Data-driven cascade control system: Response estimation and controller design

In this study, we propose a data-driven design method for a cascade control system with inner and outer control loops. First, the input-output response of a controlled plant, which varies with the controller parameters of a fixed-structure inner-outer control law, is estimated directly from open-loop input-output data. Next, based on the estimated response, the controller parameters are optimized to minimize the difference between a reference model with a controlled closed-loop system. In the proposed method, the response of a fictitious reference input, which varies with the controller parameters, is estimated, and then the closed-loop response is estimated. Therefore, a closed-loop input-output data is not required, and the controller parameters are determined directly from an open-loop input-output data. Furthermore, the time constant of a reference model is also optimized so as to reduce the control error. The proposed method is compared with both conventional single-loop and cascade data-driven methods by means of numerical examples.

Human papillomavirus infection and lung adenocarcinoma: special benefit is observed in patients treated with immune checkpoint inhibitors

BACKGROUND

Human papilloma virus (HPV) has been associated with the development and modulation of response in a series of neoplasms. In the case of lung adenocarcinoma, its role in etiology and pathogenesis is still controversial. Considering that this infection brings foreign epitopes, it could be of prognostic significance in patients with lung adenocarcinoma treated with immunotherapy.

METHODS

In a retrospective cohort study we evaluated the presence of HPV genomic material in lung adenocarcinoma primary lesions with the INNO-LiPA platform. Viral replication was also evaluated by detecting the presence of oncoprotein E6/E7 messenger RNA (mRNA) by quantitative RT-PCR. To confirm possible hypotheses regarding viral oncogenesis, vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1 (HIF1) were evaluated with stromal fibrosis and immunoscore.

RESULTS

A total of 133 patients were included in the analysis, of whom 34 tested positive for HPV, reaching an estimated prevalence of 25.6% [95% confidence interval (CI) 18.2% to 32.9%]. E6/7 mRNA was identified in 28 out of the 34 previously positive cases (82.3%). In immune checkpoint inhibitor (ICI)-treated patients, the median overall survival reached 22.3 months [95% CI 19.4 months- not reached (NR)] for HPV-negative and was not reached in HPV-positive (HPV+) ones (95% CI 27.7-NR; P = 0.008). With regard to progression-free survival, HPV- patients reached a median of 9.2 months (95% CI 7.9-11.2 months) compared to 14.3 months (95% CI 13.8-16.4 months) when HPV was positive (P = 0.001). The overall response rate for HPV+ patients yielded 82.4% compared to 47.1% in negative ones. No differences regarding programmed death-ligand 1, VEGF, HIF1, stromal fibrosis, or immunoscore were identified.

CONCLUSIONS

In patients with HPV+ lung adenocarcinoma, a significant benefit in overall response and survival outcomes is observed.

ESMO expert consensus statements on the management of EGFR mutant non-small-cell lung cancer

The European Society for Medical Oncology (ESMO) held a virtual consensus-building process on epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer in 2021. The consensus included a multidisciplinary panel of 34 leading experts in the management of lung cancer. The aim of the consensus was to develop recommendations on topics that are not covered in detail in the current ESMO Clinical Practice Guideline and where the available evidence is either limited or conflicting. The main topics identified for discussion were: (i) tissue and biomarkers analyses; (ii) early and locally advanced disease; (iii) metastatic disease and (iv) clinical trial design, patient's perspective and miscellaneous. The expert panel was divided into four working groups to address questions relating to one of the four topics outlined above. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the recommendations developed, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation.

Nivolumab versus docetaxel in previously treated advanced non-small-cell lung cancer (CheckMate 017 and CheckMate 057): 3-year update and outcomes in patients with liver metastases

Background

Long-term data with immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC) are limited. Two phase III trials demonstrated improved overall survival (OS) and a favorable safety profile with the anti-programmed death-1 antibody nivolumab versus docetaxel in patients with previously treated advanced squamous (CheckMate 017) and nonsquamous (CheckMate 057) NSCLC. We report results from ≥3 years' follow-up, including subgroup analyses of patients with liver metastases, who historically have poorer prognosis among patients with NSCLC.

