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Postmastectomy Radiation Therapy in Women With ypN0-N3 Breast Cancer
Volume 96 Number 2S Supplement 2016
2064 Radiation TherapyeDependent Predictors of Adverse Breast Reconstruction Outcomes L.W. Salama,1 B. Lavajo Vieira,2,3 L.Z. Braunstein,4 N. Horick,5 M.S. Asdourian,1 M. Skolny,1 M.P. Tighe,5 N.R. Taghian,5 S. MacDonald,5 A.S. Colwell,6 J.M. Winograd,6 M.A. Gadd,7 M. Specht,7 B.L. Smith,7 and A.G. Taghian5; 1Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA, 2(AROME) Association of Radiotherapy and Oncology of the Mediterranean Area, Paris, France, 3Massachusetts General Hospital, Harvard Medical School, Boston, MA, 4Harvard Radiation Oncology Program, Boston, MA, 5Massachusetts General Hospital, Boston, MA, 6Division of Plastic Surgery, Massachusetts General Hospital, Boston, MA, 7Division of Surgical Oncology, Gillette Center for Women’s Cancers, Massachusetts General Hospital, Boston, MA Purpose/Objective(s): To identify predictors of breast reconstruction failure (RF) following post mastectomy radiation therapy (PMRT). Materials/Methods: We conducted a retrospective cohort study of 656 breast cancer patients who underwent a total of 966 mastectomies with reconstruction, all treated at one institution from 1997-2013. Of the total breasts undergoing mastectomy, 571 (59%) received no PMRT, while 395 (41%) had PMRT. Median prescribed PMRT dose to the chest wall was 50.4 Gy (range 45-50.4 Gy). Two hundred thirty-nine patients (60.5%) received a chest wall boost (10-16 Gy) and 310 (78.5%) received regional lymph node radiation (RLNR). Of mastectomies without PMRT, 275 (28.5%) were undertaken prophylactically in an uninvolved breast. With regard to reconstruction type, 731/966 (75.6%) were implant-based and 215/966 (22.3%) involved autologous tissue reconstruction (ATR). Those that were implant-based, 428/731 (58.5%) involved tissue expander/implant (TE/I) exchange and 303/731 (41.5%) were single-stage permanent implants (PI). Twenty reconstructions involving other methods were excluded. RF was defined as primary implant removal with or without a second attempt at reconstruction; or complicated ATR. The association of clinical and pathologic parameters with RF was evaluated using Cox proportional hazards models, while the cumulative incidence of RF was estimated using the Kaplan-Meier method. Results: Median follow-up was 60 months with 5-year predicted RF rate of 26.5% (95% CI 22.3-31.4) following PMRT vs 15.8% without PMRT (95% CI 12.8-19.4). Regardless of reconstruction type, the use of a chest wall boost was associated with a higher 5-year RF rate: 29.5% (95% CI 23.8-36.2) vs 22.6% (95% CI 16.8-30) with no boost. 66/731 (9%) implant-based reconstructions were nonsalvageable, while 114/731 (15.6%) had a successful second reconstruction. Two hundred eighty-six of 731 (39.1%) were irradiated and 445/731 (60.8%) were not. Patients who underwent PMRT with TE/I were at higher risk of RF than those opting for PI, with 5-year predicted RF rate of 33.1% (95% CI 26.4-40.9) for the TE/I group; vs 22% (95% CI 15.3-31.7) for the PI group. In the absence of PMRT, 5-year RF rate did not differ between TE/I and PI groups (15.4% vs 15.3%), respectively. Similarly, 5-year RF rate among patients with ATR did not differ based on PMRT use (17.0% with PMRT vs 16.5% without). RF was significantly associated with PMRT (hazard ratio [HR] Z 2.2; P<0.0001) and with use of a tissue expander prior to permanent implant placement (HR Z 1.66; P Z 0.01). Radiotherapeutic parameters such as total chest wall dose, dose per fraction, chest wall boost, and RLNR were not predictive of RF, nor were a number of patient-related factors including age, BMI or smoking history. Conclusion: These data suggest that PMRT is associated with a significantly higher rate of RF in select settings, and is particularly adverse when the use of a tissue expander precedes a permanent implant. Single-stage PI or ATR yielded favorable outcomes in the setting of PMRT and may be preferable alternatives. Author Disclosure: L.W. Salama: None. B. Lavajo Vieira: None. L.Z. Braunstein: None. N. Horick: None. M.S. Asdourian: None. M. Skolny: None. M.P. Tighe: None. N.R. Taghian: None. S. MacDonald: None.
