Cancer Screening Debate Reveals Risks, Benefits of Testing

MARGARET WARNER:

Science and medicine have long grappled with the tradeoffs involved in cancer screening. What's not clear is whether today's new Pap smear guidelines, coupled with another panel's recommendations earlier this week to scale back mammograms for women under 50, mark an important milestone in that debate.

We explore that now with Dr. Douglas Kamerow of Georgetown University — he's a former assistant surgeon general and chief scientist at RTI International, a research institution — and Dr. Julie Gralow of the American Society of Clinical Oncology. She is the director of breast oncology at the Seattle Cancer Care Alliance.

And welcome to you, both.

Dr. Kamerow, the fact that we have had these two new sets of guidelines in the same week, is this just a coincidence, or is there some new thinking going on more broadly about how to at least weigh the tradeoffs in cancer screening?

DR. DOUGLAS KAMEROW, Georgetown University:

Well, the answer to your question is, it's a coincidence, two different organizations. They have nothing to do with each other. They came out with these at that time.

But you're right. It raises the point, what is a good screening test and who gets it and when do you get it?

MARGARET WARNER:

Well, OK, how would you define that? And is there a consensus emerging that maybe — this seems to fly in the face of everything we have been told about the value of preventive screening, preventive care, early. How do you jibe those two?

DR. DOUGLAS KAMEROW:

Well, it's nice to think that all prevention is good. But the answer is, it isn't. You need to have a proven test and you need to have a disease that is amenable to screening. In both these cases, both breast cancer and cervical cancer, we have a disease that is pretty good at being screened, that is, has a long, usually a long asymptomatic phase, especially in cervical cancer.

And that's good for a screening test. But then you have got to have an accurate screening test as well.

MARGARET WARNER:

Dr. Gralow, what is your thought about the sort of broader message from these two new guidelines this week?

DR. JULIE GRALOW, Seattle Cancer Care Alliance:

I think an important message is that we need to be talking to our individual patients about the risks and benefits to be gained and to be lost with all of these procedures.

I think these are two very different cases. Cervical cancer picked up by a Pap smear is found at usually a very pre-invasive phase that will take many years to evolve into a dangerous invasive cancer. And these guidelines today don't really surprise us. We have a lot of new information that has come into play since some of the older guidelines reflecting annual screening of Pap smears were made.

MARGARET WARNER:

But you feel it is different with breast cancer?

DR. JULIE GRALOW:

Breast cancer, we have got good, solid randomized trials of, mammography or not, that show that we save lives.

Most breast cancers picked up on mammograms are already invasive, meaning they can spread throughout the body and they can lead to death. We don't have as long a pre-clinical phase as we do in cervical cancer, where we can watch it for a while or we can have a few years. Most breast cancers picked up even by annual screening mammography have already moved to the invasive, the risky, life-threatening phase.

MARGARET WARNER:

So, Dr. Kamerow, why would this panel conclude that, for women under 50, routine exams are not indicated?

DR. DOUGLAS KAMEROW:

Well, I think you heard when you last talked about this with the co-chair of the panel — I'm not on this panel — that they probably didn't word their recommendations as well as they could have.

And they didn't say not to screen in the 50s. What they said is exactly what Dr. Gralow said, is that, for the best evidence, for women 50 and over is to get routine mammograms, pretty much everybody. But, for people younger than that, women younger than that, they need to talk to their doctors and discuss it, so they can understand what the benefits are and what the risks are.