The role of postmastectomy radiation therapy after neoadjuvant chemotherapy in clinical stage II-III breast cancer patients with pN0: a multicenter, retrospective study (KROG 12-05).

The purpose of this study was to investigate the role of postmastectomy radiation therapy (PMRT) after neoadjuvant chemotherapy (NAC) in clinical stage II-III breast cancer patients with pN0. We retrospectively identified 417 clinical stage II-III breast cancer patients who achieved an ypN0 at surgery after receiving NAC between 1998 and 2009. Of these, 151 patients underwent mastectomy after NAC. The effect of PMRT on disease-free survival (DFS), locoregional recurrence-free survival (LRRFS), and overall survival (OS) was evaluated by multivariate analysis including known prognostic factors using the Kaplan-Meier method and compared using the log-rank test and Cox proportional regression analysis. Of the 151 patients who underwent mastectomy, 105 (69.5%) received PMRT and 46 patients (30.5%) did not. At a median follow-up of 59 months, 5 patients (3.3%) developed LRR (8 sites of recurrence) and 14 patients (9.3%) developed distant metastasis. The 5-year DFS, LRRFS, and OS rates were 91.2, 98.1, and 93.3% with PMRT and 83.0%, 92.3%, and 89.9% without PMRT, respectively (all P values not significant). By univariate analysis, only age (≤40 vs >40 years) was significantly associated with decreased DFS (P=.027). By multivariate analysis, age (≤40 vs >40 years) and pathologic T stage (0-is vs 1 vs 2-4) were significant prognostic factors affecting DFS (hazard ratio [HR] 0.353, 95% confidence interval [CI] 0.135-0.928, P=.035; HR 2.223, 95% CI 1.074-4.604, P=.031, respectively). PMRT showed no correlation with a difference in DFS, LRRFS, or OS by multivariate analysis. PMRT might not be necessary for pN0 patients after NAC, regardless of clinical stage. Prospective randomized clinical trial data are needed to assess whether PMRT can be safely omitted in pN0 patients after NAC and mastectomy for clinical stage II-III breast cancer.

Shim SJ ，Park W ，Huh SJ ，Choi DH ，Shin KH ，Lee NK ，Suh CO ，Keum KC ，Kim YB ，Ahn SD ，Kim SS ，Ha SW ，Chie EK ，Kim K ，Shin HS ，Kim JH ，Lee HS ... -  《-》

Radiotherapy for stage II and stage III breast cancer patients with negative lymph nodes after preoperative chemotherapy and mastectomy.

To evaluate the effect of postmastectomy radiotherapy (PMRT) in Stage II-III breast cancer patients with negative lymph nodes (pN0) after neoadjuvant chemotherapy (NAC). Of 1,054 breast cancer patients treated with NAC at our institution between 1990 and 2004, 134 had pN0 status after NAC and mastectomy. The demographic data, tumor characteristics, metastatic sites, and treatments were prospectively recorded. The effect of PMRT on locoregional recurrence-free survival and overall survival (OS) was evaluated by multivariate analysis, including known prognostic factors. Of the 134 eligible patients, 78 (58.2%) received PMRT and 56 (41.8%) did not. At a median follow-up time of 91.4 months, the 5-year locoregional recurrence-free survival and OS rate was 96.2% and 88.3% with PMRT and 92.5% and 94.3% without PMRT, respectively (p = NS). The corresponding values at 10 years were 96.2% and 77.2% with PMRT and 86.8% and 87.7% without PMRT (p = NS). On multivariate analysis, PMRT had no effect on either locoregional recurrence-free survival (hazard ratio, 0.37; 95% confidence interval, 0.09-1.61; p = .18) or OS (hazard ratio, 2.06; 95% confidence interval, 0.71-6; p = .18). This remained true in the subgroups of patients with clinical Stage II or Stage III disease at diagnosis. A trend was seen toward poorer OS among patients who had not had a pathologic complete in-breast tumor response after NAC (hazard ratio, 6.65; 95% confidence interval, 0.82-54.12; p = .076). The results from the present retrospective study showed no increase in the risk of distant metastasis, locoregional recurrence, or death when PMRT was omitted in breast cancer patients with pN0 status after NAC and mastectomy. Whether the omission of PMRT is acceptable for these patients should be addressed prospectively.

Le Scodan R ，Selz J ，Stevens D ，Bollet MA ，de la Lande B ，Daveau C ，Lerebours F ，Labib A ，Bruant S ... -  《-》

Is regional lymph node irradiation necessary in stage II to III breast cancer patients with negative pathologic node status after neoadjuvant chemotherapy?

