Immunohistochemical Study of p53 Overexpression in Radiation-Induced Colon Cancers.

Abstract

The expressions of p53 and proliferating cell nuclear antigen (PCNA) were studied immunohistochemically from paraffin sections of 7 cases (9 lesions) of radiation-induced colon cancer and 42 cases of spontaneous colon cancer. Age distribution of radiation-induced and spontaneous colon cancer were 68.1 years (range, 56 to 77 years) and 67.4 years (range, 31 to 85 years), respectively. Among the radiation-induced colon cancers, there were 3 lesions of mucinous carcinoma (33%), a much higher than found for spontaneous mucinous cancer. Immunohistochemically, p53 protein expression was detected in 7/9 (78%) of radiation-induced cancers and in 23/42 (55%) of spontaneous colon cancers. chi 2 analysis found no significant differences between radiation-induced and spontaneous colon cancers in age distribution or p53-positive staining for frequency, histopathology, or Dukes' classification. In radiation colitis around the cancers including aberrant crypts, spotted p53 staining and abnormal and scattered PCNA-positive staining were observed. In histologically normal cells, p53 staining was almost absent and PCNA-positive staining was regularly observed in the lower half of the crypt. In radiation colitis including aberrant glands, cellular proliferation increased and spotted p53 expression was observed. This study suggests that radiation colitis and aberrant glands might possess malignant potential and deeply associate with carcinogenesis of radiation-induced colon cancer.

Radiation-associated colon cancer: A case report

“…In the present case, there was no detected hereditary tendency for malignancy, and there was no MSI, although the first flat tumor harbored a p53 mutation. Similar to the present case, Minami et al (17) reported that p53 protein overexpression was detected using immunohistochemistry in 7 of 9 patients with radiation-associated colon cancer; however, they found no definite correlation between the overexpression of p53 in radiation-associated and spontaneous colon cancers. This suggested that the occurrence of p53 gene mutations was not specific to the carcinogenesis of radiation-associated colon cancers compared with spontaneous colon cancers.…”

Recent advances in the management of radiation colitis

“…Besides, in radiation colitis involving aberrant glands, cellular proliferation increases and spotted oncogene p53 expression is noticed. Therefore, radiation colitis and aberrant glands with p53 overexpression might predict malignant potential of this condition [37] . Three typical phases of radiation proctitis are defined on histological grounds (acute damage, and early and late regenerative phases), essentially correlating with the time interval between radiotherapy and surgery.…”

Expression of ICAM-1 and Acute Inflammatory Cell Infiltration in the Early Phase of Radiation Colitis in Rats

“…Radiation-induced colitis may be encountered as one of the most harmful side-effects of radiation therapy for pelvic malignancies 1) . During the treatment of these malignancies with external, intracavitary, or combined irradiation, the rectum often receives a substantial expo-…”