 |
 |
 |
 |
 |
 |
|
||||||||||||||
| Tracks 1-13 | ||||||||||||||||||||||||||||
|
Select Excerpts from the Interview
Tracks 2-3
DR LOVE: What are some of the most common questions you receive
from surgeons in practice?
DR DIXON: How much extra tissue around the tumor do you need to remove
to say the tumor is completely excised? In consults from all over the world, the
surgeons remove the cancer with clear margins, but the oncologist is unhappy
and says, “Go back and remove more tissue.”
We have good data because we treat large numbers of women and we accept a one-millimeter margin. Do you achieve better control rates with two millimeters, three millimeters or four millimeters? Certainly not. A fantastic review by Eva Singletary concluded that wider margins will not necessarily reduce local recurrence rates. Also, it is important to understand that wider margins will produce more detrimental cosmetic outcomes.
The main purpose of performing breast-conserving surgery is to leave a reasonable amount of breast tissue, and to do that, you have to remove the cancer with a minimal margin of normal tissue. If you don’t remove the cancer or you remove it and leave the breast looking terrible, you’ve failed. It’s that simple.
DR LOVE: What is your procedure, and do you see any technical caveats?
DR DIXON: First, it’s useful to have the radiologist determine how deep the
tumor is in the breast before you begin surgery. If it’s one and a half centimeters
deep, it is not necessary to scrape all the fat off under the skin when performing
the wide excision because that leaves a poor cosmetic result.
Second, if you have a defect in the breast after removing the tumor, in most instances you’re better off trying to mobilize tissue from around the margins and closing the defect. That requires skill and a little more surgery, but it tends to produce better cosmetic results.
Additionally, segmental excision is a waste of time. You do not need to remove tissue beyond the periphery of the breast or down toward the nipple. There is no evidence that more frequent local recurrence occurs down toward the nipple than out peripherally or around the edges.
Track 7
DR LOVE: For a woman who has received five years of adjuvant tamoxifen
and is now off of therapy, how do you calculate the residual risk of
recurrence, and how do you decide whether or not to start her on an
aromatase inhibitor?
DR DIXON: You consider the factors associated with recurrence beyond five
years of tamoxifen. If she had Grade I, node-negative disease, for example, I
wouldn’t start her on anything because the rates of local recurrence are low over
a long period.
We’ve found that after five years, the recurrences for patients with Grade II disease were similar to those with Grade III disease. The reason is that patients with Grade III disease tend to experience recurrence early, and then their rates of recurrence come down and are similar to those of patients with Grade II disease. I consider treating Grade II disease.
The other issue is duration of endocrine treatment. Five years is almost certainly not enough. One of the important lessons from MA17 (Goss 2005) is that breast cancer is a chronic disease. It requires chronic care in terms of follow-up and treatment. Even if you switch women after two or three years of adjuvant tamoxifen to an aromatase inhibitor, you will probably need to use five years of an aromatase inhibitor.
DR LOVE: Would you consider delayed adjuvant endocrine therapy for a
woman who declined tamoxifen five years ago for a moderately high-risk,
node-negative tumor?
DR DIXON: Absolutely. All the evidence we have indicates that it doesn’t
matter when you start tamoxifen or an aromatase inhibitor — you still derive
a benefit (Delozier 2000; Robert 2006).
Track 9
DR LOVE: What is your approach to monitoring bone density in patients
who are receiving an aromatase inhibitor?
DR DIXON: Rob Coleman and some of the metabolic bone specialists in the
United Kingdom have drawn up sensible guidelines. If the initial DEXA
scan shows osteoporosis, then those patients definitely need treatment with
a bisphosphonate, but we use the aromatase inhibitor anyway if their cancer
requires it.
If they have osteopenia, we will still use the aromatase inhibitor, but then we’d monitor the bone. If they have normal bone density, then we would repeat their DEXA scan, and if it was normal within a couple of years, we probably wouldn’t repeat it again during their treatment with an aromatase inhibitor.
We don’t do as many DEXA scans as you do in the United States. When we first heard about the bone data, there was a bit of worry and panic, but the fracture rate levels off after you stop the aromatase inhibitor (Buzdar 2006; [1.1]). The bone effects have not been nearly as bad as we thought they might be.
Track 11
DR LOVE: What is your approach to neoadjuvant endocrine therapy?
DR DIXON: Neoadjuvant endocrine therapy is valuable for our group, partly
because we have an elderly population. Currently, between 40 and 45 percent
of all patients with breast cancer are older than 70 years of age. Most of these
women aren’t candidates for neoadjuvant chemotherapy if they present with
larger tumors. However, they are eligible for neoadjuvant endocrine therapy
because increasing age is associated with increasing ER expression.
DR LOVE: Is the intent to make them eligible for a lumpectomy, or is it the
overall treatment?
DR DIXON: Both. In patients who aren’t fit for any other treatment, neoadjuvant
aromatase inhibitors alone will often provide a prolonged response and allow
them to survive long enough to die of something other than breast cancer.
DR LOVE: What about the patient who wants to have breast-conserving
surgery, but it’s not technically feasible?
DR DIXON: Most of these patients have tumors with high levels of ER. In
patients with high-ER tumors, you have a greater than 75 percent chance
of obtaining a response within three to four months. That’s a pretty high
response rate, even for some of the more potent chemotherapies. There is also
very little chance of progression.
| Table of Contents | Top of Page |
Editor:
Neil Love, MD
Interviews
J Michael Dixon, MD
- Select publications
Maura N Dickler, MD
- Select publications
William C Wood, MD
- Select publications
John Mackey, MD
- Select publications
 |
 |
 |
 |
 |
