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一种针对一些最严重癌症的新疫苗可以防止病人在首次外科手术或者药物治疗后出现复发。一个对来自英国和其它欧盟国家的700名肾癌病人进行治疗的计划将在今年内起动。过去的经验显示这种治疗是安全的，它通过激发人体自身的免疫系统来攻击肿瘤。
直肠癌和乳腺癌同样也被列入该疫苗临床验证的计划之中。明年一种名为Gardasil的能预防妇女子宫癌的新疫苗同时也有可能会面市。伦敦南区ST乔治医院的肿瘤教授格斯·达尔格里斯博士帮助开发出了一种能有效预防前列腺癌的疫苗，该疫苗目前正在英国全国范围内进行大规模试验。
英文原文：
NUH team discovers how gene affects drug dosage
Singapore doctors have solved the puzzle of why Indian, Chinese and Malay patients need different dosages of the commonly-used anti-clotting drug - warfarin - to achieve the same effect, raising the possibility that medicine, in the future, could be prescribed based on ethnicity.
The key to solving the decades-old mystery is genetics, and research by a National University Hospital (NUH) team has tracked down a gene which determines why Indians need about 60 to 70 per cent more warfarin than their Chinese and Malay counterparts.
This knowledge can benefit thousands of patients.
Similar studies are being carried out on drugs being used in chemotherapeutic treatment of cancer patients.
\"That drug behaviour is different between races is something we have always been very interested in,\" said senior consultant of NUH's haematology-oncology department, Dr Goh Boon Cher, the leader of the research team.
And that is the case with warfarin which is widely used by doctors, including orthopaedic specialists, cardiologists, surgeons and gynaecologists.
\"The problem with this drug is that if you give too much the patient will bleed to death,\" explained Dr Goh.
But if too little is given, the clot persists.
\"One has to be very tight with dosage. Previously, after the drug was given, blood tests would be carried out to determine the amount of thinning in the blood,\" said Dr Goh.
Currently, hospitals take three weeks of laboratory work to establish how much warfarin a patient needs.
But the discovery that a gene decides the matter may soon put the issue at rest.
In its study, conducted over two months last year, the NUH team found that this gene recycles the body's Vitamin K, which is the target of warfarin in the anti-clotting process, consultant Dr Lee Soo Chin, another member of the team, told Today.
The study focused on 275 people in the Chinese, Malay and Indian ethnic groups as indicated by their Identity Cards, and whose parents and grandparents were also from the same ethnic group.
Dr Goh noted that the forefathers of the Chinese and Indian subjects were mostly from the south of both countries.
The study found that there are variations in the makeup of the gene in different races.
This means that Indians need 6mg a day of warfarin, compared to 3.5mg a day for the Chinese.
Malays need an intermediate dosage.
Dr Goh added that a person with mixed parentage may have \"intermediate\" genetic makeup and may thus require an intermediate dosage of warfarin.
The study was published in the January issue of the prestigious international peer-reviewed journal, Clinical Pharmacology and Therapeutics.
As the study is clinically significant and has immediate application, NUH will soon embark on another project to validate the findings of the study, this time among volunteer patients.
If validated, warfarin may well be the first drug in the world to be prescribed in dosages based on the patient's ethnic group.
The NUH is also studying some 10 drugs - most of them used in chemotherapy - which the various ethnic groups demonstrate different reactions to.
\"Currently, we prescribe according to literature that comes from the West,\" said Dr Goh. Recent studies conducted in the West show that Caucasian patients may require higher dosages compared to non-Caucasians.
What if the patient shows adverse side-effects? The obvious step would be to reduce the dosage in subsequent treatment, he said, though there is also the possibility that the initial dosage can result in fatal consequences.
Dr Goh added that doctors in Singapore often have to adjust the dosage of chemotherapeutic drugs in 20 to 30 percent of patients.
Vaccine hope for Cancer patients
A new vaccine which targets some of the most serious forms of cancer may prevent patients from suffering a relapse once they have had initial surgery or drugs treatment, the Guardian reported yesterday.
A trial involving 700 patients with kidney cancer will start this year across Britain and other European countries.
The work already done suggests the therapy is safe and that it triggers the body's own immune system to attack the tumour.
Other clinical trials looking at the vaccine's impact on patients with colorectal and breast cancer are also planned.
Also likely to see introduction within the next year is a vaccine, Gardasil, to prevent women developing cervical cancer, while Dr Gus Dalgleish, professor of oncology at St George's Hospital in south London, has helped to develop a vaccine which may prove effective against prostate cancer, and is now embarking on a large-scale randomised trial across the country. |
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发表于 2007-6-25 08:09:11