Local excision and treatment of early node-negative anal squamous cell carcinomas in a highly HIV prevalent population

Background

Anal squamous cell carcinoma (ASCC) is an uncommon cancer associated with human immunodeficiency virus (HIV) infection. There has been increasing interest in providing organ-sparing treatment in small node-negative ASCC’s, however, there is a paucity of evidence about the use of local excision alone in people living with HIV (PLWH). The aim of this study was to evaluate the efficacy of local excision alone in this patient population.

Methods

We present a case series of stage 1 and stage 2 ASCC in PLWH and HIV negative patients. Data were extracted from a 20-year retrospective cohort study analysing the treatment and outcomes of patients with primary ASCC in a cohort with a high prevalence of HIV.

Results

Ninety-four patients were included in the analysis. Fifty-seven (61%) were PLWH. Thirty-five (37%) patients received local excision alone as treatment for ASCC, they were more likely to be younger (p = 0.037, ANOVA) and have either foci of malignancy or well-differentiated tumours on histology (p = 0.002, Fisher’s exact test).

There was no statistically significant difference in 5-year disease-free survival and recurrence between treatment groups, however, patients who had local excision alone and PLWH were both more likely to recur later compared to patients who received other treatments for ASCC. (72.3 months vs 27.3 months, p = 0.06, ANOVA, and 72.3 months vs 31.8 months, p = 0.035, ANOVA, respectively).

Conclusions

We recommend that local excision be considered the sole treatment for stage 1 node-negative tumours that have clear margins and advantageous histology regardless of HIV status. However, PLWH who have local excision alone must have access to an expert long-term surveillance programme after treatment to identify late recurrences.

Session 3: Boosting primary and recurrent rectal cancer: how far can we push the radiotherapy envelope?

Neoadjuvant pelvic radiotherapy is widely used for patients with advanced rectal cancer. The trade-off between dose and response is well-established, yet little consensus remains on the precise methods of delivery and doses given in different scenarios. Professor Vuong reviews the evidence base and trial evidence on the escalation of radiotherapy dose and the methods of achieving this.

Session 3: Intra-operative radiotherapy - creating new surgical boundaries

In patients with advanced and recurrent colorectal cancer, surgical resection with clear margins is the greatest challenge and is limited by known anatomical constraints. Preoperative or intra-operative assessment of the limits of surgical dissection may help to explore the possibility of improving resectability through either targeted external beam radiotherapy or intra-operative radiotherapy. Professor Chang reviews the evidence base and potential advantages and disadvantages of this approach, whilst the expert panel agree a consensus on the evidence for assessment and therapy of such patients.

Deep vein thrombosis following hip fracture and prevalence of hyperhomocysteinaemia in the elderly

INTRODUCTION

The prevalence of deep vein thrombosis (DVT) in the West is reported to be as high as 50% after hip surgery. A study performed 14 years ago showed the incidence in Singapore to be <10%. Lately, some case-control and cross-sectional studies have suggested hyperhomocysteinaemia as an independent risk factor for DVT. This study investigates the local incidence of DVT and plasma hyperhomocysteinaemia in elderly patients presenting with proximal hip fracture.

MATERIALS AND METHODS

We recruited 104 consecutive patients from April 2001 to November 2001 who satisfy certain criteria. Firstly, patients of both genders who were >55 years old with radiological diagnosis of neck of femur fracture, intertrochanteric or subtrochanteric fracture. Secondly, these patients must not have any haemorrhagic or thrombogenic disease. Thirdly, patients were not given folate and B complex pre- or postoperation. Duplex ultrasound was then done for these patients on the 5th to 7th postoperative day.

RESULTS

The incidence of DVT above the trifurcation was 7.7%, no incidence of pulmonary embolism (PE) was detected. The incidence of hyperhomocysteinaemia was 52.3%.

CONCLUSIONS

The incidence of DVT in the local population after proximal hip fracture is much lower than in the West. The use of DVT prophylaxis in Asians should be selective to avoid incurring extra cost and its associated morbidity. Case-control studies and cross-sectional studies clearly indicate that hyperhomocysteinaemia is an independent risk factor for venous thrombosis. Given the high incidence of hyperhomocysteinaemia in our elderly with hip fracture, the prophylactic correction of hyperhomocysteinaemia with folate and vitamin B supplements is justified.

Regulation of macrophage inflammatory protein-2 gene expression by oxidative stress in rat alveolar macrophages

Chemokines are important mediators in the development of inflammation. Our previous work demonstrated that an oxidative stress can up-regulate mRNA expression of a CC chemokine macrophage inflammatory protein (MIP)-1alpha in rat alveolar macrophages. In the present study, we further investigate whether an oxidative stress can regulate the gene expression of a related CXC chemokine MIP-2, involved in both neutrophil chemotaxis and activation. A rat alveolar macrophage cell line (NR8383) was exposed to 10 microg/ml bacterial lipopolysaccharide (LPS) and MIP-2 mRNA levels dramatically increased after 4 hr of stimulation. This increase by LPS was attenuated by co-treatment with the antioxidants N-acetylcysteine and dimethylsulphoxide, suggesting that the induction of MIP-2 mRNA is mediated via the generation of reactive oxygen species. To assess directly the role of oxidative stress on regulation of MIP-2 mRNA expression, macrophages were exposed to H2O2. MIP-2 mRNA levels had significantly increased after 1 hr exposure to 0.5 mm H2O2, were maximally increased after 4 hr and decreased after 6 hr. Co-treatment of macrophages with the transcriptional inhibitor actinomycin D eliminated the H2O2-induction of MIP-2 mRNA, implicating a role for transcriptional activation in increased expression of MIP-2. Genomic cloning of the rat MIP-2 gene 5'-flanking region has identified a consensus nuclear factor-kappaB (NF-kappaB) binding site. Gel-mobility shift assays revealed NF-kappaB binding to the MIP-2 promoter/enhancer sequence was induced by H2O2. LPS treatment for 4 hr also significantly activated NF-kappaB binding, which could also be attenuated by pretreatment with N-acetylcysteine at the doses that reduced MIP-2 mRNA expression. The half-life of MIP-2 mRNA transcripts was also increased by H2O2 treatment. These observations indicate that MIP-2 gene expression is subject to both transcriptional and post-transcriptional control in response to an H2O2 oxidative stress.

High Critical-Current Density in the Heavily Pb-Doped Bi2Sr2CaCu2O8+delta Superconductor: Generation of Efficient Pinning Centers

Critical-current density (Jc) is a parameter of primary importance for potential applications of high-temperature copper oxide superconductors. It is limited principally by the breakdown of zero-resistive current due to thermally activated flux flow at high temperatures and high magnetic fields. One promising method to overcome this limitation is to introduce efficient pinning centers into crystals that can suppress the flux flow. A marked increase in Jc was observed in Bi2Sr2CaCu2O8+delta (Bi-2212) single crystals doped with a large amount of Pb. By electron microscopy, characteristic microstructures were revealed that probably underlie the observed enhancement in Jc: thin (10 to 50 nanometers), platelike domains having a modulation-free structure appeared with spacings of 50 to 100 nanometers along the b axis.