240 resultados para 1112 Oncology and Carcinogenesis


Relevância:

30.00% 30.00%

Publicador:

Resumo:

PURPOSE Desmoid tumors are mesenchymal fibroblastic/myofibroblastic proliferations with locoregional aggressiveness and high ability to recur after initial treatment. We present the results of the largest series of sporadic desmoid tumors ever published to determine the prognostic factors of these rare tumors. PATIENTS AND METHODS Four hundred twenty-six patients with a desmoid tumor at diagnosis were included, and the following parameters were studied: age, sex, delay between first symptoms and diagnosis, tumor size, tumor site, previous history of surgery or trauma in the area of the primary tumor, surgical margins, and context of abdominal wall desmoids in women of child-bearing age during or shortly after pregnancy. We performed univariate and multivariate analysis for progression-free survival (PFS). Results In univariate analysis, age, tumor size, tumor site, and surgical margins (R2 v R0/R1) had a significant impact on PFS. PFS curves were not significantly different for microscopic assessment of surgical resection quality (R0 v R1). In multivariate analysis, age, tumor size, and tumor site had independent values. Three prognostic groups for PFS were defined on the basis of the number of independent unfavorable prognostic factors (0 or 1, 2, and 3). CONCLUSION This study clearly demonstrates that there are different prognostic subgroups of desmoid tumors that could benefit from different therapeutic strategies, including a wait-and-see policy.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

