Cancer Screening

There has been a great deal in the news just in the past month about new studies and recommendations regarding cancer screening. This is all very interesting, but also pretty complicated.

First off, these stories are based on findings of the New England Journal of Medicine, the U.S. Preventive Services Task Force, and the American College of Obstetrics and Gynecology. The have yet not been widely adopted by other organizations such as the American Cancer Society and medical insurance companies or MediCare. Also, the are not related to present Congressional legislation on health care reform and addressed clinical effectiveness not cost. In other words, it's about the outcomes not the money.

Also, these findings related to people at average risk for cancer, and not to persons at high risk due to family history or other factors.



First, the study in the New England Journal pointed out that screening for breast and prostate cancer was associated with an increase in early detection of localized cancers, but not with a decrease in more advanced cancer.

This is concerning because the idea of screening is to find cancer early, before they have a chance to spread. If that is what is actually happening with breast and prostate cancer screening then we should be seeing a rise in early cancers and a resulting decrease in later stage ones. Which we're not.

What this seems to mean is that there are two types of such cancers. One kind is very slow growing and it may be that a wait and see approach may be as reasonable as biopsies and surgery. The other kind is so aggressive that it may become detectable between screening test intervals.

The thrust of this article is that we need to do more research in tumor biology so that we can identify which tumors should be aggressively treated, and which can be watched over time.



Coming hard on the heels of this, the U.S. Preventive Services Task Force (which has been around for decades) is recommending that breast cancer screening not be started until 50, the to be performed by breast examination and mammography every other year until 70-75 and then discontinued. They have also found that monthly breast self-examination is not generally helpful.

Much of the concern is over the naturally fibrous nature of female breast tissue up to age 50, and therefore the potential of self-examination and mammography to both miss cancers and also to over-call benign nodules and cysts.

The same recommendation stresses that individual patients may wish to proceed with screening between 40-50 based on personal preference, and that the recommendation does not apply to high risk patients such as those with family members with breast or ovarian cancer or positive genetic testing of BRCA mutation which increases risk of developing breast cancer.

The American Cancer Society has strongly disputed this recommendation.



Just this morning, the American College of OB/G announced a recommendation that cervical cancer screening (Pap smears) should not start until 21 years of age regardless of sexual activity prior that age due to the very low rates of cervical cancer in such young women. Further they recommend Pap smears every other year up to 30, then every third year to 70. This assumes no abnormal Pap smears are found.

This is probably based on the already established observation that it takes about 10 years to go from normal Pap smear to cancer and is a best effort at conservative screening without over-kill.

So, there you go: all the news on cancer screening! For now, anyways.