摘要:我們過去之研究顯示利用發光二極體(LED)或雷射紅光之低光劑量局部塗抹5-胺基酮戊酸 (ALA) 之光動力療法(100焦耳局部ALA-PDT),對口腔疣狀增生及口腔紅白斑病變之治療非常有效,但對於相對較大之口腔疣狀增生及口腔紅白斑病變,仍然需要4-6次光動力治療,才能讓病變完全消失。同時我們發現100焦耳或200焦耳局部ALA-PDT,對口腔白斑病變之療效仍然較差。最近之研究發現,抗癌藥物methotrexate (MTX)前處理過之攝護腺癌細胞,其coproporphyrinogen oxidase (CPO) 之表現增加3倍,因此癌細胞內protoporphyrine IX (PpIX) 之產量也增加3倍。以vitamin D (Vit D)前處理過之癌細胞,也可增加細胞內PpIX之產量。重要的是,安全、無毒、低劑量之MTX (0.6 nmol/L–2 mmol/L) 或 Vit D (10-12–10-10 M),即可以增加細胞內PpIX之產量。我們假設當口腔癌前病變或早期口腔癌患者,先服用低劑量之MTX或Vit D三天時,再以200焦耳或500焦耳局部ALA-PDT治療,應可以增加光動力治療之療效,及減少治癒口腔病變所需光動力治療之次數。因此,此三年研究計畫將利用635-nm雷射紅光為光源之200焦耳或500焦耳局部ALA-PDT療法,來治療600例口腔癌前病變及早期口腔癌。此600例口腔癌前病變及早期口腔癌病變,將隨機分成6組治療,每組100個病例,包括30例口腔白斑,30例口腔紅白斑,30例口腔疣狀增生及10例早期口腔癌病例。控制組200病例,不經MTX或Vit D前處理,直接以200焦耳或500焦耳局部ALA-PDT治療。另外200例口腔癌前病變及早期口腔癌病例,經MTX前處理3天(2.5 mg MTX錠,一天一次),再以200焦耳或500焦耳局部ALA-PDT治療。另外200例口腔癌前病變及早期口腔癌病例,經Vit D前處理3天(1.0 mcg Onealfa錠,一種Vit D3,一天一次),再以200焦耳或500焦耳局部ALA-PDT治療,以測試MTX或Vit D前處理,是否可以增加病變細胞內PpIX之產量,並增加光動力治療之療效,進而減少光動力治療次數。當患者第一次來門診時,先以VELscope,利用400-460 nm藍光檢查病變,並於病變最暗處(病變最嚴重處),作例行組織活體切片檢查,以確定口腔病變之組織病理診斷。對於MTX或Vit D前處理之口腔癌前病變及早期口腔癌病例,於患者第二次來門診時,於塗抹20% ALA後0.25、0.5、0.75、1、1.25、1.5小時,利用410-nm激發光,分別量測其PpIX螢光光譜,我們預測PpIX於病變細胞內之產量,將於1.5小時內,達到最高峰。於患者第三次來門診時,開始以200焦耳或500焦耳局部ALA-PDT治療口腔癌前病變及早期口腔癌病變,每星期治療一次。同時,我們也將利用OCT組織造影技術,追蹤監測上述600例口腔癌前病變及早期口腔癌病例,經光動力治療前、中、後之變化。另外我們也利用免疫組織化學染色法,研究Bcl-2, Bax, Mcl-1, Bak於這些口腔癌前病變及早期口腔癌標本中之表現及Bax/Bcl-2和Bak/Mcl-1標記積分比值,看其是否可以作為預測以200焦耳或500焦耳局部ALA-PDT來治療口腔癌前病變及早期口腔癌病例之臨床療效指標。於完成此三年研究計畫後,我們將了解200焦耳或500焦耳局部ALA-PDT之療效,是否比100焦耳局部ALA-PDT之療效為佳。500焦耳局部ALA-PDT之療效,是否比200焦耳局部ALA-PDT之療效為佳。經MTX或Vit D前處理過之200焦耳或500焦耳局部ALA-PDT之療效,是否比無MTX或Vit D前處理過之200焦耳或500焦耳局部ALA-PDT之療效為佳。OCT組織造影技術,是否可以用來追蹤監測口腔癌前病變及早期口腔癌病例,經光動力治療前、中、後之變化。了解Bcl-2, Bax, Mcl-1, Bak於這些口腔癌前病變及早期口腔癌標本中之表現及Bax/Bcl-2和Bak/Mcl-1標記積分比值,是否可以作為預測MTX或Vit D前處理過之200焦耳或500焦耳局部ALA-PDT用來治療口腔癌前病變及早期口腔癌之臨床療效指標。
Abstract: Our previous studies found that the low-light dose topical ALA-PDT (100-J topical ALA-PDT) with either the 635-nm light emitting diode (LED) or laser red light is very effective for treatment of oral verrucous hyperplasia (OVH) and oral erythroleukoplakia (OEL) lesions. However, for relatively large OVH and OEL lesions 4-6 PDT treatments are needed to achieve a complete response (CR) of the lesion. In addition, 100-J or 200-J topical ALA-PDT is not effective for oral leukoplakia (OL) lesions. Recent studies found that pretreatment of prostate cancer cells with methotrexate (MTX) can have a 3-fold upregulation of expression of coproporphyrinogen oxidase (CPO) proteins, resulting in a 3-fold increase in intracellular protoporphyrine IX (PpIX) production. Pretreatment of vitamin D (Vit D) also has a similar effect on the production of intracellular PpIX. The most important point is that even a safe, nontoxic, low-dose of MTX (0.6 nmol/L–2 mmol/L) or Vit D (10-12–10-10 M) can result in a significant elevation of PpIX production in cancer cells. We hypothesize that when oral precancer or early oral cancer patients are preconditioned with a low oral dose of MTX or Vit D and then treated with 200-J