Clinical characteristics and clinicopathological correlations of bilateral breast cancer in China:A multicenter study from Chinese Society of Breast Surgery(CSBrS-006)

Objective:To investigate the clinical characteristics and clinicopathological correlations of bilateral breast cancer(BBC)in China.Methods:Data of 440 patients diagnosed with BBC in 2018 were collected from 33 centers of the Chinese Society of Breast Surgery.Demographic characteristics,bilateral tumor characteristics,and comprehensive treatment data were obtained.Correlations between the clinicopathological characteristics of bilateral tumors were analyzed.Results:The proportion of BBC was 0.22%-3.08%.A total of 33(7.5%)patients had a family history of malignant tumors,304(69.1%)patients had synchronous BBC.Only 1(0.2%)patient was male.More than half of all patients received concurrent or asynchronous endocrine/chemotherapy,32.5%of all human epidermal growth factor receptor 2(HER2)-positive patients received HER2-targeted therapy,and approximately 21.6%of all patients received radiotherapy.The most common pathological cancer type was invasive ductal cancer(>60%).Approximately 70%of all patients had bilateral hormone receptor(HR)-positive tumors and presented with a single breast mass.Significant correlations were found with pathological type,histological grade,locations of tumor,molecular subtype,Ki-67 index,tumor site and size of bilateral tumors.Results of the subgroup analysis showed more clinicopathological characteristics when synchronous BBC was compared with metachronous BBC.Conclusions:In China,the clinicopathological characteristics of bilateral tumors showed significant correlations,and more significant clinicopathological correlations were observed when synchronous BBC was compared with metachronous BBC.

Metaplastic breast cancer with chondrosarcomatous differentiation combined with concurrent bilateral breast cancer:A case report

BACKGROUND Metaplastic breast carcinoma(MBC)is a rare subtype of invasive breast cancer comprising malignant epithelial and mesenchymal cells.Compared with other invasive breast cancers,MBC is not only histologically distinctly heterogeneous but also has a rapid and aggressive growth pattern,which leads to a significant risk of recurrence and mortality.CASE SUMMARY In this study,we report the case of a patient with a large left breast mass diagnosed with bilateral invasive ductal carcinoma in both breasts after a preoperative core needle aspiration biopsy of the bilateral breast mass.The patient received neoadjuvant chemotherapy and underwent bilateral breast modified radical mastectomy.Postoperative pathology suggested carcinosarcoma with predominantly chondrosarcoma in the left breast and invasive ductal carcinoma(luminal B)in the right breast.As the patient did not achieve complete pathological remission after six cycles of neoadjuvant chemotherapy,we administered six months of intensive capecitabine treatment.Then the patient was switched to continuous treatment with endocrine therapy using letrozole+goserelin,and the patient is currently in stable condition.However,as MBC of the breast is concurrently diagnosed with chondrosarcoma differentiation,our case is sporadic.CONCLUSION Given the variety of immunohistochemical types of bilateral breast cancer,achieving effective chemotherapy should be a key research focus.

Benefits and Limitations of Volumetric Modulated Arc Therapy in Treating Bilateral Breast Cancer with Regional Lymph Nodes

Purpose: The study was performed comparing dosimetric characteristics of volumetric modulated arc therapy (VMAT) and field-in-field (FiF) techniques on a patient with synchronous bilateral breast carcinoma. Methods: The patients with bilateral breast cancer treatment were included in this study. A total dose of 40.05 Gy in 15 fractions was prescribed to the Planning Target Volume (PTV) of the whole bilateral breast cancer with the supraclavicular and infraclavicular nodes, with a complementary boost of 10 Gy in 4 fractions to the surgical bed (PTVboost). For both radiotherapy techniques, several VxGy parameters were analyzed for the PTVs, together with the Conformity index (CI), the Homogeneity index (HI) and the critical organs at risk (OARs), lungs and heart. Results: The patient was treated by the VMAT technique and the daily treatment time was less than 20 minutes with daily CBCT imaging. In the VMAT plan, the PTV 95% dose covered 38.89 ± 0.81 Gy, compared to 37.26 ± 1.02 Gy in the FiF technique. The VMAT plan improved the dose homogeneity index and lower dose in lung towards high dose region. Conclusion: The study demonstrates the viability of the VMAT technique in the treatment of bilateral breast cancer. The introduced single isocentric VMAT technique is fast to deliver and it increases the dose homogeneity of the target volume with some limitations. The treatment was well tolerated, without interruption of the treatment courses caused by treatment-related toxicities.

Optimizing Adjuvant Radiation Planning Outcomes in Patients with Synchronous Bilateral Breast Cancer

Background: Breast cancer is the most common cancer diagnosed worldwide, synchronous bilateral breast cancer accounts for unique entity of the disease, particularly post-operative radiotherapy for Synchronous Bilateral Breast Cancer (SBBC) is challenging with lack of evidence about the best irradiation technique. In this study, we tried to explore the optimum radiotherapy technique regarding the dosimetric parameters. Methods: We recruited 15 SBBC patients in whom post-operative radiotherapy was indicated and we established three plans for each patient using 3DCRT, IMRT and VMAT, and then we compared the three plans as regard target volume coverage parameters and organs at risk (OAR) doses. Results: We found that PTV coverage parameter was superior with IMRT compared with 3DCRT and VMAT in terms of Dmean (p = 0.001), D95% (p = 0.001), Dmax (p = 0.0001), conformity index (p = 0.0001) and HI (p = 0.0001). Doses to OAR were not significantly different between the three techniques in cardiac dose and LAD maximum dose, but 3DCRT was superior in LAD mean dose (p = 0.03) and lung volume receiving 20 Gy (V20) and 10 Gy (V10) (p = 0.0001), but this difference was non-significant between 3DCRT and IMRT (p = 0.4 and 0.06 respectively), while VMAT led to the highest doses to LAD and lung. Conclusions: IMRT showed the best target coverage parameters in post-operative radiotherapy for SBBC compared with 3DCRT and VMAT. For OAR doses IMRT showed comparable results with 3DCRT, while VMAT delivered a significantly higher dose to OAR.