節拍式治療

Metronomic therapy

目前針對後期癌症或復發癌症的最主要治療方式，就是進行全身性的化療。化療藥物是具有細胞毒性的藥物，可以藉由干擾細胞內去氧核糖核酸的作用，終止複製，最後造成細胞的死亡。因此治療方針都致力於產生最大的細胞毒性、殺死最多的癌細胞。然而，使用化療藥物的同時，也會傷害宿主的正常細胞，導致上述的原理無法成，這也進一步限制了化療藥物的使用劑量。癌症病患的治療，往往需要在殺死癌細胞以及對宿主造成傷害之間取得平衡，也就是儘可能給予最高劑量的化療藥物來根絕癌細胞的存在，並且減少宿主正常細胞或器官的傷害。雖然隨著照護能力顯著提升，大部分的治療都著重於「劑量越大越好」的論點。但是，近年來，由於癌症開始被視為慢性病的一種，所以利用慢性病治療方式，將癌細胞控制在「休眠狀態」的觀念，漸漸為愈來愈多人所接受。因此，更密集且連續的施打化療藥物方式，並降低劑量、同時配合他種標靶藥物的治療，這樣的做法也獲得更多的注意。這就是所謂的「節拍式的治療」。但是這個新興領域仍舊有許多有待研究之處，例如，如何安排最良好且適當的藥物、劑量與施打時間，以及適用的癌症種類。本篇綜論先介紹節拍式治療機轉的研究。

Systemic chemotherapy is a main choice in the management of advanced-stage cancer. The mechanisms of these chemotherapy agents are: inference of DNA function, termination of replication, and subsequent death. The administration dose is much more maximal and the effect is much better. However, the similar toxicity also attacks the normal cells of the body; therefore, how to balance the maintenance of therapeutic effect and avoidance of cytotoxicity (therapeutic window) is also considered in the management of cancer patients. In addition, the issue of 'is more dosage more effective' is challenged recently. Cancer patients can be considered as patients with chronic illness. Therefore, therapy as low dose, short interval, and continuing schedule has become popular. Metronomic therapy is a term to describe the above condition. Although the mechanisms and therapeutic efficacy are not well established, this hot topic needs our attention. In this review, we would like to introduce 'metronomic therapy'.