Zheng Rong, Wang Li-E, Bondy Melissa L, Wei Qingyi, Sturgis Erich M
Department of Head and Neck Surgery, The University of Texas M D Anderson Cancer Center, Houston, Texas 77030-4009, USA.
Cancer. 2004 Feb 1;100(3):561-7. doi: 10.1002/cncr.11944.
The salivary gland is a highly radiosensitive organ. Exposure to gamma radiation is a risk factor for both malignant (MSTs) and benign salivary gland tumors (BSTs), but the exact mechanisms remain unknown. The objectives of the current study were to determine whether gamma radiation-induced chromatid breaks increase the risk of MSTs and BSTs and whether there is any difference in risk between these two diseases.
The authors performed a pilot case-control study of 57 patients with salivary gland diseases (45 patients with MSTs and 12 patients with BSTs) and 105 cancer-free controls. Peripheral blood lymphocytes from these participants were cultured and exposed to gamma radiation (1.5 grays). Five hours later, metaphase spread slides were evaluated. The chromatid breaks in 50 well-spread metaphase slides were counted to determine the average number of chromatid breaks per cell (b/c).
Multivariate logistic regression analyses revealed that gamma radiation-induced b/c values greater than the median of the controls were a significant risk factor for salivary gland tumors (adjusted odds ratio [OR], 17.25; 95% confidence interval [CI], 4.92-60.49). The risk remained significant for MSTs (adjusted OR, 40.45; 95% CI, 5.27-310.17) but was of borderline significance for BSTs (adjusted OR, 4.73; 95% CI, 0.94-23.87) when these tumors were analyzed separately.
In the current study, high levels of chromatid breaks in lymphocytes induced by gamma irradiation were associated with an independent risk for MSTs and were likely to increase the risk of BSTs. However, larger studies are needed to verify these findings.
唾液腺是对辐射高度敏感的器官。暴露于伽马辐射是恶性唾液腺肿瘤（MSTs）和良性唾液腺肿瘤（BSTs）的一个危险因素，但确切机制仍不清楚。本研究的目的是确定伽马辐射诱导的染色单体断裂是否会增加MSTs和BSTs的风险，以及这两种疾病在风险上是否存在差异。
作者对57例唾液腺疾病患者（45例MSTs患者和12例BSTs患者）和105名无癌对照者进行了一项前瞻性病例对照研究。培养这些参与者的外周血淋巴细胞并使其暴露于伽马辐射（1.5戈瑞）。5小时后，评估中期染色体铺展玻片。对50张铺展良好的中期玻片上的染色单体断裂进行计数，以确定每个细胞的染色单体断裂平均数（b/c）。
多因素逻辑回归分析显示，伽马辐射诱导的b/c值大于对照者中位数是唾液腺肿瘤的一个显著危险因素（调整优势比[OR]，17.25；95%置信区间[CI]，4.92 - 60.49）。当分别分析这些肿瘤时，MSTs的风险仍然显著（调整OR，40.45；95%CI，5.27 - 310.17），而BSTs的风险具有临界显著性（调整OR，4.73；95%CI，0.94 - 23.87）。
在本研究中，伽马辐射诱导的淋巴细胞中高水平的染色单体断裂与MSTs的独立风险相关，并且可能增加BSTs的风险。然而，需要更大规模的研究来验证这些发现。
