[Clinicopathological features and prognosis of hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer].

objectiveTo investigate the clinicopathological features and prognosis of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2 -) breast cancer.

methodsIn the study, 3 035 consecutive breast cancer patients diagnosed in Breast Disease Center, Peking University First Hospital from January 2008 to December 2017 were collected. The prognostic signi-ficance of important pathological factors in HR +/HER2 - patients with complete clinicopathological information was analyzed.

resultsWithin the 1 920 (63.26%) cases of HR +/HER2 - breast cancer, there were 1 624 cases with complete clinicopathological data, of which, 124 cases (7.64%) recurred and/or metastasized and 63 cases died of the disease, and the 5-year overall survival (OS) rate and disease-free survival (DFS) rate was 93.0% and 92.6% respectively. The stage of pT1-2 was 92.80%, while pN0 was 69.03%. 89.66% cases belonged to histologically non-specific type and 30.11%, 55.60%, 14.29% were credited to Grade 1, 2 and 3 respectively. The distribution of ER negative, low or high expression groups were 1.60%, 2.09% and 96.31%, while PR were 6.83%, 10.47%, 82.70%, respectively. The group of Ki67 index < 10% was 19.52%, ≥10% & < 20% for 32.02%, ≥20% for 48.46%. Survival analysis showed that cases with pT1 stage had lower risk of recurrence than those with pT3, while cases with pT2 and pT3 had shorter DFS than those with pT1, with higher risk of recurrence and metastasis. Analysis proved that both pN stage and histological grade were negatively correlated with DFS. The cases with pN0, pN1 and pN2 were lower risk of recurrence than those with pN3, while cases with Grade 1 and 2 had lower risk of recurrence than cases with Grade 3. And the group of Ki67 index ≥20% showed higher risk of recurrence and metastasis. The prognostic significance of ER expression in HR+/HER2- breast cancer was not significant. However, the negative/low PR expression groups showed higher risk of recurrence and metastasis, of which PR < 10% group had shortest DFS and OS, followed by 10%-60% group and then > 60% group. The most common site of metastasis was bone (55 cases, 44.35%), while cases with liver metastasis (30 cases, 24.20%) had the worst outcome.

conclusionOur study revealed that pT, pN, Grade, HR expression level and Ki67 index were important prognostic factors for HR +/HER2 - breast cancer, although there are variables in prognostic value. Factors of pN and Grade showed independent prognostic significance. PR expression level had prognostic significance for the risk of recurrence and metastasis. The stratified level of PR expression (< 10%, 10%-60%, >60%) had independent prognostic value, showing successively longer DFS and OS, lower risk of recurrence. PR>60% group had the longest DFS and OS as well as the lowest risk of recurrence.