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A.S. Colwell: None. J.M. Winograd: None. M.A. Gadd: None. M. Specht: None. B.L. Smith: None. A.G. Taghian: None.
2065 Postmastectomy Radiation Therapy in Women With ypN0-N3 Breast Cancer T. Shaikh, T.M. Churilla, N.G. Zaorsky, C.T. Murphy, R. Carlson, S.E. Weiss, P.R. Anderson, and S.B. Hayes; Fox Chase Cancer Center, Philadelphia, PA Purpose/Objective(s): Data are limited regarding the role of post mastectomy radiation therapy (PMRT) following neoadjuvant chemotherapy. We aim to estimate the impact of PMRT on overall survival (OS) and cancer specific survival (CSS) in women undergoing neoadjuvant systemic therapy followed by mastectomy. Materials/Methods: The Surveillance, Epidemiology, and End Results registry was queried from 2004-2012 for women >18 years old who underwent mastectomy and met criteria for “yp” staging according to recorded “CS Tumor Size/Ext Eval” and “CS Lymph Nodes Eval” fields. Patient with M1 disease were excluded from the analysis. The primary endpoints were OS and CSS for patients with or without PMRT, and were assessed utilizing the Kaplan-Meier method and Cox proportional hazards model. Results: A total of 3234 patients were included, 1928 (59.6%) received radiation. Median age was 51 (range 19-98) and the median follow-up was 30 months (range 2-95). A total of 1091 (33.7%) patients had ypT3-T4 disease and 2414 (74.6%) were ypN1-N3. The majority of women were ER/PR positive (67.2%). Patients receiving radiation were more likely to be <60 years old (P<0.001), have ypT3-T4 (P Z 0.009) or ypN1-N3 disease (P<0.001), and not undergo reconstruction (P Z 0.007). The 3year actuarial OS with and without PMRT was 84% and 77.9%, respectively (P<0.001). The 3-year actuarial CSS with and without PMRT was 85.6% and 82.6%, respectively (P Z 0.123). On multivariable analysis, PMRT was associated with an improved OS (HR 0.72 95% CI 0.61-0.86 P<0.001) and CSS (HR 0.81 95% CI 0.66-0.98 P Z 0.026). Subgroup analysis according to nodal status is demonstrated in the attached table; women with ypN1-3 (P Z 0.001) benefited from PMRT while there was no benefit in the ypN0 (P Z 0.660) cohort. When examining only women with ypN0 disease, we were unable to identify any subgroup which would benefit from PMRT according to the number of lymph nodes examined, hormone receptor status, grade, histology, and ypT stage. When examining only women with ypN1-N3 disease, the only subgroup who did not benefit from PMRT were women with ypT1-T2 disease (P Z 0.143), all other ypN1-3 patients appeared to benefit from PMRT.
Abstract 2065; Table 1. Radiation (n [ 1928) versus No Radiation (n [ 1306) 3-year overall Psurvival value All (n [ 3234) ypN1-N3 (n [ 2414) ypN0 (n [ 820)
Adjusted Hazard Ratio (95% Confidence Interval)
Pvalue
84% vs 78%
<0.001
0.72 (0.61-0.86)
<0.001
82% vs 73%
<0.001
0.74 (0.62-0.89)
0.001
93% vs 91%
0.619
1.13 (0.66-1.92)
0.660
Conclusion: The presented analysis supports the administration of PMRT among women with persistent node positive disease following neoadjuvant chemotherapy. Our results further suggest equipoise in the administration of PMRT among women with a pathologic complete response in the axilla while awaiting the results of NSABP B-51. Author Disclosure: T. Shaikh: None. T.M. Churilla: None. N.G. Zaorsky: None. C.T. Murphy: None. R. Carlson: None. S.E. Weiss: None. P.R. Anderson: None. S.B. Hayes: None.
