[Intravesical radioimmunotherapy of carcinoma in situ of the urinary bladder after BCG failure]

BACKGROUND

In failure to respond to bacillus Calmette-Guérin (BCG) in patients with carcinoma in situ (CIS) of the urinary bladder, radical cystectomy remains the mainstay after BCG failure.

OBJECTIVES

The aim of this pilot study was to evaluate tolerability and safety of the α‑emitter radioimmunoconjugate instillation in patients after BCG failure.

MATERIALS AND METHODS

Nine patients were included. After emptying the bladder via a transurethral catheter, Bi-213-anti-EGFR-mAb was instilled. Treatment was terminated by emptying of the radioimmunoconjugate from the bladder 120 min after instillation. Efficacy was evaluated via endoscopy and histology 6 weeks after instillation.

RESULTS

All patients showed excellent toleration of the treatment without any side effects. Treatment resulted in complete eradication of tumor cells in 3 patients and persistent tumor detection in the other 6 patients.

CONCLUSIONS

Intravesical instillation of Bi-213-anti-EGFR-mAb is a promising therapeutic option for treatment of in situ bladder cancer after BCG failure for patients who wish to preserve the bladder.

A pilot Project Exploring the Utility and Acceptability of a Socially-assistive Robot in an Assessment Unit for People with Neuropsychiatric Symptoms

Objectives

Socially-assistive robots have been used with older adults with cognitive impairment in residential care, and found to improve mood and well-being. However, there is little known about the potential benefits in adults with other neuropsychiatric symptoms.

Aims

The aim of this project was explore the utility and acceptability of a socially-assistive robot in engaging adults with a variety of neuropsychiatric symptoms.

Methods

Betty, a socially-assistive robot was installed in a unit which specialises in the assessment and diagnosis of adults presenting with neuropsychiatric symptoms. She is 39 cm tall, has a baby-face appearance and has the ability to engage individuals through personalised services which can be programmed according to individuals’ preferences. These include singing songs and playing games. Training for the nursing staff who were responsible for incorporating Betty into the unit activities was provided. The frequency, duration and type of activity which Betty was involved in was recorded. Patients admitted who could provide informed consent were able to be included in the project. These participants completed pre- and post-questionnaires.

Results

Eight patients (mean age 54.4 years, SD 13.6) who had diagnoses ranging from depression and schizophrenia participated. Types of activities included singing songs, playing Bingo and reading the news. Participants reported that they were comfortable with Betty and did not feel concerned in her presence. They enjoyed interacting with her.

Conclusions

This pilot project demonstrated that participants found Betty to be acceptable and she was useful in engaging them in activities. Future directions would involve larger sample sizes and different settings.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Abstract P5-07-03: GD2-mediated FAK signaling regulates breast cancer stem cell function in triple negative breast cancer

Ganglioside GD2 identifies breast cancer stem cells (BCSCs, Battula et al., JCI, 2012) and expression of GD2 is tightly regulated by GD3 synthase (GD3S). GD3S is highly expressed in GD2+ cells and inhibition of GD3S inhibits tumor formation and metastasis of breast cancer cells. However, the mechanism of GD2-mediated regulation of BCSC function is not known. Here we hypothesize that GD2 regulates signaling pathways involved in cell adhesion, migration and invasion of breast cancer cells. To identify these signaling pathways, antibody micro-arrays were used with 850 validated antibodies specific to total or phosphorylated proteins. Interestingly, focal adhesion kinase (FAK) was the most significantly phosphorylated protein in GD2+ compared to GD2- cells (S910 and S722). In addition, expression of FAK downstream mediators including Csk, PKCq, PKCl/I, Pyk2, and p38MAPK, was up-regulated in GD2+ compared to GD2- cells. Western blot analysis of FACS sorted SUM159 cells also revealed increased phosphorylation of FAK >80% at Y397 and >25% at Y861 in GD2+ compared to GD2- cells. FAK downstream targets including paxillin, p130 Cas, pERK were also up-regulated in GD2+ cells compared to GD2- cells indicating definitive activation of FAK signaling in GD2+ BCSCs. To investigate the functional role of GD2 in FAK mediated functions, we genetically deleted GD3S using the CRISPR knock-out system in SUM159 cells. only <1% GD2expression compared to >20% in parental cells was observed. GD3S-KO cells grew 5-10% slower in cell culture mostly because of the reduction (15±5%) in adherence. Trans-well assays revealed 3-5 fold reduction in migration and invasion of GD3S-KO compared to parental cells. These data indicate that GD2 and GD3S are not only the markers of BCSCs but also regulators of their function. Finally, we tested the effect of FAK inhibitor (PF-573228) against GD2+ BCSCs and GD3S-KO SUM159 cells. PF-573228 treatment decreased the number of mammospheres generated by GD2+ cells 3-4 fold in a dose dependent manner (100nM-1µm). In addition, treatment of PF-573228, inhibited migration and invasion of GD2+ cells 2 and 3 fold, respectively. However, treatment with PF-573228 on GD3S-KO cells further reduced their ability to migrate and invade by over 70% compared to untreated cells. In addition, GD3S-KO cells failed to form any mammospheres when cultured under low adherence conditions (p<0.00001), whereas the parental cells formed 15-20 mammospheres per 1,000 cells plated. In conclusion, our data demonstrate that FAK signaling is activated in GD2+ cells but that FAK inhibition alone may not be sufficient to inhibit BCSC function. Combined FAK and GD3S inhibition may exert highly synergistic effects against BCSCs.

