Recent Publications by CFE Educators

BACKGROUND

Evidence from the Nurses' Health Study II (NHSII) suggests that red meat consumption is associated with increased breast cancer risk in premenopausal women. Iron may be responsible by contributing to oxidative stress or effects on immune function.

METHODS

We conducted a case-control study nested within the NHSII, examining prediagnostic plasma ferritin (n = 795 cases, 795 controls), 15 hemochromatosis gene (HFE) single-nucleotide polymorphisms (SNP; n = 765 cases, 1,368 controls), and breast cancer risk. Cases were diagnosed after providing blood samples between 1996 and 1999. ORs and 95% confidence intervals (CI) were calculated for ferritin levels by conditional logistic regression and for HFE SNPs by unconditional logistic regression.

RESULTS

We did not observe a significant association between ferritin levels and breast cancer (top vs. bottom quartile multivariate OR: 1.05; 95% CI, 0.77-1.45; PTrend = 0.77). Results did not change when restricted to women who were premenopausal at blood draw, and were similar when cases were examined by hormone receptor status, and menopausal status at diagnosis. No HFE SNPs were significantly associated with breast cancer in a log-additive manner. Among controls, ferritin levels were nominally associated with SNPs rs9366637 (PTrend = 0.04), rs6918586 (PTrend = 0.06), and rs13161 (PTrend = 0.07), but results did not remain significant after adjusting for multiple testing.

CONCLUSIONS

Ferritin levels and HFE SNPs were not associated with breast cancer risk in this population.

IMPACT

Components of red meat other than iron are likely responsible for its positive association with breast cancer in premenopausal women.

We conducted a retrospective cohort study assessing the association between diabetes mellitus (DM) and immune recovery in HIV-infected adults. Immune reconstitution after initiating antiretroviral therapy was more rapid in DM patients (120.4 cells/year) compared to non-DM patients (94.2 cells/year, p0.023). Metformin use was associated with improved CD4 recovery (p=0.034).

The incidence of esophageal cancer has been increasing while the prognosis remains very poor. Endoscopic submucosal dissection (ESD) was developed in Japan for en bloc resection of early gastric cancer with excellent results. The use of ESD in early squamous cell cancer (SCC) of the esophagus in Japan has been increasing with long-term results comparable to those in early gastric cancer. The use of ESD in Barrett's neoplasia in western countries has been challenged by the low complete resection rates and the risk of metachronous lesions from surrounding non-dysplastic Barrett's epithelium. Efforts to combine ESD with other treatment modalities such as radiofrequency ablation in Barrett's neoplasia and chemoradiation in SCC appear to be promising. The use of steroid therapy (local or systemic) has been demonstrated to prevent post-ESD stenosis, which is the most common complication after esophageal ESD.

OBJECTIVE

To develop and validate a reference image module aimed at calibration of readers using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) to assess radiographic progression in spondyloarthritis.

METHODS

Our working group comprised 6 rheumatologists and 3 musculoskeletal radiologists. The following developmental steps were conducted: (1) review of the literature to identify aspects of the mSASSS requiring methodologic clarity; (2) independent assessment of baseline and 2-year radiographs from 25 patients using the mSASSS (pilot exercise); (3) development of a training module (the Spondyloarthritis Radiography [SPAR] module) that clarifies definitions, rules, and scoring methodology and a set of reference radiographic images; (4) scoring exercise 1 by 6 readers on 39 patients, where baseline and 2-year radiographs were scored blinded to time point; and (5) revision of the SPAR module followed by scoring exercise 2 conducted by the same 6 readers on 35 patients. Reliability of status and 2-year change scores was assessed by the intraclass correlation coefficient (ICC) method.

RESULTS

ICCs for change scores for the radiologist reader pair improved from 0.46 to 0.62 after minimal calibration with the SPAR module. Recalibration from exercise 1 to exercise 2 with the SPAR module led to substantial improvement in interreader reliability for change in mSASSS score from ICC 0.44 (range 0.31-0.62) to ICC 0.62 (range 0.34-0.84). Simultaneous assessment of anteroposterior and lateral lumbar radiographs did not enhance reliability or detection of progression.

CONCLUSION

Calibration according to the SPAR module led to improved reliability in the scoring of the mSASSS, even for expert readers.

The longitudinal integrated clerkship is a model of clinical education driven by tenets of social cognitive theory, situated learning, and workplace learning theories, and built on a foundation of continuity between students, patients, clinicians, and a system of care. Principles and goals of this type of clerkship are aligned with primary care principles, including patient-centered care and systems-based practice. Academic medical centers can partner with community health systems around a longitudinal integrated clerkship to provide mutual benefits for both organizations, creating a sustainable model of clinical training that addresses medical education and community health needs. A successful one-year longitudinal integrated clerkship was created in partnership between an academic medical center and an integrated community health system. Compared with traditional clerkship students, students in this clerkship had better scores on Clinical Performance Examinations, internal medicine examinations, and high perceptions of direct observation of clinical skills.Advantages for the academic medical center include mitigating the resources required to run a longitudinal integrated clerkship while providing primary care training and addressing core competencies such as systems-based practice, practice-based learning, and interprofessional care. Advantages for the community health system include faculty development, academic appointments, professional satisfaction, and recruitment.Success factors include continued support and investment from both organizations' leadership, high-quality faculty development, incentives for community-based physician educators, and emphasis on the mutually beneficial relationship for both organizations. Development of a longitudinal integrated clerkship in a community health system can serve as a model for developing and expanding these clerkship options for academic medical centers.

PURPOSE/OBJECTIVE

Dose calculation in treatment planning must account for tissue heterogeneity, especially for tumors within low-density lung tissues. While Monte Carlo (MC) calculation methods are the most accurate, Ray Tracing (RT) methods are also commonly employed. We evaluated dose calculation differences between the RT and MC algorithms in central and peripheral lung tumors treated with CyberKnife SBRT to determine which planning parameters may predict dose differences. We also examined clinical outcomes of local-regional control (LRC) and long-term treatment-related toxicity as a function of calculation method.

MATERIALS/METHODS

A retrospective series of 70 patient plans (19 central and 51 peripheral lung lesions) treated between 2009 and 2011 were analyzed. Among those, 33 were primary lung cancer and 37 were metastatic lesions. Thirty-three treatment plans were developed with the RT method, and 37 plans used MC. Groups were recalculated with the reciprocal method for dose comparison. Parameters examined to quantify dose differences between the two algorithms included: dose delivered to 95% (D95) of the planning target volume (PTV), dose heterogeneity, and dose to organs at risk (OAR). Dose differences were analyzed as a function of target volume, distance to soft tissue, and fraction of target overlap with soft tissue. For the subset of primary lung tumors, LRC was assessed radiographically at a median follow-up of 19 months (mo) (range, 2 to 41 mo).

RESULTS

Compared to MC, the RT algorithm largely overestimated the dose delivered to the PTV. The dose difference between RT and MC plans correlated to the volume of PTV overlapping with soft tissue; the smaller the overlap volume, the larger the dose differences between RT and MC. Compared to MC, the RT algorithm overestimated the dose delivered to 10% of the ipsilateral lung (D10%). Evidence of local progression was noted in only one of the 31 patients treated for primary lung malignancy. DFS and OS were not significantly different between RT and MC plans.

CONCLUSION

There is a significant range of discordance between MC and RT dose calculations for SBRT treated peripheral lung tumors. While variation is correlated to target size and proximity to soft tissue, no single parameter can reliably predict dose differences. Ultimately, local control and long-term toxicity appear independent of the dose calculation method.