Teaching Brief - MedPage Today

From: Subject: Teaching Brief - MedPage Today Date: Wed, 29 Mar 2006 19:00:08 +0200 MIME-Version: 1.0 Content-Type: multipart/related; type="text/html"; boundary="----=_NextPart_000_002F_01C65362.FF853C20" X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_002F_01C65362.FF853C20 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.medpagetoday.com/tbprint.cfm?tbid=2938 =EF=BB=BF Teaching Brief - MedPage Today

	Visit us = online at=20 www.MedPageToday.com
	Re-Assessment Urged for = Intravenous=20 Vitamin C and Cancer
	By Michael Smith, MedPage Today = Staff=20 Writer Reviewed by Zalman S. Agus, MD; Emeritus Professor at = the=20 University of Pennsylvania School of Medicine. March 27, = 2006

	MedPage Today Action Points Note that despite some early studies that showed a benefit = for oral=20 and intravenous high-dose vitamin C as a treatment for cancers,=20 subsequent controlled randomized trials failed to confirm the = finding.=20 Advise patients who ask that there is still no conclusive = evidence=20 that high-dose intravenous vitamin C has a benefit in cancer = therapy,=20 but note that this report suggests the approach now has some = clinical=20 and biological plausibility. Note also that further study and more conclusive evidence is = necessary before high-dose vitamin C is accepted as a cancer = treatment.=20
	Review BETHESDA, = Md., March=20 27 - Three case reports of benefit from intravenous use of = high-dose=20 vitamin C for cancer are being promoted here as a sign that = perhaps a=20 reassessment of the long-discredited approach is in order.=20 For years high-dose vitamin C as a treatment for cancer was = banished to=20 the category of alternative therapy, after clinical trials of oral = vitamin=20 C showed no benefit.=20 But the three case studies, as well as new pharmacological = evidence,=20 suggest that the role of high-dose vitamin C administered = intravenously=20 should be re-assessed, according to Sebastian Padayatty, M.D., of = the=20 National Institute of Diabetes and Digestive and Kidney Diseases = here.=20 The three case reports increase the "clinical plausibility" = that=20 vitamin C may have a benefit, Dr. Padayatty and colleagues wrote = in the=20 March 28 issue of the Canadian Medical Association = Journal.=20 It is now known, they said, that high-dose intravenous -- but = not oral=20 -- vitamin C therapy results in plasma concentrations of about = 14,000=20 micromole per liter. Oral doses result in plasma concentrations of = at best=20 220 micromole per liter.=20 At those concentrations in vitro, Dr. Padayatty and colleagues = said,=20 the vitamin is toxic to some cancer cells, but not to normal cells = -- a=20 finding that increases the "biological plausibility" of a = beneficial=20 effect.=20 Early studies of high-dose oral and intravenous vitamin C = appeared to=20 show a benefit, but a randomized controlled trial of oral vitamin = C failed=20 to confirm the finding, the researchers noted, and the idea was = abandoned.=20 The three case studies -- of patients whose disease had a poor=20 prognosis but an unusually favorable outcome -- can't be regarded = as=20 conclusive, but they "were analyzed in accordance with the = National Cancer=20 Institute's Best Case Series process, which reports and interprets = apparent responses to alternative therapies," the researchers = noted.=20 In the first study, a 51-year-old woman was found to have a = tumor=20 involving her left kidney, shown after nephrectomy to be a renal = cell=20 carcinoma. CT scans of the chest and abdomen showed no evidence of = metastatic disease. However, six months later, CT chest scans = showed new=20 small rounded and well-defined soft tissue masses that were judged = consistent with metastatic cancer. After another seven months, = multiple=20 cannonball lesions were seen.=20 The patient refused conventional therapy and opted instead for=20 high-dose intravenous vitamin C -- 65 grams twice a week for 10 = months --=20 as well as a range of other alternative therapies, including = thymus=20 protein extract, N-acetylcysteine, niacinamide, and whole thyroid = extract.=20 Seven months after the cannonball lesions were seen, chest = radiography=20 was normal, except for a possible pulmonary scar in the left lung. = The conclusion that the vitamin C had a beneficial effect would = be=20 strengthened, the researchers noted, if there had been = histological proof=20 that the cannonball lesions were actually malignant - evidence = that does=20 not exist. However, the researchers said, the clinical = characteristics and=20 evolution of the pulmonary lesions "make any other diagnosis = unlikely."