Alternative Medicine: The Cases of Vitamin C and Cancer
Harry Collins and Trevor Pinch, Dr. Golem: How to Think about Medicine (Chicago and London: The University of Chicago Press, 2005), pp. 84-111.
前言
1. 與orthodox medicine相互定義下的alternative medicine：
w Many of these treatment parallel standard medicine in that they offer drugs available in over-the-counter forms at pharmacies, health food stores or via the Internet. (p.86)
w The inexorable rise of modern medical science meant that by the middle of the twentieth century folk cures and remedies had either been coopted or displace to the margins as “alternative medicine.” (p.86)
2. 社會環境使得alternative medicine興起：
w The recent extraordinary growth in alternative medicine seems to be a by-product of sixties counterculture with its focus on Eastern religions, the whole body as well as the whole earth, and its suspicion of capitalism and its products. (p.86)
w Patient demand is growing. (p.88)
w It is the recalcitrant chronic illness (such as asthma) and low-grade ailments (such as backache), however, that provide the “bread and butter” for these alternative practitioners. (p.88)
為何需要randomize clinical trial (RCT)?
1. 為了確認療效，必須兩組病人相互對照：
Experimental group（實驗組）：給予待測新藥。
Control Group（對照組）：給予placebo（安慰劑）。
2. Reporting bias:
experimenter's reporting bias (1)
patient’s reporting bias: true placebo effect (2) & false placebo effect (3)
3. Expectancy Effect (4)
Vitamin C and Cancer: 一段爭議的歷史
1. 背景：
w President Nixon’ s “War on Cancer”
w Pauling’s “orthomolecular” medicine: 人類在演化的過程中，喪失了自體合成vitamin C的能力，而vitamin C是人體內最重要的orthomolecular substance。
w Cameron’s “PHI (physiological hyaluronidase inhibitor)” theory:
w 無意間發現vitamin C的效用：Cameron’s cocktail treatment of hormones with megadoses of vitamin C (intravenously 5gday, orally 2g/day → intravenously 10g/day, orally 8g/day)
w Cameron stressed that “he did not expect to cure cancer, but rather to control it.”(p.93)
2. The Study at the Vale of Leven Hospital:
w Standard Response: On receiving vitamin C they initially showed no improvement and in fact sometimes got worse, which for Cameron was evidence ruling out the placebo effect. (p.94) → About weeks after commencement of therapy, patient began to experience a feeling of well-being, recovered their appetites, and began to gain weight. (p.95)
w 腫瘤並未消失，但是獲得控制，不再長大，並且失去侵襲的能力（轉化成為良性腫瘤）。
w 缺陷：”whirlwind” reactivation of the cancer and death in few days
w 批評：
(1) NCI (National Cancer Institute) responded that “they would have to be convincing evidence in animals before any trials were begun with human.”(p.96)
(2) Historical Control Matching → The trail is not blinded!
3. The Study at the Sloan-Kettering Cancer Institute:
w Negative Result: The case histories showed no sign of any benefit. (p.97)
w Cameron和Pauling的反擊：
(1) Sloan-Kettering did not select the right group, and “the cancer in the Sloan-Kettering patients…had already been extensively treated with radiation and chemotherapy.” (p.97)
(2) Rebound Effect（反彈效應）
4. The First Trial at the Mayo Clinic:
w 實驗組：vitamin C 10g/day orally；對照組：placebo
w Negative Result: There was no statistically significant difference in two outcome. (p.101)
w Cameron和Pauling的反擊：
(1) The overwhelming majority of these patients ,however, had previously received chemotherapy and/or radiotherapy. (p.101)
(2) Patient Compliance: Dying patients in the control group would take ascorbic acid without supervision and thus muddy the comparison between the two limbs of trial. (p.103)
5. The Second Trail at the Mayo Clinic:
w Negative Result: No patient had measurable tumor shrinkage, the malignant disease in patients taking vitamin C progressed just as rapidly as in those taking placebo, and patients lived just as long on sugar pills as those on high-dose vitamin C.
