Risk factors for seroma evacuation in breast cancer patients treated with intraoperative radiotherapy.
BACKGROUND
Novel techniques in oncology provide new treatment opportunities but also introduce different patterns of side effects. Intraoperative radiotherapy (IORT) allows a shortened overall treatment time for early breast cancer either combined with whole breast radiotherapy (WBRT), or alone. Although the early side effects of IORT are well known, data on clinically important late side effects, which require medical intervention, are scarce.


OBJECTIVE
In this study, we analyze risk factors for seroma evacuation more than 6 months after IORT.


METHODS
We evaluated 120 patients with a mean follow-up of 27.8 months (range: 7-52 months). Fifty-one patients received IORT only and 69 were additionally treated with WBRT.


RESULTS
Seroma evacuation was performed 6-38 months after IORT. Two (3.9%) events were observed in the IORT group and 14 (20%) in the IORT + WBRT group. Univariate (Kaplan-Meier) analysis showed that addition of WBRT to IORT increased the risk of seroma evacuation [hazard ratio = 5.5, 95% confidence interval: 2.0-14.7, P = 0.011]. In a multivariate analysis (Cox proportional hazards regression), WBRT and axillary lymph node dissection were significant risk factors for seroma evacuation (model P value = 0.0025).


CONCLUSIONS
WBRT applied after IORT is associated with increased risk of seroma evacuation, which might be considered as a late side effect.
Radiation Oncology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Michał
M
Falco
Radiation Oncology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Bartłomiej
B
Masojć
Radiation Oncology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Magdalena
M
Rolla
Radiation Oncology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Agnieszka
A
Czekała
Radiation Oncology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Jolanta
J
Pietruszewska
Radiation Oncology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Agnieszka
A
Rubik-Leszczyńska
Radiation Oncology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Mirosław
M
Lewocki
Radiation Oncology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Magdalena
M
Łukowiak
Pathology Department, West Pomeranian Oncology Center, Strzałowska 22, 71-730 Szczecin, Poland.
Andrzej
A
Kram
Accelerated partial breast irradiation; Breast cancer; Intraoperative radiotherapy; Seroma; Side effects