Radiotherapy for and prognosis of breast cancer patients with isolated chest wall recurrence after mastectomy / 中华放射肿瘤学杂志

ABSTRACT

Objective:To investigate the radiation field and dose selection of patients with isolated chest wall recurrence (ICWR) after modified radical mastectomy, and analyze the prognostic factors related to subsequent chest wall recurrence.Methods:Clinical data of 201 patients with ICWR after mastectomy admitted to the Fifth Medical Center, Chinese PLA General Hospital from 1998 to 2018 were retrospectively analyzed. None of the patients received postoperative adjuvant radiotherapy. After ICWR, 48 patients (73.6%) underwent surgery and 155 patients (77.1%) received radiotherapy. Kaplan-Meier method was used to calculate the post-recurrence progression-free survival (PFS) rates and the difference was compared by log-rank test. Multivariate analysis was performed using Cox regression model. Competing risk model was adopted to estimate the subsequent local recurrence (sLR) rates after ICWR and the difference was compared with Gray test. Multivariate analysis was conducted using F&G analysis. Results:With a median follow up of 92.8 months after ICWR, the 5-year PFS rate was 23.2%, and the 5-year sLR rate was 35.7%. Multivariate analysis showed that patients with surgery plus radiotherapy and recurrence interval o F>12 months had a lower sLR rate. Patients with recurrence interval o F>48 months, local plus systemic treatment and surgery plus radiotherapy had a higher PFS rate. Among the 155 patients who received chest wall radiotherapy after ICWR, total chest wall irradiation plus local boost could improve the 5-year PFS rate compared with total chest wall irradiation alone (34.0% vs. 15.4%, P=0.004). Chest wall radiation dose (≤60 Gy vs.>60 Gy) exerted no significant effect upon the sLR and PFS rates (both P>0.05). In the 53 patients without surgery, the 5-year PFS rates were 9.1% and 20.5%( P=0.061) with tumor bed dose ≤60 Gy and>60 Gy, respectively. Conclusions:Local radiotherapy is recommended for patients with ICWR after modified radical mastectomy of breast cancer, including total chest wall radiation plus local boost. The radiation dose for recurrence should be increased to 60 Gy, and it should be above 60 Gy for those who have not undergone surgical resection. In addition, patients with ICWR still have a high risk of sLR, and more effective treatments need to be explored.