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Analysis of Local Failure After Breast Conserving Therapy for Locally Advanced Breast Cancer

Reviewer: S. Jack Wei, MD
Abramson Cancer Center of the University of Pennsylvania
Ultima Vez Modificado: 22 de octubre del 2003

Presenter: Eugenio F. Vines, MD
Presenter's Affiliation: Instituto de Radiomedicina, Santiago, Chile
Type of Session: Scientific

Background

Locally advanced breast cancer remains a large problem in developing countries. The standard treatment for LABC remains mastectomy; however, in Chile, patients with LABC who achieve adequate response to neoadjuvant chemotherapy are offered breast conserving therapy (BCT). This study analyzes local control following BCT for LABC treated with neoadjuvant chemotherapy and identifies some potential predictive factors for this treatment.

Materials and Methods

• Patients with LABC were treated with pre-operative anthrcycline-based chemotherapy.
• After evaluation at a multi-disciplinary oncology conference, patients deemed suitable candidates were offered BCT.
• BCT consisted of an oncologic surgical resection of the tumor with axillary dissection and radiation therapy (RT) consisting of 45-50 Gy to the whole breast, supraclavicular nodes, and internal mammary nodes and a 14-16 Gy boost to the tumor bed.
• Patients determined to be borderline candidates were treated with neoadjuvant RT followed by the same surgery.
• After BCT, patients were offered consolidation chemotherapy.
• Tamoxifen was used for all ER(+) patients.

Results

• 300 patients with LABC were treated from 1989-2002.
• 71 of these patients underwent treatment with BCT.
• Median age of those undergoing BCT was 48 yrs (range 21-64).
• 20% of patients were less than 40 years old.
• 81% of patients had tumors >5 cm in size.
• 92% of patients were stage IIIa.
• 47% of patients were ER(+)
• 59% of patients underwent post-operative RT while 41% underwent pre-operative RT.
• Median FU = 57 mo.
• 5-year overall survival = 97%
• 5-year disease-free survival = 76%
• 5-year local control (LC)= 89%
• 25% of patients experience distant metastatic failure, 5% local failure, and 3% region failure (all in the supraclavicular fossa).
• A significant difference in LC was seen for patients when analyzed by age (patients < 40 yrs did worse, p=0.002) and a trend towards difference in LC was seen for patients when analyzed by ER status (ER(+) did worse, p=0.09).
• No difference was seen when patients were analyzed by T size, response rate, pre- vs. post-menopausal, or pre- vs. post-operative RT.
• On multivariate analysis, only age was found to be a significant predictor for LC

Author's Conclusions

• Overall survival, local control, and regional control were all adequate with this treatment regimen of BCT following neoadjuvant chemotherapy for LABC.
• More research and follow-up is needed to confirm the efficacy of this treatment.
• Younger patients should not be treated with BCT following neoadjuvant chemotherapy for LABC outside of a research protocol.

Clinical/Scientific Implications

This study reports high levels of local-regional control and overall survival in patients with LABC treated with neoadjuvant chemotherapy. To date, there are no randomized trials examining the efficacy of this treatment; however, this study in conjunction with several other non-randomized studies have indicated that BCT is feasible even in the setting of locally advanced disease. The risk of recurrence for breast cancer remains significant, even years after completion of treatment. It is important to note that the good control seen in this study is found over a limited follow-up time, and further follow-up is needed to demonstrate continued efficacy of this treatment. In addition, the findings that women less than age 40 had a lower rate of local control indicates that BCT should be used judiciously for this patient population with LABC. A randomized trial of BCT in LABC is warranted.

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