Thursday, January 21, 2010

Virus alert: this one could cause cancerL HPV

Virus alert: this one could cause cancer
This is a virus as deadly as the HIV and as common as the cold. A German virologist who has shown that the human papilloma virus (HPV) triggers cervical cancer shares the 2008 Nobel prize (for physiology or medicine)
by Benita Sen
It’s the year of the virus. The Nobel Prize for physiology or medicine for 2008 is shared by French researchers Luc Montagnier and Françoise Barré-Sinoussi, and German virologist Harald zur Hausen for “the discovery of two viruses of great importance in diseases for humans”, according to a statement by the Nobel Committee. Montagnier and Barré-Sinoussi’s conclusion that the human immuno-deficiency virus (HIV) causes AIDS, and Prof. Hausen’s discovery that the human papilloma virus (HPV) causes cervical cancer have armed mankind in its fight against these two dreaded diseases.
Stemming infection: Bhudev Das with German virologist Harald zur Hausen.
SWe know about the deadly HIV. But HPV? Most of us haven’t even heard of it. But a growing number of doctors from all over the world have started believing that HPV is an equally deadly virus. Worse, it is as common as the cold, anywhere in the world.
HPV and cancer
Not many of us know viruses can cause cancer. The hepatitis B and C viruses, for instance, cause liver cancer. The human T-cell virus causes T-cell leukaemia and the human herpesvirus 8 (HHV8) causes Kaposi’s sarcoma. Now, thanks to Prof. Hausen’s pioneering work, the world knows that HPV triggers cervical cancer.
Youngsters, beware
According to the American Cancer Society (ACS), HPV is transmitted largely by an infected sexual partner. “About one-half to three-fourths of the people who have ever had sex will have HPV at some time in their life,” it says.
Also Read Counting on curcumin
HPV also finds a ready host in younger people. In the US, for instance, virtually one in two HPV-infected people is below 25. Studies suggest that most sexually active men and women will contract HPV at some time in their lifetime. The good news, though, is that most will never even know it and the virus does not always cause disease. Often, the body clears up HPV infections on its own within two years or less.
Cervical cancer, however, is largely incurable. It goes undetected in developing economies where there are no facilities for early detection. Incidentally, according to World Health Organization, since developing countries do not have a mandatory screening programme (the pap smear test for women, for example, and anal pap smear tests for men), they account for 80% of cervical cancer cases worldwide.
Pioneering work
Prof. Hausen, from the German Cancer Research Center in Heidelberg, cloned the virus in 1984. Says Dr Bhudev C. Das, professor of biomedical sciences, Ambedkar Center for Biomedical Research, University of Delhi, and formerly founder director, Institute of Cytology and Preventive Oncology (ICPO) of the Indian Council of Medical Research, Noida: “In spite of the fact that the two high-risk and carcinogenic HPV types 16 and 18, against which two vaccines have been developed, were cloned by Prof. Hausen and his group in the late 1970s, his work was not given much importance compared to HIV, HBV and other viral diseases for more than a decade.” Experts claim that the HPV vaccine offers 95% protection from the HPV 16 and HPV 18 viruses.
HPV vaccine
India’s first vaccine to help prevent cervical cancer caused by HPV was launched recently by MSD Pharmaceuticals (India), the local affiliate of Merck & Co., Inc. of the US. The vaccine, Gardasil (Quadrivalent Human Papillomavirus Vaccine, against Types 6, 11, 16 and 18), helps prevent diseases such as cervical cancer, abnormal and precancerous cervical lesions, vaginal lesions, vulvar lesions and genital warts, all caused by these types of HPV. It is recommended for women between 9 and 26 years of age.
Do I have HPV?
Although genital HPV infection is very common, most of us, except those who develop genital and anal warts, do not know we are carriers. At a later stage, an infected woman may complain of irregular bleeding or bleeding after intercourse. Ironically, the warts are caused by the lower-risk HPV variants, HPV 6 and 11. The high-risk HPV 16 and 18, on which Prof. Hausen has been working and which accounts for about 70% of cervical cancer cases (source: ACS) and cancers of the genital region, show up as cervical lesions, on the way to morphing into cancer. HPV also causes some cancers of tonsils and tongue.
Research in India
The elected president of the Indian Association for Cancer Research for 2006-2009 and recipient of the President’s Medal for the Dr B.C. Roy National Award, Dr Das has worked with Prof. Hausen for several years. He says HPV is present in almost 98% of Indians. His work with herbal preparations such as curcumin (found in turmeric) to counter HPV (reported in Mint earlier, see bottom left) is now in the clinical trial phase. Other cures he is exploring include Praneem, a polyherbal product used against HIV too.
Dr Das says: “In spite of the Nobel Prize and the realization that HPV infection and cervical cancer incidence in India is the highest in the world, it is time we launched a mass awareness programme even among doctors, healthcare workers, public health personnel and NGOs, a majority of whom are ignorant of HPV. The message must reach the youth, who are most susceptible to HPV.”
HPV & You
Genital HPV travels from one person to another through vaginal and anal sex. In the absence of a mass vaccination programme or proper screening, Dr Das warns that the changing sexual behaviour, early exposure to sex and multiple sexual partners are dangerous signs for India
5,00,000: The number of people affected by HPV every year. The American Cancer Society suggests that it is the second largest cause of cancer among women worldwide.
74,000: The number of women who die due to cervical cancer in India. This is more than one-fourth of the deaths attributed to the disease.
2.5%: The percentage of lifetime risk of women in India getting this cancer. This is almost double the risk compared with the worldwide figures (1.3%).
One-in two: HPV-infected persons in the US is below 25, according to the American Cancer Society
One-half to three-fourths of people who have ever had sex will have HPV at some time in their life, studies suggest.

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