Effect of young age, positive margins, and triple negative status on disease recurrence after breast conserving therapy

Background: To determine the risk factors for disease recurrence after breast conserving therapy (BCT) for breast cancer in a group of South-East Asian women. Methods: Medical and pathological records of women who underwent BCT during the 10-year period from 2001 to 2010 were reviewed. Data collected included age <= 35 years defined as the young, type of operation, pathological data, hormonal receptor (HR) status, human epidermal growth factor receptor-2 (HER-2) expression status, and surgical margin status. Data on adjuvant therapy were also collected. Main outcomes were overall breast cancer recurrence, locoregional, and distant recurrence. Risk factors for each type of recurrence were identified using Cox proportional hazards regression models. Results: There were 294 BCTs in 290 patients during the study period. The overwhelming majority (91%) had early stage (stages I-II) breast cancers. Young age patients constituted 9% of all patients, and triple negative cancers (HR negative and HER-2 negative) were seen in 19%. Involved margins on initial surgery were found in 9% of cases, and after reoperation, only 2% had involved margins. After a median follow-up of 50 months, and a maximum follow-up of 135 months, there were 30 recurrences and 6 deaths. Of the 30 recurrences, 19 included locoregional, 20 included distant, and 13 had in-breast recurrences. The disease-free survival at 10 years was 82.5% (95% CI: 74.8% to 88.1%), and the cumulative in-breast recurrence was 9.3% (95% CI: 4.9% to 17.2%) at 10 years. Multivariable Cox regression analysis revealed that young age, larger tumor size, involved margins, and no breast irradiation were associated with higher risk of locoregional recurrence. Triple negative status, larger tumor size, more positive nodes, and involved margins were associated with higher risk of distant recurrence. Conclusions: We found young age to be a significant prognosticator of locoregional recurrence, and triple negative status of distant recurrence. Involved surgical margin status was associated with both recurrences. Tumor size was associated with both recurrences, and axillary lymph node metastasis was associated with distant recurrence.