New clinical and biological insights from the international TARGIT-A randomised trial of targeted intraoperative radiotherapy during lumpectomy for breast cancer.

BACKGROUND: The TARGIT-A trial reported risk-adapted targeted intraoperative radiotherapy (TARGIT-IORT) during lumpectomy for breast cancer to be as effective as whole-breast external beam radiotherapy (EBRT). Here, we present further detailed analyses. METHODS: In total, 2298 women (≥45 years, invasive ductal carcinoma ≤3.5 cm, cN0-N1) were randomised. We investigated the impact of tumour size, grade, ER, PgR, HER2 and lymph node status on local recurrence-free survival, and of local recurrence on distant relapse and mortality. We analysed the predictive factors for recommending supplemental EBRT after TARGIT-IORT as part of the risk-adapted approach, using regression modelling. Non-breast cancer mortality was compared between TARGIT-IORT plus EBRT vs. EBRT. RESULTS: Local recurrence-free survival was no different between TARGIT-IORT and EBRT, in every tumour subgroup. Unlike in the EBRT arm, local recurrence in the TARGIT-IORT arm was not a predictor of a higher risk of distant relapse or death. Our new predictive tool for recommending supplemental EBRT after TARGIT-IORT is at https://targit.org.uk/addrt . Non-breast cancer mortality was significantly lower in the TARGIT-IORT arm, even when patients received supplemental EBRT, HR 0.38 (95% CI 0.17-0.88) P = 0.0091. CONCLUSION: TARGIT-IORT is as effective as EBRT in all subgroups. Local recurrence after TARGIT-IORT, unlike after EBRT, has a good prognosis. TARGIT-IORT might have a beneficial abscopal effect. TRIAL REGISTRATION: ISRCTN34086741 (21/7/2004), NCT00983684 (24/9/2009).

Effect of Delayed Targeted Intraoperative Radiotherapy vs Whole-Breast Radiotherapy on Local Recurrence and Survival: Long-term Results From the TARGIT-A Randomized Clinical Trial in Early Breast Cancer.

Importance: Conventional adjuvant radiotherapy for breast cancer given daily for several weeks is onerous and expensive. Some patients may be obliged to choose a mastectomy instead, and some may forgo radiotherapy altogether. We proposed a clinical trial to test whether radiotherapy could be safely limited to the tumor bed. Objective: To determine whether delayed second-procedure targeted intraoperative radiotherapy (TARGIT-IORT) is noninferior to whole-breast external beam radiotherapy (EBRT) in terms of local control. Design, Setting, and Participants: In this prospective, randomized (1:1 ratio) noninferiority trial, 1153 patients aged 45 years or older with invasive ductal breast carcinoma smaller than 3.5 cm treated with breast conservation were enrolled from 28 centers in 9 countries. Data were locked in on July 3, 2019. Interventions: The TARGIT-A trial was started in March 2000; patients were randomized after needle biopsy to receive TARGIT-IORT immediately after lumpectomy under the same anesthetic vs EBRT and results have been shown to be noninferior. A parallel study, described in this article, was initiated in 2004; patients who had their cancer excised were randomly allocated using separate randomization tables to receive EBRT or delayed TARGIT-IORT given as a second procedure by reopening the lumpectomy wound. Main Outcomes and Measures: A noninferiority margin for local recurrence rate of 2.5% at 5 years, and long-term survival outcomes. Results: Overall, 581 women (mean [SD] age, 63 [7] years) were randomized to delayed TARGIT-IORT and 572 patients (mean [SD] age, 63 [8] years) were randomized to EBRT. Sixty patients (5%) had tumors larger than 2 cm, or had positive nodes and only 32 (2.7%) were younger than 50 years. Delayed TARGIT-IORT was not noninferior to EBRT. The local recurrence rates at 5-year complete follow-up were: delayed TARGIT-IORT vs EBRT (23/581 [3.96%] vs 6/572 [1.05%], respectively; difference, 2.91%; upper 90% CI, 4.4%). With long-term follow-up (median [IQR], 9.0 [7.5-10.5] years), there was no statistically significant difference in local recurrence-free survival (HR, 0.75; 95% CI, 0.57-1.003; P = .052), mastectomy-free survival (HR, 0.88; 95% CI, 0.65-1.18; P = .38), distant disease-free survival (HR, 1.00; 95% CI, 0.72-1.39; P = .98), or overall survival (HR, 0.96; 95% CI, 0.68-1.35; P = .80). Conclusions and Relevance: These long-term data show that despite an increase in the number of local recurrences with delayed TARGIT-IORT, there was no statistically significant decrease in mastectomy-free survival, distant disease-free survival, or overall survival. Trial Registration: ISRCTN34086741, ClinicalTrials.gov Identifier: NCT00983684.

