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Introduction

Concurrent partnerships (CPs) have been suggested as a risk factor for transmitting HIV, but their impact on the epidemic depends upon how prevalent they are in populations, the average number of CPs an individual has and the length of time they overlap. However, estimates of prevalence of CPs in Southern Africa vary widely, and the duration of overlap in these relationships is poorly documented. We aim to characterize concurrency in a more accurate and complete manner, using data from three disadvantaged communities of Cape Town, South Africa.

Methods

We conducted a sexual behaviour survey (n=878) from June 2011 to February 2012 in Cape Town, using Audio Computer-Assisted Self-Interviewing to collect sexual relationship histories on partners in the past year. Using the beginning and end dates for the partnerships, we calculated the point prevalence, the cumulative prevalence and the incidence rate of CPs, as well as the duration of overlap for relationships begun in the previous year. Linear and binomial regression models were used to quantify race (black vs. coloured) and sex differences in the duration of overlap and relative risk of having CPs in the past year.

Results

The overall point prevalence of CPs six months before the survey was 8.4%: 13.4% for black men, 1.9% for coloured men, 7.8% black women and 5.6% for coloured women. The median duration of overlap in CPs was 7.5 weeks. Women had less risk of CPs in the previous year than men (RR 0.43; 95% CI: 0.32–0.57) and black participants were more at risk than coloured participants (RR 1.86; 95% CI: 1.17–2.97).

