São Paulo State University - UNESP, Cristóvão Colombo, 2265, São José do Rio Preto, 15054-000, São Paulo, Brazil.
São José do Rio Preto Medical School - FAMERP, Av. Brigadeiro Faria Lima, 5416, São José do Rio Preto, 15090-000, São Paulo, Brazil.
Endocrine. 2018 Oct;62(1):242-249. doi: 10.1007/s12020-018-1624-2. Epub 2018 May 24.
Changes in the circadian rhythm may contribute to the development of cancer and are correlated with the high risk of breast cancer (BC) in night workers. Melatonin is a hormone synthesized by the pineal gland at night in the absence of light. Levels of melatonin and the metabolite of oxidative metabolism AFMK (acetyl-N-formyl-5-methoxykynurenamine), are suggested as potential biomarkers of BC risk. The aims of this study were to evaluate levels of melatonin and AFMK in women recently diagnosed with BC, women under adjuvant chemotherapy, and night-shift nurses, and compare them with healthy women to evaluate the relation of these compounds with BC risk.
Blood samples were collected from 47 women with BC, 9 healthy women, 10 healthy night shift nurses, and 6 patients under adjuvant chemotherapy. Compound levels were measured by mass spectrometry.
Our results showed that women with BC had lower levels of melatonin compared to control group women, and even lower in night-shift nurses and in patients under adjuvant chemotherapy. There was no significant difference of AFMK levels between the groups. In addition to this, high levels of melatonin and AFMK were related to patients with metastasis, and high levels of AFMK were related to the presence of lymph node-positive, tumor > 20 mm and patients who sleep with light at night. Our results showed a reduction of melatonin levels in BC patients, suggesting a relation with the disease, and in addition, point to the importance of melatonin supplementation in women that work at night to reduce the BC risk.
昼夜节律的变化可能导致癌症的发生，并与夜班工人乳腺癌（BC）的高风险相关。褪黑素是夜间在没有光线的情况下由松果体合成的激素。褪黑素及其代谢物氧化代谢产物 AFMK（乙酰-N-甲酰-5-甲氧基犬尿氨酸胺）的水平被认为是 BC 风险的潜在生物标志物。本研究旨在评估最近被诊断为 BC 的女性、接受辅助化疗的女性和夜班护士的褪黑素和 AFMK 水平，并将其与健康女性进行比较，以评估这些化合物与 BC 风险的关系。
采集了 47 名 BC 女性、9 名健康女性、10 名健康夜班护士和 6 名接受辅助化疗的患者的血液样本。通过质谱法测量化合物水平。
我们的结果表明，与对照组女性相比，BC 女性的褪黑素水平较低，夜班护士和接受辅助化疗的患者甚至更低。各组之间 AFMK 水平没有显著差异。此外，高褪黑素和 AFMK 水平与转移患者有关，高 AFMK 水平与淋巴结阳性、肿瘤>20mm 和夜间开着灯睡觉的患者有关。我们的研究结果表明，BC 患者的褪黑素水平降低，提示与疾病有关，此外，还表明在夜间工作的女性中补充褪黑素以降低 BC 风险的重要性。