Citation Format: Nguyen K, Sun JC, Hortobagyi GN, Andreeff M, Battula VL. GD2-mediated FAK signaling regulates breast cancer stem cell function in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-07-03.

Abstract P5-07-02: ST8SIA1 regulates tumorigenesis in triple negative breast cancer

Recurrence in breast cancer is mainly due to metastases and drug resistance in a fraction of primary tumors cells which are also known as cancer stem cells or tumor initiating cells. We found that Ganglioside GD2 identifies breast cancer stem cell (BCSCs) in triple negative breast cancer (TNBC) and that GD2 biosynthesis is tightly regulated by enzyme ST8SIA1 (GD3 synthase) in GD2+ cells. We have reported that ST8SIA1 is highly expressed in TNBC and its expression is highly correlated with p53 mutations primary tumors (Yan et al, SABCS abstract 2016). Here we hypothesize that ST8SIA1 has a functional role in BCSC mediated tumorigenesis in TNBC. To test the hypothesis, we deleted ST8SIA1 in SUM159 cells using CRISPR-Cas9 technology. As expected, deletion of ST8SIA1 in SUM159 cells reduced GD2+ cells from 17±1.5% to 0.3±0.1%. However, cell proliferation assay revealed no significant difference between ST8SIA1-KO and Cas9 control cells. In contrast, in-vitro tumorigenesis by soft-agar assays revealed a complete loss of colony formation in ST8SIA1-KO cells, whereas Cas9 control cells produced 30±10 colonies out of 1000 cells plated. To investigate tumor initiation potential, ST8SIA1-KO- or Cas9 control- SUM159 cells were transplanted in mammary fat pad of NSG mice. Cas9 control cells produced tumors within 1-2 weeks and reached the maximum allowed size by IACUC (1.5cm) within 3-4 weeks. In contrast, ST8SIA1-KO cells failed to produce any tumors even 15 weeks after injections. In addition, survival analysis by log-rank test revealed that most of the cas9 control cell injected mice died within 4 weeks after cell implantation whereas no deaths were observed in ST8SIA1-KO cells injected mice even 100 days after tumor implantation. These data indicate that loss of ST8SIA1 in TNBC cells depletes GD2+ BCSCs and inhibits in-vitro and in-vivo tumorigenesis.

