title: Comparison of Clinicopathological Features and Treatments between Young (≤40 Years) and Older (>40 Years) Female Breast Cancer Patients in West China: A Retrospective, Epidemiological, Multicenter, Case Only Study.
abstract: The incidence of young cases of breast cancer is higher in China compared to the western world. We aimed to explore differences in risk factors, clinicopathological features and treatment modes of young female breast cancer compared to older patients in West China. We collected clinical information from 12,209 female breast cancer patients in West China, including risk factors, clinicopathological features and treatment modes, from January 2010 to December 2012. Chi-square tests and the multivariate logistic regression analysis were applied for statistical analysis. There were 2,682 young (≤40 years) cases and 9,527 older cases at the time of breast cancer diagnosis. Young patients had a greater tumor diameter at diagnosis, and a higher probability of axillary lymph node and distant metastasis (P < 0.05). The progesterone receptor positive expression rate, estrogen receptor/progesterone receptor double positive expression rate, and human epidermal growth factor receptor 2 (HER2) negative expression rate was higher in young patients compared to older patients (P < 0.05). For young patients, the age at menarche was earlier, they had lower marriage rates, fewer pregnancies and births, and a lower breastfeeding rate (P < 0.05). A higher proportion of young patients underwent advanced operations, neoadjuvant and adjuvant chemotherapy, radiotherapy, and endocrine therapy compared to older patients (P < 0.05). We found significant differences in the clinicopathological features, risk factors and treatment modes between young (≤40 years) and older (>40 years) female breast cancer patients in West China. As some of these results differ from those found in the western female population, it is likely that the mechanism of tumorigenesis of young female breast cancer patients in West China may differ from that in western developed countries. Further investigation into the regional differences in breast cancer tumorigenesis is warranted.
authors.affiliation: Department of Breast Surgery, the First Affiliated Hospital of Xi'an Jiaotong Universtiy, Xi'an, Shaanxi Province, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Breast Surgery, the First Affiliated Hospital of Xi'an Jiaotong Universtiy, Xi'an, Shaanxi Province, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Zheng
authors.affiliation: Department of Breast Disease Center, Third Military Medical University, Chongqing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Breast Cancer Research Center, Yunnan Tumor Hospital, Kunming, Yunnan Province, China.
authors.forename: Tianning
authors.initials: T
authors.lastname: Zou
authors.affiliation: Department of Breast and Neck Surgery, Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang Province, China.
authors.forename: Binlin
authors.initials: B
authors.lastname: Ma
authors.affiliation: Department of Breast Surgery, Sichuan Province Tumor Hospital, Chengdu, Sichuan Province, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Surgical Oncology, Affiliated Hospital of Ningxia Medical University, Yinchuan, Ningxia Province, China.
authors.forename: Qilun
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Breast Surgery, Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang Province, China.
authors.forename: Jianghua
authors.initials: J
authors.lastname: Ou
authors.affiliation: Department of Vascular and Endocrine Surgery, Xijing Hospital of Fourth Military Medical University, Xi'an, Shaanxi Province, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Breast Surgery, Cancer Hospital of Guangxi Medical University, Nanning, Guangxi Province, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: Department of Breast Surgery, the First Affiliated Hospital of Xi'an Jiaotong Universtiy, Xi'an, Shaanxi Province, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Ren
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000401:mortality / Q000628:therapy; D002681:China / Q000453:epidemiology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D012189:Retrospective Studies
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human