A study published August 7, 1996 in the Journal of the National Cancer Institute shows that, in effect, a husband can take cancer home to his wife. The number of deaths from cancer of the cervix is 500,000 a year, world wide and the incidence of this caner is 40 per 100,000 women world-wide. (Human papilloma virus infection – HPV virus – British Medical Journal, Vol 312, Mar. 2, 1996).
The idea that genital wars is a sexually transmitted disease has been around since the Roman era. Yet it was not until the late 1970’s that zur Hausen proposed that HPV was related to caner of the uterine cervix. To date over 75 varieties of HPV have been described. HPV is divided into low grade varieties which usually regress if the virus become latent. And intermediate types (type numbers 31, 33, 35, 45, 51, 52, 56) and high grade types (16 and 18). Though the risk of developing cancer is relatively low, even with high grade viruses, the incidence of HPV is so high that cancer of the cervix is the second most common cancer in women.
HVP 16 is the most commonly associated with cancer and HPV 18, 45 and 56 are associated with cancer and with the most rapidly spreading cancer. There were 15,800 cervical cancer cases with 4,800 deaths in the U.S.A. in 1995. Figures for Canada would be approximately one-tenth of these numbers.
HPV infection is one of the most common sexually transmitted diseases in the U.S.A. and Canada and there is strong evidence that HPV plays a central role in carcinoma of the cervix. One study shows that 33 percent of female university students had HPV. Overall available data show that it is common. Different studies in a general practice setting have shown an incidence of between 5 per cent and 70 per cent. Eight per cent of men between the ages of 15 and 49 years have been shown to have HPV.
Why is HPV so common?
The answer is simple. Promiscuous sexual behavior is common. The risk factors are sexual intercourse at an early age, multiple male sexual partners, and male sexual partners who themselves have had multiple sexual partners. A prograde study by Kutsky et al. of women who attended a clinic for sexually transmitted disease found HPV in 45 per cent. HPV infection was associated with an extremely high-grade cervical dysplasia tends to develop into cancer. Types 16, 18, 45 and 56 genotypes of HPV were associated with high grade cervical lesions and cancer (odds ratio of 250 for these lesions in an HPV infected woman).
A researcher from John Hopkins University School of Medicine has concluded that unfaithful husbands five their wives cancer. The study (reported in the New York Times of Aug. 6, 1996) found that women are 5 to 11 times as likely to develop cervical cancer if their male partners frequent prostitutes or have had many sexual partners. “Male behavior is the important thing in this cancer” said Dr. Keerti V. Shah, a professor at Johns Hopkins. “In effect, the husband takes cancer home to his wife” said Shah. The risk of cervical cancer was increased 11 times for wives of men who had 21 or more sexual partners, and was eight times greater among men who frequented prostitutes.
Dr. Willard Barnes of Georgetown University School of Medicine said that the study reinforced evidence that cervical cancer in similar to classic venereal disease. “The message from studies like this, is that men should stay at home,” he said (New York Times, Aug. 6. 1996). On the other hand, Dr. Shah also warned that any woman could put herself at risk by having many sexual partners, and that the cancer risk for a woman increases with the number of direct or indirect sexual exposures.
Squamous epithelial lesions (SIL) occur in younger women (under 40 years of age). Cancer, though occurring during a broad age range, usually occurs at a mean age of 54 years. Thus there is usually a long (20 years latency period. The earliest sign of possible cancer is low grade atypical cervical mucosal cells on a PAP smear. SIL is graded low, intermediate and high (LSIL, SIL, HSIL). HSIL is highly correlated to high risk HPV (16, 18) and also with a high incidence of cancer. Seventy to eighty per cent of HSIL, 40 per cent of SIL and 15 per cent of LSIL progress to cancer. Therefore women with LSIL or SIL on more than one PAP smear should have direct visual examination of the uterus. Those with HSIL should undergo a biopsy. The role of HPV DNA testing (determining which type, e.g. 16, 18 etc.) is debated but at present is believed to be best used for guiding therapy in women with lesions of the cervix.
