Abstract PD06-01: A Single Treatment with Targeted Intraoperative Radiotherapy (TARGIT) Is Similar to Several Weeks of External Beam Radiotherapy (EBRT) with Respect to Efficacy and Safety, and Has Obvious Advantages to the Patient and the Economy

Background: After breast-conserving surgery, 90% of local recurrences occur within the index quadrant despite the presence of multicentric cancers elsewhere in the breast. Thus, restriction of radiation therapy to the tumour bed during surgery might be adequate for selected patients. Materials and methods: Having safely piloted the new technique of single-dose targeted intraoperative radiotherapy (TARGIT) with Intrabeam, we launched the TARGIT-A trial on March 24, 2000. In this prospective, randomised, non-inferiority trial, women aged 45 years or older with invasive ductal breast carcinoma undergoing breast-conserving surgery were enrolled to compare TARGIT with whole breast external beam radiotherapy (EBRT). The primary outcome was local recurrence in the conserved breast with a predefined absolute non-inferiority margin of 2-5%. Analysis was by intention-to-treat.

Results: 1113 patients were randomly allocated to TARGIT and 1119 were allocated to EBRT. The Kaplan-Meier estimate of local recurrence in the conserved breast at 4 years was 1-20% (95% CI 0-53-2-71) in the TARGIT and 0-95% (0.39-2-31) in the EBRT group (difference between groups 0.25%, −1.04 to 1.54; p=0.41). The frequency of any complications and major toxicity (TARGIT 3.3% vs. EBRT 3.9% p=0·44) was similar. Radiotherapy toxicity was lower in the TARGIT group (0.5% vs. 2.1%, p=0.002). 14% of patients who received TARGIT also received EBRT as per the protocol, i.e., the remaining 86% patients could safely avoid 3-6 weeks of daily radiotherapy treatments and its obvious associated costs in economic and human terms.

Discussion: For selected patients with early breast cancer, a single-dose targeted intraoperative radiotherapy should be considered as an alternative to whole breast EBRT delivered over several weeks. It could save time, effort, and money for the patient and the healthcare system, which is particularly relevant in the present times of healthcare reform. NB the main trial results have been presented in ASCO 2010 and published in the Lancet Online First.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD06-01.

Chemoradiotherapy with or without induction chemotherapy for locally advanced pancreatic cancer: a UK multi-institutional experience

AIMS

The optimal management for patients with unresectable locally advanced adenocarcinoma of the pancreas (LAPC) is unclear. The aim of this study was to determine the outcome of patients treated with chemoradiotherapy (CRT) with or without induction chemotherapy.

MATERIALS AND METHODS

We conducted a multi-centre retrospective analysis of 48 patients with biopsy-proven LAPC treated with CRT in four regional oncology centres in the UK between March 2000 and October 2007. The prescribed radiotherapy dose was 4500-5040 cGy in 25-28 fractions and was given concurrent with gemcitabine (n=37), gemcitabine/cisplatin (n=9), 5-fluorouracil (n=1) or capecitabine (n=1).

RESULTS

Four patients (8.3%) did not complete the intended treatment due to CRT-related toxicities. The disease control rate (Objective response rate (ORR) and stable disease (SD)) was 81.3%. The median overall survival was 17 months (range 5-66 months). In subgroup analysis, a trend towards improved survival was seen in patients who completed the intended treatment (17.1 months vs 11.0 months, P=0.06) and in patients undergoing surgery (27 months vs 16 months, P=0.023).

CONCLUSIONS

This is the largest reported series from the UK focussing on patients who received CRT for pancreas cancer. It shows that it is possible to deliver pancreatic CRT with acceptable toxicity. Induction chemotherapy followed by gemcitabine-based CRT shows promising activity and should be evaluated in phase III studies.

