HOW TO AVOID CERVICAL CANCER

Rebecca B. Singson, M.D., FPOGS

Globally, one woman dies of cervical cancer every 2 minutes, and some 500 thousand new cases of this disease are seen every year. Cervical cancer is the 2^nd most common cancer in women second only to breast cancer, afflicting 7225 new cases in in the Philippines according to our National Cancer Institute 2005 statistics. However, cervical cancer is a more deadly disease because for every 4 Filipino women who survive cancer of the breast, only 2 or 3 will survive cancer of the cervix.

Using a protocol assembled by the International Agency for Research on Cancer (IARC) from biopsy specimens from 22 countries, it was shown that the Human Papillomavirus (HPV) was present and is a necessary cause of cervical cancer (2,3) There are also other cancers to which the HPV has been linked to such as cancers of the vulva and the anus and penis. They start off as warts which eventually become tumorous growths. Increasing evidence has also been linking HPV as an important carcinogenic agen in cancers of the oral cavity, pharynx and larynx. 4.

HOW DO YOU GET IT?

The virus is acquired sexually and it seems the younger a woman starts sexual intercourse (especially

WHO ARE AT HIGH RISK?

HOW IS IT PREVENTED?

1, Male circumcision. The IARC multicentric study on maile cicrumscion revealed that circumcised men were about 3 times less likely to harbor HPV in their male organ than uncircumcised males.

The Young Adult Fertility Study (YAFS) 2002 revealed that 1.2% of our youth will have had their 1^st sexual contact before 13 yrs old, the youngest reported was at 8 years old. Twelve percent of the females while 28% of the males would have started sexual contact before 18. In fact, 38% of our youth are already in a live-in arrangement. These statistics are disturbing. If these youth knew that early sex and early pregnancy and multiple sexual partners increased their risk for acquiring the virus that causes cervical cancer, would they be empowered to make more intelligent choices?

During the recent Asia Oceania (research organization on) Genital Infection & Neoplasia (AOGIN), world experts on the Human Papilloma Virus and cervical cancer gathered from 18 countries to discuss global initiatives on cervical cancer prevention.

In Asia, there are 266,000 new cases of cervical cancer diagnosed each year. In 2005, alone our National Cancer Institute statistics reveals that there are 7225 new cases of cervical cancer in the Philippines. The sad thing is that two-thirds of these cases are diagnosed at a late stage when they are beyond the operative stage. So it is not surprising that 32.3% of them die in 1 year and 73% will die in 5 years. The sad part is that it is completely preventable, or at least diagnosable before it becomes life threatening.

WHAT CAUSES CERVICAL CANCER?

In the past 2 decades, substantial progress in our understanding of the natural history of cervical cancer have led us to conclude that a virus called the Human papillomavirus (HPV) is now recognized as the main cause of cervical cancer. ¹ There are more than 70 distinct site-specific types (meaning they will grow on one part of the body but not on another). Of these, about 35 types are found in the anus and the genital areas, causing warts and cervical cancer, the most notorious being types 16 and 18. It is a virus acquired through sexual contact and infects the lining cells of the genitalia and can be detected in 5%-40% of women of reproductive age.² It has been found that infections are relatively short-lived lasting usually 8-10 months.³ This indicates that our bodies are indeed capable of clearing the virus which is why in women over 30 years old, the prevalence drops down to 5-10%. Persistent infections, however, are found in 5-10% in women over 35 years old.⁴ It is in this group of women who are not able to clear the virus from their bodies that cancer in the cervix now has a chance to progress. The virus is apparently able to thrive in the cells without killing it and without inducing any immunologic reaction from the patient. The body therefore “ignores” the virus allowing it to eventually alter the genetic code of the cells. As a result, the cervix starts multiplying cells which become cancerous after many years.

FACTORS THAT INCREASE ONE’S RISK FOR CERVICAL CANCER

It is important to understand the risk factors that increase your chances of acquiring the virus as well as the co-existing factors that mediate progression to cancer. In a case-control study of women with invasive cervical cancer in four Latin American countries where they evaluated cervical cancer risk in relation to sexual behavior, histories of specific venereal diseases, and hygiene practices, it was noted that early age at first sexual intercourse and increasing number of sexual partners were associated with significantly increased risk for cervical cancer. Risk increased over twofold among women reporting first intercourse at 14 to 15 years of age compared with those who started after 20 years old.⁵ An initial pregnancy before 18 yrs. old and multiple pregnancies (over 5) as well as a history of having acquired a sexually transmitted disease (STD) also increase your risk. Having an uncircumcised male partner, cigarette smoking, an impaired immune system (such as AIDS patients), and poor nutrition (diet low on fruits & vegetables and deficient in Vit A, C & folic acid) all increase ones’s risk for cervical cancer. ⁶

