- Email: [email protected]
56
Proceedings of the 48th Annual ASTRO Meeting
Author Disclosure: R.R. Parikh, None; Q. Yang, None; S.A. Higgins, None; B.G. Haffty, None.
56
Significant Benefit of Boost Irradiation in Younger Patients With DCIS
G. Gruber1,2, A. Omlin2, M. Amichetti3, D. Azria4, P. Fourneret5, P. Poortmans6, D. Naehrig7, R. Miller8, M. Krengli9, B. Cole10, et al. 1 State Hospital, Radiation Oncology, Aarau, Switzerland, 2University of Berne, Radiation Oncology, Berne, Switzerland, 3 Oncological Hospital a Businco, Radiation Oncology, Cagliari, Italy, 4Department of Radiation Oncology, Val d’AurellePaul Lamarque Cancer Institute, Montpellier, France, 5University Hospital, Radiation Oncology, Grenoble, France, 6Dr Bernard Verbeeten Institute, Radiation Oncology, Tilburg, The Netherlands, 7University Hospital, Radiation Oncology, Basel, Switzerland, 8Mayo Clinic, Radiation Oncology, Rochester, MN, 9University of Piemonte Orientale, Radiation Oncology, Novara, Italy, 10Dartmouth Medical School, Hanover, NH Background: Despite an increasing incidence of ductal carcinoma in situ (DCIS), outcome data especially in younger patients are rare. Furthermore, the value of boost irradiation in these patients is unknown. Materials/Methods: A total of 373 young patients from 19 institutions could be analyzed retrospectively in a ‘Rare Cancer Network’ study. Eligibility criteria were ‘pure DCIS’, ‘age up to 45yrs at diagnosis’ and ‘breast conserving surgery-BCS’. Major endpoint was ‘local relapse-free survival’ (LRFS). The log-rank test was used to compare survival estimates. Proportional hazards regression analysis was used to estimate the effect of radiotherapy - RT (with and without boost) after adjustment for the following baseline prognostic factors: method of detection, tumor size, necrosis, tumor grade, tumor margin status, and estrogen-receptor status. Results: A total of 57 patients (15%) were treated with no additional RT after BCS, 166 patients (45%) were treated with RT without boost (median 50Gy SD1), and 150 patients (40%) were treated with RT with boost (median 60Gy SD1). After a mean follow-up of 81 months (1-281), 55 (15%) experienced local failure (invasive: 28; DCIS: 26; n.a.: 1). The 10-year LRFS estimates based on the product-limit method were 46% SD11 (no RT), 72% SD6 (RT without boost) and 86% SD4 (RT with boost). The 2-sided log-rank p-value for comparing the three treatment groups was ⬍ 0.0001. The multivariable proportional hazards regression analysis demonstrates that margin status and RT are highly significant predictors of LRFS even after adjustment for baseline characteristics. In particular, when compared to no RT, RT without boost was associated with a 66% (95% CI: 28-84%) reduction in the risk of relapse or death (p ⫽ 0.005), and RT with boost was associated with an 85% (95% CI: 64-94%) reduction in risk (p ⬍ 0.0001). When comparing RT with boost versus RT without boost, a significant advantage was apparent for boost. In particular, RT with boost was associated with a 56% decrease in risk (p ⫽ 0.019). Conclusions: This is by far the largest series of younger (-45yrs) patients with DCIS. BCS with no additional RT had unacceptable high local failure rates (54% @10yrs) and corresponding data even for RT without boost were unsatisfactory (28% @10yrs). In the absence of randomized trials boost irradiation should be considered for younger patients with DCIS. Author Disclosure: G. Gruber, None; A. Omlin, None; M. Amichetti, None; D. Azria, None; P. Fourneret, None; P. Poortmans, None; D. Naehrig, None; R. Miller, None; M. Krengli, None; B. Cole, None.
57
WITHDRAWN
58
Long-Term Toxicity Outcomes After High Dose Conformal Radiotherapy for Clinically Localized Prostate Cancer
A. M. Shippy, M. A. Hunt, Y. Yamada, H. M. Chan, S. Greenstein, H. I. Amols, M. J. Zelefsky Memorial Sloan-Kettering Cancer Center, New York, NY Purpose/Objective(s): To report long-term treatment-related toxicity outcomes for patients with clinically localized prostate cancer treated with high-dose conformal external beam radiotherapy.
