Early Detection of Breast Cancer through Population-Based Mammographic Screening in Asian Women: A Comparison Study between Screen-Detected and Symptomatic Breast Cancers

Abstract

The first nation-wide mammographic screening program in Asia, BreastScreen Singapore (BSS), was launched in Singapore in January 2002. This study compared the presentation and results of screen-detected breast cancers with symptomatic breast cancers in two affiliated high-volume institutions, one of which was an assessment centre for BSS. The medical records of patients diagnosed with primary breast cancer at the Department of General Surgery, Singapore General Hospital and the Department of Surgical Oncology, National Cancer Centre, Singapore, during the period January 2002 to December 2003 were reviewed. Clinical and pathological comparisons were made between screen-detected lesions and symptomatic lesions. Of a total of 767 cases, 640 (83.4%) were invasive carcinomas and 127 (16.6%) were ductal carcinoma in-situ (DCIS) lesions. Only 13.4% of them were screen-detected. Compared to symptomatic cancers, screen-detected lesions were of smaller size (median size 18 versus 23 mm), a lower stage (stages 0-2, 95 versus 83.2%) and histologic grade (grade 1-2, 71 versus 60%), with a higher incidence of DCIS (31.0 versus 14.3%) and had higher rates of breast conservation (45.6 versus 28.2%) (all p-values <0.05). By multivariate analysis, tumor palpability, tumor size >20 mm, nodal involvement, cerbB2 overexpression, and advanced disease stage were independent poor prognostic factors for disease-free survival, whereas nodal involvement, advanced disease, and recurrence predicted poor cancer-specific survival. However, there was no statistically significant difference in disease-free survival or cancer-specific survival between the two groups at a median follow-up of 38 months. Screening mammography has allowed the detection of smaller and hence oncologically more favorable lesions in Asian women. Although no significant survival benefit was demonstrated in our study, a longer period of follow-up is essential before the benefit of mortality reduction, as a result of mammography screening becomes evident in our population.

Comparison of clinical and pathological characteristics between screen-detected and self-detected breast cancers: a Hong Kong study

“…This is consistent with the findings of similar studies in other countries, such as Singapore. 6 This study may provide evidence that supports the benefits of regular screening to detect breast cancer lesions at an early stage in Hong Kong women. This will facilitate less invasive surgery and a possibly better overall clinical outcome.…”

Evaluation of Eligibility and Utilization of Breast Conservation Treatment in an Asian Context

“…The majority of the patients in the study cohort were Chinese, and expected to have similar physical attributes in terms of breast tissue volume as Chinese women elsewhere. Still, BCT rates in the study cohort are higher than in other Chinese-dominant countries (Chuwa et al, 2009;Yau et al, 2009;Yip et al, 2009;Chang et al, 2011;Wang et al, 2011) and are similar to, if not also higher than, those reported in Western countries (Lee et al, 2009;McGuire et al, 2009;Garcia-Etienne et al, 2012;Agarwal et al, 2014). Hence, the issue of smaller breast tissue volume and its impact on BCT rates needs further investigation.…”

Economic burden of patients with inoperable advanced breast cancer receiving early or late capecitabine or trastuzumab as second-line treatment: A population-based study

“…The obtained results showed that the IABC incidence rates reduced from 2004 to 2006, possibly because of the annual increase in early screening and detection [28,29] . However, the proportion of capecitabine or trastuzumab administration has increased in the recent years, indicating that higher patients with IABC are receiving ATT and ATC.…”