Identification and in vitro expansion of functional antigen-specific CD25+ FoxP3+ regulatory T cells in hepatitis C virus infection

CD4(+)CD25(+) regulatory T cells (CD25(+) Tregs) play a key role in immune regulation. Since hepatitis C virus (HCV) persists with increased circulating CD4(+)CD25(+) T cells and virus-specific effector T-cell dysfunction, we asked if CD4(+)CD25(+) T cells in HCV-infected individuals are similar to natural Tregs in uninfected individuals and if they include HCV-specific Tregs using the specific Treg marker FoxP3 at the single-cell level. We report that HCV-infected patients display increased circulating FoxP3(+) Tregs that are phenotypically and functionally indistinguishable from FoxP3(+) Tregs in uninfected subjects. Furthermore, HCV-specific FoxP3(+) Tregs were detected in HCV-seropositive persons with antigen-specific expansion, major histocompatibility complex class II/peptide tetramer binding affinity, and preferential suppression of HCV-specific CD8 T cells. Transforming growth factor beta contributed to antigen-specific Treg expansion in vitro, suggesting that it may contribute to antigen-specific Treg expansion in vivo. Interestingly, FoxP3 expression was also detected in influenza virus-specific CD4 T cells. In conclusion, functionally active and virus-specific FoxP3(+) Tregs are induced in HCV infection, thus providing targeted immune regulation in vivo. Detection of FoxP3 expression in non-HCV-specific CD4 T cells suggests that immune regulation through antigen-specific Treg induction extends beyond HCV.

Biochemical, molecular and behavioral phenotypes of Rab3A mutations in the mouse

Ras-associated binding (Rab) protein 3A is a neuronal guanosine triphosphate (GTP)-binding protein that binds synaptic vesicles and regulates synaptic transmission. A mouse mutant, earlybird (Ebd), with a point mutation in the GTP-binding domain of Rab3A (D77G), exhibits anomalies in circadian behavior and homeostatic response to sleep loss. Here, we show that the D77G substitution in the Ebd allele causes reduced GTP and GDP binding, whereas GTPase activity remains intact, leading to reduced protein levels of both Rab3A and rabphilin3A. Expression profiling of the cortex and hippocampus of Ebd and Rab3a-deficient mice revealed subtle differences between wild-type and mutant mice. Although mice were backcrossed for three generations to a C57BL/6J background, the most robust changes at the transcriptional level between Rab3a(-/-) and Rab3a(+/+) mice were represented by genes from the 129/Sv-derived chromosomal region surrounding the Rab3a gene. These results showed that differences in genetic background have a stronger effect on gene expression than the mutations in the Rab3a gene. In behavioral tests, the Ebd/Ebd mice showed a more pronounced mutant phenotype than the null mice; Ebd/Ebd have reduced anxiety-like behavior in the elevated zero-maze test, reduced response to stress in the forced swim test and a deficit in cued fear conditioning (FC), whereas Rab3a(-/-) showed only a deficit in cued FC. Our data implicate Rab3A in learning and memory as well as in the regulation of emotion. A combination of forward and reverse genetics has provided multiple alleles of the Rab3a gene; our studies illustrate the power and complexities of the parallel analysis of these alleles at the biochemical, molecular and behavioral levels.

Impact of age on treatment effect in locally advanced head and neck cancer (HNC): Two individual patient data meta-analyses

5501

Background: The Meta-Analysis of Radiotherapy in Carcinomas of Head & Neck (MARCH; Bourhis J, ASTRO 2002) showed that altered fractionation radiotherapy (Alt-RT) could improve survival as compared to standard RT in patients with locally advanced HNC (pooled hazard ratio - HR -: 0.92, 95% confidence interval: 0.86–0.97). The Meta-Analysis of Chemotherapy in Head and Neck Cancer (MACH-NC; Bourhis J, ASCO 2004) demonstrated that concomitant chemotherapy (CT), added to RT, improved survival (HR: 0.82, 95% CI: 0.78–0.86). This study considers age as a potential modifier of the treatment effect. Methods: 15 randomized trials with 6,515 patients were included in MARCH (median follow up: 6.0 years), and 50 with 9,471 patients in concomitant part of MACH-NC (median follow up: 5.6 years). The interaction between age and treatment effect, using HR of death, was tested with heterogeneity test. Effect of prognostic factors on the interaction was analysed using Cox model. Results: The effect of Alt-RT in MARCH and of concomitant CT in MACH-NC on overall survival decreased with increased age ( table ). Patients aged 71+ had a lower performance status, less advanced stage, and more often laryngeal cancer than the younger patients; there were more women in the oldest patients group. However, adjusting on covariates did not modify the results. Causes of death was available in MARCH and in recent (1994–2000) trials of MACH-NC. The proportion of deaths not due to HNC increased with age, from 18% at age 50 to 41% at age 71+ in MARCH, and from 15% to 39% in MACH-NC. Conclusions: Treatment benefit decreases with increasing age. Patients aged 71+ did not benefit from Alt- RT nor from concomitant CT. The increasing risk of death from other causes with age may explain part of these observations. Supported by PHRC, ARC, LNCC

[Table: see text]

No significant financial relationships to disclose.

