Clinicopathologic features of breast cancer patients with type 2 diabetes mellitus in southwest of China.

The aim of this study was to study the prevalence and clinicopathologic features of breast cancer patients with type 2 diabetes mellitus in southwest of China for providing clinical guidance and prognosis appreciation for these patients. Through a case-control study of 3,381 primary breast cancer patients initially diagnosed from January 2007 to May 2013, one case group (164 female breast cancer patients with type 2 diabetes) and two control groups (first control group consists of 328 randomly selected nondiabetic breast cancer patients and second control group consists of 279 nondiabetic breast cancer patients without diabetes-related diseases such as cardiovascular or cerebrovascular diseases) were selected. The clinicopathological features between them were statistically analyzed. (1) Of 3,381 primary breast cancer patients with the average age of 50.5, ranging from 21 to 97 years of age, 164 (4.9 %) cases (with the average age of 60.7) suffered diabetes (previously diagnosed diabetes). (2) The differences of clinicopathologic features between the case group and first control group (with the average age of 61.5) were the ratio of hypertension (41.5 vs 26.1 %, P = 0.001) and axillary lymph node metastasis (51.1 vs 38.1 %, P = 0.046); and the differences of clinicopathologic features between the case group and second control group (with the average age of 64.3) were axillary lymph node metastasis (51.1 vs 35.8 %, P = 0.017), tumor size (≥ T2: 62.3 vs 53.1 %, P = 0.019) and p53 expression (51.0 vs 62.7 %, P = 0.018). No statistical significances (P > 0.05) of histological type, histological grade, or the expressions of estrogen receptor (ER), progesterone receptor, human epidermal growth factor 2 (HER2) and Ki67 were found between them. (3) The clinicopathologic features of ER-positive and ER-negative patients in each group were as follows: (1) In the case group, the ER-negative patients have more advanced tumor histological grade (G3, 19.0 vs 2.8 %, P = 0.012), more positive expression of Her-2 (16.9 vs 8.1 %, P = 0.029) and more axillary lymph node metastasis (63.3 vs 44.4 %, P = 0.048). (2) In the first control group, the same results with tumor histological grade (G3, 15.6 vs 6.2 %, P = 0.025) and positive expression of Her-2 (16.7 vs 4.3 %, P = 0.001), and more positive expression of Ki67 (65.1 vs 52.0 %, P < 0.001) were found. (3) In the second control group, the ER-negative patients have more positive expression of Ki67 (70.5 vs 55.7 %, P = 0.009) and fewer family history of malignancy (1.9 vs 10.0 %, P = 0.013). Diabetes has a high incidence in breast cancer patients and is more common with postmenopausal patients. It is suggested that initially diagnosed breast cancer patients should undertake oral glucose tolerance test screening for occult diabetes and prediabetes. More concerns should be put onto diabetic patients with breast cancer.