PURPOSE: To analyze the clinical characteristics, prognosis, and treatment outcome of pelvic cryptorchid seminoma (PCS), and to determine whether whole abdominal-pelvic irradiation for Stage I disease is necessary. METHODS AND MATERIALS: From 1958 to 1991, 60 patients with PCS were treated at the Cancer Hospital of Chinese Academy of Medical Sciences, Beijing. They presented with a lower abdominal mass and showed a predominance for the right side. A high proportion of patients with PCS [26 of 60 (43%)] had metastatic disease, compared to 20% of those with scrotal seminoma, and there was a tendency toward a higher frequency of pelvic nodal metastases. There were 34 Stage I, 6 Stage IIA, 11 Stage IIB, 5 Stage III, and 4 Stage IV patients. Of these 60 patients, 56 underwent laparotomy with or without cryptorchiectomy (37 radical orchiectomy, 7 partial orchiectomy, and 12 biopsy of the primary or cervical node), and 4 cervical node biopsy only. All patients were further treated with radiotherapy, chemotherapy, or a combination of both. Patients with Stage I and II disease received radiotherapy, whereas patients with Stage III and IV were treated with chemotherapy. RESULTS: The overall and disease-free survivals at 5 and 10 years were 92% and 87%, and 88% and 84%, respectively. The 5- and 10-year survivals were 100% for Stage I, 94% and 87% for Stage II, and 56% and 42% for Stage III/IV, respectively (p < 0.05). Volume of irradiation, i.e., whole abdominal-pelvic radiotherapy (10 patients), versus hockey-stick encompassing paraaortic, ipsilateral iliac nodes and the primary tumor or tumor bed (17) did not influence outcome in Stage I patients. Five patients relapsed within 2-12 years after treatment, and four of these patients were successfully salvaged. Four patients developed a second malignant tumor and died. CONCLUSION: Stage I and II PCS can be adequately controlled by radiotherapy regardless of the surgical procedure. Whole abdominal-pelvic irradiation for Stage I and IIA disease is not required, and fields can be limited to the paraaortic, ipsilateral iliac nodes and primary tumor or tumor bed. We recommend platinum-based chemotherapy for Stage IIB-IV PCS.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Malignant gliomas, notably glioblastoma are among the most vascularized and angiogenic cancers, and microvascular proliferation is one of the hallmarks for the diagnosis of glioblastoma. Angiogenesis is regulated by a balance of pro- and antiangiogenic signals; overexpression of VEGF and activation of its receptors, most notable VEGFR-2 and -3, results in endothelial cell proliferation and leaky vasculature. Heterogeneous perfusion and oxygenation, peritumoral edema and increased interstitial pressure are the consequence. Both endothelial and tumour cells are strongly dependent on integrin-mediated adhesion for cell proliferation, survival, migration and invasion.Strategies aiming at inhibition of cell signaling and angiogenesis, including integrin inhibitors, have been clinically investigated in gliomas over the last 5 years. Radiological responses, a decreased requirement of corticosteroids and temporary improvement in performance status have repeatedly been observed. Toxicity was mild-moderate and manageable, notably there was no evidence for a substantially increased incidence of intracranial bleeding. However definitive comparative (randomized !) investigation has failed to demonstrate improved outcome with singleagent inhibition of EGFR, or PDGFR or VEGF/VEGFRs pathways in recurrent glioblastoma. Definitive phase III trials combining the anti- VEGF monoclonal antibody bevacizumab, or cilengitide, a peptidic integrininhibitor, together with temozolomide and radiotherapy are ongoing (accrual completed).The integration of anti-angiogenic strategies in the management of malignant glioma also poses entirely new challenges in patient management: 1) Many agents are known for increasing the risk of thrombosis, embolism and intracranial bleeding. 2) Evaluation of treatment efficacy is difficult and new biomarkers of activity, including functional, metabolic or molecular imaging techniques are urgently needed. Normalization of vasculature leads to decrease in contrast enhancement without necessarily reflecting tumour shrinkage. Tumour heterogeneity, putative prognostic or predictive factors require early controlled trials, novel trial designs and endpoints.3) Activation of alternate pathways and tumour escape mechanisms may require combination of multiple agents, which is often not feasible due to regulatory restrictions and potential complex toxicities. Emerging clinical and experimental evidence suggests that anti-angiogenic drugs might need to be combined with drugs targeting tumour adaptive mechanisms in addition to cytotoxic chemotherapy and irradiation for a maximal antitumour effect.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: Pancreatic carcinoma remains a treatment-refractory cancer with a poor prognosis. Here, we compared anti-epidermal growth factor receptor (EGFR) and anti-HER2 monoclonal antibodies (2mAbs) injections with standard gemcitabine treatment on human pancreatic carcinoma xenografts. MATERIALS AND METHODS: Nude mice, bearing human pancreatic carcinoma xenografts, were treated with either combined anti-EGFR (cetuximab) and anti-HER2 (trastuzumab) or gemcitabine, and tumor growth was observed. RESULTS AND CONCLUSION: In first-line therapy, mice survival was significantly longer in the 2mAbs group compared with gemcitabine (P < 0.0001 for BxPC-3, P = 0.0679 for MiaPaCa-2 and P = 0.0019 for Capan-1) and with controls (P < 0.0001). In second-line therapy, tumor regressions were observed after replacing gemcitabine by 2mAbs treatment, resulting in significantly longer animal survival compared with mice receiving continuous gemcitabine injections (P = 0.008 for BxPC-3, P = 0.05 for MiaPaCa-2 and P < 0.001 for Capan-1). Therapeutic benefit of 2mAbs was observed despite K-Ras mutation. Interestingly, concerning the mechanism of action, coinjection of F(ab')(2) fragments from 2mAbs induced significant tumor growth inhibition, compared with controls (P = 0.001), indicating that the 2mAbs had an Fc fragment-independent direct action on tumor cells. This preclinical study demonstrated a significant improvement of survival and tumor regression in mice treated with anti-EGFR/anti-HER2 2mAbs in first- and second-line treatments, compared with gemcitabine, independently of the K-Ras status.