Conclusions

Our results indicate that in this population the prevalence of CPs is relatively high and is characterized by overlaps of long duration, implying there may be opportunities for HIV to be transmitted to concurrent partners.  相似文献   
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The purpose of this retrospective study was to assess the efficacy of salvage radiation therapy (RT) or chemoradiation therapy (CRT) for locoregional recurrence (LR) of esophageal cancer after curative surgery. Forty‐two patients who received salvage RT or CRT for LR of esophageal cancer after curative surgery between November 2000 and May 2012 were reviewed. The intended RT regimen was 60 Gy in 30 fractions combined with concurrent platinum‐based chemotherapy. Median follow‐up periods were 17.9 months for all evaluable patients and 28.2 months for patients still alive (19 patients) at analysis time. The 1‐, 2‐, and 3‐year survival rates were 81.2 ± 6.4%, 51.3 ± 8.6%, and 41.1 ± 8.7%, respectively, with a median survival time of 24.3 ± 4.1 months. Out of 41 evaluable patients, 16 patients (39%) were alive beyond 2 years from salvage therapy. However, univariate analyses for overall survival showed no significant prognostic factor. Grade 3 or higher leukocytopenia was observed in 46% of the patients. Salvage RT or CRT for LR after surgery for esophageal cancer was safe and effective. These therapies may offer long‐term survival to some patients. RT or CRT should be considered for LR.  相似文献   
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The optimal treatment for patients with local esophageal cancer (cT2N0 disease) has not yet been defined. We sought to determine whether neoadjuvant chemoradiotherapy (CRT) can improve prognosis compared with direct esophagectomy in this patient group. Between 1994 and 2005, patients with cT2N0 esophageal squamous cell carcinoma who underwent either neoadjuvant CRT or surgery as first-line treatment were retrospectively reviewed. We collected information on their demographic characteristics, staging modality, clinical and pathological stages, perioperative course, and survival. The study endpoints included tumor recurrence, disease-specific survival (DSS), and overall survival rate. Of the 71 eligible patients, 14 received an esophagectomy first, whereas the remaining 57 received neoadjuvant CRT first. Despite the high pathological complete response (pCR) rate of 37% after neoadjuvant CRT, routine neoadjuvant CRT did not translate into better survival compared to direct surgery (5-year DSS: 39% vs. 68%, P= 0.17). The dramatic survival difference between pCR and non-pCR patients (5-year DSS: 85% vs. 4%, P < 0.001) accounts for these unsatisfactory results. In our series, the administration of neoadjuvant CRT to patients with clinical stage T2N0 esophageal squamous cell carcinoma did not significantly improve outcomes compared with direct esophagectomy.  相似文献   
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Aim There is a lack of prognostic factors of preoperative chemoradiation for locally advanced rectal cancer. Thymidylate synthase (TS) is the most important target of 5‐fluorouracil; three main genetic polymorphisms of TS have been described. We analysed the prognostic value of these in patients with locally advanced rectal cancer treated with fluoropyrimidine‐based chemoradiation. Method Ninety‐nine patients treated between November 2001 and March 2009 were included. All were treated by radiotherapy (5040 cGy) and concomitant fluoropyrimidine‐based chemotherapy. Three polymorphisms were analysed: (i) a double (2R) or triple (3R) repeat of a 28 base pair (bp) tandem sequence upstream of the ATG codon initiation site in the 5′‐terminal regulatory region, (ii) a functional G > C single nucleotide polymorphism present in the second repeat of the 3R alleles and (iii) a 6 bp deletion at nucleotide 1494 in the 3′‐untranslated region. DNA was extracted from paraffin‐embedded core biopsies taken from the tumour and the genotype was analysed using polymerase chain reaction restriction fragment length polymorphism. Results The 6 bp polymorphism was significantly associated with disease‐free survival (+ 6 bp/+ 6 bp vs?6 bp/?6 bp, P = 0.032 logistic regression). No differences were found in disease‐free survival according to the other polymorphisms studied. No relationship was observed between the different TS genotypes and pathological regression. Conclusion The study suggests that the TS 6 bp polymorphism may be a predictor of disease‐free survival in patients with locally advanced rectal cancer treated with fluoropyrimidine‐based chemoradiation.  相似文献   
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目的:探讨动脉内灌注化疗在局部晚期宫颈癌(Ⅰb2~Ⅳa 期)同步放化疗中应用的可行性及临床疗效。方法42例有详细临床病理资料的局部晚期宫颈癌患者行应用动脉内灌注化疗的同步放化疗。评估患者临床疗效,统计不良反应及生存时间,并与60例单纯行放疗患者对照比较。结果应用动脉内灌注化疗的同步放化疗总有效率为92.8%,其中完全缓解24例(57.1%);患者5年生存率较对照组明显提高(76.2% vs 49.3%,P =0.01)。多因素 COX 风险比例模型分析显示,临床分期(P =0.016)和淋巴转移(P =0.007)是影响应用动脉内灌注化疗的同步放化疗患者预后的独立因素。结论动脉内灌注化疗在局部晚期宫颈癌同步放化疗中应用安全有效,临床分期和淋巴转移是影响预后的重要因素。  相似文献   
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The purpose of this systematic review was to summarise the evidence from studies investigating the integration of tumour bed boosts into whole breast irradiation for patients with Stage 0-III breast cancer, with a focus on its impact on acute and late toxicities. A comprehensive systematic electronic search through the Ovid MEDLINE, EMBASE and PubMed databases from January 2000 to January 2015 was conducted. Studies were considered eligible if they investigated the efficacy of hypo- or normofractionated whole breast irradiation with the inclusion of a daily concurrent boost. The primary outcomes of interest were the degree of observed acute and late toxicity following radiotherapy treatment. Methodological quality assessment was performed on all included studies using either the Newcastle–Ottawa Scale or a previously published investigator-derived quality instrument. The search identified 35 articles, of which 17 satisfied our eligibility criteria. Thirteen and eleven studies reported on acute and late toxicities respectively. Grade 3 acute skin toxicity ranged from 1 to 7% whilst moderate to severe fibrosis and telangiectasia were both limited to 9%. Reported toxicity profiles were comparable to historical data at similar time-points. Studies investigating the delivery of concurrent boosts with whole breast radiotherapy courses report safe short to medium-term toxicity profiles and cosmesis rates. Whilst the quality of evidence and length of follow-up supporting these findings is low, sufficient evidence has been generated to consider concurrent boost techniques as an alternative to conventional sequential techniques.  相似文献   
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