11 resultados para Cancer imaging
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Breast cancer metastasis is a leading cause of death by malignancy in women worldwide. Efforts are being made to further characterize the rate-limiting steps of cancer metastasis, i.e. extravasation of circulating tumor cells and colonization of secondary organs. In this study, we investigated whether angiotensin II, a major vasoactive peptide both produced locally and released in the bloodstream, may trigger activating signals that contribute to cancer cell extravasation and metastasis. We used an experimental in vivo model of cancer metastasis in which bioluminescent breast tumor cells (D3H2LN) were injected intra-cardiacally into nude mice in order to recapitulate the late and essential steps of metastatic dissemination. Real-time intravital imaging studies revealed that angiotensin II accelerates the formation of metastatic foci at secondary sites. Pre-treatment of cancer cells with the peptide increases the number of mice with metastases, as well as the number and size of metastases per mouse. In vitro, angiotensin II contributes to each sequential step of cancer metastasis by promoting cancer cell adhesion to endothelial cells, trans-endothelial migration and tumor cell migration across extracellular matrix. At the molecular level, a total of 102 genes differentially expressed following angiotensin II pretreatment were identified by comparative DNA microarray. Angiotensin II regulates two groups of connected genes related to its precursor angiotensinogen. Among those, up-regulated MMP2/MMP9 and ICAM1 stand at the crossroad of a network of genes involved in cell adhesion, migration and invasion. Our data suggest that targeting angiotensin II production or action may represent a valuable therapeutic option to prevent metastatic progression of invasive breast tumors.
Resumo:
The aim of this study was to evaluate the prognostic implications of the sonographic appearance of prostate cancers. All patients with biopsy-proven prostate cancer between January 2003 and July 2004 (and at least 5 years of follow-up) were selected retrospectively. After exclusions, 101 patients constituted our study population and were divided into isoechoic (or nonvisible) and hypoechoic (or visible) lesion. The clinical outcomes of these two groups were compared. The outcomes for the two groups were significantly different (p < 0.01). For nonvisible lesions, 37 of the 41 patients (90.2%) had no disease relapse and 2 (4.9%) had biochemical failure. For the visible lesions, 37 of the 60 (61.6%) patients were free of recurrence, 7 (11.7%) had systemic metastases and 10 (16.7%) died of complications related to prostate cancer. Our data show that patients with nonvisible prostate cancer had significantly better outcomes than patients with visible lesions during a five-year period of evaluation. (E-mail: fmuglia@fmrp.usp.br) (c) 2012 World Federation for Ultrasound in Medicine & Biology.
Resumo:
Purpose: To estimate the metabolic activity of rectal cancers at 6 and 12 weeks after completion of chemoradiation therapy (CRT) by 2-[fluorine-18] fluoro-2-deoxy-D-glucose-labeled positron emission tomography/computed tomography ([18 FDG] PET/CT) imaging and correlate with response to CRT. Methods and Materials: Patients with cT2-4N0-2M0 distal rectal adenocarcinoma treated with long-course neoadjuvant CRT (54 Gy, 5-fluouracil-based) were prospectively studied (ClinicalTrials. org identifier NCT00254683). All patients underwent 3 PET/CT studies (at baseline and 6 and 12 weeks fromCRT completion). Clinical assessment was at 12 weeks. Maximal standard uptakevalue (SUVmax) of the primary tumor wasmeasured and recorded at eachPET/CTstudy after 1 h (early) and3 h (late) from 18 FDGinjection. Patientswith an increase in early SUVmax between 6 and 12 weeks were considered " bad" responders and the others as "good" responders. Results: Ninety-one patients were included; 46 patients (51%) were "bad" responders, whereas 45 (49%) patients were " good" responders. " Bad" responders were less likely to develop complete clinical response (6.5% vs. 37.8%, respectively; PZ. 001), less likely to develop significant histological tumor regression (complete or near-complete pathological response; 16% vs. 45%, respectively; PZ. 008) and exhibited greater final tumor dimension (4.3cmvs. 3.3cm; PZ. 03). Decrease between early (1 h) and late (3 h) SUVmax at 6-week PET/CTwas a significant predictor of " good" response (accuracy of 67%). Conclusions: Patients who developed an increase in SUVmax after 6 weeks were less likely to develop significant tumor downstaging. Early-late SUVmax variation at 6-week PET/CT may help identify these patients and allow tailored selection of CRT-surgery intervals for individual patients. (C) 2012 Elsevier Inc.