2064 Radiation TherapyeDependent Predictors of Adverse Breast Reconstruction Outcomes L.W. Salama,1 B. Lavajo Vieira,2,3 L.Z. Braunstein,4 N. Horick,5 M.S. Asdourian,1 M. Skolny,1 M.P. Tighe,5 N.R. Taghian,5 S. MacDonald,5 A.S. Colwell,6 J.M. Winograd,6 M.A. Gadd,7 M. Specht,7 B.L. Smith,7 and A.G. Taghian5; 1Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA, 2(AROME) Association of Radiotherapy and Oncology of the Mediterranean Area, Paris, France, 3Massachusetts General Hospital, Harvard Medical School, Boston, MA, 4Harvard Radiation Oncology Program, Boston, MA, 5Massachusetts General Hospital, Boston, MA, 6Division of Plastic Surgery, Massachusetts General Hospital, Boston, MA, 7Division of Surgical Oncology, Gillette Center for Women’s Cancers, Massachusetts General Hospital, Boston, MA Purpose/Objective(s): To identify predictors of breast reconstruction failure (RF) following post mastectomy radiation therapy (PMRT). Materials/Methods: We conducted a retrospective cohort study of 656 breast cancer patients who underwent a total of 966 mastectomies with reconstruction, all treated at one institution from 1997-2013. Of the total breasts undergoing mastectomy, 571 (59%) received no PMRT, while 395 (41%) had PMRT. Median prescribed PMRT dose to the chest wall was 50.4 Gy (range 45-50.4 Gy). Two hundred thirty-nine patients (60.5%) received a chest wall boost (10-16 Gy) and 310 (78.5%) received regional lymph node radiation (RLNR). Of mastectomies without PMRT, 275 (28.5%) were undertaken prophylactically in an uninvolved breast. With regard to reconstruction type, 731/966 (75.6%) were implant-based and 215/966 (22.3%) involved autologous tissue reconstruction (ATR). Those that were implant-based, 428/731 (58.5%) involved tissue expander/implant (TE/I) exchange and 303/731 (41.5%) were single-stage permanent implants (PI). Twenty reconstructions involving other methods were excluded. RF was defined as primary implant removal with or without a second attempt at reconstruction; or complicated ATR. The association of clinical and pathologic parameters with RF was evaluated using Cox proportional hazards models, while the cumulative incidence of RF was estimated using the Kaplan-Meier method. Results: Median follow-up was 60 months with 5-year predicted RF rate of 26.5% (95% CI 22.3-31.4) following PMRT vs 15.8% without PMRT (95% CI 12.8-19.4). Regardless of reconstruction type, the use of a chest wall boost was associated with a higher 5-year RF rate: 29.5% (95% CI 23.8-36.2) vs 22.6% (95% CI 16.8-30) with no boost. 66/731 (9%) implant-based reconstructions were nonsalvageable, while 114/731 (15.6%) had a successful second reconstruction. Two hundred eighty-six of 731 (39.1%) were irradiated and 445/731 (60.8%) were not. Patients who underwent PMRT with TE/I were at higher risk of RF than those opting for PI, with 5-year predicted RF rate of 33.1% (95% CI 26.4-40.9) for the TE/I group; vs 22% (95% CI 15.3-31.7) for the PI group. In the absence of PMRT, 5-year RF rate did not differ between TE/I and PI groups (15.4% vs 15.3%), respectively. Similarly, 5-year RF rate among patients with ATR did not differ based on PMRT use (17.0% with PMRT vs 16.5% without). RF was significantly associated with PMRT (hazard ratio [HR] Z 2.2; P<0.0001) and with use of a tissue expander prior to permanent implant placement (HR Z 1.66; P Z 0.01). Radiotherapeutic parameters such as total chest wall dose, dose per fraction, chest wall boost, and RLNR were not predictive of RF, nor were a number of patient-related factors including age, BMI or smoking history. Conclusion: These data suggest that PMRT is associated with a significantly higher rate of RF in select settings, and is particularly adverse when the use of a tissue expander precedes a permanent implant. Single-stage PI or ATR yielded favorable outcomes in the setting of PMRT and may be preferable alternatives. Author Disclosure: L.W. Salama: None. B. Lavajo Vieira: None. L.Z. Braunstein: None. N. Horick: None. M.S. Asdourian: None. M. Skolny: None. M.P. Tighe: None. N.R. Taghian: None. S. MacDonald: None.
