Toxicity at three years with and without irradiation of the internal mammary and medial supraclavicular lymph node chain in stage I to III breast cancer (EORTC trial 22922/10925).
BACKGROUND
The EORTC 22922/10925 trial investigated the potential survival benefit and toxicity of elective irradiation of the internal mammary and medial supraclavicular (IM-MS) nodes Accrual completed in January 2004 and first results are expected in 2012. We present the toxicity reported until year 3 after treatment.


METHODS
At each visit, toxicity was reported but severity was not graded routinely. Toxicity rates and performance status (PS) changes at three years were compared by chi(2) tests and logistic regression models in all the 3,866 of 4,004 patients eligible to the trial who received the allocated treatment.


RESULTS
Only lung (fibrosis; dyspnoea; pneumonitis; any lung toxicities) (4.3% vs. 1.3%; p < 0.0001) but not cardiac toxicity (0.3% vs. 0.4%; p = 0.55) significantly increased with IM-MS treatment. No significant worsening of the PS was observed (p = 0.79), suggesting that treatment-related toxicity does not impair patient's daily activities.


CONCLUSIONS
IM-MS irradiation seems well tolerated and does not significantly impair WHO PS at three years. A follow-up period of at least 10 years is needed to determine whether cardiac toxicity is increased after radiotherapy.
Matzinger
Oscar
O
European Organisation for Research and Treatment of Cancer (EORTC), Headquarters, Brussels, Belgium. Oscar.Matzinger@chuv.ch
Heimsoth
Irma
I
Poortmans
Philip
P
Collette
Laurence
L
Struikmans
Henk
H
Van Den Bogaert
Walter
W
Fourquet
Alain
A
Bartelink
Harry
H
Ataman
Fatma
F
Gulyban
Akos
A
Pierart
Marianne
M
Van Tienhoven
Geertjan
G
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D005260:Female; D006321:Heart / Q000528:radiation effects; D006801:Humans; D008207:Lymphatic Metastasis / Q000532:radiotherapy*; D008408:Mastectomy; D008875:Middle Aged; D009367:Neoplasm Staging; D011658:Pulmonary Fibrosis / Q000209:etiology; D011878:Radiotherapy / Q000009:adverse effects*; D012720:Severity of Illness Index