or 500-J topical ALA-PDT, the PDT efficacy can be augmented and the PDT treatment number to achieve a CR can be reduced. Therefore, in the following 3-year research project, we plan to use the 200-J or 500-J topical ALA-PDT with the 635-nm laser red light to treat 600 oral precancer or early oral cancer patients with or without MTX or Vit D pretreatment. For MTX or Vit D premedication, patients will take a low oral dose of MTX (2.5 mg MTX tablet, one time a day) or of Vit D (1.0 mcg Onealfa tablet, a kind of Vit D3, one time a day) for 3 consecutive days before topical ALA-PDT treatment. The 600 oral precancer or early oral cancer patients are randomly divided into 6 groups with each group containing 30 OL, 30 OEL, 30 OVH, and 10 early oral cancer patients. The two control group patients are treated with either 200-J or 500-J topical ALA-PDT without drug pretreatment. The two MTX group patients are treated with either 200-J or 500-J topical ALA-PDT with MTX pretreatment. Furthermore, the two Vit D group patients are treated with either 200-J or 500-J topical ALA-PDT with Vit D pretreatment. At the patient’s first visit, the oral lesion is examined under the blue excitation light (400 to 460 nm) using the VELscope in the dark. Biopsy is taken from the darkest area of the lesion which is supposed to be the most severe part of the lesion. Histopathological diagnoses of oral lesions are made through examination of the H&E-stained tissue sections. For the MTX- or Vit D-pretreated patients, ALA-induced PpIX fluorescence spectra at 410-nm excitation are measured 0.25, 0.5, 0.75, 1, 1.25 and 1.5 hours after local application of 20% ALA to each oral lesion to see when PpIX reaches its peak level in the lesional epithelial cells at the patient’s second visit. Either 200-J or 500-J topical ALA-PDT will be carried out once a week starting from the patient’s third appointment. Optical coherence tomography (OCT) is used to monitor the changes of oral lesions before, during and after PDT treatments. In addition, immunohistochemical stain of the biopsy specimens is performed to see the expression of Bcl-2, Bax, Mcl-1 or Bak in oral lesional epithelial cells. At the end of this 3-year study, we will realize whether 200-J and 500-J topical ALA-PDT can have a better efficacy than the 100-J topical ALA-PDT, will understand whether 500-J topical ALA-PDT can have a better efficacy than the 200-J topical ALA-PDT, and will know whether MTX- or Vit D-pretreated 200-J and 500-J topical ALA-PDT can have better clinical outcomes than the control 200-J and 500-J topical ALA-PDT without drug premedication for treatment of oral precancers and early oral cancers. In addition, we will know whether we can use OCT to monitor the changes of oral lesions after topical ALA-PDT treatments, and will realize whether the expression of a specific biomarker in the tissue specimen of an oral lesion can predict the clinical outcome of the oral precancers and early oral cancers treated with MTX- or Vit D- pretreated topical ALA-PDT.