鼻咽癌组织照射前后PCNA的表达及其意义

Expression and Significance of PCNA Prior to and After Different Doses of Radiotherapy in Patients with Nasopharyngeal Carcinoma

目的了解鼻咽癌细胞在小剂量放射治疗前后肿瘤细胞的增殖细胞核抗原 (PCNA)有无改变 ,并初步探讨其临床意义。 方法 2 5例病理证实的鼻咽低分化鳞状细胞癌患者接受根治性放射治疗。患者分 5组 ,每组 5例 ,分别在接受 1.9Gy 次、3.8Gy 2次、5 .7Gy 3次、7.6Gy 4次及 9.5Gy 5次 ,取肿瘤组织。免疫组化染色检测PCNA表达水平 ,PCNA阳性细胞数≥ 2 .6 %时为阳性 ,<2 .6 %时为阴性。 结果中位随访时间 45月 (范围 34～ 5 6月 )。末次随访时 ,1例鼻咽复发 ,2例颈部复发 ,5例远处转移 ,5例死亡。放疗前后PCNA阳性率均为 42 %( P >0 .0 5 )。总体 4年生存率及无瘤生存率分别为 5 5 .3%和 6 8%。放疗前PCNA阳性与阴性病例的无瘤生存率分别为 5 0 %和 78.6 %,两组无瘤生存曲线无显著差异 (P =0 .14 )。单因素和多因素分析未显示出放疗前、后PCNA对无瘤生存率具独立的预后价值。 结论鼻咽癌小剂量放疗前、后PCNA无显著性差异。本组病例鼻咽癌放疗前、后PCNA未显示出预后价值 ,可能与本组研究病例数少相关 ,有待进一步探索。

Objective To investigate the expression of tumor cell proliferating cell nuclear antigen (PCNA) prior to and after different doses of radiotherapy in patients with nasopharyngeal carcinoma and analyze the correlation between the expression of PCNA and the prognosis of patients. Methods 25 patients histologically proven nasopharyngeal squamous cell carcinoma were eligible to enter into analysis. The median age of patients was 43. Twenty-five patients were divided into five groups, 5 patients per group. Pretherapy biopsy and second biopsy from the nasopharyngeal tumor 3 ～6h after 1 ～5 fractions irradiation respectively (1.9Gy per fraction a day) were performed. The expression of PCNA was identified by immunohistochemical stain. The level of PCNA expression were rated into two levels: PCNA positive in which there were more than or equal to 2.6 percent PCNA positive tumor cells and PCNA negative less than 2.6 percent. Results At a median follow-up of 45 months (range: 34 ～56), one patient suffered local failure in nasopharynx; 2 patients developed neck regional lymph nodes recurrence; 5 patients had distant metastases; and 5 patients have died of disease. PCNA positive was 42% in patients both prior to and after radiotherapy. 4-year actuarial survival and disease free survival were 55.3%, 68% respectively. The disease free survival for the patients with PCNA positive prior to irradiation were 50%, and 78.6% for the patients with PCNA negative. Univariate and multivariate analysis of disease free survival demonstrated that both PCNA status prior to and after radiotherapy showed no prognostic value. Conclusion There were no statistical difference between the status of PCNA prior to therapy and that after irradiation. Analysis with Cox regression models did not show PCNA status prior to and after the radiotherapy to be an independent prognotic factor.