TITLE:
Histopathological Evidence for Irradiation Angiopathy in Head and Neck Cancer
AUTHORS:
Nobuhiro Uwa, Hiroyuki Hao, Yoshitane Tsukamoto, Tomonori Terada, Kosuke Sagawa, Takeshi Mohri, Takashi Daimon, Hiroshi Doi, Yohei Sotsuka, Guillaume van Eys, Marie-Luce Bochaton-Piallat, Seiichi Hirota, Masafumi Sakagami
KEYWORDS:
Angiopathy, Endothlial Cell, Pathology, Radiation, Head and Neck
JOURNAL NAME:
International Journal of Otolaryngology and Head & Neck Surgery,
Vol.4 No.2,
March
12,
2015
ABSTRACT: Objective: To
evaluate the incidence of cervical angiopathy caused by radiation therapy for
head and neck cancer. Methods: Segments of 57 cervical arteries were obtained
during surgery for head and neck malignant tumors and divided into two groups
(irradiated group and non-irradiated group) based on the treatment prior to
vascular resection. In order to evaluate vascular injury after radiation
therapy, we examined the degree of medial atrophy, medial fibrosis, smooth
muscle cell (SMC) differentiation in the media and intima, intimal hyperplasia
and endothelial cell (EC) injury. Sections of arterial segments were stained
with hematoxylin-eosin, Elastica van Gieson and Masson’s trichrome, and
immunohistochemistry for α-smooth
muscle actin (α-SMA), smoothelin,
S100A4 and CD31 in the resected vessels was conducted. Results: The median
interval between the completion of radiation therapy and vascular resection was
nine months. No significant differences were observed between the two groups in
terms of medial atrophy, medial fibrosis and intimal hyperplasia. The ratio of
the smoothelin-positive area per α-SMA-positive
area in the media and the S100A4-positive proportion in the intima, indicating
the degree of differentiation of the medial SMC and dedifferentiation of the
intimal SMC, respectively, showed no significant differences, despite the tendency
toward a lower smoothelin-positive area per α-SMA-positive
area in the media of the irradiated arteries. The EC coverage revealed on CD31
immunohistochemistry was significantly decreased, with mural thrombus adhesion,
in the irradiated group. Conclusions: The ECs of small arteries are damaged by
irradiation. Although we did not confirm the statistical significance of medial
SMC dedifferentiation, a decreased expression of smoothelin tended to be
observed in the media of the irradiated arteries. Our findings provide
histopathological evidence of irradiation angiopathy in head and neck cancer
and may help to improve the surgical safety of microvascular anastomosis and
determine the treatment strategy for head and neck tumors.