Long term survival and local control outcomes from single dose targeted intraoperative radiotherapy during lumpectomy (TARGIT-IORT) for early breast cancer: TARGIT-A randomised clinical trial.

OBJECTIVE: To determine whether risk adapted intraoperative radiotherapy, delivered as a single dose during lumpectomy, can effectively replace postoperative whole breast external beam radiotherapy for early breast cancer. DESIGN: Prospective, open label, randomised controlled clinical trial. SETTING: 32 centres in 10 countries in the United Kingdom, Europe, Australia, the United States, and Canada. PARTICIPANTS: 2298 women aged 45 years and older with invasive ductal carcinoma up to 3.5 cm in size, cN0-N1, eligible for breast conservation and randomised before lumpectomy (1:1 ratio, blocks stratified by centre) to either risk adapted targeted intraoperative radiotherapy (TARGIT-IORT) or external beam radiotherapy (EBRT). INTERVENTIONS: Random allocation was to the EBRT arm, which consisted of a standard daily fractionated course (three to six weeks) of whole breast radiotherapy, or the TARGIT-IORT arm. TARGIT-IORT was given immediately after lumpectomy under the same anaesthetic and was the only radiotherapy for most patients (around 80%). TARGIT-IORT was supplemented by EBRT when postoperative histopathology found unsuspected higher risk factors (around 20% of patients). MAIN OUTCOME MEASURES: Non-inferiority with a margin of 2.5% for the absolute difference between the five year local recurrence rates of the two arms, and long term survival outcomes. RESULTS: Between 24 March 2000 and 25 June 2012, 1140 patients were randomised to TARGIT-IORT and 1158 to EBRT. TARGIT-IORT was non-inferior to EBRT: the local recurrence risk at five year complete follow-up was 2.11% for TARGIT-IORT compared with 0.95% for EBRT (difference 1.16%, 90% confidence interval 0.32 to 1.99). In the first five years, 13 additional local recurrences were reported (24/1140 v 11/1158) but 14 fewer deaths (42/1140 v 56/1158) for TARGIT-IORT compared with EBRT. With long term follow-up (median 8.6 years, maximum 18.90 years, interquartile range 7.0-10.6) no statistically significant difference was found for local recurrence-free survival (hazard ratio 1.13, 95% confidence interval 0.91 to 1.41, P=0.28), mastectomy-free survival (0.96, 0.78 to 1.19, P=0.74), distant disease-free survival (0.88, 0.69 to 1.12, P=0.30), overall survival (0.82, 0.63 to 1.05, P=0.13), and breast cancer mortality (1.12, 0.78 to 1.60, P=0.54). Mortality from other causes was significantly lower (0.59, 0.40 to 0.86, P=0.005). CONCLUSION: For patients with early breast cancer who met our trial selection criteria, risk adapted immediate single dose TARGIT-IORT during lumpectomy was an effective alternative to EBRT, with comparable long term efficacy for cancer control and lower non-breast cancer mortality. TARGIT-IORT should be discussed with eligible patients when breast conserving surgery is planned. TRIAL REGISTRATION: ISRCTN34086741, NCT00983684.

Binding and inhibition of drug transport proteins by heparin: a potential drug transporter modulator capable of reducing multidrug resistance in human cancer cells.