Patients and methods

Patients were randomized 1 : 1 to nivolumab (3 mg/kg every 2 weeks) or docetaxel (75 mg/m2 every 3 weeks) until progression or discontinuation. The primary end point of each study was OS. Patients with baseline liver metastases were pooled across studies by treatment for subgroup analyses.

Results

After 40.3 months' minimum follow-up in CheckMate 017 and 057, nivolumab continued to show an OS benefit versus docetaxel: estimated 3-year OS rates were 17% [95% confidence interval (CI), 14% to 21%] versus 8% (95% CI, 6% to 11%) in the pooled population with squamous or nonsquamous NSCLC. Nivolumab was generally well tolerated, with no new safety concerns identified. Of 854 randomized patients across both studies, 193 had baseline liver metastases. Nivolumab resulted in improved OS compared with docetaxel in patients with liver metastases (hazard ratio, 0.68; 95% CI, 0.50-0.91), consistent with findings from the overall pooled study population (hazard ratio, 0.70; 95% CI, 0.61-0.81). Rates of treatment-related hepatic adverse events (primarily grade 1-2 liver enzyme elevations) were slightly higher in nivolumab-treated patients with liver metastases (10%) than in the overall pooled population (6%).

Conclusions

After 3 years' minimum follow-up, nivolumab continued to demonstrate an OS benefit versus docetaxel in patients with advanced NSCLC. Similarly, nivolumab demonstrated an OS benefit versus docetaxel in patients with liver metastases, and remained well tolerated.

Clinical trial registration

CheckMate 017: NCT01642004; CheckMate 057: NCT01673867.

Association of neurologic manifestations and CEA levels with the diagnosis of brain metastases in lung cancer patients

PURPOSE

Lung cancer (LC) is the most common source of brain metastases (BM). Because of the difficulty in predicting LC patients who will develop BM, we aimed to identify the clinical and serologic markers that could predict the presence of BM in LC patients.

METHODS

We analyzed a cohort of LC patients sent for neurooncological consultation for any neurologic symptom at a cancer center from June 2013 to July 2017.

INCLUSION CRITERIA

histologically confirmed LC, age ≥ 18 years and complete clinical records.

EXCLUSION CRITERIA

BM diagnosis before our consultation and absence of MRI. Oncologic history, clinical symptoms and comorbidities were analyzed.

RESULTS

From 199 patients, most (70%) had > 1 neurological symptom. The most common was headache (n = 46, 21%), followed by seizures (17%), altered mental status (16%) and focal motor weakness (13%). BM was found in 74% of the patients during follow-up. Multivariate logistic regression analysis showed factors associated with a higher frequency of BM: age < 65 years [OR 3.15, 95% CI 1.3-7.5], headache (OR 3.8, 95% CI 1.2-11.8), seizures (OR 3.2, 95% CI 1.1-9.3) and CEA ≥ 15 ng/mL (OR 5.5, 95% CI 2.2-13.8). Focal sensory deficit was associated with a lower frequency of BM (OR 0.2, 95% CI 0.06-0.92). The presence of certain clinical neurologic symptoms, together with CEA level, was associated with a higher risk of BM in LC patients.

CONCLUSION

The clinical manifestations of patients with LC should not be overlooked because some may have a substantial correlation with BM.

Robust PI/PID controllers for load disturbance based on direct synthesis

It is recognized that disturbance rejection is much more important than set-point tracking for many process control applications, leading set-point tracking to a secondary level of interest. In this paper a proposal for robust tuning of PI/PID controllers designed under the direct synthesis for load disturbance (DS-d) approach is presented. As with the IMC-like approaches, the resulting DS-d tunings are expressed in terms of a unique parameter that determines the desired speed of response of the regulatory behavior. Even at first sight it may seem quite simple, there is no known guide on how to select such parameter in order to achieve some desired robustness. As it will be shown, for some process dynamics, this selection is not as simple as it may seem. Tuning expressions for the most common types of process models are provided such that the closed loop time constant is the fastest one that allows to reach the desired robustness. Simulation examples show the application of the suggested tuning.