To investigate gene expression changes due to loss of ST8SIA1 in CRISPR knockout cells, we analyzed mRNA expression in ST8SIA1-KO- and Cas9 control- SUM159 cells by RNAseq analysis (done in triplicates for each cell type). At p<0.05 and fold change >2, we found 1502 genes down-regulated and 842 genes up-regulated in ST8SIA1-KO- compared to cas9 control- cells. Ingenuity pathway analysis revealed that several stem cell associated signaling pathway including, wnt, stat3, NFκB, nanog and IL8 whereas tumor suppressor PTEN and p38 MAPK signaling were activated in ST8SIA1-KO- compared to cas9 control- cells. In specific, proteins associated with stem cell function including NOTCH3, PDGFRB, PDGFRA, VCAM1, CXCR4, CXCL12, SOX2, wnt5a were down regulated in ST8SIA1-KO cells whereas DKK1 which acts as an antagonist for wnt-β-catenin signaling, was up-regulated in ST8SIA1-KO cells. These findings were validated by flow cytometry and western blot analysis using specific antibodies. In conclusion, our data suggests that deletion of ST8SIA1 in TNBC cells depletes BCSCs and inhibits tumorigenesis in-vitro and in-vivo. Development of specific inhibitors of ST8SIA1 could be of potential therapeutic value for patients with TNBC.

Citation Format: Battula VL, Nguyen K, Sun JC, Dasgupta A, Bartholomeusz C, Andreeff M. ST8SIA1 regulates tumorigenesis in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-07-02.

Abstract P6-02-01: Metabolic stress induces GD2 expression and cancer stem cell phenotype in triple negative breast cancer

Breast cancer stem cells (BCSCs) have been characterized as a fraction of cells in primary tumors that are drug resistant and have metastatic potential. Ganglioside GD2 has been shown by us and others as a marker for BCSCs. Furthermore, nutrient deprivation associated metabolic stress seen during tumor progression is reportedly associated with the cancer stem cell phenotype. We hypothesized that metabolic stress could induce spontaneous generation of GD2+ BCSCs during tumor progression. To test our hypothesis, we cultured breast cancer cell lines MDA-MB-231 and SUM159 at low seeding density and measured percentage and absolute number of GD2+ cells daily. Flow cytometry analysis revealed that the percentage of GD2+ cells increased from 4.5 ± 2.5 on day 2 to 15 ± 3.8% on day 5 in MDA MB-231 cells and from 8.5 ± 2.8% on day2 to 28 ± 6.2% on day 5 in SUM159 cells (both designated as triple-negative breast cancer, TNBC). To investigate this phenomenon in-vivo, we injected GFP+ MDA-MB-231 cells in NSG mice mammary fat pads and examined GD2 expression in the implanted tumors weekly. Interestingly, we noticed that the percentage of GD2+ also increased from 12 ± 1.5% on week 1 to 30 ± 2.5% on week 6. Next, SUM159 cells were cultured in either nutrient rich (NR, i.e., 10% serum) or nutrient deprived (ND, 1% serum) for 4 days. We found that the percentage of GD2+ cells in NR medium at the end of 4 day culture was ~20% of the total cell population, whereas in ND medium was almost 50%. We then tested the effects of nutrient rich environment on GD2 expression by refreshing the media daily. Interestingly, cells that received fresh media had lower number of GD2+ cells (15 ± 1.5%) compared to cells cultured in the same medium for 4 days (33 ± 2.5%). Our data suggests that nutrient deprivation induces a stem cell phenotype in TNBC cells.

Next, we performed global metabolic profiling (i.e., for a total of 300 biochemical metabolites) using a mass spectroscopy-based approach. We profiled SUM159 cells cultured with NR vs. ND medium (set-1); GD2+ vs GD2- SUM159 cells (set -2); GD2+ vs GD2- MDA-MB-231 cell (set-3). Metabolites associated with amino acid metabolism, in particular glutathione metabolism, including glutamyl-alanine, 5-oxy-proline, proline, glutamine, and glutathione itself were found to be most highly up-regulated in GD2+ compared to GD2- cells and also in cells cultured in serum starved compared to serum rich conditions. Further analysis of these metabolites and their association with GD2+ cell signature raveled that gamma-glutamyl transferase (GGT5), was one of the most highly up-regulated (>150-fold) gene across all the groups. GGT is expressed on cell surface and transfers glutamyl group to amino acids, which then get transported across the membrane. In cancer, cells expressing GGT has been shown to be resistant to chemotherapeutic agents including cisplatin. Targeting glutathione metabolism could be future therapeutic strategy to inhibit BCSC growth in TNBC.

Citation Format: Battula VL, Piyaranthna B, Nguyen K, Sun JC, Jin F, Coarfa C, Nagireddy P, Andreeff M. Metabolic stress induces GD2 expression and cancer stem cell phenotype in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-02-01.