Resumo:
Purpose: Oral mucositis is a major complication of concurrent chemoradiotherapy (CRT) in head-and-neck cancer patients. Low-level laser (LLL) therapy is a promising preventive therapy. We aimed to evaluate the efficacy of LLL therapy to decrease severe oral mucositis and its effect on RT interruptions. Methods and Materials: In the present randomized, double-blind, Phase III study, patients received either gallium-aluminum-arsenide LLL therapy 2.5 J/cm(2) or placebo laser, before each radiation fraction. Eligible patients had to have been diagnosed with squamous cell carcinoma or undifferentiated carcinoma of the oral cavity, pharynx, larynx, or metastases to the neck with an unknown primary site. They were treated with adjuvant or definitive CRT, consisting of conventional RT 60-70 Gy (range, 1.8-2.0 Gy/d, 5 times/wk) and concurrent cisplatin. The primary endpoints were the oral mucositis severity in Weeks 2, 4, and 6 and the number of RT interruptions because of mucositis. The secondary endpoints included patient-reported pain scores. To detect a decrease in the incidence of Grade 3 or 4 oral mucositis from 80% to 50%, we planned to enroll 74 patients. Results: A total of 75 patients were included, and 37 patients received preventive LLL therapy. The mean delivered radiation dose was greater in the patients treated with LLL (69.4 vs. 67.9 Gy, p = .03). During CRT, the number of patients diagnosed with Grade 3 or 4 oral mucositis treated with LLL vs. placebo was 4 vs. 5 (Week 2, p = 1.0), 4 vs. 12 (Week 4, p = .08), and 8 vs. 9 (Week 6, p = 1.0), respectively. More of the patients treated with placebo had RT interruptions because of mucositis (6 vs. 0, p = .02). No difference was detected between the treatment arms in the incidence of severe pain. Conclusions: LLL therapy was not effective in reducing severe oral mucositis, although a marginal benefit could not be excluded. It reduced RT interruptions in these head-and-neck cancer patients, which might translate into improved CRT efficacy. (C) 2012 Elsevier Inc.
Resumo:
Background: Adjuvant chemoradiotherapy is part of a multimodality treatment approach in order to improve survival outcomes after surgery for gastric cancer. The aims of this study are to describe the results of gastrectomy and adjuvant chemoradiotherapy in patients treated in a single institution, and to identify prognostic factors that could determine which individuals would benefit from this treatment. Methods: This retrospective study included patients with pathologically confirmed gastric adenocarcinoma who underwent surgical treatment with curative intent in a single cancer center in Brazil, between 1998 and 2008. Among 327 patients treated in this period, 142 were selected. Exclusion criteria were distant metastatic disease (M1), T1N0 tumors, different multimodality treatments and tumors of the gastric stump. Another 10 individuals were lost to follow-up and there were 3 postoperative deaths. The role of several clinical and pathological variables as prognostic factors was determined. Results: D2-lymphadenectomy was performed in 90.8% of the patients, who had 5-year overall and disease-free survival of 58.9% and 55.7%. The interaction of N-category and N-ratio, extended resection and perineural invasion were independent prognostic factors for overall and disease-free survival. Adjuvant chemoradiotherapy was not associated with a significant improvement in survival. Patients with node-positive disease had improved survival with adjuvant chemoradiotherapy, especially when we grouped patients with N1 and N2 tumors and a higher N-ratio. These individuals had worse disease-free (30.3% vs. 48.9%) and overall survival (30.9% vs. 71.4%). Conclusion: N-category and N-ratio interaction, perineural invasion and extended resections were prognostic factors for survival in gastric cancer patients treated with D2-lymphadenectomy, but adjuvant chemoradiotherapy was not. There may be some benefit with this treatment in patients with node-positive disease and higher N-ratio.
Resumo:
The ability of nanoassisted laser desorption-ionization mass spectrometry (NALDI-MS) imaging to provide selective chemical monitoring with proper spatial distribution of lipid profiles from tumor tissues after plate imprinting has been tested. NALDI-MS imaging identified and mapped several potential lipid biomarkers in a murine model of melanoma tumor (inoculation of B16/F10 cells). It also confirmed that the in vivo treatment of tumor bearing mice with synthetic supplement containing phosphoethanolamine (PHO-S) promoted an accentuated decrease in relative abundance of the tumor biomarkers. NALDI-MS imaging is a matrix-free LDI protocol based on the selective imprinting of lipids in the NALDI plate followed by the removal of the tissue. It therefore provides good quality and selective chemical images with preservation of spatial distribution and less interference from tissue material. The test case described herein illustrates the potential of chemically selective NALDI-MS imaging for biomarker discovery.