Breast-conserving Surgery with Intra-operative Radiotherapy: The Right Approach for the 21st Century?

Wide local excision followed by external beam radiation therapy (EBRT) to the whole breast has become the standard of care for most patients with localised 'early' breast cancer in the UK, Europe, and the USA. Local relapse rates are low, and overall survival figures have improved during the past decade, with the advent of more effective systemic endocrine- and chemo-therapy. A policy of EBRT for every patient undergoing breast conserving surgery (BCS) is however associated with a number of practical difficulties, acute radiation side effects and longer term toxicity, all of which detract from the obvious benefits of EBRT. In addition, with a disease as common as early breast cancer and a treatment programme typically requiring sophisticated radiation planning and many fractions of treatment, the policy of BCS plus EBRT has enormous resource implications within departments of oncology, greatly contributing to lengthy pre-treatment delays. For all these reasons, we and others have developed an increasing interest in techniques of partial breast irradiation, with an emphasis in our own Department on the emerging technique of intra-operative radiotherapy (IORT), which we initially employed as a boost to the tumour bed for use in conjunction with EBRT to the whole breast. To test the possibility of replacing the whole of the EBRT 3-6 week programme by a single application of IORT at the time of surgery, we and others have commenced a large scale prospectively randomised clinical trail in selected patients. Nine international centres are currently participating, and 350 patients have now been randomised to receive either IORT as part of the initial surgical excision or conventional EBRT with a pragmatic dose policy according to the preference of the contributing centre. The majority of patients undergoing IORT receive this at the time of initial surgery but it is also permissible within the trial programme to randomise suitable patients after the excised specimen has been histologically examined, thus avoiding any unsuitable patients - for example, those with a lobular carcinoma. These patients will be stratified and assessed separately from the 'pre-pathology' group, whose surgery and IORT is completed within a single session; if the latter patients are found to have unfavourable histology we have the facility, within the trial, to add EBRT. The trial is ongoing and our early experience has been encouraging. We have also recently assessed the long term local failure rate in patients offered IORT as a tumour bed boost, in conjunction with conventional EBRT. This methodology will also be the subject of a future randomised clinical trial.

Recent advances in endocrine therapy for postmenopausal women with early breast cancer: implications for treatment and prevention

BACKGROUND

In the treatment of advanced breast cancer, third-generation aromatase inhibitors (AIs) have shown superior efficacy and tolerability compared with tamoxifen and megestrol acetate, the previous standard endocrine therapies in the first- and second-line settings, respectively. AIs are now being assessed in the adjuvant and prevention settings.

DESIGN

Literature review (PubMed search).

RESULTS

Tamoxifen is currently the only endocrine option available for adjuvant therapy and chemoprevention in postmenopausal women. However, results from the ATAC ('Arimidex', Tamoxifen, Alone or in Combination) trial have shown anastrozole to be more effective than tamoxifen as adjuvant therapy for postmenopausal women with hormone-responsive early breast cancer. Other third-generation AIs, including letrozole and exemestane, are also being investigated as adjuvant therapies. In the chemoprevention setting, tamoxifen is the only available endocrine option for women at high risk of breast cancer but, given that these are healthy subjects, is associated with an unacceptable rate of adverse events. Raloxifene is being further assessed in the STAR (Study of Tamoxifen and Raloxifene) trial, while anastrozole is being evaluated in the second IBIS-II (International Breast Intervention Study II).

CONCLUSIONS

AIs, in particular anastrozole, are set to change the way that early breast cancer is treated. Effective and better-tolerated endocrine alternatives for breast cancer prevention may become available in the future.

