Biochemistry, Laënnec Hospital, 44093 Nantes, France.
J Photochem Photobiol B. 2012 Feb 6;107:14-9. doi: 10.1016/j.jphotobiol.2011.11.003. Epub 2011 Nov 22.
Photodynamic therapy (PDT) generates singlet oxygen ((1)O(2)) and Reactive Oxygen Species (ROS) that are counteracted by patient's defenses. As cancer treatments are among the most important PDT applications the aim of this pilot study was to determine whether the serum of cancer patients produces more or less secondary ROS or peroxides after a photoreaction as compared to healthy persons. Fifty-three volunteers and 105 cancer patients were recruited. The capacity of (1)O(2) or secondary oxidant production was found to be increased in 6 healthy donors and 36 cancer patients (23/69 women and 13/31 men p<0.007 and p<0.04) with a mean value of 1.52 as compared to 1.29 in the healthy subjects (p<0.05) when considering values higher than the normal range (norm=1±10%) or 1.1 vs. 0.85 (p<0.01) in the whole cohort. This increase correlated with a poor prognosis, TNM and SBR classification. Serum (1)O(2) deactivation capacity was impaired and secondary ROS were more produced during cancer progression. Although it is currently unclear whether this is the cause or effect of cancer, this finding may hold interest as a potential marker of cancer severity. It would also support the interest of PDT as an adjuvant for cancer treatment, even for aggressive tumors particularly when associated to surgery for bulk removal.
光动力疗法 (PDT) 会产生单线态氧 ((1)O(2)) 和活性氧 (ROS)，这些物质会被患者的防御机制所中和。由于癌症治疗是 PDT 最重要的应用之一，因此本初步研究的目的是确定与健康人相比，癌症患者的血清在光反应后是否会产生更多或更少的次级 ROS 或过氧化物。招募了 53 名志愿者和 105 名癌症患者。研究发现，在 6 名健康供体和 36 名癌症患者（23/69 名女性和 13/31 名男性，p<0.007 和 p<0.04）中，(1)O(2) 或次级氧化剂的产生能力增加，平均值为 1.52，而健康对照组的平均值为 1.29（p<0.05），当考虑高于正常范围（norm=1±10%）的值时，或在整个队列中，平均值为 1.1 与 0.85（p<0.01）相比。这种增加与不良预后、TNM 和 SBR 分类相关。血清 (1)O(2) 失活能力受损，在癌症进展过程中产生更多的次级 ROS。尽管目前尚不清楚这是癌症的原因还是结果，但这一发现可能作为癌症严重程度的潜在标志物具有一定的意义。它还支持将 PDT 作为癌症治疗的辅助手段，即使是对侵袭性肿瘤，尤其是与手术切除大块肿瘤联合使用时。
