Cancer control : journal of the Moffitt Cancer Center
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Comparative Study
Immortal Time Bias in Observational Studies of Time-to-Event Outcomes: Assessing Effects of Postmastectomy Radiation Therapy Using the National Cancer Database.
The objectives of this study are to illustrate the effects of immortal time bias (ITB) using an oncology outcomes database and quantify through simulations the magnitude and direction of ITB when different analytical techniques are used. A cohort of 11 626 women who received neoadjuvant chemotherapy and underwent mastectomy with pathologically positive lymph nodes were accrued from the National Cancer Database (2004-2008). Standard Cox regression, time-dependent (TD), and landmark models were used to compare overall survival in patients who did or did not receive postmastectomy radiation therapy (PMRT). ⋯ Estimates of TD models were closest to the true treatment effect. Landmark model results were highly dependent on landmark timing. Appropriate statistical approaches that account for ITB are critical to minimize bias when examining relationships between receipt of PMRT and survival.
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The number of patients with cancer being admitted to intensive care units (ICUs) is increasing worldwide, and these patients are vulnerable to infection. This study aimed to address the long-term impact of positive cultures during admission on 1-year mortality among patients with cancer who received perioperative intensive care. This retrospective cohort study enrolled adult patients with cancer who were admitted to ICUs and received surgery during 2011 to 2016 at a tertiary hospital in central Taiwan. ⋯ Multivariable Cox proportional hazards regression analysis found that positive cultures of blood, the respiratory tract, the urinary tract, or the skin and soft tissue (hazard ratio: 1.621; 95% confidence interval: 1.087-2.419) were significantly associated with 62.1% increased hazards of death within 1 year after the ICU admission. A positive culture during admission was associated with a worsened long-term survival among patients with cancer who received perioperative intensive care. Further studies are needed to confirm this association.
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The unique radiobiological properties of protons have been understood for many years. In addition, many of the clinical benefits of radiotherapy were first noted in tumors involving the skull base. More public attention has been given to proton beam therapy due to the increasing number of centers now in operation or in the planning stages for offering this treatment option. ⋯ Use of proton beam therapy may be beneficial in select patients. Surgical and medical oncologists should have a general understanding of such cases to facilitate their appropriate referral.
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Hematological biomarkers of inflammation such as the neutrophil-to-lymphocytic rate have been reported as predictors of survival in a variety of cancers. The aim of the present study was to investigate the prognostic value of the perioperative platelet-to-lymphocyte ratio in patients with non-small-cell lung cancer (NSCLC) and to elucidate the effects of the perioperative use of nonsteroidal anti-inflammatory drugs (NSAIDs) on tumor recurrence and survival in patients undergoing surgical resection for NSCLC. ⋯ A higher preoperative inflammatory status is associated with decreased rates of RFS and OS in patients with NSCLC undergoing curative surgery. Perioperative use of NSAIDs was not found to be an independent predictor of survival.
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The treatment of oligometastatic disease has become common as imaging techniques have advanced and the management of systemic disease has improved. Use of highly targeted, hypofractionated regimens of stereotactic body radiotherapy (SBRT) is now a primary management option for patients with oligometastatic disease. ⋯ SBRT offers an excellent management option for patients with oligometastases. However, additional research is still needed to optimize dose and fractionation schedules.