Changing patterns and survival improvements of young breast cancer in China and SEER database, 1999-2017.

Rong Guo,Yayun Chi,Jing Si,Jiong Wu,Benlong Yang,Jingyan Xue,Miao Mo,Qi Zhang,Yonghui Su,Weiru Chi

doi:10.21147/j.issn.1000-9604.2019.04.09

Abstract

ObjectiveBreast cancer in young females was usually considered more aggressive and requires aggressive therapy. We investigated whether early detection and improved treatments changed the patterns of characteristics, management and outcomes of young breast cancer patients over time.MethodsFemales under 40 years of age diagnosed with breast cancer during the periods 1999−2017 and 1999−2015 were identified in the Fudan University Shanghai Cancer Center (FUSCC) and the population-based Surveillance, Epidemiology, and End Results (SEER) registry, respectively. Clinicopathologic characteristics and treatment information were collected. Patients diagnosed before 2013 were followed up.ResultsThe proportions of young breast cancer patients were 15.0% and 5.3% in the FUSCC and SEER cohorts, respectively. In the FUSCC cohort, there was a significant increase in the proportion of ductal carcinoma in situ (DCIS) (from 8.8% to 16.9%; P<0.0001) and it remained stable in SEER cohort. The proportion of T1-stage tumors increased dramatically in the FUSCC cohort (from 35.3% to 41.9%; P=0.008), whereas it decreased in SEER cohort (from 42.4% to 33.0%; P<0.0001). The percentage of estrogen receptor (ER)-positive cancers was consistently increased in both the invasive ductal carcinoma (IDC) and DCIS patients in the two cohorts. Breast-conserving surgery and immediate implant reconstruction after mastectomy both exhibited increased use over time in the FUSCC cohort. Both the FUSCC and SEER cohorts showed a significantly better prognosis in the recent time period. ConclusionsWith the increased early-stage and ER-positive diseases in young patients as well as better systemic treatment strategies, improved survival has been observed in recent years. There has been a substantial de-escalation in surgical therapies in young breast cancer patients.

Highlights

Breast cancer is still the most common cancer incidence and mortality worldwide among 20−39-year-old women [1]
The SEER cohort was derived from the SEER database (November 2015 submission) by using SEER*Stat software provided by the National Cancer Institute (NCI)
We found that patients diagnosed after 2008 had significantly longer breast cancer-specific survival (BCSS) than patients diagnosed before 2008 (HR=0.826, 95% confidence interval (95% CI), 0.780−0.876, P

Summary

Introduction

Breast cancer is still the most common cancer incidence and mortality worldwide among 20−39-year-old women [1]. The incidence and mortality of breast cancer in young patients have experienced an increase these years. In 2012, the incidence rate was 30.2% and the mortality rate was 25.1% in all the young patients diagnosed as cancer [1]. In China, over 50,000 women under the age of 40 are diagnosed as breast cancer each year. Chin J Cancer Res 2019;31(4):653662 most common cancer diagnosed in young adults [2,3]. In the 20- to 39-year-old age group, breast cancer is the leading cause of death in China [2]. Young breast cancer has become a major public health problem

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