.

Sex-based differences in response to anti-PD-1 or PD-L1 treatment in patients with non-small-cell lung cancer expressing high PD-L1 levels. A systematic review and meta-analysis of randomized clinical trials

Background

In our previous works, we demonstrated that patients’ sex affects the efficacy of immune checkpoint inhibitors (ICIs) in patients with several advanced solid tumors. Here, we assessed the sex-based heterogeneity of efficacy of anti-programmed cell death protein 1 (anti-PD-1)/anti-programmed death-ligand 1 (anti-PD-L1) given as monotherapy, for advanced non-small-cell lung cancer (NSCLC) expressing high PD-L1 levels, to evaluate if available evidence supports this therapeutic option for both women and men.

Methods

We carried out a systematic review and meta-analysis including all randomized, controlled trials testing anti-PD-1/anti-PD-L1 drugs in monotherapy, as first-line treatment of advanced NSCLC expressing high PD-L1 levels. The primary endpoint was the difference in efficacy of anti-PD-1/anti-PD-L1 drugs versus chemotherapy, between men and women, measured in terms of the difference in overall survival (OS) log [hazard ratio (HR)] reported in male and female study participants.

Results

We analyzed four randomized, controlled trials, including 1672 patients, of whom 1224 (73.2%) were men and 448 (26.8%) were women. The pooled OS-HR comparing anti-PD-1/anti-PD-L1 versus chemotherapy was 0.59 [95% confidence interval (CI), 0.50-0.69] for men and only 0.84 (95% CI, 0.64-1.10) for women. The pooled ratio of the OS-HRs reported in men versus women was 0.71 (95% CI, 0.52-0.98; P-heterogeneity: 0.04), indicating a significantly greater effect for men. No heterogeneity among single-study estimates was observed in either male patients (Q = 2.39, P = 0.50, I² = 0%) or in female patients (Q = 1.13, P = 0.50, I² = 0%).

Conclusion

Evidence available indicates anti-PD-1/anti-PD-L1 monotherapy as highly effective in men but not in women, even in NSCLCs expressing high PD-L1 levels. Prospective trials testing sex-based tailored immunotherapy strategies are needed.

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Sex-based heterogeneity of efficacy of immune checkpoint inhibitors.

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Sex-tailored immunotherapy strategies.

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NSCLC expressing high PD-L1 levels.

Novel insights on Andersen-Tawil syndrome type 1

Background

Andersen-Tawil Syndrome type 1 (ATS1) in a rare arrhythmogenic disease caused by loss-of-function mutations in the KCNJ2 gene and characterized by ventricular arrhythmias, dysmorphic features and episodes of periodic paralysis. Although the prognosis of ATS1 patients is typically considered benign, definitive outcome data are lacking.

Purpose

We aimed to: 1) define the risk of life-threatening arrhythmic events (LAEs); 2) identify risk factors for such events; 3) assess the efficacy of anti-arrhythmic drugs in preventing LAEs.

Methods

We included 118 ATS1 patients from 57 families with confirmed pathogenic or likely pathogenic KCNJ2 mutations. Clinical and genetical data were acquired by investigators from 23 centers in 9 countries.

Results

Baseline characteristics of the population are presented in the Table. Over a follow-up of 6.2 years, 17/118 (14%) patients experienced a first LAE, with a 5-year cumulative probability of 7.9% (Figure). Cox multivariable analysis demonstrated that a previous history of syncope (HR 4.5, p=0.02), the documentation of sustained VT (HR 9.3, p=0.001) and the administration of amiodarone (HR 268, p<0.001) were associated with an increased risk of LAE. The baseline rate of LAE was not reduced by beta-blockers alone (1.37 per 100 py; p=1), or in combination with class Ic antiarrhythmic drugs (1.46 per 100 py, p=1).

Conclusions

Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope, and documentation of sustained ventricular tachycardia are independently associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in ATS1 patients.

ATS1: Diagnosis, Outcome, Risk Factors

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): ERN Guard-Heart European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart

Evaluation of endocrine therapy and patients preferences in early breast cancer: results of Elena study

PURPOSE

The development of the adjuvant therapy requires that clinicians and patients should discuss the magnitude of benefit of treatment for individual patient, estimating the pros and cons and the personal preferences. The aim of the present study was to determine the preferences of women treated with adjuvant hormonal therapy (HT) for breast cancer.

METHODS

The analyses were conducted into three different groups of early breast cancer patients to evaluate the survival benefit needed to make treatment worthwhile before starting HT (A), after a few months from the beginning (B) and after several years of HT (C). The questionnaires, showing hypothetical scenarios based on potential survival times and rates without HT, were used to determine the lowest gains women judged necessary to make the treatment worthwhile.

RESULTS

A total of 452 patients were included in the study: 149 in group A, 150 in group B and 153 in group C. In group C, 65% of patients were receiving HT with aromatase inhibitors (with or without a LHRH analogue). In the groups A, B, C 8%, 20% and 26%, respectively, received adjuvant chemotherapy. Overall, 355 women (79%) had children. The responses were quite similar between the three groups. A median gain of 10 years was judged necessary to make adjuvant HT worthwhile based on the hypothetical scenario of untreated mean survival time of 5 and 15 years. Median gain of 20% more women surviving was judged necessary to make adjuvant HT worthwhile based on an untreated 5-year survival rate expectation of 60%. Cognitive dysfunction was considered the side effect least compatible with the continuation of treatment in all three groups.

CONCLUSIONS

This is a large study of patient preferences on HT. Compared with other studies with similar design, the patients included in the present study required larger benefits to make adjuvant therapy worthwhile.

P3685Can 3D echocardiography give a contribute to the diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)?