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Author Disclosure: R.R. Parikh, None; Q. Yang, None; S.A. Higgins, None; B.G. Haffty, None.
56
Significant Benefit of Boost Irradiation in Younger Patients With DCIS
G. Gruber1,2, A. Omlin2, M. Amichetti3, D. Azria4, P. Fourneret5, P. Poortmans6, D. Naehrig7, R. Miller8, M. Krengli9, B. Cole10, et al. 1 State Hospital, Radiation Oncology, Aarau, Switzerland, 2University of Berne, Radiation Oncology, Berne, Switzerland, 3 Oncological Hospital a Businco, Radiation Oncology, Cagliari, Italy, 4Department of Radiation Oncology, Val d’AurellePaul Lamarque Cancer Institute, Montpellier, France, 5University Hospital, Radiation Oncology, Grenoble, France, 6Dr Bernard Verbeeten Institute, Radiation Oncology, Tilburg, The Netherlands, 7University Hospital, Radiation Oncology, Basel, Switzerland, 8Mayo Clinic, Radiation Oncology, Rochester, MN, 9University of Piemonte Orientale, Radiation Oncology, Novara, Italy, 10Dartmouth Medical School, Hanover, NH Background: Despite an increasing incidence of ductal carcinoma in situ (DCIS), outcome data especially in younger patients are rare. Furthermore, the value of boost irradiation in these patients is unknown. Materials/Methods: A total of 373 young patients from 19 institutions could be analyzed retrospectively in a ‘Rare Cancer Network’ study. Eligibility criteria were ‘pure DCIS’, ‘age up to 45yrs at diagnosis’ and ‘breast conserving surgery-BCS’. Major endpoint was ‘local relapse-free survival’ (LRFS). The log-rank test was used to compare survival estimates. Proportional hazards regression analysis was used to estimate the effect of radiotherapy - RT (with and without boost) after adjustment for the following baseline prognostic factors: method of detection, tumor size, necrosis, tumor grade, tumor margin status, and estrogen-receptor status. Results: A total of 57 patients (15%) were treated with no additional RT after BCS, 166 patients (45%) were treated with RT without boost (median 50Gy SD1), and 150 patients (40%) were treated with RT with boost (median 60Gy SD1). After a mean follow-up of 81 months (1-281), 55 (15%) experienced local failure (invasive: 28; DCIS: 26; n.a.: 1). The 10-year LRFS estimates based on the product-limit method were 46% SD11 (no RT), 72% SD6 (RT without boost) and 86% SD4 (RT with boost). The 2-sided log-rank p-value for comparing the three treatment groups was ⬍ 0.0001. The multivariable proportional hazards regression analysis demonstrates that margin status and RT are highly significant predictors of LRFS even after adjustment for baseline characteristics. In particular, when compared to no RT, RT without boost was associated with a 66% (95% CI: 28-84%) reduction in the risk of relapse or death (p ⫽ 0.005), and RT with boost was associated with an 85% (95% CI: 64-94%) reduction in risk (p ⬍ 0.0001). When comparing RT with boost versus RT without boost, a significant advantage was apparent for boost. In particular, RT with boost was associated with a 56% decrease in risk (p ⫽ 0.019). Conclusions: This is by far the largest series of younger (-45yrs) patients with DCIS. BCS with no additional RT had unacceptable high local failure rates (54% @10yrs) and corresponding data even for RT without boost were unsatisfactory (28% @10yrs). In the absence of randomized trials boost irradiation should be considered for younger patients with DCIS. Author Disclosure: G. Gruber, None; A. Omlin, None; M. Amichetti, None; D. Azria, None; P. Fourneret, None; P. Poortmans, None; D. Naehrig, None; R. Miller, None; M. Krengli, None; B. Cole, None.
57
WITHDRAWN
58
Long-Term Toxicity Outcomes After High Dose Conformal Radiotherapy for Clinically Localized Prostate Cancer
A. M. Shippy, M. A. Hunt, Y. Yamada, H. M. Chan, S. Greenstein, H. I. Amols, M. J. Zelefsky Memorial Sloan-Kettering Cancer Center, New York, NY Purpose/Objective(s): To report long-term treatment-related toxicity outcomes for patients with clinically localized prostate cancer treated with high-dose conformal external beam radiotherapy.
S33