恐らく発癌性の物質NDMA混入バルサルタン使用に伴う癌発現上昇は認められず BioTodayニュースレター 2018年9月17日
デンマークでの調査の結果、恐らく発癌性の物質・NDMA混入により欧米などで最近回収となった中国Huahai Pharmaceuticals社製バルサルタン使用に伴う癌の発現リスク上昇はひとまず認められませんでした。更なる追跡で長期の癌リスクを調べる必要 があると著者は言っています。
Tainted Valsartan Not Linked to Cancer Risk in the Short Term
Recalled blood pressure drugs not linked to increased short term cancer risk
Exposure to Contaminated Valsartan Doesn't Appear to Raise Short-Term Cancer Risk

Use of N-nitrosodimethylamine (NDMA) contaminated valsartan products and risk of cancer: Danish nationwide cohort study. BMJ. 12 September 2018
Regulatory response to contaminated valsartan. BMJ. 12 September 2018

●This contamination, which far exceeded regulatory exposure limits, seems to be related to a change in the manufacturing process that was implemented in 2012

●NDMA is the simplest dialkylnitrosamine and is known to be a by-product in various industries―for example, the manufacture of pesticides, rubber tyres, alkylamines, and dyes.

●NDMA is one of the most well characterised and most potent animal carcinogens known and has been shown to be a potent carcinogen across all species that have been investigated, both as single doses and with long term exposure to lower quantities. Although no in vivo data are available for humans, NDMA seems to be metabolised similarly in human tissue and rodent tissue.6 The International Agency for Research on Cancer (IARC) has on this basis classified NDMA as “probably carcinogenic to humans” (group 2A), emphasising that NDMA“should be regarded for practical purposes as if it were carcinogenic to humans.”
NMDAは非常によく研究されており,単回投与,低濃度の長期間暴露のいずれでも,動物種を限定しない発がん作用が明らかになっている.人体への直接の影響こそデータはないが,齧歯類組織とヒトの組織での代謝も共通しており,IARCは実質的な発がん物質として,“probably carcinogenic to humans” (group 2A)に分類している.

●From the 128 unique valsartan drug products used during 2012-18 within our study population, we identified 18 drug products (which constituted 18% of all prescriptions filled) that were manufactured using an active pharmaceutical ingredient from Zhejiang Huahai Pharmaceuticals. These drug products were classified as probably contaminated with NDMA. An additional 36 drug products (26% of all prescriptions) were classified as possibly contaminated with NDMA, as they contained an active pharmaceutical ingredient both from Zhejiang Huahai Pharmaceuticals and from other companies. Seventy four drug products (55% of all prescriptions) were classified as unlikely to be contaminated with NDMA as they did not contain an active pharmaceutical ingredient from Zhejiang Huahai Pharmaceuticals.
バルサルタンを含んだ製剤128のうち18がファーハイ製の原末を含み(probably contaminated with NDMA),その製剤を使った処方箋の割合はバルサルタン製剤を含む処方箋全体の18%,それに加えて36の製剤がファーハイと他の会社の原末を含んでおり(possibly contaminated with NDMA),その製剤を使った処方箋の割合はバルサルタン製剤を含む処方箋全体の26%であり,結局のところバルサルタン製剤を含む処方箋全体の45%が,NDMA汚染の可能性があると考えられた

リスクとしては,数年以上のスパンで顕在化する可能性があるが,暴露量,顕在化する時期,誰が顕在化するかが予想できないという意味で,変異型クロイツフェルトヤコブ病(vCJD)と類似している.最近のvCJDの発症状況に関しては,エジンバラ大学のNCJDRSU (National CJD Research & Surveillance Unit)のLatest NCJDRSU annual report, covering the period 1990-2017を参考にされたい.