observational study of intra-operative partial irradiation of invasive ductal breast carcinomas with a good prognosis

Conditions: Invasive Breast Cancer; Breast-conserving Surgery

Summary: due to screening, t1n0 early-stage breast cancer now accounts for more than 50% of the tumors diagnosed in france. the prognosis of these tumors is good, even excellent in women ≥ 65 years of age, with specific survival of 98% at 5 years. the treatment of these tumors combines breast-conserving surgery and external whole breast irradiation for 6.5 weeks. a true de-escalation of treatment is taking place with these tumors, both surgically and medically. surgery therefore now prefers breast-conserving methods in combination with exeresis of the sentinel lymph node only. in the same way, in many international studies, radiotherapy has been evaluating the possibility of reducing both: * the irradiation volume at the excision site (partial irradiation) * the duration of this irradiation (accelerated radiotherapy) between 2004 and 2007, the crlc \[regional anti-cancer center\] evaluated the feasibility and the oncological results of intra-operative partial irradiation via a phase ii study in women 65 years of age and older with t1n0m0 hormone-sensitive tumors with a good prognosis. from 2010 to 2013, the icm carried out an observational study of these tumors with an excellent prognosis. in july 2009, the american society for radiation oncology (astro) published a consensus statement with specific recommendations and indications for accelerated partial breast irradiation (apbi). this apbi technique has been developing in france over the past 5 years within the framework of clinical studies and in compliance with the 2012 recommendations of the french national cancer institute. this apbi can be given by 3d external radiotherapy or, as in this study, by intra-operative radiotherapy (iort) in order to obtain optimal precision and spare as much of the surrounding healthy tissue as possible. the investigator therefore propose a cohort study to prospectively analyze the results of this technique applied to the indications strictly defined by the astro.

after registration, particpants have as treatment "combination extended tumorectomy with axillary dissection (sentinel lymph node) in addition to 20 gy of per-operative partial irradiation at the tumor site. follow up after this treatment during 5 years

Eligibility criteria:
inclusion criteria: * women 60 years of age or older, * histologically proven invasive ductal breast cancer or of a histologically favorable sub-type (mucinous, tubular or colloid), -. unifocal tumor, * t1 (diameter ≤ 20 mm), * n0 (pn0 or pni+), * m0, * gland exeresis margins ≥ 2 mm, * estrogen receptor positive, * information and non-opposition of the patient. exclusion criteria: -. inflammatory breast cancer, * associated peri-tumoral lymphatic emboli * associated extensive intra-ductal component * invasive lobular carcinoma * pure ductal carcinoma in situ, * sarcoma or lymphoma-type non-epithelial tumor * synchronous bilateral breast cancer, * any prior neo-adjuvant treatment: radiotherapy, chemotherapy, hormone therapy

Keywords: breast cancer good prognosis surgery intra-operative partial irradiation