The role of STAT1 in viral sensitization to LPS

The phenomenon of endotoxin sensitization by virus infection is well documented but not yet well understood. Infection by virtually any viral agent will quickly induce expression of type I interferons (IFN-α/β), and type II IFN-γ production will follow as NK cells and T cells are activated. It has been well established that type II IFN pretreatment can intensify the effects of endotoxin. We have recently demonstrated that type I IFN induction by lymphocytic choriomeningitis virus (LCMV) infection dramatically increases TNF-α production following LPS treatment, and that this sensitization by type I IFN is STAT1 dependent. Taken together these data suggest that the STAT1-mediated, MyD88-independent, arm of the LPS signaling pathway plays an important role in endotoxin toxicity, and that this pathway mediates a major component of virus-enhanced LPS sensitization.

Abstract P1-06-03: Epithelial to mesenchymal transition (EMT) regulates the spontaneous generation of GD2+ breast cancer stem-like cells through NFκB activation

Breast cancer recurrence may be a consequence of persistent breast cancer stem-like cells (BCSCs) that survive chemo- or hormonal therapy. Therefore, targeting BCSCs could complement standard chemotherapy. We discovered that the ganglioside GD2 is expressed on and defines BCSCs (Battula et al., JCI, 2012), as consequence of activation of the enzyme GD3 synthase (GD3S). Inhibition of GD3S expression inhibited breast cancer metastasis to lung. We also observed that GD2- breast cancer cells spontaneously generate GD2+ cells in vitro. As induction of EMT generates a stem cell–like phenotype, we hypothesized that EMT regulates the generation of GD2+ breast cancer cells. To test this hypothesis, MDA-MB-231and SUM159 cells were cultured in vitro and the percentage of GD2+ cells was measured over time. Interestingly, the percentage and absolute number of GD2+ cells increased in a time-dependent manner, suggesting the spontaneous generation of GD2+ cells. Concomitantly, mesenchymal-related markers including vimentin, N-cadherin, and twist increased 3 to 6 - fold. To further investigate whether this process is operational in vivo, GFP+ MDA-MB-231 cells were transplanted into mammary fat pads of NOD/SCID mice. Each week, a group of mice was sacrificed, tumors were extracted and the number of GFP+GD2+ cells was determined by flow cytometry. In line with our in vitro results, we observed significant increases in GD2+ BCSCs with increasing tumor volume from 15.1%±4.6% to 37%±8.7% over a 6 week period, suggesting that breast cancer cells spontaneously undergo EMT during tumor progression and generate GD2+ BCSCs.

To identify possible targets to inhibit EMT in breast cancer cells, proteomic analysis using Kinexus® antibody arrays revealed activation of NFκB and focal adhesion kinase (FAK) signaling in GD2+ breast cancer cells. The activation of NFκB (phospho p65) in GD2+ cells was validated by CyTOF mass cytometry using metal tagged antibodies. These data suggest that inhibition of NFκB signaling may inhibit GD2+ BCSC growth. Indeed, the IKK inhibitor BMS345541 reduced GD2+ cells by >95% and inhibited GD3S expression (determined by qRT-PCR) in a dose- and time-dependent fashion. In contrast, treatment with doxorubicin increased the percentage of GD2+ cells, from 13.5±2.5% to 21±2.6% in MDA-MB-231 cells, suggesting that GD2+ cells are resistant to doxorubicin. In addition, treatment with BMS345541 inhibited the ability of breast cancer cells to form mammospheres by >90% in vitro. In-vivo tumorigenesis assay demonstrated that BMS345541 induced a significant decrease (p <0.01) in tumor volume, and increased survival of tumor bearing mice: median survival was 78 days for BMS345541-treated mice vs. 58 days for controls (p<0.002).

Conclusion: GD2+ BCSCs are spontaneously produced during tumor progression by EMT and NFκB and FAK mediated signaling might regulate this process. Inhibition of NFκB and FAK signaling pathways may inhibit the spread of BCSCs and reduce breast cancer metastases.

