Biological subtype predicts locoregional recurrence after postmastectomy radiotherapy in Chinese breast cancer patients.

To investigate the impact of biological subtypes in locoregional recurrence in Chinese breast cancer patients receiving postmastectomy radiotherapy (PMRT). About 583 patients who received postmastectomy radiation between 2010 and 2012 were retrospectively analyzed. According to immunohistochemical staining profile, patients were classified into: Luminal A-like, Luminal B-like, HER2-positive, and triple-negative breast cancer (TNBC). Local and regional recurrence (LRR) cumulative incidences were calculated by competing risks methodology and the power of prognostic factors was examined by Gray's test and the test of Fine and Gray. The median follow-up was 70.9 months. About 34 LRR events occurred. For Luminal A, Luminal B, HER2-positive, and TNBC patients, the 5-year LRR cumulative incidence rates were 1.57%, 4.09%, 10.74%, and 10.28%. Compared with Luminal A, HER2-positive subtype and TNBC had a significant increased risk of LRR (HR was 5.034 and 5.188, respectively). In univariate analysis, predictive factors for higher LRR were HER2-positive subtype (HR = 4.43, P < .05), TNBC (HR = 4.70, P < .05), and pN3 (HR = 5.83, P < .05). In the multivariate model, HER2-positive subtype (HR = 5.034, P < .05), TNBC (HR = 5.188, P < .05), and pN3 (HR = 9.607, P < .01) were independent predictors of LRR. LRR without trastuzumab was similar to that of TNBC (without vs TNBC, 17.88% vs 10.28%, P > .05) in HER2-positive subtype patients, while LRR with trastuzumab was approximate to Luminal A (with vs Luminal A, P > .05). Additionally, endocrine therapy also significantly reduced LRR incidence in the luminal subtype cohort (without vs with therapy, 6.25% vs 2.89%, HR = 0.365, P < .1). Biological subtype was a prognostic factor of LRR in the PMRT setting among Chinese breast cancer patients.

Wang J ，Luo J ，Jin K ，Wang X ，Yang Z ，Ma J ，Mei X ，Wang X ，Zhou Z ，Yu X ，Chen X ，Guo X ... -  《Cancer Medicine》

The Effect of Molecular Subtype and Residual Disease on Locoregional Recurrence in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy and Postmastectomy Radiation.

Yang TJ ，Morrow M ，Modi S ，Zhang Z ，Krause K ，Siu C ，McCormick B ，Powell SN ，Ho AY ... -  《-》

Biological Subtype Predicts Risk of Locoregional Recurrence After Mastectomy and Impact of Postmastectomy Radiation in a Large National Database.

To evaluate locoregional recurrence (LRR) after mastectomy and impact of postmastectomy radiation (PMRT) by breast cancer subtype. Between 2000 and 2009, 5673 patients with stage I to III breast carcinoma underwent mastectomy and nodal evaluation; 30% received PMRT. Isolated LRR (iLRR) and LRR were compared across groups defined by biological subtype and receipt of trastuzumab: luminal A (estrogen [ER]/progesterone [PR]+, HER2-, low/intermediate grade), luminal B (ER/PR+, HER2-, high grade), HER2 with trastuzumab, HER2 without trastuzumab, and triple negative (TN; ER-, PR-, HER2-). LRR hazard ratios (HR) were estimated with multivariable Fine and Gray models. The effect of PMRT on LRR was evaluated with Fine and Gray models stratified by propensity for PMRT. With a median follow-up time of 50.1 months, there were 19 iLRR and 109 LRR events. HER2 patients with trastuzumab had no iLRR and only a single LRR. Compared with luminal A patients, TN patients had significantly greater adjusted risk of iLRR (HR 14.10; 95% CI 2.97%-66.90%), with a similar trend among luminal B (HR 4.94; 95% CI 0.94%-25.82%) and HER2 patients without trastuzumab (HR 4.41; 95% CI 0.61%-32.11%). Although PMRT reduced LRR, the effect of PMRT varied by subgroup, with the greatest and smallest effects seen among luminal A (HR 0.17; 95% CI 0.05%-0.62%) and TN patients (HR 0.59; 95% CI 0.25%-1.35%), respectively. TN patients had the highest risk of LRR and the least benefit from PMRT; these patients may benefit from alternative treatment strategies. In contrast, in the era of HER2-directed therapy, the role of local therapy may need to be reassessed among HER2 patients.

Tseng YD ，Uno H ，Hughes ME ，Niland JC ，Wong YN ，Theriault R ，Blitzblau RC ，Moy B ，Breslin T ，Edge SB ，Hassett MJ ，Punglia RS ... -  《-》

Prognostic Significance of Progesterone Receptor Expression in Estrogen-Receptor Positive, HER2-Negative, Node-Negative Invasive Breast Cancer With a Low Ki-67 Labeling Index.

We showed the clinical implications of the Ki-67 labeling index (LI) in hormone receptor (HR)-positive, HER2-negative (HER2-) breast cancer patients with lower risk (luminal A [LA]-like) and higher risk (luminal B [LB]-like) subtypes. Three hundred sixty-nine patients with HR+, HER2- cancers were eligible and we dichotomized these patients into LA-like and LB-like according to Ki-67 LI (14% cutoff) and analyzed prognostic significance of progesterone receptor (PR) expression. Of 205 LA-like and 163 LB-like subtypes, PR was positive in 149 (73%) and 103 (63%). PR expression was a prognostic factor in the LA-like subtype but not in the LB-like subtype. In LA/PR+, LA/PR-, and LB-like subtypes, the 12-year disease-free survival (DFS) rates were 94.8%, 81.6%, and 79.7% (P = .03), and breast cancer-specific survival (BCSS) rates were 98.4%, 97.4%, and 92.0%, respectively (P = .05). Late recurrence occurred in LA/PR- subtype, and differences in prognosis between LA/PR+ and LA/PR- subtypes emerged >5 years after surgery. Twelve-year DFS rates of the LA/PR- subtype were almost equal to those of the LB-like subtype, whereas 12-year BCSS of the LA/PR- subtype was superior to that of the LB-like subtype. In multivariate analysis, PR expression and tumor size were significant or nearly significant prognostic factors. PR expression and tumor size were independent prognostic factors in the LA-like subtype, and the LA/PR- subtype had the higher risk of recurrence, especially late recurrence, than the LA/PR+ subtype. In LA-like breast cancers, stratification of prognosis according to PR expression and tumor size is important.

Ono M ，Tsuda H ，Yoshida M ，Shimizu C ，Kinoshita T ，Tamura K ... -  《-》

The influence of breast cancer subtypes on the response to anthracycline neoadjuvant chemotherapy in locally advanced breast cancer patients.

Stamatovic L ，Susnjar S ，Gavrilovic D ，Minic I ，Ursulovic T ，Dzodic R ... -  《Journal of BUON》