Ductal carcinoma in situ of breast: detection and treatment pattern in Hong Kong.

INTRODUCTION

The treatment of ductal carcinoma in situ has been widely reported in the western and other Asian countries, but the relevant data in Hong Kong are relatively limited. This study aimed to evaluate the latest detection and treatment pattern for ductal carcinoma in situ in Hong Kong so as to guide planning of future service provision.

METHODS

This was a retrospective case series study. A total of 573 patients who registered with the Hong Kong Breast Cancer Registry, and were diagnosed and treated in Hong Kong from January 2001 to December 2011 were reviewed.

RESULTS

Compared with invasive breast cancer patients, patients with ductal carcinoma in situ were younger (median, 48.6 vs 50.3 years; P<0.001), had a higher education level (P<0.001), had a higher total monthly family income (P<0.001), and more common breast-screening habits (P<0.001). Significantly more patients with ductal carcinoma in situ underwent breast-conserving surgery than their invasive cancer counterparts (55.8% vs 36.7%; P<0.001). The percentage of screen-detected ductal carcinoma in situ was relatively lower than that reported in other studies, but was still much higher than that in invasive breast cancer patients (29.0% vs 4.7%; P<0.001). Screen-detected patients with ductal carcinoma in situ tended to choose a private hospital instead of a public hospital for treatment (P=0.05) and to undergo breast-conserving surgery (P=0.02). With a median follow-up of 3 years, the crude local recurrence rate after mastectomy and breast-conserving surgery was 0.4% and 3.3%, respectively; 44% of recurrent tumours had developed invasive components. No regional recurrence, distant recurrence, or cancer-related deaths were recorded.

CONCLUSIONS

In the absence of a population-based breast screening programme in Hong Kong, ductal carcinoma in situ is more frequently found in the higher social classes and managed in the private sector. The clinical outcome of ductal carcinoma in situ is excellent and more than half of the patients can be successfully managed with breast-conserving surgery.