Transcript Radiotherapy in Carcinoma of the Breast

Radiotherapy
in Carcinoma of the Breast
Patrick S Swift, MD
Director, Radiation Oncology
Alta Bates Comprehensive Cancer Center
Berkeley, CA
Breast Conserving Therapy
BCT
70-80% of patients with stage I or II
disease are candidates for BCT
 6 major randomized trials comparing
mastectomy to BCT

 No
difference in DFS
 No difference in OS
Distant Failure
Trial
#
Time pt.
Mast.
BCT
WHO
1972-79
179
22 yrs
24%
23%
Milan I
1973-80
701
20
51%
54%
NSABP06 1976-84
1406
20
33%
40%
US NCI
1979-89
279
20
34%
39%
EORTC
10801
1980-86
903
10
34%
30%
Denmark
82TM
1983-89
859
6
32%
34%
Overall Survival
Trial
#
Time pt.
Mast.
BCT
WHO
1972-79
179
22 yrs
41%
42%
Milan I
1973-80
701
20
47%
46%
NSABP06 1976-84
1406
20
58%
53%
US NCI
1979-89
279
20
66%
65%
EORTC
10801
1980-86
903
10
79%
82%
Denmark
82TM
1983-89
859
6
67%
67%
Absolute Contraindications to
BCT
Repeatedly positive margins
 Multicentric disease ( >2 quadrants)
 Diffuse malignant calcifications on
mammogram
 Prior RT to breast
 Pregnancy

Relative Contraindications to
BCT
History of scleroderma
 Large tumor in small breast

 Cosmetically
undesirable
NOT contraindications to BCT
Age
 Skin or nipple retraction
 Histology other than IDC
 Extensive intraductal component

 As
long as margins are clear
Positive nodes
 Location of primary in breast
 Positive family history

Positive Margins after
Lumpectomy
Single most important predictor of local
failure in BCT
 Consider re-excision to get negative
margins
 Focal positivity - may be okay

 Especially

if chemo or HT given
Extensive positivity - re-excise!
Extensive Intraductal Component (EIC)
Intraductal component a prominent part
of the main tumor
 Intraductal carcinoma extends BEYOND
the infiltrating margin of the mass
 Of uncertain significance if margins are
clearly negative

Treatment by Stage
DCIS
Ductal Carcinoma in Situ

MRM is acceptable


no node dissection
BCT is an acceptable approach if:


Lesion is small (< 3 cm)
Margins must be negative




preferably > 10 mm in all dimensions
Nuclear grade is low to intermediate
Adjuvant radiotherapy can be delivered
S alone can be considered if margins >10
mm

controversial
NSABP-17
814 pts. with DCIS, negative margins
 Randomized to RT v no RT

 50

Gy to entire breast, no boost
At 12 years, local failure rates
 31.7%
for no RT
 15.7% for RT

Only comedo necrosis was a significant
factor predicting for local failure
EORTC 10853
500 pts with DCIS, clear margins
 Randomized to 50 Gy whole breast or
no RT
 At 4.25 years, local failure

 16%
no RT
 9% with RT (p=0.005)
UKCCCR DCIS Working Group
1030 pts with DCIS, clear margins
 S alone
 S + Tam
 S + RT
 S + RT + Tam
 At 4.4.years, local failure

 14% in no RT
 6% in RT arm
 S + Tam intermediate
Radiation Technique
DCIS
Opposed tangential fields
 Breast only
 No boost
 1.8-2.0 Gy daily to 50 Gy
 2.65 Gy daily to 40 Gy

Van Nuys Prognostic Index
Scores of 3-4 - 98% local control without RT
Scores of 5-7 - 32% failed without RT, 16% with RT
Scores of 8-9 - 100% failure without RT, 60% with RT
Radiation Technique
T1-2 N0
Opposed tangential fields
 Breast only
 Boost optional
 50 Gy in 25-28 fractions
 42.5 Gy in 16 fractions (Canadian)

ASTRO 2008 Plenary
42.5 Gy in 16 fractions v. 50 Gy in 25 fractions
ASTRO 2008 Plenary
Canadian Trial 1993-1996
 N= 1234 women
 Median followup - 12 years
 Local recurrence at 10 years - 6%
 Excellent cosmesis at 10 yrs - 70%
 No difference between 16 and 25
fractions

If getting chemotherapy…
Radiation is usually withheld until after
the systemic therapy is complete
 Delay of up to 4-6 months from surgery
generally not considered a problem
 Possible problem with inflammatory
cancer or other locally aggressive
cancers
 Hypofractionated schemes may allow
for early RT while waiting for Oncotype

Surgery alone without RT?

Meta-analysis results
 Lancet. 2005 Dec 17, vol. 366(9503):2087-106
 “Effects of radiotherapy and of differences in the
extent of surgery for early breast cancer on local
recurrence and 15-year survival: an overview of the
randomised trials.”
 An average of 75% reduction in local failure rates
with the addition of RT, in even the lowest risk
groups.
 A survival benefit was seen in the meta-analysis
Surgery alone without RT?



One possible subset may benefit
Patients > 70 years of age
 with small ER+ tumors
 who will get tamoxifen
No survival benefit with RT
Radiation Technique
T3-4 (after neoadjuvant chemo)
Opposed tangential fields
 Boost

 10
Gy for neg margins
 18 Gy for positive or close margins

50 Gy in 25-28 fractions
Nodal Irradiation
N0 - no role for axillary RT
 N+

 1-3
> 4

nodes, “adequate sampling” - no RT
nodes, RT to SCLV and axilla
IM Nodal RT
 > 4 axillary nodes positive
 Medial T3 tumors with any
nodes positive
axilla
 Awaiting
EORTC)
results of two large trials (France and
Full SCLV Field
IM Nodal Radiation Technique
Post-mastectomy RT

Indications





T3 lesions with any positive nodes
Smaller lesions with > 3 nodes
T4 lesions
Pectoralis fascia involvement
Technique



Tangential beams for the chest wall
Axillary/SCLV coverage
IM node coverage for medial lesions or > 3 nodes
positive
Post-MRM RT Trials
(all with chemo and modern RT)
Danish 82b
Vancouver
Danish 82c
1708
318
1375
RT
Local
failure
9%
Overall
Survival
54%
No RT
32%
45%
RT
13%
54%
No RT
33%
46%
RT
8%
45%
No RT
35%
36%
RT Complications

Lymphedema
 After
full axillary dissection + RT - 37%
 Level I/II dissection + RT - 7%
Rib fracture - 1.8%
 Pneumonitis - 1-5%
 Cardiac toxicity - avoidable
 Radiation-induced sarcoma

 0.78%
at 30 yrs.
Reducing Risk
 Respiratory
 IM
Gating
nodal techniques
 IMRT
Partial Breast Irradiation

RTOG / NSABP Trial comparing
 Standard
whole breast RT
 3D conformal technique
 Mammosite
 Interstitial Implant technique
5 days, twice daily radiation
 Outcome results pending