Relevância:

30.00% 30.00%

Publicador:

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective. Mandibular osteoradionecrosis (ORN) is a serious complication of radiotherapy (RT) in head and neck cancer patients. The aim of this study was to analyze the incidence of and risk factors for mandibular ORN in squamous cell carcinoma (SCC) of the oral cavity and oropharynx.Study Design. Case series with chart review.Setting. University tertiary care center for head and neck oncology.Subjects and Methods. Seventy-three patients treated for stage I to IV SCC of the oral cavity and oropharynx between 2000 and 2007, with a minimum follow-up of 2 years, were included in the study. Treatment modalities included both RT with curative intent and adjuvant RT following tumor surgery. The log-rank test and Cox model were used for univariate and multivariate analyses.Results. The incidence of mandibular ORN was 40% at 5 years. Using univariate analysis, the following risk factors were identified: oral cavity tumors (P < .01), bone invasion (P < .02), any surgery prior to RT (P < .04), and bone surgery (P < .0001). By multivariate analysis, mandibular surgery proved to be the most important risk factor and the only one reaching statistical significance (P < .0002).Conclusion. Mandibular ORN is a frequent long-term complication of RT for oral cavity and oropharynx cancers. Mandibular surgery before irradiation is the only independent risk factor. These aspects must be considered when planning treatment for these tumors.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background: To report a single-center experience in 19 patients (pts) with anal canal cancer treated with helical tomotherapy (HT) and concurrent chemotherapy, and compare the dosimetric results with fixed-field intensitymodulated radiotherapy (IMRT) and 3D conformal radiotherapy (3D RT). Materials and Methods: Between 2007 and 2008, 19 consecutive pts were treated with HT and concurrent CT for anal canal cancer. Median age was 59 years (range, 38−83), and female/male ratio was 14/5. The majority of the pts had T2 or T3 tumours (68.4%), and 52.6% had positive lymph nodes. In all 19 pts, pelvic and inguinal nodes, and tumour irradiation was given using HT upto a median dose of 36 Gy (1.8 Gy/fr) followed by a 1-week gap. A boost dose of 23.4 Gy (1.8 Gy/fr) was delivered to the tumour and involved nodes using 3DRT (n = 12), HT (n = 6), or IMRT (n = 1). Simultaneous integrated boost was used in none of the pts. All but one patient with a T1N0 tumour received concomitant mitomycin/5- fluorouracil (n = 12) or mitomycin/capecitabin (n = 7) CT. Toxicity was scored according to the Common Terminology Criteria for Adverse Events (NCICTCAE v3.0). HT plans and treatments were generated using Tomotherapy, Inc., software and hardware; and 3D or IMRT boost plans with the CMS treatment planning system (TPS), using 6−18 MV photons from a Siemens Primus accelerator. For dosimetric comparison, computed tomography data sets of 10 pts were imported into the TPS, and 3D and 5-field step-andshoot IMRT plans were generated for each case. Plans were optimized with the aim of assessing organs at risk (OAR) and healthy-tissue sparing while enforcing highly conformal target coverage, and evaluated by dose-volume histograms (DVH) of planning target volumes (PTV) and OAR. Results: With a median follow-up of 13 months (range, 3−18), all pts are alive and well; except one patient developing local recurrence at 12 months. No patient developed grade 3 or more acute toxicity. No unplanned treatment interruption was necessary because of toxicity. With 360-degree-of-freedom beam projection, HT showed an advantage over 3D or IMRT plans in terms of dose conformity around the PTV, and dose gradients were steeper outside the PTV, resulting in reduced doses to OARs. Using HT, acute toxicity was acceptable, and seemed to be better than historical standards. Conclusion: We conclude that HT combined with concurrent chemotherapy for anal canal cancer is effective and tolerable. Compared to 3DRT or 5-field IMRT, there is better conformity around the PTV, and OAR sparing.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

