Stereotactic image-guided neoadjuvant ablative single-dose radiation, then lumpectomy, for early breast cancer: the SIGNAL prospective single-arm trial of single-dose radiation therapy.

Background and Purpose: Adjuvant whole-breast irradiation after breast-conserving surgery, typically delivered over several weeks, is the traditional standard of care for low-risk breast cancer. More recently, hypofractionated, partial-breast irradiation has increasingly become established. Neoadjuvant single-fraction radiotherapy (rt) is an uncommon approach wherein the unresected lesion is irradiated preoperatively in a single fraction. We developed the signal (Stereotactic Image-Guided Neoadjuvant Ablative Radiation Then Lumpectomy) trial, a prospective single-arm trial to test our hypothesis that, for low-risk carcinoma of the breast, the preoperative single-fraction approach would be feasible and safe. Methods: Patients presenting with early-stage (T < 3 cm), estrogen-positive, clinically node-negative invasive carcinoma of the breast with tumours at least 2 cm away from skin and chest wall were enrolled. All patients received prone breast magnetic resonance imaging (mri) and prone computed tomography simulation. Treatable patients received a single 21 Gy fraction of external-beam rt (as volumetric-modulated arc therapy) to the primary lesion in the breast, followed by definitive surgery 1 week later. The primary endpoints at 3 weeks, 6 months, and 1 year were toxicity and cosmesis (that is, safety) and feasibility (defined as the proportion of mri-appropriate patients receiving rt). Results: Of 52 patients accrued, 27 were successfully treated. The initial dosimetric constraints resulted in a feasibility failure, because only 57% of eligible patients were successfully treated. Revised dosimetric constraints were developed, after which 100% of patients meeting mri criteria were treated according to protocol. At 3 weeks, 6 months, and 1 year after the operation, toxicity, patient- and physician-rated cosmesis, and quality of life were not significantly different from baseline. Conclusions: The signal trial presents a feasible method of implementing single-dose preoperative rt in early-stage breast cancer. This pilot study did not identify any significant toxicity and demonstrated excellent cosmetic and quality-of-life outcomes. Future randomized multi-arm studies are required to corroborate these findings.

Recurrence and mortality after breast-conserving surgery without radiation.

Background: Breast-conserving surgery (bcs) and radiation therapy (rt) are the standard of care for early breast cancer; studies have demonstrated that adjuvant rt confers a protective effect with respect to recurrence, although no randomized trials have shown a survival benefit. Methods: This retrospective cohort study used Ontario data linked through ices to examine patients treated for breast cancer between 1 April 2007 and 31 March 2014. The primary outcome was death or recurrence. Outcomes were compared between patients who did and did not receive rt. Results: The total cohort size was 26,279. The hazard ratios (hrs) for various outcomes were significantly higher for patients who did not receive rt than for patients who did: recurrence or death combined [hr: 2.49; 95% confidence interval (ci): 2.25 to 2.75], recurrence (hr: 2.33; 95% ci: 1.91 to 2.84), and death (hr: 2.28; 95% ci: 2.03 to 2.56). The hr for death was 1.81 (95% ci: 1.65 to 1.99) for patients having stage ii cancer compared with those having stage i disease. The hr for death was 1.97 (95% ci: 1.74 to 2.22) for patients having high comorbidity compared with those having little comorbidity. Conclusions: Adjuvant rt carries a protective effect with respect to recurrence and survival in patients with early-stage breast cancer. That survival benefit has not been appreciated in previous randomized trials and underscores the importance of rt as a component of breast cancer treatment.

Appropriate treatment receipt after breast-conserving surgery.

Background: Breast-conserving surgery (bcs) and radiation therapy (rt) are the standard of care for early breast cancer, although some women receive ipsilateral mastectomy or adjuvant tamoxifen, both of which can be appropriate alternatives to rt. Objectives of the present study were to determine the proportion of women who are treated appropriately after bcs and to identify factors associated with non-receipt of rt. Methods: This retrospective cohort study used Ontario data linked at the Institute for Clinical and Evaluative Sciences to examine 33,718 patients who received bcs during 2004-2010. Primary outcome was rt receipt. The ipsilateral mastectomy rate and patient, surgeon, and setting variables were measured. Results: Of the study patients, 86.1% received either rt or completion mastectomy; in the cohort less than 70 years of age, 90.8% received rt or completion mastectomy. Among patients less than 70 years of age, 3 risk factors for non-receipt of rt were identified: age less than 46 years, treatment in a non-academic institution, and earlier year of initial bcs. Additionally, in the overall cohort, rt non-receipt was associated with high comorbidity, more than 40 km to the cancer centre, income quintile, and breast care specialization. Conclusions: In Ontario, 90.8% of patients less than 70 years of age are appropriately treated for early breast cancer; approximately 1 in 10 do not receive rt or completion mastectomy. Based on those findings, women less than 46 years of age might be at increased risk of recurrence and death because of incomplete treatment. It also appears that academic centres more effectively treat breast cancer; however, breast cancer care appears to be improving over time in Ontario.