Resumo:
OBJECTIVE. The objective of our study was to evaluate the effectiveness of MRI in the detection of possible residual lesions after radiofrequency ablation (RFA) in the treatment of breast cancer. SUBJECTS AND METHODS. We prospectively evaluated 14 patients who had undergone ultrasound-guided core biopsies diagnostic of invasive ductal carcinoma (IDC; range of diameters, 1.0-3.0 cm) and then ultrasound-guided percutaneous RFA with sentinel node biopsy as the primary treatment. Breast MRI was performed 1 week before RFA to evaluate tumor extension and again 3 weeks after RFA to verify the presence of possible residual lesions. Conventional surgical resection of the tumors was performed 1 week after RFA. The MRI findings were compared with histopathologic analyses to confirm the presence or absence of residual tumor. RESULTS. There was no residual enhancement in seven lesions on the postablation breast MRI scans. These findings were confirmed by negative histopathologic findings in the surgical specimens. The MRI scans of five patients showed small areas of irregular enhancement that corresponded to residual lesions. In the two remaining patients, we observed enhancement of almost the entire lesion, indicating that RFA had failed. CONCLUSION. Breast MRI is effective in detecting residual lesions after RFA in patients with IDC.
Resumo:
Several dosimetric methods have been proposed for estimating red marrow absorbed dose (RMAD) when radionuclide therapy is planned for differentiated thyroid cancer, although to date, there is no consensus as to whether dose calculation should be based on blood-activity concentration or not. Our purpose was to compare RMADs derived from methods that require collecting patients' blood samples versus those involving OLINDA/EXM software, thereby precluding this invasive procedure. This is a retrospective study that included 34 patients under treatment for metastatic thyroid disease. A deviation of 10 between RMADs was found, when comparing the doses from the most usual invasive dosimetric methods and those from OLINDA/EXM. No statistical difference between the methods was discovered, whereby the need for invasive procedures when calculating the dose is questioned. The use of OLINDA/EXM in clinical routine could possibly diminish data collection, thus giving rise to a simultaneous reduction in time and clinical costs, besides avoiding any kind of discomfort on the part of the patients involved.
Resumo:
Purpose: To evaluate if the Breast Imaging Reporting and Data System (BI-RADS) ultrasound descriptor of orientation can be used in magnetic resonance imaging (MRI). Materials and Methods: We conducted a retrospective study to evaluate breast mass lesions identified by MRI from 2008 to 2010 who had ultrasound (US) and histopathologic confirmation. Lesions were measured in the craniocaudal (CC), anteroposterior (AP), and transverse (T) axes and classified as having a nonparallel orientation, longest axis perpendicular to Cooper's ligaments, or in a parallel orientation when the longest axis is parallel to Cooper's ligaments. The MR image data were correlated with the US orientation according to BI-RADS and histopathological diagnosis. Results: We evaluated 71 lesions in 64 patients. On MRI, 27 lesions (38.0%) were nonparallel (8 benign and 19 malignant), and 44 lesions (62.0%) were parallel (33 benign and 11 malignant). There was significant agreement between the lesion orientation on US and MRI (kappa value = 0.901). The positive predictive values (PPV) for parallel orientation malignancy on MR and US imaging were 70.4% and 73.1%, respectively. Conclusion: A descriptor of orientation for breast lesions can be used on MRI with PPV for malignant lesions similar to US. J. Magn. Reson. Imaging 2012; 36:13831388. (C) 2012 Wiley Periodicals, Inc.
Resumo:
A mucinous tubular and spindle cell carcinoma (MTSCC) is a rare and recently described kidney neoplasm with distal nephron differentiation. It can affect patients of all ages and is more prevalent among women. In this case report, we present a 50-year-old woman who had a renal mass, which was accidently discovered during an investigation for chronic anemia. The final diagnosis of MTSCC was made after the lesion was removed and a pathology work-up was performed. The clinical, pathological and imaging findings of this rare neoplasm are described in this report.
Resumo:
A 36 year-old man after tests for assessing male infertility was diagnosed with primary infertility, bilateral cryptorchidism, non-obstructive azoospermia and discontinuous splenogonadal fusion. Carcinoma in situ was found in his left testicle, which was intra-abdominal and associated with splenogonadal fusion. To our knowledge, this is the fourth case of splenogonadal fusion associated with testicular cancer reported. One should always bear in mind the possibility of this association for the left cryptorchid testicle.