Tracks 1-16

Track 1 Historical perspective on the local treatment of breast cancer Track 2 Methods of partial breast irradiation (PBI) Track 3 Delivery of intraoperative radiation therapy Track 4 Eligibility criteria for the TARGIT study of intraoperative versus conventional external beam radiation therapy Track 5 Oncoplastic breast cancer surgery Track 6 Thermal tumor ablation with cryosurgery or radiofrequency procedures Track 7 Surgical margins and the necessity of radiation therapy in DCIS Track 8 Breast cancer-specific mortality after invasive local recurrence among patients with DCIS Track 9 Radiation therapy for small, node-negative invasive breast tumors Track 10 Use of the Oncotype DX™ multigene assay in clinical practice Track 11 Comparison of the Oncotype DX and MammaPrint® assays Track 12 Adjuvant trastuzumab in HER2- positive early breast cancer Track 13 Delayed and extended adjuvant hormonal therapy Track 14 Quality of life for patients treated with an aromatase inhibitor compared to tamoxifen Track 15 Sentinel lymph node biopsy (SLNB) for patients with DCIS Track 16 Use of radioisotope and blue dye in SLNB

Select Excerpts from the Interview

Track 7

DR LOVE: Has anything new emerged in the debate about ductal carcinoma in situ (DCIS) and radiation therapy?

DR SILVERSTEIN: The debate asks, does every patient with DCIS need radiation therapy? I’m on the “no” side. The proponents — the NSABP and some radiation therapists from the East Coast — believe that everybody needs radiation therapy.

Clearly American physicians and patients don’t buy into that because the Surveillance, Epidemiology and End Results (SEER) data suggest that about 35 percent of patients with DCIS in this country do not undergo radiation therapy (Baxter 2004).

DR LOVE: What fraction of your patients with DCIS don’t receive radiation therapy?

DR SILVERSTEIN: Probably double that. We try hard not to administer radiation therapy, but some patients do receive it. At the American Society of Breast Surgeons meeting we presented an update of our 1999 DCIS paper, in which we found that patients with 10-mm margins had an extremely low local recurrence rate — two or three percent — with or without radiation therapy (Silverstein 1999).

Now they have all been followed for a median of 123 months. The recurrence rates are only slightly higher for the excision-only patients (in the range of seven percent) versus the radiation therapy patients (about two and a half percent).

Compare that to the gold standard set by the NSABP: At 12 years they have a 16 percent recurrence rate for all their patients with DCIS who undergo excision with radiation therapy (Fisher 2001).

DR LOVE: Of course, that’s an indirect comparison.

DR SILVERSTEIN: Yes, it’s indirect and not a fair comparison. However, our data show exactly what the randomized trial data show: If you administer radiation therapy, you decrease the relative recurrence risk by about 50 or 60 percent.

Among the patients with 10-mm margins, that translates to an absolute benefit of only about five percent. I have to irradiate 100 patients to prevent five recurrences, of which only two will be invasive.

I can also cure at least eight out of 10 invasive recurrences because we follow them closely. This means I have to irradiate 400 patients to prevent one death.

Track 8

DR LOVE: Can you discuss the prognosis of invasive local recurrence after DCIS?

DR SILVERSTEIN: We’ve evaluated the long-term prognosis of invasive recurrences. At 12 years, approximately 15 percent of those with invasive recurrence had metastatic disease and about 12 percent died (Lee 2006; [1.1]).

Among our recurrences in excision-only patients, 34 percent were invasive. Among patients who received excision and radiation therapy, 53 percent of recurrences were invasive. That’s approximately a 20 percent difference, which is statistically significant.

Why is that happening? I believe it’s because some patients treated with radiation therapy develop fibrosis. When that happens, their mammographic follow-up is much more difficult. People believe it’s just scarring, but when the biopsy is done, it’s actually a large, invasive tumor.

We can prevent recurrences with radiation therapy, but if a patient develops a recurrence, it has a higher probability of being invasive. That evens the issue out for us.

What it boils down to is how much risk a patient wants to take. In medical oncology surveys, some women have said, “For a one percent survival benefit, I’ll be happy to receive the chemotherapy.”

We can reduce the recurrence rate for patients with 10-mm margins from seven or eight percent to two or three percent. Only two of those recurrences are invasive. If you treat 250 patients with 10-mm margins, you will probably save one life.

But what are the costs of radiation therapy? Not every radiation therapist is a great radiation therapist. Will everybody use CT planning and protect the heart and lungs? Will you see more lung cancer, more esophageal cancer, more pulmonary disease or more heart disease?

Radiation techniques are much better today than they were in 1980, so I believe you have a good chance of preventing much of that, but you can’t prevent it all.

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Editor:
Neil Love, MD

Interviews

Melvin J Silverstein, MD
- Select publications

David M Hyams, MD
- Select publications

Charles E Geyer Jr, MD
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Hope S Rugo, MD
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Highlights of a CME Symposium Held in Conjunction with The American Society of Breast Surgeons Eighth Annual Meeting
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A CME Audio Series and Activity

Faculty Disclosures

Editor's Office