Acute radiotherapy-associated oral pain may promote tumor growth at distant sites.

Introduction: Patients developing acute radiotherapy induced dermatitis or oral mucositis commonly experience pain. When severe, this radiotherapy-associated pain (RAP) can necessitate treatment breaks; unfortunately, in a variety of cancers, prolongation of the radiotherapy course has been associated with early cancer relapse and/or death. This is often attributed to accelerated repopulation, but it is unknown whether pain or pain signaling constituents might alter tumor behavior and hasten metastatic disease progression. We studied this by testing the hypothesis that severe acute RAP at one site can hasten tumor growth at a distant site. Methods: Mice underwent single fraction tongue irradiation (27 Gy, or 0 Gy "sham" control) to induce severe glossitis. At the time of maximal oral RAP, one of three luciferase-transfected tumor cell lines were injected via tail vein (4T1, B16F10, MOC2; each paired to their syngeneic host: BALB/c or C57BL/6); tumor burden was assessed via in vivo transthoracic bioluminescence imaging and ex vivo pulmonary nodule quantification. Survival was compared using Kaplan-Meier statistics. Results: Tongue irradiation and resultant RAP promoted lung tumor growth of 4T1-Luc2 cells in BALB/c mice. This effect was not a result of off-target radiation, nor an artefact of environmental stress caused by standard (subthermoneutral) housing temperatures. RAP did not affect the growth of B16F10-Luc2 cells, however, C57BL/6 mice undergoing tail vein injection of MOC2-Luc2 cells at the time of maximal RAP experienced early lung tumor-attributable death. Lung tumor growth was normalized when RAP was reduced by treatment with resiniferatoxin (300 µg/kg, subcutaneously, once). Discussion: This research points towards radiation-induced activation of capsaicin-responsive (TRPV1) neurons as the cause for accelerated growth of tumors at distant (unirradiated) sites.

Probable paraneoplastic leukocytosis in a dog with a gastrointestinal stromal tumor.

A 9-year-old female spayed Boston Terrier presented for diagnostic investigation of lethargy, poor appetite, weight loss, and a marked leukocytosis. Significant muscle wasting and a palpable abdominal mass were present on physical examination. Abdominal imaging revealed the mass to be of small intestinal origin; consequently, an intestinal resection and anastomosis were performed without complication. The histopathologic diagnosis was a gastrointestinal stromal tumor, verified by immunohistochemical positivity to CD117 (KIT). Two weeks after discharge, the leukocytosis had resolved. Though the exact molecular mediator of the severe leukocytosis was undetermined, resolution following tumor removal suggests a paraneoplastic cause. To the authors' knowledge, this is the first reported case of probable paraneoplastic leukocytosis secondary to a gastrointestinal stromal tumor in the dog. Gastrointestinal tract imaging should be performed when this uncommon hematologic abnormality is present.

Comparison of a stationary digital breast tomosynthesis system to magnified 2D mammography using breast tissue specimens.

RATIONAL AND OBJECTIVES: The objective of this study was to compare the stationary digital breast tomosynthesis (s-DBT) system to a conventional mammography system in a study of breast specimens. Radiologist evaluation of image quality was assessed in a reader study. This study represents the first human tissue imaging with the novel carbon nanotube-based s-DBT device. MATERIALS AND METHODS: Thirty-nine patients, with known breast lesions (Breast Imaging Reporting and Data System 4 or 5) by conventional mammography and scheduled for needle localization biopsy, were recruited under an institutional review board-approved protocol. Specimen images were obtained using a two-dimensional (2D) mammography system with a ×1.8 magnification factor and an s-DBT system without a high magnification factor. A reader study was performed with four breast fellowship-trained radiologists over two separate sessions. Malignancy scores were recorded for both masses and microcalcifications (MCs). Reader preference between the two modalities for MCs, masses, and surgical margins was recorded. RESULTS: The s-DBT system was found to be comparable to magnified 2D mammography for malignancy diagnosis. Readers preferred magnified 2D mammography for MC visualization (P < .05). However, readers trended toward a preference for s-DBT with respect to masses and surgical margin assessment. CONCLUSIONS: Here, we report on the first human data acquired using a stationary digital breast tomosynthesis system. The novel s-DBT system was found to be comparable to magnified 2D mammography imaging for malignancy diagnosis. Given the trend of preference for s-DBT over 2D mammography for both mass visibility and margin assessment, s-DBT could be a viable alternative to magnified 2D mammography for imaging breast specimens.