=20 Unfortunately, the woman -- a long-time smoker -- was diagnosed = four=20 years later with small-cell lung cancer. She again opted for = vitamin C=20 treatment, but the second cancer did not respond.=20 In the second case, a 49-year-old man was found to have a = primary=20 bladder tumor with multiple satellite tumors. Transurethral = resection of=20 the primary and satellite tumors was carried out. Histopathologic = review=20 at the NIH revealed a grade 3/3 papillary transitional cell = carcinoma=20 invading the muscularis propria.=20 The patient declined chemotherapy and radiotherapy, opting = instead for=20 30 grams of vitamin C twice a week for three months, followed by = 30 grams=20 once every one to two months for four years, interspersed with = periods=20 during which he had more frequent infusions. He also used = supplements=20 including botanical extract, chondroitin sulfate, chromium = picolinate,=20 flax oil, glucosamine sulfate, a-lipoic acid, Lactobacillus=20 acidophilus, L. rhamnosus, and selenium.=20 Nine years after diagnosis, the patient is in good health with = no=20 symptoms of recurrence or metastasis, the researchers reported.=20 The outcome would have been unexpected, Dr. Padayatty and = colleagues=20 noted. With only local treatment, as in this case, invasive = transitional=20 cell bladder cancer "almost invariably develops into clinically = apparent=20 local or metastatic disease within a short period."=20 In the third case, a 66-year-old woman was found to have a = large left=20 paraspinal mass medial to the iliopsoas muscle at the L4-5 level, = with=20 evidence of extension into the posterior paraspinal muscle and = bone=20 invasion, although chest radiography results were normal. A biopsy = was=20 diagnostic of a diffuse large B-cell lymphoma. Later = histopathologic=20 analysis at the NIH confirmed the diagnosis.=20 The patient agreed to a five-week course of radiation, but = refused=20 chemotherapy, opting instead for 15 grams of intravenous vitamin C = twice=20 weekly for two months, 15 grams once to twice a week for seven = months, and=20 then 15 grams once every two to three months for about a year. The = patient=20 also used additional products: beta-carotene, bioflavonoids, = chondroitin=20 sulfate, coenzyme Q10, dehydroepiandrosterone, a multiple vitamin=20 supplement, N-acetylcysteine, a botanical supplement, and bismuth = tablets.=20 Over the year following diagnosis and the beginning of = treatment, the=20 patient had several occasions when axillary, cervical, = sub-mandibular, or=20 supraclavicular lymph nodes were palpable, but at the end of that = time --=20 and for the 10 years since -- the patient was in normal health, = with no=20 signs of B-cell lymphoma.=20 The three cases "do not provide grounds for advocating = intravenous=20 vitamin C therapy as a cancer treatment," the researchers said. = These=20 patients received other alternative medicine therapies and = spontaneous=20 remission of some tumors is known to occur rarely.=20 On the other hand, Dr. Padayatty and colleagues said, they = "increase=20 the clinical plausibility of the notion that vitamin C = administered=20 intravenously might have effects on cancer under certain = circumstances."=20 Primary source: Canadian Medical = Association Journal Source reference:=20 Sebastian J. Padayatty, et al "Intravenously administered vitamin C as cancer = therapy:=20 three cases" CMAJ 2006;174(7):937-42.=20 Disclaimer The information = presented=20 in this activity is that of the authors and does not necessarily = represent=20 the views of the University of Pennsylvania School of Medicine, = MedPage=20 Today, and the commercial supporter. Specific medicines discussed = in this=20 activity may not yet be approved by the FDA for the use as = indicated by=20 the writer or reviewer. Before prescribing any medication, we = advise you=20 to review the complete prescribing information, including = indications,=20 contraindications, warnings, precautions, and adverse effects. = Specific=20 patient care decisions are the responsibility of the healthcare=20 professional caring for the patient. Please review our Terms of=20 Use.
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