Radiotherapeutic management of isolated local-regional recurrence following mastectomy.

Abstract

Abstract Abstract #5135 Background: Postmastectomy isolated local-regional recurrence(ILRR) remains a therapeutic challenge. This retrospective study aims to evaluate the role of radiotherapy(RT) in these patients and to analyze factors that influence local-regional control and survival.
 Methods: 255 pts with chest-wall(CW) and/or regional nodes recurrence(supraclavicular SC, axillary AXI and internal mammary nodes IMN) as first failure and received RT during 1990 and 2005 were analyzed, included 109 CW recurrence only, 114 regional nodes only and 32 pts with both, resulted in 304 recurrent sites. The median dose was 60Gy(47-74). Systemic treatment was give to 190 pts, including chemotherapy in 171, endocrine therapy(ET) in 69, and both in 41 pts.
 Results: The median disease-free interval(DFI) was 22 mo(2-260 mo), which were 37 and 17 mo in pts with positive hormonal receptor (HR) and negative HR respectively. Median follow-up was 45 mo (9 mo -15.5 yrs). The 2, 5 and 8-yr overall survival rate was 86.4%, 56.5% and 35% respectively. Median survival time after recurrence was 79 mo. The 2, 5 and 8-yr local control rate was 56.1%, 36.3% and 27.6% respectively. 79 second recurrence in the initial recurrent region and 83 subsequent recurrence in other local-regional sites were found.
 
 CW is the most common site of second recurrence. Multivariate analysis showed that no CW involvement, non-diffuse recurrence and radiation to the entire recurrent region were independent prognostic factors on local control of initial recurrent sites. ET proved to be the only independent prognostic factors on subsequent recurrence in other sites. In pts with CW recurrence, small field(67 pts) resulted in significantly lower 5-yrs local control compared to entire CW irradiation(74 pts) (33.6% vs 55.6%, p=0.023). Cox regression model found that DFI≥1yr, positive HR, solitary CW or non-supraclavicular nodal recurrence were independent favorable prognostic factors on overall survival .
 Conclusions: RT is an effective approach for ILRR after mastectomy. Radiation fields should cover the entire recurrent region. Elective irradiation to the CW in pts with nodal recurrence is recommended. Prognostic Index based on the positive multivariate analysis could be established as to stratify different prognostic sub-groups. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5135.