High HER2 Intratumoral Heterogeneity Is a Predictive Factor for Poor Prognosis in Early-Stage and Locally Advanced HER2-Positive Breast Cancer.

PURPOSE: Breast cancer tumors frequently have intratumoral heterogeneity (ITH). Tumors with high ITH cause therapeutic resistance and have human epidermal growth factor receptor 2 (HER2) heterogeneity in response to HER2-targeted therapies. This study aimed to investigate whether high HER2 heterogeneity levels were clinically related to a poor prognosis for HER2-targeted adjuvant therapy resistance in primary breast cancers. METHODS: This study included patients with primary breast cancer (n = 251) treated with adjuvant HER2-targeted therapies. HER2 heterogeneity was manifested by the shape of HER2 fluorescence in situ hybridization amplification (FISH) distributed histograms with the HER2 gene copy number within a tumor sample. Each tumor was classified into a biphasic grade graph (high heterogeneity [HH]) group or a monophasic grade graph (low heterogeneity [LH]) group based on heterogeneity. Both groups were evaluated for disease-free survival (DFS) and overall survival (OS) for a median of ten years of annual follow-up. RESULTS: Of 251 patients with HER2-positive breast cancer, 46 (18.3%) and 205 (81.7%) were classified into the HH and LH groups, respectively. The HH group had more distant metastases and a poorer prognosis than the LH group (DFS: p < 0.001 (HH:63% vs. LH:91% at 10 years) and for the OS: p = 0.012 (HH:78% vs. LH:95% at 10 years). CONCLUSIONS: High HER2 heterogeneity is a poor prognostic factor in patients with HER2-positive breast cancer. A novel approach to heterogeneity, which is manifested by the shape of HER2 FISH distributions, might be clinically useful in the prognosis prediction of patients after HER2 adjuvant therapy.

A Comparison of the Oncological Outcomes After Breast-Conserving Surgery With or Without Latissimus Dorsi Myocutaneous Flap Reconstruction for Breast Cancer.

BACKGROUND: There is little information on the oncological outcomes of breast-conserving surgery (BCS) with immediate reconstruction using a latissimus dorsi myocutaneous flap (LDMF) for breast cancer compared with BCS alone. PATIENTS AND METHODS: We conducted a retrospective cohort study from a single institution comparing the margin positivity rates after initial surgery, re-excision rates, and local recurrence (LR) between BCS with immediate LDMF reconstruction (n = 145) and BCS alone (n = 1040) performed from 2012 to 2017 for newly diagnosed stage 0-3 breast cancer. RESULTS: The positive rates of surgical margin after initial surgery were significantly lower in the BCS with LDMF group than in the BCS alone group (4.1 vs. 10.8%; P = .006). There were no marked differences in the re-excision rates between the BCS with LDMF and BCS alone groups (P = .1). At a median follow-up of 61 months, the surgical method (BCS with LD vs. BCS alone) was not associated with the LR-free survival after adjusting for various clinicopathologic factors (P = .8). CONCLUSION: Our findings suggest that BCS with immediate LDMF reconstruction is oncologically safe for breast cancer compared with BCS alone. However, further studies are needed.

Axillary management based on American college of surgeons oncology group Z0011 criteria makes it possible to omit intraoperative diagnosis of sentinel lymph nodes in early breast cancer patients.

The ACOSOG Z0011 trial has resulted in the omission of axillary lymph node dissection (ALND) in early breast cancer patients with one or two metastatic sentinel lymph nodes (SLNs). There has been increasing interest in the necessity of intraoperative assessment of SLNs in patients treated based on the Z0011 criteria. We evaluated the utility of intraoperative assessment in these eligible patients. A total of 1396 patients were treated following the Z0011 criteria from April 2012 to December 2019. We examined the proportion and clinicopathological features of patients who underwent ALND due to three or more metastatic SLNs and the sensitivity of intraoperative assessment. Only 16 (1.1%) patients had three or more metastatic SLNs diagnosed by intraoperative assessment, and they immediately underwent ALND. Of the clinicopathological factors, high clinical tumor stage (p = 0.002) and high Ki-67 labeling index value (p = 0.056) were more likely to be associated with the presence of three or more metastatic SLNs. The major independent risk factor for three or more metastatic SLNs was high clinical tumor stage (OR 3.94 [95% CI 1.42-11.0]; p = 0.009). Intraoperative assessment had low sensitivity (70.5%) and a high false-negative rate (29.5%) in detecting SLN metastases. The main finding of our study was the small proportion of patients who required ALND due to three or more metastatic SLNs according to the Z0011 criteria. The Z0011 strategy enables intraoperative assessment of SLNs to be omitted in early breast cancer patients.

[Primary Rhabdomyosarcoma of the Breast in a 16-Year-Old Girl].

We report a case of primary breast rhabdomyosarcoma. A 16-year-old girl noticed tumor of her right breast and consulted a local clinic. From the result of core needle biopsy, breast sarcoma was suspected, so she attended our hospital. Breast ultrasonography showed a mosaic pattern tumor occupying the whole right breast. CT images revealed an axillary node metastasis and no distant organ metastasis. Immunohistochemical staining of the tumor yielded positive results for desmin, MyoD1, and myogenin. Based on reverse transcription polymerase chain reaction(RT-PCR), she was diagnosed as an alveolar rhabdomyosarcoma with PAX3-FKHR(FOXO1)fusion transcripts[t(2;13)(q35;q14)]. She underwent total mastectomy and dissection of axillary lymph nodes. After surgery, the whole-body magnetic resonance imaging(MRI) demonstrated metastases of sacrum and left foot, so she was under systemic chemotherapy.