w Cameron和Pauling的反駁：
(1) 在一百個patients中只有十一個人接受尿液檢測。這十一人中有六人吃的是placebo，更重要的是，這六人中的其中一個人，他尿液中的vitamin C含量超過550mg/day（一般而言，cancer patient: 0-10mg/day，normal healthy patient: 30mg/day）。 ← 意味著控制組的人並未被限制攝取vitamin C。
(2) What happened was that vitamin C was halted once tumor progressions were noted and the patient were given a highly toxic chemotherapy treatment. (p.105)
(3) Rebound Effect（反彈效應）
(4) The Mayo patients were ambulatory and were not examined during the first month of vitamin c treatment, so initial improvements documented so assiduously by Cameron went unnoticed. (p.106)
(5) The Mayo oncologists had tested vitamin C as if it were a cytotoxic drug to be administered for a short period of time, and whose therapeutic impact is measured primarily in terms of tumor shrinkage. (p.106-107)
結論
1. Cancer clinical trial methodologies have undergone evolution precisely because of the sorts of criticism made by Cameron of the Mayo studies. (p.108)
2. Also important in shaping the debate and in particular the issue of replication was the differing cancer treatment regimes in operation in the United States and Britain. (p.108)
3. The argument has in effect been closed in favor of orthodoxy. Experiments alone did not settle matters, but given the implausibility of Pauling and Cameron’s claims within the orthodox framework of cancer theory and practice, the experimental evidence offered a credible source of rebuttal. (p.109)
4. 我們沒有辦法證明vitamin C的具有療效：Assuming that the result of experiments were meaningful, what was shown was that those who had already been treated with chemo- or radiotherapy would not benefit, nor would those who were given vitamin C for a relatively short time. (p.110)
5. The trouble is that what we already know about science shows us that any piece of scientific research which is examined closely enough will reveal the same deficiencies when compared with quasi-logical standards. (p.110)
6. To say “leave it to people” is to risk the abrogation of our long-term collective responsibility to scientific medicine, even if sick and dying individuals might still wise to try the cure. (p.111)
問題與討論
1. 為了理解placebo effect，我讀了本文出處的第一章（The Hole in the Heart of Medicine: The Placebo Effect）。作者認為幾乎沒有辦法避免placebo effect，即使完全做到double-blind，病人們仍然可能透過各式各樣的「管道」來猜測自己是否服用真藥，例如：吃藥後的副作用—口乾舌燥。因此，新藥被認定有效（實驗組和對照組有足夠的統計差異），很有可能只是新藥有很強的副作用罷了！反過來說，如果實驗組和對照組的統計差異不明顯時，也不代表新藥根本無效，很可能只是因為對照組的placebo effect太強了！
因此由本例來說，證明vitamin C有效的實驗，很可能只是因為vitamin C帶來很強的副作用（雖然作者在文章中並未提及）；而證明vitamin C無效的實驗，除了前述Cameron和Pauling的反駁之外，也很可能只是因為對照組的病患也有很強的求生意志罷了！
2. 把醫療視為科學和把醫療視為輔助（succor），造成截然不同結果。如果我們把醫療定位為科學，那麼就必須遵從科學的內在價值—普遍性，我們必須使藥物對所有人一體適用，因此存在個體差異的實驗並不能夠被允許：病人有沒有事先經過放射或化學治療不應該列入考慮。相反的，如果我們把醫療定位為輔助，因為它不涉及普遍性問題，所以個體差異可以被接受，而訴諸於個人經驗亦可被接受。
3. 有趣的一個地方是，最後這個爭議的收場（並沒有解決！）乃是回歸到主流醫學的優先地位（The argument has in effect been closed in favor of orthodoxy.），也就是說，主流醫學佔據了發言的位置與地盤，想要與之抗衡，就必須先得與它同高度的發言位置，而取得發言位置的方法，就是必須先進入它的地盤（因為幾乎所有的地盤都被它佔走了），進入地盤的方法，就是要用它的代幣（實驗方法）買到門票。這是一種權力的不平等，你必須要證明自己有能力與之對話，而它卻不必證明自己其實已經擁有那個「高度」。
4. 接續前述，在這個權力不平等的狀態下，何謂alternative medicine就必須靠orthodox medicine來定義，在本文中，作者所使用到的定義全部來自於「社會脈絡」，而不是本質上的。從學期開始到現在，我們一樣遭遇了這個困難，我們幾乎無法從本質、內在來定義什麼是alternative medicine、什麼是中草藥，我們只能從「社會脈絡」下手，尤其是在「西洋鏡」（西醫）的反射下，我們才能看清楚中草藥的樣貌。（從這點來說，將alternative medicine翻譯成「替代療法」或「互補療法」似乎不適當。）
5. 我一直感覺作者的論證非常奇怪（或許是我讀錯），他點出了許多現代醫學的限制與缺失之後，但他卻認為唯有視醫學為科學（具有普遍性）才可能對大眾集體健康負起責任，難道，大眾健康就必須擺在醫學這個笨重的Golem身上？不具普遍性的集體醫療與管理，就不能使人們有健康的身體？更奇怪的是，作者在第一章（The Hole in the Heart of Medicine: The Placebo Effect）中，為了分析Placebo effect，他假設所有的alternative medicine有效都是因為placebo effect，接著他竟然說：“It is almost bound to be true because there are many orthodox treatments that have no potency, and it would be very odd if all the alternative treatments worked.”！這個論證難道不奇怪嗎？
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