A major problem in cancer treatment is the development of resistance to chemotherapeutic agents, multidrug resistance (MDR), associated with increased activity of transmembrane drug transporter proteins which impair cytotoxic treatment by rapidly removing the drugs from the targeted cells. Previously, it has been shown that heparin treatment of cancer patients undergoing chemotherapy increases survival. In order to determine whether heparin is capable reducing MDR and increasing the potency of chemotherapeutic drugs, the cytoxicity of a number of agents toward four cancer cell lines (a human enriched breast cancer stem cell line, two human breast cancer cell lines, MCF-7 and MDA-MB-231, and a human lung cancer cell line A549) was tested in the presence or absence of heparin. Results demonstrated that heparin increased the cytotoxicity of a range of chemotherapeutic agents. This effect was associated with the ability of heparin to bind to several of the drug transport proteins of the ABC and non ABC transporter systems. Among the ABC system, heparin treatment caused significant inhibition of the ATPase activity of ABCG2 and ABCC1, and of the efflux function observed as enhanced intracellular accumulation of specific substrates. Doxorubicin cytoxicity, which was enhanced by heparin treatment of MCF-7 cells, was found to be under the control of one of the major non-ABC transporter proteins, lung resistance protein (LRP). LRP was also shown to be a heparin-binding protein. These findings indicate that heparin has a potential role in the clinic as a drug transporter modulator to reduce multidrug resistance in cancer patients.

Venous thromboembolism prophylaxis for the general surgical patient: where do we stand?

Venous thromboembolism (VTE) is a frequent complication in surgical patients, with the potential for long-term disability or fatal outcome. The rationale behind routine use of thromboprophylaxis can be summarized in three points: (1) VTE is frequent in certain surgical populations, (2) VTE may be fatal, (3) thromboprophylaxis is highly effective and safe. In addition to these clinical benefits it has the potential for lowering overall treatment costs by preventing diagnostic procedures and delayed discharge or readmission due to thromboembolism. Surgical patients tend to have more than one risk factor for VTE, and in view of the fact that the effect of that risk is cumulative, it is important to stratify the risk to tailor an adequate prophylaxis strategy. There is consensus that heparins are both effective and safe in preventing VTE in surgical patients. Evidence-based local strategies should be available locally to clinicians and adhered to in order to maximize outcomes. Guidelines are intended to assist surgeons in making decisions in regard to DVT prophylaxis when performing surgical procedures.

Treatment of venous thromboembolism in cancer patients.

Venous thromboembolism (VTE) is a common complication in patients with malignant disease. Its management remains challenging because patients with a cancer-associated thrombosis are at higher risk of recurrent VTE than are noncancer subjects with thrombosis and also have a greater risk for anticoagulant-associated bleeding complications while receiving therapy to prevent recurrent VTE. Recently, anticoagulant strategies based on the administration of low-molecular-weight heparin (LMWH) rather than vitamin K antagonists for up to 6 days to prevent recurrent VTE have been evaluated. These studies indicate that LMWH is associated with a lower rate for recurrent VTE and similar rates of bleeding when compared with oral anticoagulant therapy. Chronic exposure to LMWH may also prolong survival of cancer patients.

Mechanisms of disease: the impact of antithrombotic therapy in cancer patients.

Venous thromboembolism is a common complication in patients with malignant disease. It is associated with a systemic hypercoagulable state that is secondary to tumor elaboration of tissue factor (the physiological initiator of blood coagulation), activation of other procoagulant mechanisms and downregulation of anticoagulant mechanisms. The consequent generation of activated coagulation serine protease in the peritumoral environment influences tumor growth, invasion, metastasis and angiogenesis. The use of antithrombotic agents, such as the low-molecular-weight heparins, might influence survival in cancer patients through several mechanisms. These mechanisms include a reduction in the frequency of overt and silent fatal thromboembolic events, interference with the activation of blood coagulation and generation of coagulation serine proteases that affect the tumor phenotype, and direct cellular effects of heparin on both epithelial and endothelial tumor elements.