A A

Characteristics of the Evidence Base

Table 2 summarises the trial populations and primary outcomes measured in the six RCTs comparing hypofractionated radiotherapy to conventionally fractionated radiotherapy. Of note:

  • Six trials identified the patient population characteristics as early invasive breast cancer T1-3, N0-1, M0.6,7,10,11,13,16-18,21
  • The Spooner trial, UK FAST trial, the Canadian trial and the RMH/GOC, limited the trial populations to those who had breast conserving surgery only.6,7,11,13,18,21
  • Women participating in the START A or START B trials had breast conserving surgery or mastectomy.10,16,17

Table 2 - Trial characteristics

Trial Population Median follow-up (range) years Intervention Comparator Outcomes measured

Studies Post Breast conserving surgery only

Spooner 201211

 

 

Early breast cancer stage I and II

16.9

(3.7-21.8)

40 Gy in 15 daily fractions over 3wks (n=181)

Supplementary boost of direct 10-14 MeV electron field of 15 Gy in five daily fractions

50Gy in 25 fractions over 5 weeks (n=177)

Supplementary boost of direct 10-14 MeV electron field of 15 Gy in five daily fractions

Primary outcomes:

  • Locoregional relapse rate at 5 years

Secondary outcomes:

  • Survival and locoregional tumour control

n=707 randomised to:

radiotherapy (n=358) or no radiotherapy (n=349)

UK FAST trial, 201121

Early stage breast cancer Tumour size <3.0cm

3.1

30 Gy in 5 once weekly fractions of 6 Gy over 5 weeks (n=308)

OR

28.5 Gy in 5 once weekly fractions of 5.7 Gy over 5 weeks (n=305)

50 Gy in 25 fractions of 2 Gy over 5 weeks (n=302)

 

Primary outcomes:

  • Change in photographic breast appearance

Secondary outcomes:

  • Radiation-induced changes in the breast
  • Local tumour control

 

Canadian trial6,13

Invasive carcinoma with negative axillary nodes

12

(range NR)

42.5 Gy in 16 fractions over 22 days (n=622)

50 Gy in 25 fractions over 35 days (n=612)
  • Local recurrence
  • Overall survival
  • Adverse events and toxicity
  • Cosmetic outcome

RMH/GOC trial7,18

 

Early breast cancer, T1-3, N0-1, M0

<75 years

 

9.7

(7.8-11.8) 

39 Gy in 13 fractions over 5 weeks (n=474)

42.9 Gy in 13 fractions over 5 weeks (n=466)

50 Gy in 25 fractions over 5 weeks (n=470)
  • Local recurrence
  • Cosmetic outcomes

Post Breast conserving surgery or post mastectomy

START A10,16

Early breast cancer T1-3a, N0-1, M0

 

9.3

39 Gy in 13 fractions over 5 weeks (n=737)

OR

41.6 Gy in 13 fractions over 5 weeks (n=750)

50 Gy in 25 fractions over 5 weeks (n=749)

Primary outcomes:

  • Local recurrence
  • Late normal tissue effects

Secondary outcomes:

  • Local-regional relapse
  • Distant relapse
  • Disease free survival
  • Overall survival
  • Adverse events and toxicity
  • Cosmetic outcome
  • Quality of life

START B10,17

Early breast cancer T1-3a, N0-1, M0

 

9.9 

40 Gy in 15 fractions over 3 weeks (n=1110)

50 Gy in 25 fractions over 5 weeks (n=1105)

Primary outcomes:

  • Local recurrence
  • Late normal tissue effects

Secondary outcomes:

  • Local-regional relapse
  • Distant relapse
  • Disease free survival
  • Overall survival
  • Adverse events and toxicity
  • Cosmetic outcome
  • Quality of life

Table 3 identifies key characteristics of patients involved in the six randomised controlled trials.

Table 3: Patient characteristics

  RMH/GOC7,18 Canadian trial6,13 START A10,16 START B10,17 Spooner 201211 UK FAST trial21
N=1410 N=1234 N=2235 N=2215 N=358 N=915

 

n

%

n

%

n

%

n

%

n

%

n

%

Treated with breast conserving surgery

1410

100%

1234

100%

1900

85%

2038

92%

358

100%

915

100%

Age ≥ 50 years

987

70%

929

75%

1727

77%

1758

79%

 

 

915

100%

T1-2

1383

98%

904

73%

1572

70%

1667

75%

173

48%

812

89%

N0

564

40%

1234

100%23

1547

69%

1635

74%

358

100%

915

100%

N1

 

 

 

 

643

29%

504

23%

 

 

 

 

Adjuvant treatment

None

Tamoxifen

Chemotherapy

 

289

1074

196

 

21%

76%

14%

 

 

593

505

136

 

48%

41%

11%

 

172

1758

793

 

8%

79%

35%

 

84

1928

491

 

4%

87%

22%

 

 

358

 

 

100%

 

106

694

 

12%

76%

High tumour grade

 

 

233

19%

629

28%

509

23%

62

17%

98

11%