Most of you can stop reading right now. The Pap smear is not a subject of general interest, but I spent five years working in a cytopathology automation research laboratory, part of an attempt to make the reading of Pap smears easier and more accurate. Thus the following headline was sure to catch my eye: Should HPV Test Replace the Pap Smear?
The primary purpose of the Pap smear is the early detection of cervical cancer, it is argued, but testing for human papillomavirus is easier and actually does a better job, although it generates more false positives, especially in younger women.
What I find most interesting is the unmentioned, but logical implication that those who are at no risk of contracting HPV, due to the simple expediencies of virginity or faithful monogamy, can dispense with both tests—surely a course of action the medical industry would not wish to endorse! Gastroenterologists have adopted a once-every-ten-year colonoscopy recommendation for low-risk patients, perhaps gynecologists should follow their example.[This] recommendation is based on a study that found that the human papillomavirus (HPV) test prevented more cases of cervical cancer than the conventional Pap smear. Results of the study were published online Jan. 19 in The Lancet Oncology.
The HPV test should become the screening tool of choice for women 35 and older, the researchers said. It could be done less frequently than the Pap test, which could be used only in women who have tested positive for HPV, they said.
Does this mean that virgins or faithful monogamists do not get cervical cancer? Or that it's just so few as to be statistically insignificant? Or are the researchers just assuming that no one is in those categories?
The clear implication to me from the article was that if you don't get HPV, you won't get cervical cancer. As far as I know that's a little optimistic, but I've been out of the field a long time. Not that I believe everything I read in the news, either. The article did not mention people in those two categories at all, seeming to assume that everyone needs to be tested for HPV. I may be wrong, but I am under the impression that HPV is strictly an STD -- so I made my own conclusion.
A quick look at the most obvious internet sources (i.e. google search results) suggests the following:
- Either 95% or 99.7% of all women with cervical cancer have been shown to have had HPV.
- Transmission of HPV occurs through skin contact. This is usually through sexual contact, but can be through touching the same items (dish towels, toothbrushes, etc.) or even through birth. There's an 1887 article (in German) on a virgin that had cervical cancer.
- Early screening has lowered the death toll of cervical cancer, but the number of pre-cancerous infections is on the rise. Women are also diagnosed with it earlier in life, because of being more promiscuous sooner.
- HPV is often not noticeable without a test, and cervical cancer often only appears 10-20 years after infection.
- Not nearly every woman with HPV contracts cervical cancer, only those where for unknown reasons the virus can overcome the immune system.
- The University of Bern says the HPV test is rather expensive and only to be used as an instrument to confirm the results of a Papanicolaou test. They only run HPV tests every 2-3 weeks.
- Cervical cancer caused by HPV can be favored by smoking, genital infections, long-time consumption of oral contraceptives, a large number of births, and a suppression of the immune system. Other factors of importance are an early begin of sexual activity, high promiscuity, a lack in sexual hygiene of both partners, and a low social status.
Interesting, especially the part about Bern saying the HPV test is expensive and difficult, and only used secondary to a Pap smear. I wonder if there's a new form of the test, because this article recommends the opposite, and even says it's simple enough for the collection to be done at home.
I suppose a new risk/benefit analysis needs to be done: How often is it worth having an invasive procedure with risks of its own if one's odds of getting the disease are extremely low?
