RESUMEN
BACKGROUND: Incidence of ductal carcinoma in situ (DCIS) has increased in recent decades because of breast cancer screening. This study comprised a long-term survival analysis of DCIS using 10-year territory-wide data from the Hong Kong Cancer Registry. METHODS: This study included all patients diagnosed with DCIS in Hong Kong from 1997 to 2006. Exclusion criteria were age <30 years or ≥70 years, lobular carcinoma in situ, Paget's disease, and co-existing invasive carcinoma. Patients were stratified into those diagnosed from 1997 to 2001 and those diagnosed from 2002 to 2006. The 5- and 10-year breast cancer-specific survival rates were evaluated; standardised mortality ratios were calculated. RESULTS: Among the 1391 patients in this study, 449 were diagnosed from 1997 to 2001, and 942 were diagnosed from 2002 to 2006. The mean age at diagnosis was 49.2±9.2 years. Overall, 51.2% of patients underwent mastectomy and 29.5% received adjuvant radiotherapy. The median follow-up interval was 11.6 years; overall breast cancer-specific mortality rates were 0.3% and 0.9% after 5 and 10 years of follow-up, respectively. In total, 109 patients (7.8%) developed invasive breast cancer after a considerable delay. Invasive breast cancer rates were comparable between patients diagnosed from 1997 to 2001 (n=37, 8.2%) and those diagnosed from 2002 to 2006 (n=72, 7.6%). CONCLUSION: Despite excellent long-term survival among patients with DCIS, these patients were more likely to die of breast cancer, compared with the general population of women in Hong Kong.
Asunto(s)
Neoplasias de la Mama/mortalidad , Carcinoma Intraductal no Infiltrante/mortalidad , Detección Precoz del Cáncer/mortalidad , Adulto , Anciano , Neoplasias de la Mama/terapia , Carcinoma Intraductal no Infiltrante/terapia , Femenino , Hong Kong/epidemiología , Humanos , Incidencia , Análisis de Series de Tiempo Interrumpido , Tamizaje Masivo/mortalidad , Mastectomía/mortalidad , Persona de Mediana Edad , Radioterapia Adyuvante/mortalidad , Sistema de Registros , Análisis de Supervivencia , Tasa de Supervivencia , Factores de TiempoRESUMEN
AIMS: The LORIS trial is an ongoing phase III clinical trial on low risk ductal carcinoma in situ (DCIS). DCIS patients aged ≥46 years with screen-detected low/intermediate nuclear grade were considered low risk and were randomised into surveillance or standard surgery. Here we review the 10-year territory-wide breast cancer registry database and evaluate the clinical outcomes of low versus high risk DCIS patients. MATERIALS AND METHODS: This was a retrospective study of a prospectively maintained territory-wide breast cancer registry in Hong Kong. RESULTS: Between 1997 and 2006, 1391 DCIS patients were identified from the Hong Kong cancer registry breast cancer database. The mean age at diagnosis was 49.2 years (range 30-70). In total, 372 patients were classified as 'low risk', whereas the remaining 777 patients were classified as 'high risk'. After a median follow-up of 11.6 years, the 10-year overall breast cancer-specific survival of the entire DCIS cohort was 1136/1149 (98.9%). Overall breast cancer-specific survival of low risk DCIS was 99.5%, whereas that in high risk DCIS was 98.6% (Log-rank test, P = 0.208). Forty-six (12.4%) patients in the LORIS low risk group did not receive surgery, whereas 93 (12%) patients in the LORIS high risk group did not receive surgery. The 10-year breast cancer-specific survival in the non-operated low risk DCIS group was 97.8%; that in the non-operated high risk DCIS group was 96.7% (P = 1). CONCLUSION: Long-term survival of DCIS was excellent, especially in low risk DCIS, regardless of surgical treatment.