Poster Viewing
E27
A.S. Colwell: None. J.M. Winograd: None. M.A. Gadd: None. M. Specht: None. B.L. Smith: None. A.G. Taghian: None.
2065 Postmastectomy Radiation Therapy in Women With ypN0-N3 Breast Cancer T. Shaikh, T.M. Churilla, N.G. Zaorsky, C.T. Murphy, R. Carlson, S.E. Weiss, P.R. Anderson, and S.B. Hayes; Fox Chase Cancer Center, Philadelphia, PA Purpose/Objective(s): Data are limited regarding the role of post mastectomy radiation therapy (PMRT) following neoadjuvant chemotherapy. We aim to estimate the impact of PMRT on overall survival (OS) and cancer specific survival (CSS) in women undergoing neoadjuvant systemic therapy followed by mastectomy. Materials/Methods: The Surveillance, Epidemiology, and End Results registry was queried from 2004-2012 for women >18 years old who underwent mastectomy and met criteria for “yp” staging according to recorded “CS Tumor Size/Ext Eval” and “CS Lymph Nodes Eval” fields. Patient with M1 disease were excluded from the analysis. The primary endpoints were OS and CSS for patients with or without PMRT, and were assessed utilizing the Kaplan-Meier method and Cox proportional hazards model. Results: A total of 3234 patients were included, 1928 (59.6%) received radiation. Median age was 51 (range 19-98) and the median follow-up was 30 months (range 2-95). A total of 1091 (33.7%) patients had ypT3-T4 disease and 2414 (74.6%) were ypN1-N3. The majority of women were ER/PR positive (67.2%). Patients receiving radiation were more likely to be <60 years old (P<0.001), have ypT3-T4 (P Z 0.009) or ypN1-N3 disease (P<0.001), and not undergo reconstruction (P Z 0.007). The 3year actuarial OS with and without PMRT was 84% and 77.9%, respectively (P<0.001). The 3-year actuarial CSS with and without PMRT was 85.6% and 82.6%, respectively (P Z 0.123). On multivariable analysis, PMRT was associated with an improved OS (HR 0.72 95% CI 0.61-0.86 P<0.001) and CSS (HR 0.81 95% CI 0.66-0.98 P Z 0.026). Subgroup analysis according to nodal status is demonstrated in the attached table; women with ypN1-3 (P Z 0.001) benefited from PMRT while there was no benefit in the ypN0 (P Z 0.660) cohort. When examining only women with ypN0 disease, we were unable to identify any subgroup which would benefit from PMRT according to the number of lymph nodes examined, hormone receptor status, grade, histology, and ypT stage. When examining only women with ypN1-N3 disease, the only subgroup who did not benefit from PMRT were women with ypT1-T2 disease (P Z 0.143), all other ypN1-3 patients appeared to benefit from PMRT.
Abstract 2065; Table 1. Radiation (n [ 1928) versus No Radiation (n [ 1306) 3-year overall Psurvival value All (n [ 3234) ypN1-N3 (n [ 2414) ypN0 (n [ 820)
Adjusted Hazard Ratio (95% Confidence Interval)
Pvalue
84% vs 78%
<0.001
0.72 (0.61-0.86)
<0.001
82% vs 73%
<0.001
0.74 (0.62-0.89)
0.001
93% vs 91%
0.619
1.13 (0.66-1.92)
0.660
Conclusion: The presented analysis supports the administration of PMRT among women with persistent node positive disease following neoadjuvant chemotherapy. Our results further suggest equipoise in the administration of PMRT among women with a pathologic complete response in the axilla while awaiting the results of NSABP B-51. Author Disclosure: T. Shaikh: None. T.M. Churilla: None. N.G. Zaorsky: None. C.T. Murphy: None. R. Carlson: None. S.E. Weiss: None. P.R. Anderson: None. S.B. Hayes: None.