Mutsaers Anthony J
Division of Molecular and Cell Biology, Sunnybrook Health Sciences Centre, Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
Top Companion Anim Med. 2009 Aug;24(3):137-43. doi: 10.1053/j.tcam.2009.03.004.
Chemotherapy drugs are usually administered at doses that are high enough to result in an obligatory break period to allow for the observation of potential side effects and institution of supportive care, if required. In recent years, efforts to administer chemotherapy on a more continuous basis, with a much shorter break period, or none at all, have received increased interest, and the practice has come to be known as metronomic chemotherapy. The basis for success with this currently investigational approach may be rooted in continuous drug exposure to susceptible cancer cells, inhibition of tumor blood vessel growth-a process known as tumor angiogenesis, and/or alterations in tumor immunology. Increased benefit also appears to occur when metronomic chemotherapy is used in combination with newer, targeted antiangiogenic agents, and therefore represents a promising approach to combination therapy, particularly as targeted oncology drugs make their way into veterinary oncology applications. There is still much to be learned in this field, especially with regard to optimization of the proper drugs, dose, schedule, and tumor applications. However, the low cost, ease of administration, and acceptable toxicity profiles potentially associated with this therapeutic strategy make metronomic chemotherapy protocols attractive and suitable to veterinary applications. Preliminary clinical trial results have now been reported in both human and veterinary medicine, including adjuvant treatment of canine splenic hemangiosarcoma and incompletely resected soft tissue sarcoma, and, further, more powerful studies are currently ongoing.
化疗药物通常以足够高的剂量给药，这必然会导致一段间歇期，以便观察潜在的副作用，并在需要时实施支持性护理。近年来，以更持续的方式给药化疗，间歇期更短甚至根本没有间歇期的努力受到了越来越多的关注，这种做法被称为节拍化疗。这种目前仍在研究的方法取得成功的基础可能源于持续让敏感癌细胞接触药物、抑制肿瘤血管生长（这一过程称为肿瘤血管生成）和/或改变肿瘤免疫学。当节拍化疗与更新的靶向抗血管生成药物联合使用时，似乎也会增加疗效，因此它是一种很有前景的联合治疗方法，特别是随着靶向肿瘤药物进入兽医肿瘤学应用领域。在这个领域仍有很多需要学习的地方，尤其是在优化合适的药物、剂量、给药方案和肿瘤应用方面。然而，这种治疗策略潜在的低成本、易于给药和可接受的毒性特征，使得节拍化疗方案具有吸引力且适用于兽医应用。目前已经在人类医学和兽医学中报告了初步临床试验结果，包括犬脾血管肉瘤和未完全切除的软组织肉瘤的辅助治疗，此外，目前正在进行更有力的研究。
