31,241 research outputs found
Optimization Aspects of Carcinogenesis
Any process in which competing solutions replicate with errors and numbers of
their copies depend on their respective fitnesses is the evolutionary
optimization process. As during carcinogenesis mutated genomes replicate
according to their respective qualities, carcinogenesis obviously qualifies as
the evolutionary optimization process and conforms to common mathematical
basis. The optimization view accents statistical nature of carcinogenesis
proposing that during it the crucial role is actually played by the allocation
of trials. Optimal allocation of trials requires reliable schemas' fitnesses
estimations which necessitate appropriate, fitness landscape dependent,
statistics of population. In the spirit of the applied conceptual framework,
features which are known to decrease efficiency of any evolutionary
optimization procedure (or inhibit it completely) are anticipated as
"therapies" and reviewed. Strict adherence to the evolutionary optimization
framework leads us to some counterintuitive implications which are, however, in
agreement with recent experimental findings, such as sometimes observed more
aggressive and malignant growth of therapy surviving cancer cells
Chemotherapy-Response Monitoring of Breast Cancer Patients Using Quantitative Ultrasound-Based Intra-Tumour Heterogeneities
© 2017 The Author(s). Anti-cancer therapies including chemotherapy aim to induce tumour cell death. Cell death introduces alterations in cell morphology and tissue micro-structures that cause measurable changes in tissue echogenicity. This study investigated the effectiveness of quantitative ultrasound (QUS) parametric imaging to characterize intra-tumour heterogeneity and monitor the pathological response of breast cancer to chemotherapy in a large cohort of patients (n = 100). Results demonstrated that QUS imaging can non-invasively monitor pathological response and outcome of breast cancer patients to chemotherapy early following treatment initiation. Specifically, QUS biomarkers quantifying spatial heterogeneities in size, concentration and spacing of acoustic scatterers could predict treatment responses of patients with cross-validated accuracies of 82 ± 0.7%, 86 ± 0.7% and 85 ± 0.9% and areas under the receiver operating characteristic (ROC) curve of 0.75 ± 0.1, 0.80 ± 0.1 and 0.89 ± 0.1 at 1, 4 and 8 weeks after the start of treatment, respectively. The patients classified as responders and non-responders using QUS biomarkers demonstrated significantly different survivals, in good agreement with clinical and pathological endpoints. The results form a basis for using early predictive information on survival-linked patient response to facilitate adapting standard anti-cancer treatments on an individual patient basis
Surgical treatment of stage IV colorectal cancer with synchronous liver metastases : a systematic review and network meta-analysis
Background: The ideal treatment approach for colorectal cancer (CRC) with synchronous liver metastases (SCRLM) remains debated. We performed a network meta-analysis (NMA) comparing the 'bowel-first' approach (BFA), simultaneous resection (SIM), and the 'liver-first' approach (LFA).
Methods: A systematic search of comparative studies in CRC with SCRLM was undertaken using the Embase, PubMed, Web of Science, and CENTRAL databases. Outcome measures included postoperative complications, 30- and 90-day mortality, chemotherapy use, treatment completion rate, 3- and 5-year recurrence-free survival, and 3- and 5-year overall survival (OS). Pairwise and network meta-analysis were performed to compare strategies. Heterogeneity was assessed using the Higgins I-2 statistic.
Results: One prospective and 43 retrospective studies reporting on 10 848 patients were included. Patients undergoing the LFA were more likely to have rectal primaries and a higher metastatic load. The SIM approach resulted in a higher risk of major morbidity and 30-day mortality. Compared to the BFA, the LFA more frequently resulted in failure to complete treatment as planned (34% versus 6%). Pairwise and network meta-analysis showed a similar 5-year OS between LFA and BFA and a more favorable 5-year OS after SIM compared to LFA (odds ratio 0.25-0.90, p = 0.02, I-2 = 0%), but not compared to BFA.
Conclusion: Despite a higher tumor load in LFA compared to BFA patients, survival was similar. A lower rate of treatment completion was observed with LFA. Uncertainty remains substantial due to imprecise estimates of treatment effects. In the absence of prospective trials, treatment of stage IV CRC patients should be individually tailored. (C) 2020 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved
Initial experience of dedicated breast PET imaging of ER+ breast cancers using [F-18]fluoroestradiol.
Dedicated breast positron emission tomography (dbPET) is an emerging technology with high sensitivity and spatial resolution that enables detection of sub-centimeter lesions and depiction of intratumoral heterogeneity. In this study, we report our initial experience with dbPET using [F-18]fluoroestradiol (FES) in assessing ER+ primary breast cancers. Six patients with >90% ER+ and HER2- breast cancers were imaged with dbPET and breast MRI. Two patients had ILC, three had IDC, and one had an unknown primary tumor. One ILC patient was treated with letrozole, and another patient with IDC was treated with neoadjuvant chemotherapy without endocrine treatment. In this small cohort, we observed FES uptake in ER+ primary breast tumors with specificity to ER demonstrated in a case with tamoxifen blockade. FES uptake in ILC had a diffused pattern compared to the distinct circumscribed pattern in IDC. In evaluating treatment response, the reduction of SUVmax was observed with residual disease in an ILC patient treated with letrozole, and an IDC patient treated with chemotherapy. Future study is critical to understand the change in FES SUVmax after endocrine therapy and to consider other tracer uptake metrics with SUVmax to describe ER-rich breast cancer. Limitations include variations of FES uptake in different ER+ breast cancer diseases and exclusion of posterior tissues and axillary regions. However, FES-dbPET has a high potential for clinical utility, especially in measuring response to neoadjuvant endocrine treatment. Further development to improve the field of view and studies with a larger cohort of ER+ breast cancer patients are warranted
Addressing current challenges in cancer immunotherapy with mathematical and computational modeling
The goal of cancer immunotherapy is to boost a patient's immune response to a
tumor. Yet, the design of an effective immunotherapy is complicated by various
factors, including a potentially immunosuppressive tumor microenvironment,
immune-modulating effects of conventional treatments, and therapy-related
toxicities. These complexities can be incorporated into mathematical and
computational models of cancer immunotherapy that can then be used to aid in
rational therapy design. In this review, we survey modeling approaches under
the umbrella of the major challenges facing immunotherapy development, which
encompass tumor classification, optimal treatment scheduling, and combination
therapy design. Although overlapping, each challenge has presented unique
opportunities for modelers to make contributions using analytical and numerical
analysis of model outcomes, as well as optimization algorithms. We discuss
several examples of models that have grown in complexity as more biological
information has become available, showcasing how model development is a dynamic
process interlinked with the rapid advances in tumor-immune biology. We
conclude the review with recommendations for modelers both with respect to
methodology and biological direction that might help keep modelers at the
forefront of cancer immunotherapy development.Comment: Accepted for publication in the Journal of the Royal Society
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