Citation Format: Battula VL, Sun J, Nguyen K, Hortobagyi G, Andreeff M. Epithelial to mesenchymal transition (EMT) regulates the spontaneous generation of GD2+ breast cancer stem-like cells through NFκB activation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-06-03.

Utility of Helicobacter spp. associated GFD markers for detecting avian fecal pollution in natural waters of two continents

Avian fecal droppings may negatively impact environmental water quality due to the presence of high concentrations of fecal indicator bacteria (FIB) and zoonotic pathogens. This study was aimed at evaluating the performance characteristics and utility of a Helicobacter spp. associated GFD marker by screening 265 fecal and wastewater samples from a range of avian and non-avian host groups from two continents (Brisbane, Australia and Florida, USA). The host-prevalence and -specificity of this marker among fecal and wastewater samples tested from Brisbane were 0.58 and 0.94 (maximum value of 1.00). These values for the Florida fecal samples were 0.30 (host-prevalence) and 1.00 (host-specificity). The concentrations of the GFD markers in avian and non-avian fecal nucleic acid samples were measured at a test concentration of 10 ng of nucleic acid at Brisbane and Florida laboratories using the quantitative PCR (qPCR) assay. The mean concentrations of the GFD marker in avian fecal nucleic acid samples (5.2 × 10(3) gene copies) were two orders of magnitude higher than non-avian fecal nucleic acid samples (8.6 × 10(1) gene copies). The utility of this marker was evaluated by testing water samples from the Brisbane River, Brisbane and a freshwater creek in Florida. Among the 18 water samples tested from the Brisbane River, 83% (n = 18) were positive for the GFD marker, and the concentrations ranged from 6.0 × 10(1)-3.2 × 10(2) gene copies per 100 mL water. In all, 92% (n = 25) water samples from the freshwater creek in Florida were also positive for the GFD marker with concentrations ranging from 2.8 × 10(1)-1.3 × 10(4) gene copies per 100 mL water. Based on the results, it can be concluded that the GFD marker is highly specific to avian host groups, and could be used as a reliable marker to detect the presence and amount of avian fecal pollution in environmental waters.

Clinical course of chronic hepatitis B (CHB) presented with normal ALT in Asian American patients

The clinical course for chronic hepatitis B (CHB) patients with normal ALT and with or without minimal histologic activity remains unclear. We assessed frequency, amplitude, disease activities, and associated factors of ALT and/or AST flares in this subpopulation. Forty-seven consecutive treatment naïve Asian patients with CHB were enrolled from two liver clinics between December 2003 and January 2013, who had normal baseline ALT by routine clinical biochemical testing performed 6 weeks before or after the liver biopsy. We defined a flare as elevation of ALT/AST above the upper limit of normal of ALT/AST. The mean follow-up was 37.6 (CI = 12, 88) months, and the mean age at entry into the study was 43.3 (CI = 19, 65); 22/47 (46.8%) were males; 15/45 (33.3%), HBeAg+; 68.1% had stage 0-1 fibrosis; 63.8% had grade 0-1 inflammation. During follow-up, 13/47 (27.7%) cases developed ALT flare at least once in a mean of 13.5 (CI = 2, 43) months after liver biopsy; ALT flare was not associated with baseline ALT level, fibrosis stage, inflammation grade, hepatitis B virus (HBV) DNA load, HBeAg status, HBV genotype, HBV precore and basal core promoter mutations. 11/13 (84/6%) of ALT flares resolved during follow-up. 13/13 (100%) of ALT flares met AASLD treatment criteria, but only 6/13 (46.2%) were on HBV treatment. Serum ALT and/or AST flares occur frequently in CHB carriers who initially presented with normal ALT during pretreatment period. Thus, regular follow-up is warranted despite status of ALT/AST. No clinical factors were found to be associated with ALT flares.