PURPOSE OF REVIEW: To review and summarize current knowledge on gender differences and sex steroid hormones in nonmuscle invasive bladder cancer. RECENT FINDINGS: Beyond the proven role of gender as a risk factor for the development of bladder cancer, recent studies indicate that women present with more advanced bladder cancer tumor stages than men, which may be due to differences in both bladder cancer care and biology. In addition, female gender has been identified as an independent prognostic factor for both recurrence and progression and may be associated with worse response to Bacillus Calmette-Guérin instillation therapy. Overall, sex steroid hormones and their receptors impact bladder carcinogenesis, recurrence and progression. Basic and transitional research evidence suggests that estrogens may initially protect against bladder cancer development, but later promote bladder cancer progression. Androgens, in contrast, seem to initiate and drive bladder cancer with its receptor playing a central role. Promising novel research shows a potential role of sex steroid hormones as therapeutic targets. SUMMARY: Whereas men are more likely to develop bladder cancer, women present generally with more advanced disease and have worse oncologic outcomes even after adjusting for tumor stage. Sex steroid hormones and their receptors play an active role in bladder cancer development and progression and represent attractive therapeutic targets for gender-specific care.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Oncogenesis is closely linked to abnormalities in cell differentiation. Notch signaling provides an important form of intercellular communication involved in cell fate determination, stem cell potential and differentiation. Here we review the role of this pathway in the integrated growth/differentiation control of the keratinocyte cell type, and the maintenance of normal skin homeostasis. In parallel with the pro-differentiation function of Notch1 in keratinocytes, we discuss recent evidence pointing to a tumor suppressor function of this gene in both mouse skin and human cervical carcinogenesis. The possibility that Notch signaling elicits signals with a duality of growth positive and negative function will be discussed.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Variability in anatomical contouring is one of the important uncertainties in radiotherapy. FALCON (Fellowship in Anatomic deLineation and CONtouring) is an educational ESTRO (European SocieTy for Radiation and Oncology) project devoted to improve interactive teaching, the homogeneity in contouring and to compare individual contours with endorsed guidelines or expert opinions. This report summarizes the experience from the first 4 years using FALCON for educational activities within ESTRO School and presents the perspectives for the future.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Despite intense efforts, the socioeconomic burden of cancer remains unacceptably high and treatment advances for many common cancers have been limited, suggesting a need for a new approach to drug development. One issue central to this lack of progress is the heterogeneity and genetic complexity of many tumours. This results in considerable variability in therapeutic response and requires knowledge of the molecular profile of the tumour to guide appropriate treatment selection for individual patients. While recent advances in the molecular characterisation of different cancer types have the potential to transform cancer treatment through precision medicine, such an approach presents a major economic challenge for drug development, since novel targeted agents may only be suitable for a small cohort of patients. Identifying the patients who would benefit from individual therapies and recruiting sufficient numbers of patients with particular cancer subtypes into clinical trials is challenging, and will require collaborative efforts from research groups and industry in order to accelerate progress. A number of molecular screening platforms have already been initiated across Europe, and it is hoped that these networks, along with future collaborations, will benefit not only patients but also society through cost reductions as a result of more efficient use of resources. This review discusses how current developments in translational oncology may be applied in clinical practice in the future, assesses current programmes for the molecular characterisation of cancer and describes possible collaborative approaches designed to maximise the benefits of translational science for patients with cancer.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Work-related stress of the oncology clinician is not only due to heavy clinical and administrative duties, but also arises when breaking bad news. However, there is important interindividual variation in stress levels during patient encounters, mainly due to the significance the situation represents for the oncologist. A reflection on his own development, his professional identity, and ways of dealing with the patient's suffering can reduce his levels of stress and distress and prevent burnout and other psychiatric disturbances. This chapter summarizes the psychological challenges the oncology clinician is facing when he announces the diagnosis of cancer, deals with the deception of relapse, discusses the transition to palliative care, copes with progression of the disease and uncertainty, and cares for the dying who is facing the unknown. Ways of refiecting on and dealing with these situations from a psychological and communicational perspective are described and illustrated by case vignettes.