Purpose-The objective of this study was to assess changes in the water apparent diffusion coefficient (ADC) and in pharmacokinetic parameters obtained from the fast-exchange regime (FXR) modeling of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) during neoadjuvant chemotherapy in breast cancer.Materials and Methods-Eleven patients with locally advanced breast cancer underwent MRI examination prior to and after chemotherapy but prior to surgery. A 1.5-T scanner was used to obtain T 1 , ADC and DCE-MRI data. DCE-MRI data were analyzed by the FXR model returning estimates of K trans (volume transfer constant), ν e (extravascular extracellular volume fraction) and τs i (average intracellular water lifetime). Histogram and correlation analyses assessed parameter changes posttreatment.Results-Significant ( P <.05) changes or trends towards significance ( P <.10) were seen in all parameters except τ i , although there was qualitative reduction in τ i values post-treatment. In particular, there was reduction ( P <.035) in voxels with K trans values in the range 0.2-0.5 min -1 and a decrease ( P <.05) in voxels with ADC values in the range 0.99×10 -3 to 1.35×10 -3 mm 2 /s. ADC and ν e were negatively correlated (r = -.60, P <.02). Parameters sensitive to water distribution and geometry (T 1 , ν e ,τs i and ADC) correlated with a multivariable linear regression model. Conclusion-The analysis presented here is sensitive to longitudinal changes in breast tumor status; K trans and ADC are most sensitive to these changes. Relationships between parameters provide information on water distribution and geometry in the tumor environment.

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Despite advances in treatment, cancer remains the 2nd most common cause of death in the United States. Poor cure rates may result from the ability of cancer to recur and spread after initial therapies have seemingly eliminated detectable signs of disease. A growing body of evidence supports a role for cancer stem cells (CSCs) in tumor regrowth and spread after initial treatment. Thus, targeting CSCs in combination with traditional induction therapies may improve treatment outcomes and survival rates. Unfortunately, CSCs tend to be resistant to chemo- and radiation therapy, and a better understanding of the mechanisms underlying CSC resistance to treatment is necessary. This paper provides an update on evidence that supports a fundamental role for CSCs in cancer progression, summarizes potential mechanisms of CSC resistance to treatment, and discusses classes of drugs currently in preclinical or clinical testing that show promise at targeting CSCs.

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Background: The purpose of this study was to determine the prevalence and nature of internal, external, and combined lymphedema and fibrosis in patients with head and neck cancer (HNC). Materials and Methods: We obtained consent from 100 patients newly diagnosed with having cancer of the head and neck for a 4-year, prospective, longitudinal descriptive study. Recruitment began in August 23, 2010, and the study was completed in April 24, 2014. Eighty-three were evaluated at regular intervals from preradiation therapy to 18 months post-treatment. Percentage developing external, internal, or both types of lymphedema and/or fibrosis and trajectories of the severity of external, internal, or both types of lymphedema and/or fibrosis were determined. Results: Before treatment, lymphedema rates were the following: external: 62.7%, internal: 41.7%, or combined: 29.2%, and/or fibrosis: 42.2%. Ranges of lymphedema late-effect rates were even higher: external: 81.9%-90.1%, internal: 80.4%-89.4%, combined: 70.6%-80.9%, and fibrosis: 66.7%-77.4%. Approximately 75% had a late-effect trajectory characterized by moderate to severe external or internal lymphedema; *47% had moderate to severe fibrosis. Conclusion: Lymphatic and soft tissue complications of HNC occur not only post-treatment but also before treatment. They are ubiquitous throughout the first 18 months post-treatment, with greater than 90% of patients in our study experiencing some form of internal, external, or combined lymphedema, and over half of those patients developing fibrosis. Further research regarding these conditions is indicated.