Background

The diagnosis of ARVC is based on the structural assessment of the heart with 2D echocardiography (2DE) and cardiovascular MRI (CMR) to detect the presence of global and segmental right ventricular (RV) abnormalities. Little is known about the diagnostic value of 3D echocardiography (3DE) in ARVC. The aim of this study was to assess whether a combination of 2DE and 3DE could replace 2DE and CMR combination with similar diagnostic accuracy in patients with suspected ARVC.

Methods

Thirty-nine subjects (59% males, 47±15 years, 41% with desmosomal mutations) with suspected or confirmed diagnosis of ARVC underwent evaluation of the RV with the use of CMR, 2DE, 3DE.

3DE and CMR were independently used to obtain RV volumes, ejection fraction and presence of segmental RV abnormalities. These studies were blindly classified as meeting none, minor, or major criteria for ARVC in accordance with the 2010 TFC. Kappa statistics were used to assess the concordance between 2DE-CMR and 2DE-3DE diagnostic approaches.

Results

Using the 2DE-CMR approach, patients were classified as follows: 5 not affected, 8 with possible, 9 with borderline and 17 with definite ARVC diagnosis. The evaluation of TFC criteria with the 2DE-3DE approach yielded a high degree of concordance with the standard of care (2DE-CMR approach, K=0.93 with 95% CI: 0.84–1.0). There was complete agreement between the 2DE-CMR and 2DE-3DE approaches for individuals with definite ARVC diagnosis (n=17) and in individuals not affected by ARVC (n=5). Two patients with possible and borderline ARVC diagnosis using the 2DE-CMR approach were confirmed as definite ARVC with 2DE-3DE approach.

Contribution of 3D echo to ARVC

Conclusions

The use of 2D and 3D echocardiography allows bedside evaluation of patients with suspected ARVC, which is diagnostically comparable to that obtained using the traditional combination of 2DE-CMR. This information is particularly relevant for patients who cannot undergo CMR such as patients with ICD.

6081Efficacy and limitations of quinidine therapy in patients with Brugada Syndrome

Background

Quinidine at high-dose is used in patients with Brugada Syndrome (BrS), but its efficacy to prevent life-threatening arrhythmic events (LAE) in BrS is unproven and its use is limited by side effects.

Objective

We assessed whether low-dose quinidine in BrS patients reduces: 1) the occurrence of a first LAE; 2) the arrhythmic burden in the high-risk group of cardiac arrest survivors.

Methods

We first compared the clinical course of 53 BrS patients treated with quinidine to that of 441 untreated controls, matched by sex, age, and symptoms. Furthermore, we calculated the annual incidence of LAEs off- and on-quinidine in 123 BrS patients who had survived a cardiac arrest.

Results

First, we compared the clinical course of 53 BrS patients treated with quinidine (i.e. “cases”: 89% males, median age 40 years) to that of 441 untreated, clinically-matched BrS patients (i.e. “controls”: 91% males, median age 41 years) present in our database of patients with inherited arrhythmias. Cases received quinidine (median dose of 450 mg per day) for 5.0±3.7 years. Quinidine was interrupted in only 3/53 cases (6%) for side effects and it conferred a nonsignificant reduction of the risk of a first LAE in cases versus controls (HR 0.74, 95% CI 0.22–2.48, P=0.62).

Secondly, we calculated the annual recurrence of LAE off- and on-quinidine in 123 BrS cardiac arrest survivors, 27 of whom were treated with quinidine for 7.0±3.5 years. The annual rate of recurrent LAEs decreased significantly from 14.7% while off-quinidine to 3.9% while on-quinidine (P=0.03). Notably, recurrent life-threatening arrhythmic events were recorded in 4/27 (15%) symptomatic patients while on-quinidine.

Conclusion

We demonstrated for the first time in the long-term that low-dose quinidine reduces the recurrence of life-threatening arrhythmias in symptomatic BrS patients, with few side effects. Remarkably, about one-fifth of symptomatic patients experience life-threatening arrhythmias while on-treatment, suggesting that quinidine cannot replace implantable defibrillators in high-risk subjects.

Sentinel lymph node biopsy in microinvasive ductal carcinoma in situ

BACKGROUND

Microinvasive breast cancer is an uncommon pathological entity. Owing to the rarity of this condition, its surgical axillary management and overall prognosis remain controversial.

METHODS

A database was analysed to identify patients with microinvasive ductal carcinoma in situ (DCIS) who had surgery for invasive breast cancer at the European Institute of Oncology, Milan, between 1998 and 2010. Women who had undergone axillary staging by sentinel lymph node biopsy were included in the study.

RESULTS

Of 257 women with microinvasive breast cancer who underwent sentinel lymph node biopsy (SLNB), 226 (87·9 per cent) had negative sentinel lymph nodes (SLNs) and 31 had metastatic SLNs. Twelve patients had isolated tumour cells (ITCs), 14 had micrometastases and five had macrometastases in sentinel nodes. Axillary lymph node dissection was performed in 16 of the 31 patients with positive SLNs. After a median follow-up of 11 years, only one regional first event was observed in the 15 patients with positive SLNs who did not undergo axillary lymph node dissection. There were no regional first events in the 16 patients with positive SLNs who had axillary dissection.

CONCLUSION

Good disease-free and overall survival were found in women with positive SLNs and microinvasive DCIS. This study is in line with studies showing that SLNB in microinvasive DCIS may not be useful, and supports the evidence that less surgery can provide the same level of overall survival with better quality of life.

Acute calcific periarthritis of the fingers

Two cases of acute calcific periarthritis of the fingers are described and some controversial clinical aspects of the syndrome discussed.