Neoadjuvant chemotherapy (NAC) generally induces significant changes in the pathologic extent of disease. This potential down-staging challenges the standard indications of adjuvant radiation therapy. We assessed the utility of lymph node irradiation (LNI) in breast cancer (BC) patients with pathologic N0 status (pN0) after NAC and breast-conserving surgery (BCS). Among 1,054 BC patients treated with NAC in our institution between 1990 and 2004, 248 patients with clinical N0 or N1 to N2 lymph node status at diagnosis had pN0 status after NAC and BCS. Cox regression analysis was used to identify factors influencing locoregional recurrence-free survival (LRR-FS), disease-free survival (DFS), and overall survival (OS). All 248 patients underwent breast irradiation, and 158 patients (63.7%) also received LNI. With a median follow-up of 88 months, the 5-year LRR-FS and OS rates were respectively 89.4% and 88.7% with LNI and 86.2% and 92% without LNI (no significant difference). Survival was poorer among patients who did not have a pathologic complete primary tumor response (hazard ratio, 3.05; 95% confidence interval, 1.17-7.99) and in patients with N1 to N2 clinical status at diagnosis (hazard ratio = 2.24; 95% confidence interval, 1.15-4.36). LNI did not significantly affect survival. Relative to combined breast and local lymph node irradiation, isolated breast irradiation does not appear to be associated with a higher risk of locoregional relapse or death among cN0 to cN2 breast cancer patients with pN0 status after NAC. These results need to be confirmed in a prospective study.

Daveau C ，Stevens D ，Brain E ，Berges O ，Villette S ，Moisson P ，Gardner M ，De la Lande B ，Lasry S ，Labib A ，Le Scodan R ... -  《-》

[The role of postmastectomy radiotherapy in clinical T1-3N1M0 breast cancer patients with pathological negative lymph nodes after neoadjuvant chemotherapy and mastectomy].

Rong QL ，Wang SL ，Tang Y ，Jin J ，Song YW ，Wang WH ，Liu YP ，Fang H ，Ren H ，Liu XF ，Yu ZH ，Li YX ... -  《-》

Impact of postmastectomy radiation on locoregional recurrence in breast cancer patients with 1-3 positive lymph nodes treated with modern systemic therapy.

Postmastectomy radiation therapy (PMRT) remains controversial for patients with 1-3 positive lymph nodes (LN+). We conducted a retrospective review of all 369 breast cancer patients with 1-3 LN+ who underwent mastectomy without neoadjuvant systemic therapy between 2000 and 2007 at Cleveland Clinic. We identified 271 patients with 1-3 LN+ who did not receive PMRT and 98 who did receive PMRT. The median follow-up time was 5.2 years, and the median number of LN dissected was 11. Of those not treated with PMRT, 79% received adjuvant chemotherapy (of whom 70% received a taxane), 79% received hormonal therapy, and 5% had no systemic therapy. Of the Her2/neu amplified tumors, 42% received trastuzumab. The 5-year rate of locoregional recurrence (LRR) was 8.9% without PMRT vs 0% with PMRT (P=.004). For patients who did not receive PMRT, univariate analysis showed 6 risk factors significantly (P<.05) correlated with LRR: estrogen receptor/progesterone receptor negative (hazard ratio [HR] 2.6), lymphovascular invasion (HR 2.4), 2-3 LN+ (HR 2.6), nodal ratio >25% (HR 2.7), extracapsular extension (ECE) (HR 3.7), and Bloom-Richardson grade III (HR 3.1). The 5-year LRR rate was 3.4% (95% confidence interval [CI], 0.1%-6.8%] for patients with 0-1 risk factor vs 14.6% [95% CI, 8.4%-20.9%] for patients with ≥2 risk factors (P=.0006), respectively. On multivariate analysis, ECE (HR 4.3, P=.0006) and grade III (HR 3.6, P=.004) remained significant risk factors for LRR. The 5-year LRR was 4.1% in patients with neither grade III nor ECE, 8.1% with either grade III or ECE, and 50.4% in patients with both grade III and ECE (P<.0001); the corresponding 5-year distant metastasis-free survival rates were 91.8%, 85.4%, and 59.1% (P=.0004), respectively. PMRT offers excellent control for patients with 1-3 LN+, with no locoregional failures to date. Patients with 1-3 LN+ who have grade III disease and/or ECE should be strongly considered for PMRT.

Tendulkar RD ，Rehman S ，Shukla ME ，Reddy CA ，Moore H ，Budd GT ，Dietz J ，Crowe JP ，Macklis R ... -  《-》