Table 1.

Clinicopathologic and breast event characteristics of evaluable patients, overall and by treatment cohort.

No radiotherapyRadiotherapyAll evaluable cases
N = 78N = 377N = 455
CharacteristicN (%)N (%)N (%)
Adjuvant endocrine therapy
 No63 (80.8)281 (74.5)344 (75.6)
 Yes14 (18.0)94 (24.9)108 (23.7)
 Unknown1 (1.3)2 (0.5)3 (0.7)
Year of DCIS diagnosis
 1995 and prior24 (30.8)78 (20.7)102 (22.4)
 1996 and after54 (69.2)299 (79.3)353 (77.6)
Age at DCIS diagnosisa
 <509 (11.5)82 (21.8)91 (20.0)
 50–5918 (23.1)119 (31.6)137 (30.1)
 60–6921 (26.9)99 (26.3)120 (26.4)
 70+30 (38.5)77 (20.4)107 (23.5)
Family history of breast cancer
 No44 (56.4)196 (52.0)240 (52.8)
 Yes32 (41.0)179 (47.5)211 (46.4)
 Unknown2 (2.6)2 (0.5)4 (0.9)
Presentation
 Routine mammogram69 (88.5)340 (90.2)409 (89.9)
 Clinical9 (11.5)37 (9.8)46 (10.1)
Palpability
 Negative70 (89.7)345 (90.2)415 (91.2)
 Positive8 (10.3)37 (9.8)40 (8.8)
Tumor gradea
 Low23 (29.5)41 (10.9)64 (14.1)
 Intermediate37 (47.4)163 (43.2)200 (44.0)
 High18 (23.1)172 (45.6)190 (41.8)
 Unknown0 (0.0)1 (0.3)1 (0.2)
Tumor size
 5 mm or less27 (34.6)109 (28.9)136 (29.9)
 6–10 mm16 (20.5)77 (20.4)93 (20.4)
 ≥10 mm10 (12.8)72 (19.1)82 (18.0)
 Unknown25 (32.1)119 (31.6)144 (31.7)
Surgical margin statusa
 Negative69 (88.5)364 (96.6)433 (95.2)
 Positive9 (11.5)13 (3.5)22 (4.8)
Tumor necrosisa
 Absent34 (43.6)91 (24.1)125 (27.5)
 Present44 (56.4)286 (75.9)330 (72.5)
Surgical excisions
 158 (74.4)265 (70.3)323 (71.0)
 217 (21.8)99 (26.3)116 (25.5)
 3 or more0 (0.0)8 (2.1)8 (1.8)
 Unknown3 (1.3)5 (1.3)8 (1.8)
Ipsilateral outcome (first documented)
 No ipsilateral event64 (82.0)338 (89.7)402 (88.4)
 Ipsilateral DCIS6 (7.7)14 (3.7)20 (4.4)
 Ipsilateral invasive BC6 (7.7)20 (5.3)26 (5.7)
 Metastasis2 (2.6)5 (1.3)7 (1.5)
Contralateral outcome (first documented)
 No contralateral event77 (98.7)359 (95.2)436 (95.8)
 Contralateral DCIS0 (0.0)7 (1.9)7 (1.5)
 Invasive contralateral BC1 (1.3)11 (2.9)12 (2.6)
  • Note: Summary statistics of clinicopathologic factors and ipsilateral and contralateral BEs for the evaluable patient population, overall and by radiotherapy treatment status.

  • Abbreviation: BC, breast cancer.

  • aStatistically significant difference (P < 0.05) between “no radiotherapy” group and “radiotherapy” group.