Scaled Quantum Mechanical scale factors for vibrational calculations using alternate polarized and augmented basis sets with the B3LYP density functional calculation model

The Scaled Quantum Mechanical (SQM) method of scaling calculated force constants to predict theoretically calculated vibrational frequencies is expanded to include a broad array of polarized and augmented basis sets based on the split valence 6-31G and 6-311G basis sets with the B3LYP density functional. Pulay's original choice of a single polarized 6-31G(d) basis coupled with a B3LYP functional remains the most computationally economical choice for scaled frequency calculations. But it can be improved upon with additional polarization functions and added diffuse functions for complex molecular systems. The new scale factors for the B3LYP density functional and the 6-31G, 6-31G(d), 6-31G(d,p), 6-31G+(d,p), 6-31G++(d,p), 6-311G, 6-311G(d), 6-311G(d,p), 6-311G+(d,p), 6-311G++(d,p), 6-311G(2d,p), 6-311G++(2d,p), 6-311G++(df,p) basis sets are shown. The double d polarized models did not perform as well and the source of the decreased accuracy was investigated. An alternate system of generating internal coordinates that uses the out-of plane wagging coordinate whenever it is possible; makes vibrational assignments via potential energy distributions more meaningful. Automated software to produce SQM scaled vibrational calculations from different molecular orbital packages is presented.

Computer-generated vs. physician-documented history of present illness (HPI): results of a blinded comparison

OBJECTIVES

Healthcare delivery now mandates shorter visits with higher documentation requirements, undermining the patient-provider interaction. To improve clinic visit efficiency, we developed a patient-provider portal that systematically collects patient symptoms using a computer algorithm called Automated Evaluation of Gastrointestinal Symptoms (AEGIS). AEGIS also automatically "translates" the patient report into a full narrative history of present illness (HPI). We aimed to compare the quality of computer-generated vs. physician-documented HPIs.

METHODS

We performed a cross-sectional study with a paired sample design among individuals visiting outpatient adult gastrointestinal (GI) clinics for evaluation of active GI symptoms. Participants first underwent usual care and then subsequently completed AEGIS. Each individual thereby had both a physician-documented and a computer-generated HPI. Forty-eight blinded physicians assessed HPI quality across six domains using 5-point scales: (i) overall impression, (ii) thoroughness, (iii) usefulness, (iv) organization, (v) succinctness, and (vi) comprehensibility. We compared HPI scores within patient using a repeated measures model.

RESULTS

Seventy-five patients had both computer-generated and physician-documented HPIs. The mean overall impression score for computer-generated HPIs was higher than physician HPIs (3.68 vs. 2.80; P<0.001), even after adjusting for physician and visit type, location, mode of transcription, and demographics. Computer-generated HPIs were also judged more complete (3.70 vs. 2.73; P<0.001), more useful (3.82 vs. 3.04; P<0.001), better organized (3.66 vs. 2.80; P<0.001), more succinct (3.55 vs. 3.17; P<0.001), and more comprehensible (3.66 vs. 2.97; P<0.001).

CONCLUSIONS

Computer-generated HPIs were of higher overall quality, better organized, and more succinct, comprehensible, complete, and useful compared with HPIs written by physicians during usual care in GI clinics.

Radiofrequency ablation of the great saphenous vein, comparing one versus two treatment cycles for the proximal vein segment

Objective

To evaluate the results of radiofrequency ablation (RFA) of the great saphenous vein (GSV) using one versus two 20 s energy cycle treatment in the proximal 7 cm segment of the GSV.

Methods

All patients who underwent RFA of the GSV from 1 May 2013 to 30 September 2013 in eight of our vein centers were included. Duplex ultrasound scans (DUSs) were performed prior to treatment on all patients and 2–3 days, and 1 month after procedure. Demographic data, GSV diameters, and other relevant data were recorded. Clinical, Etiologic, Anatomic, Pathologic (CEAP) classification and Venous Clinical Severity Scores (VCSSs) were determined prior to ablation and one month later. Patients who developed endovenous heat induced thrombosis (EHIT) were followed till resolution.

Results

A total of 205 patients had one cycle treatment (group A) and 204 had two cycle treatment (group B). The two groups were comparable in their demography, CEAP classification, and VCSS scores. The rate of failure of ablation and incidence of EHIT were also not significantly different. The incidence of complications was low, <5% in both groups and all were minor.

Conclusion

Two cycle treatment of the proximal GSV for vein ablation does not improve the success rate of vein closure in the short term, compared to one cycle treatment. It also does not increase the risks of DVT, EHIT, major bleeding, and other complications. However, we do not know at what diameter two cycles may be superior to one cycle.