How does HPV cause cancer?
First, the virus enters the superficial mucosal cells of the cervix, and later enters the basal cells. This is called “integration.” Integration leads to the uncontrolled production of proteins by two genes of the virus, E6 and E7. These proteins ‘immortalize’ cervical cancer cells assuring their continued proliferation. This is partly die to the E6 binding to the normal cell protein p53 and its rapid degradation. The protein p53 normally regulated cell growth of the cervix. Almost 100 per cent of cells that show evidence of cancer contain HPV. There are some cases of cervical cancer that do not contain HPV, but they are rare.
In the HPV positive group, other factors have been associated with cervical cancer. They include smoking, oral contraceptive use, early age at first pregnancy and parity. Apart from parity, these factors are not statistically significant and are probably part of the life style that led to HPV infection in the first place.
The incidence of genital HPV in the newborn baby acquired from the mother in the amniotic fluid during birth, is 4 per cent. The incidence of pharyngneal HPV in the newborn is 50 percent. This is presumably caused because the baby swallows the amniotic fluid.
It is also known that the majority of younger woman who are HIV positive and are also HPV positive have high grade pre-cancer or cancer of the cervix. In them, there is no long latent period which commonly occurs in patients without HIV. There is also an association between HPV and cancer of the vulva. HPV is found in 83 per cent of these cancers in young woman.
Despite more radical surgery and the use of more sophisticated adjuvant radiation and chemotherapy in patients with high risk cancers, the overall survival has improved only marginally in the last 3 years. This emphasizes the importance of prevention, early diagnosis and improved treatment.
Prevention of HPV, cervical cancer
How can we try to prevent the cervical cancer associated with HPV?
1) Regular PAP smears (bi-annual);
2) Where necessary, direct visual examination of the cervix by the gynaecologist;
3) Where necessary, direct biopsy of the lesions;
4) Avoiding smoking may improve immune response;
5) It may become possible to develop the following,
a: small molecule drugs that interfere with the interaction between the HPV E6 protein and the p53 protein, thereby restoring normal inhibitory function of p53 in cell cycle regulation.
b: cellular immunity to E7 peptides to prime or boost the patient’s immunity when the patient has residual disease following conventional treatment for cancer.
6) Physicians across the nation originally advocated the use of the condom in order to assure their patients that safe sex was possible. A study in Florida of heterosexual couples showed that 30 per cent had caught HIV from their spouse, even though they knew their makes were HIV positive and consistently used condoms 16. Similarly the condoms failed to protect against other viruses such as the herpes and the papilloma virus. The medical profession, more recently has been using the term ‘safer sex.’ An obvious reason is that the use of the term ‘safer sex’ is safer in the defence of the physician sued by a patient who acquired HIV despite following the advice to use of the condom. As condom expert Malcolm Potts said” “Telling a person who indulges in high risk behaviour is like telling someone who is driving drunk to use a seatbelt.”
Since promiscuity is avoidable, all sexually transmitted diseases can be avoided. ‘Just say no’ is a valid policy. It works in the prevention of substance abuse and also would in the case of carcinoma of the cervix.
Young women must be fully apprised of the risks involved if they are promiscuous an should be encouraged to practice the virtue of chastity. This virtue, which is a good in its own right, will prevent an appalling avalanche of medical woes.
This is an ideal climate to promote the virtue of chastity for both single people and married couples. Sexually transmitted disease has forced a renewed examination of chastity and healthy living.
Although it is not politically correct to suggest that sexually transmitted disease is nature’s way of discouraging promiscuity, there s clearly something to be said for chastity and abstinence in an age of instant gratification. Perhaps monogamy within the marriage bond has become fashionable again. Perhaps it never really went out of style. It would be ideal if today’s media would turn away from a glorification of promiscuity and begin to promote the healthy, positive values.