Evaluation of serum KL-6 as a predictive marker of radiation pneumonitis in patients with breast-conservation therapy.
BACKGROUND
Although radiation pneumonitis in radiotherapy following breast-conservation surgery is rare, it may lead to severe pneumonitis as well as to other types of pulmonary dysfunction. This study examined the usefulness of the serum KL-6 level as a new marker for the early detection of radiation pneumonitis.


METHODS
Twenty-nine consenting patients served as subjects (age range, 32-78 years; mean age, 51 years) between 2001 and 2002. A total tangential irradiation dose of 50 Gy/25 fractions (fr) was administered for 5 weeks, using a 4-MV X-ray, and an additional 10 Gy/5 fr for 1 week of 6-MeV electron-beam irradiation was performed for patients with pathological tumor cell findings in the excised tumor margins. Levels of serum KL-6 were measured before and after radiotherapy.


RESULTS
Four patients developed radiation pneumonitis, all of whom had elevated post-therapy KL-6 levels. Patients with lower or unchanged KL-6 levels did not develop radiation pneumonitis. There was a significant difference in serum KL-6 levels between patients with and without radiation pneumonitis (P = 0.0421). KL-6 levels remained below the threshold value of 465 U/ml in all patients.


CONCLUSIONS
For the early detection of radiation pneumonitis following breast-conservation surgery, and to assess the efficacy of therapy, the monitoring and measuring of changes in KL-6 levels before and after radiotherapy is more important than comparing KL-6 levels against the threshold value. Measuring KL-6 serum levels is also useful in assessing the efficacy of therapy for radiation pneumonitis.
Tokiya
Ryoji
R
Department of Radiation Oncology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan. radoncol@med.kawasaki-m.ac.jp
Hiratsuka
Junichi
J
Yoshida
Kenji
K
Imai
Shigeki
S
Kajihara
Yasumasa
Y
Imajo
Yoshinari
Y
D000328:Adult; D000368:Aged; D000941:Antigens / Q000032:analysis*; D000951:Antigens, Neoplasm; D015415:Biomarkers / Q000032:analysis*; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D018396:Mucin-1; D009077:Mucins; D011237:Predictive Value of Tests; D017564:Radiation Pneumonitis / Q000209:etiology*; D012680:Sensitivity and Specificity
D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers; D006023:Glycoproteins; C060192:MUC1 protein, human; D018396:Mucin-1; D009077:Mucins