Cervical-cancer guardian
Merck Sharp and Dohme's Gardasil offers protection from cervical cancer and genital warts
By Sunly Coo, Contributing Writer
Cervical cancer is the second-leading cause of cancer death among women in the Philippines. Fifty-two percent of those afflicted with the disease will die within five years of diagnosis, according to the Philippine Cancer Facts and Statistics (2005). The staggering number is due to a number of factors, ranging from a lack of awareness of both the disease and the importance of undergoing regular Pap test, to the reluctance of Filipinas to subject themselves to the invasive procedure that screens for abnormal cell changes in the cervix.
The fact that only 42 percent of 389 hospitals in the country offer the test, as the Department of Health found out, does not help either. About two-thirds of those who are diagnosed with cervical cancer have already entered the advanced stages, where the chances of a cure are drastically limited.
But now, there is hope for many, and it comes in the form of a prophylactic vaccine.
Enter Gardasil
Gardasil, manufactured by Merck Sharp and Dohme (MSD), is the first cervical-cancer vaccine. Approved by the United States Food and Drug Administration (FDA) in June 2006 and recommended by the US Center for Disease Control and Prevention, Gardasil is now available in about 80 countries, including the Philippines, where it was approved by the Bureau of Food and Drugs (BFAD) in November last year. The company says that 10 million doses have already been administered around the world.
Gardasil is a quadrivalent vaccine, which means that it protects against four types of the human papillomavirus, specifically types 16 and 18, which account for 70 percent of cervical cancer, and types 6 and 11, which are responsible for nearly 90 percet of genital warts. Gardasil is administered through a three-shot regimen given in the course of six months. It does not cause serious side effects.
The HPV vaccine works in the same principle as other viral immunizations. The technology hinges on the idea that the virus's unique surface component, made up of the major capsid L1 proteins, could be used to trigger an antibody response that will protect the body against infection. It essentially contains these surface components that have self-assembled to form into virus-like particles (VLP) that will stimulate the immune system to attack the completed or real virus when it enters the body. These VLPs do not contain the virus' genetic material, and hence cannot multiply and infect.
Whom the vaccine is for
The US FDA has licensed the use of Gardasil in females ages nine to 26. Some states are lobbying to make the vaccination mandatory in 11- to 12-year-old girls, a move that has sparked some controversy. Not only do many Americans believe that a compulsory inoculation encroaches on a parent's right to choose what is best for their children, they are also concerned it would send a message to young kids that it is all right to engage in sex.
School-age kids are targeted for the vaccine, since it is most effective in females who have not had sex yet. The US National Cancer Institute states that studies demonstrate the vaccine's effectiveness for up to at least four years, preventing nearly 100% of the precancerous cervical cell changes caused by the vaccine's targeted HPV strains. Therefore, it makes sense to give it at the right age range-before one gets sexually active but not too soon. That age bracket would naturally vary from culture to culture.
In the Philippines, the 2002 Young Adult Fertility and Sexuality Study-a nationwide study involving 20,000 15- to 27-year-olds-revealed that 1.2 percent of both males and females had already had sex before they were 13. The probability of early sexual initiation (age 18 or earlier) was 12 percent in females and 28 percent in males.
MSD reminds the public that even with vaccination and proper condom use, which provides limited protection, a female can still be infected with 30 percent of cancer-causing HPV and about 10 percent of genital warts. Regular screening through the Pap test is still a must.
Two papers published in the New England Journal of Medicine found that Gardasil is less effective in women who have once been exposed to types 16 and 18. MSD says that studies are ongoing to include women beyond the upper age limit of 26. Gardasil is also licensed for use in boys ages nine to 15. Studies show that it elicits a stronger immune response in males than females.
Available through gynecologists, Gardasil is also administered at a Greenhills clinic that provides "a complete line of adult vaccines." Each shot costs PhP6,000 and a full series at Ph18,000.
Another cervical-cancer vaccine, GlaxoSmithKline's Cervarix, obtained approval from the European Union in September, but was formally launched in the Philippines in October (See related story). It was designed to be a bivalent vaccine that zeroes in on types 16 and 18, but ongoing studies have shown it can provide protection against 12 other types of cancer-causing HPVs. Cervarix is licensed for a wider age group, females from 10 to 45 years old. The cost of the vaccine will be announced shortly.
M
Facts on HPV
-
There are over 100 types of the human papillomavirus. About 40 of them affect the genitals of men and women.
-
According to the American Cancer Society, HPV is so common that most people who have had sex had HPV at one point in their life. The US Center for Disease Control and Prevention states that HPV infection could happen as soon as one starts having sex.
-
Since HPV infection is usually asymptomatic and the body tends to fights it off within two years, many people do not even know they had it. Those that stay longer in the body may develop cancer cells.
-
HPV infection is just as prevalent in males as it is in females, but its health implications in females are more serious. The US CDC says that the types of HPV that place women at high risk for cervical cancer rarely create health problems in most men.
-
In men, genital warts are the most common health problem caused by HPV. They do not lead to cancer.
-
Genital HPV is acquired through sexual intercourse and any type of skin-contact with infected genitals. The virus can also be transmitted from mother to newborn, and less commonly from infected undergarments, surgical gloves, and biopsy forceps.
-
There are two ways to screen for cervical cancer: the Pap test, which detects abnormalities in cervix cells, and the HPV test. Early detection saves lives.
-
There is no HPV test for men.
-
Symptoms of cervical cancer include increased vaginal discharge, pelvic pain, pain during sexual intercourse, and abnormal vaginal bleeding-bleeding between menstrual periods, bleeding after intercourse or pelvic exam, longer and heavier periods, or bleeding after menopause. Early stages of cervical cancer generally do not manifest any symptoms.
-
Certain types of HPV infection can also result to cancer of the oropharynx, anus, vulva, vagina, and penis.
-
The only sure way to prevent HPV infection is sexual abstinence.
How men can stop the spread of HPV
Men can be carriers of HPV, which is generally harmless. However, HPV, in some cases, may cause penile or anal cancer in men and cervical cancer in women. Since there is no test that detects the virus in males, they are advised to regularly check for signs and symptoms of infection:
-
Genital warts-raised, flat, or cauliflower-shaped-on the penis, testicles, groin, anus, or thighs; usually do not hurt and may appear weeks or months after having sex with infected individual
-
Anal bleeding, itching, pain, or discharge
-
Swollen lymph nodes on groin or anal area
-
Change in bowel habits
-
Penile discoloration
-
Skin-thickening or tissue buildup around the penis
-
The appearance of a sore on the penis
Lack of visible signs of infection does not mean that a person is free from HPV. Many types of HPV are asymptomatic, and early stages of penile or anal cancer may not exhibit any signs. Regular and proper use of condom provides protection but not complete coverage. Having a monogamous sexual relationship is no guarantee either. Your partner may already be exposed to the virus. Getting boys inoculated with the cervical-cancer vaccine can strongly reduce the chances of infection and transmission.
|