SEXUAL PRACTICES OF THE YOUTH IN THE PHILIPPINES

WHAT TO DO

It is vital for us to educate our youth that it is prudent for men as well as women to delay having sex as late as possible. This is because the earlier you engage in sexual intercourse, the higher the chances for having multibple sexual partners which will increase the chances of acquiring the carcinogenic Human Papillomavirus. Men should realize that although the virus does not cause much harm to them in general other than occasionally causing unsightly penile warts, through their sexual practices, they can transmit the virus to their unsuspecting, innocent monogamous sexual partners. Engaging in sex early has also been linked to increased number of early, unwanted pregnancies which can also increase chance for the virus to mutate the genetic code (because of the immunocompromised state during pregnancy) of the cell to promote cervical cancer. The youth must know that promiscuity can be potentially lethal if one acquires the HPV virus or worse, AIDS so sex should be limited to a significant other or to one destined to be a lifetime partner. It might help them to know that choosing a circumcised male partner can also decrease one’s risk for cervical cancer.

Once the females start becoming sexually active, she should start seeing a gynecologist. Within 3 years from her first sexual contact, she should start getting Pap smears, which has been the most widely used screening test for cervical cancer. Unfortunately, there are many pitfalls to this since nearly half of specimens miss a cancer in the reading; about one-third of these false-negative readings are attributable to errors in interpreting slides and two-thirds to poor sample collection and slide preparation.⁷

However, a test already exists to detect the presence of the virus which uses a method similar to the Pap smear using a different cervical brush. It is currently available at the Makati Medical Center, the Asian Hospital & Medical Center, Medical City, St Luke’s and one center in Cebu. Made by the Digene Co, the Human Papillomaviurs test may be recommended to all women over 30 years and above together with a Pap smear. If both tests trun up negative, and the last three Pap smears were normal, you can even defer you next Pap smear test for 3 years because in the absence of the virus, is unlikely that you will develop cervical cancer in 3 years. If your test turns up positive, you may either opt for a repeat testing in 1 year or colposcopy of the cervix to check for possible.precancerous changes.

FUTURE THRUSTS

The era has arrived where two major pharmaceuticals (GSK and Merck) are already doing human trials on an HPV vaccines in the hope of reducing the risk for cervical cancer. Hopefully in 2 years, at least one of them will receive FDA approval from the U.S and be commercially available. It is hoped that such vaccines would boost an immune response against the development of cancer or even existing tumors. Preliminary trials of the vaccine have shown some promising success. Hopefully, mass vaccinations at around 10 years old before the woman becomes sexually active can someday help to eradicate a deadly cancer from the face of the earth.

1. Ladines-Llave , Cecilia, Burden of Cervical Cancer in the Philippines and Efforts to Combat the Disease (This paper was presented at the John Hopkins-JHPIEGO Global Conference on Low-Resource Setting Cervical Cancer Prevention, held in Bangkok, Thailand on Dec. 4, 2005)
2. Bosch FX, et al, The ABSCC study group. Prevalence of human papillomavirus in cervical cancer: a worldwide perspective. J Natl Cancer Inst 1995; 87: 796-802.
3. Walboomers JM, et al. Human papillomavirus is a necessary cause of invasive cervical cancer worldwide. J Pathol 1999: 189:12-9.
4. .Munoz N, et al. Chapter 1: HPV in the etiology of human cancer. Vaccine 24S3 (2006) S3/1-3/10.

¹Jan M. M. Walboomers, et al. Human papillomavirus is a necessary cause of invasive cervical cancer worldwide. The Journal of Pathology, 189: 1, 12-19.
² Franco EL, Villa LL, Richardson H, Rohan T, Ferenczy A. Epidemiology of cervical human papillomavirus infection. In: Franco EL, Monsonégo J, editors. New developments in cervical cancer screening and prevention. Oxford (UK): Blackwell Science; 1997. p. 14-22.
³Ho GYF, et al. Natural history of cervicovaginal papillomavirus infection in young women. N Engl J Med 1998; 338: 423-28.
⁴Shah KV, Howley PM Papillomavirus. In: Fields MN, et al, ed. Fields Virology, 3rd edition, Philadelphia: Lippencott Raven, 1988:2077-2109.
⁵Herrero R, et al. Sexual behavior, venereal diseases, hygiene practices, and invasive cervical cancer in a high-risk population. Cancer. 1990 Jan 15;65(2):380-6.
⁶www.emoryhealthcare.org/HealthGate/32624.html

⁷McCrory DC, Matchar DB, Bastian L, Datta S, Hasselblad V, Hickey J, et al. Evaluation of cervical cytology. Evidence report/technology assessment no 5; AHCPR publ no 99-E010. Rockville (MD): Agency for Health Care Policy and Research; 1999.