Results of the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial after completion of 5 years' adjuvant treatment for breast cancer

The standard adjuvant endocrine treatment for postmenopausal women with hormone-receptor-positive localised breast cancer is 5 years of tamoxifen, but recurrences and side-effects restrict its usefulness. The aromatase inhibitor anastrozole was compared with tamoxifen for 5 years in 9366 postmenopausal women with localised breast cancer. After a median follow-up of 68 months, anastrozole significantly prolonged disease-free survival (575 events with anastrozole vs 651 with tamoxifen, hazard ratio 0.87, 95% CI 0.78-0.97, p=0.01) and time-to-recurrence (402 vs 498, 0.79, 0.70-0.90, p=0.0005), and significantly reduced distant metastases (324 vs 375, 0.86, 0.74-0.99, p=0.04) and contralateral breast cancers (35 vs 59, 42% reduction, 12-62, p=0.01). Almost all patients have completed their scheduled treatment, and fewer withdrawals occurred with anastrozole than with tamoxifen. Anastrozole was also associated with fewer side-effects than tamoxifen, especially gynaecological problems and vascular events, but arthralgia and fractures were increased. Anastrozole should be the preferred initial treatment for postmenopausal women with localised hormone-receptor-positive breast cancer.

Laser augmented by brachytherapy versus laser alone in the palliation of adenocarcinoma of the oesophagus and cardia: a randomised study

BACKGROUND

Many patients with advanced malignant dysphagia are not suitable for definitive treatment. The best option for palliation of dysphagia varies between patients. This paper looks at a simple technique for enhancing laser recanalisation.

AIM

To assess the value of adjunctive brachytherapy in prolonging palliation of malignant dysphagia by endoscopic laser therapy.

PATIENTS

Twenty two patients with advanced malignant dysphagia due to adenocarcinoma of the oesophagus or gastric cardia, unsuitable for surgery or radical chemoradiotherapy.

METHODS

Patients able to eat a soft diet after laser recanalisation were randomised to no further therapy or a single treatment with brachytherapy (10 Gy). Results were judged on the quality and duration of dysphagia palliation, need for subsequent intervention, complications, and survival.

RESULTS

The median dysphagia score for all patients two weeks after initial treatment was 1 (some solids). The median dysphagia palliated interval from the end of initial treatment to recurrent dysphagia or death increased from five weeks (control group) to 19 weeks (brachytherapy group). Three patients had some odynophagia for up to six weeks after brachytherapy. There was no other treatment related morbidity or mortality. Further intervention was required in 10 of 11 control patients (median five further procedures) compared with 7/11 brachytherapy patients (median two further procedures). There was no difference in survival (median 20 weeks (control), 26 weeks (brachytherapy)).

CONCLUSIONS

Laser therapy followed by brachytherapy is a safe, straightforward, and effective option for palliating advanced malignant dysphagia, which is complementary to stent insertion.

Targeted intra-operative radiotherapy (Targit): an innovative method of treatment for early breast cancer

INTRODUCTION

We believe that conservative treatment of early breast cancer may not require radiotherapy that encompasses the whole breast. We present here the clinico-pathological basis for this view, as well as a novel therapeutic approach that allows intra-operative radiotherapy to be safely and accurately delivered to the target tissues in a standard operating theatre. THE RATIONALE: Whole-organ analysis of mastectomy specimens reveals that 80% of occult cancer foci are situated remote from the index quadrant. In contrast, over 90% of local recurrences after breast conservative therapy occur near the original tumour, even when radiotherapy is not given. Therefore, the remote occult cancer foci may be clinically irrelevant and radiotherapy to the index quadrant alone might be sufficient. A NOVEL TECHNIQUE: The Photon Radiosurgery System (PRS) is an ingenious portable electron-beam driven device that can typically deliver intra-operative doses of 5-20 Gy, respectively, to 1 cm and 0.2 cm from the tumour bed over about 22 min. The pliable breast tissue--the target--wraps around the source, providing perfect conformal radiotherapy. Being soft X-rays, the dose attenuates rapidly (alpha approximately 1/r3), reducing distant damage.

RESULTS

In our pilot study of 25 patients (age 30-80 years, T = 0.42-4.0 cm), we replaced the routine post-operative tumour bed boost with targeted intra-operative radiotherapy. There have been no major complications and no patient has developed local recurrence, although the median follow-up time is short, at 24 months.

CONCLUSION

It is safe and feasible to deliver targeted intraoperative radiotherapy (Targit) for early breast cancer. We have begun a randomised trial--the first of its kind--comparing Targit with conventional six-week course of radiotherapy. If proven equivalent in terms of local recurrence and cosmesis, it could eliminate the need for the usual six-week course of post-operative radiotherapy.