Breast Cancer and Lymph Nodes: Q. and A.
By THE NEW YORK TIMES
An article in Wednesday’s Times describes how a routine procedure for the treatment of early breast cancer — the surgical removal of cancerous lymph nodes from the armpit — has been found unnecessary for many patients. The finding turns 100 years of standard medical practice on its head.
Today the author of the article, Denise Grady, is taking questions about the finding and its implications. Please post your questions in the Comments box below.
Q.
From what I understand, removing even only one or two lymph nodes can result in chronic swelling of the arm. How certain is it that taking fewer nodes will result in a measurable reduction in the risk of developing lymphedema?
— Claudia Boyle, Mount Prospect, Ill.
— Claudia Boyle, Mount Prospect, Ill.
A.
There is still a risk of lymphedema even after only a few nodes are taken for sentinel biopsy, but the risk is much lower than when many nodes are removed.
Q.
Is there any information on the advisability of not doing the lymph node removal for women who had a mastectomy, chemotherapy and radiation rather than lumpectomy?
— Donna Landerman, Bloomfield, Conn.
— Donna Landerman, Bloomfield, Conn.
A.
The results apply to women whose condition is like those in the study: stage T1 or T2 tumors (less than two inches across), no palpable lymph nodes, no metastases to other parts of the body and no more than two positive lymph nodes on the sentinel node biopsy. A woman with these characteristics who is having a mastectomy and the other treatments would seem to fit the bill, but the ultimate decision has to be made with a surgeon and an oncologist.
Q.
My breast surgeon told me that lymph node ratio is also important, and I’ve seen studies to support it. They’ve shown that a person who has 1 positive lymph node out of 20 removed does better than a person who had 1 out of 5 who does better than the person who had 1 out of 1. This implies that that there is some survival benefit to the patient who has more nodes removed. Can you find out from your sources: what about the studies that show that lymph node ratio is important? Does this new study trump them, and if so why? Also, what about the length of follow-up in this study?
Breast cancer can recur at any time — even 25 years after initial diagnosis. I’m very glad for all these treatments that improve 5-year survival rates, but are they just pushing back our relapses to a later date? If so, the results of this study may be premature. Are they planning to continue following-up on these patients?
— Breast Cancer Patient, NYC
Breast cancer can recur at any time — even 25 years after initial diagnosis. I’m very glad for all these treatments that improve 5-year survival rates, but are they just pushing back our relapses to a later date? If so, the results of this study may be premature. Are they planning to continue following-up on these patients?
— Breast Cancer Patient, NYC
A.
There is evidence that a higher number of positive nodes is associated with a worse outcome, because it may mean that the cancer is more advanced or spreading more quickly. In the past, the number was used to help plan what kind of chemotherapy to give. But the doctors interviewed for the article published on Wednesday said that in most cases nowadays, the number of lymph nodes does not determine the treatment. Women with any positive nodes are advised to have chemotherapy or hormone-blocking treatment, or both, and the chemotherapy is the same regardless of the number of nodes.
As the article states, the researchers considered the follow-up time long enough to detect a difference in local cancer recurrence rates, meaning in the armpit, because those tend to occur fairly early. There was no difference. A local recurrence is not trivial: It would require more treatment, and 20 to 25 percent of women who have local recurrences ultimately die from the cancer.
It is true that cancer can return at any time. More follow-up time would be more reassuring. I don’t know whether there will be continuing follow-up of these women, but I will ask and post the answer.
As the article states, the researchers considered the follow-up time long enough to detect a difference in local cancer recurrence rates, meaning in the armpit, because those tend to occur fairly early. There was no difference. A local recurrence is not trivial: It would require more treatment, and 20 to 25 percent of women who have local recurrences ultimately die from the cancer.
It is true that cancer can return at any time. More follow-up time would be more reassuring. I don’t know whether there will be continuing follow-up of these women, but I will ask and post the answer.
Q.
My niece has Stage 3C melanoma. She recently had a number of lymph nodes removed. She originally had two nodes removed that were diagnosed as positive. Thereafter, she had additional nodes removed that were negative. Does the data you’ve written about, as it pertains to lymph nodes, translate to specific cancers other than breast cancer?
— Dave Collopy, Hilo, Hawaii
— Dave Collopy, Hilo, Hawaii
A.
No, the data really applies only to patients with breast cancer, and only to breast cancer patients like the women in the study.
Q.
I am curious about your opinion of reaching a negative conclusion based on a statistical sample. First of all, the type of error that may be associated with such a conclusion — i.e. that there is in fact a difference that was not detected — is typically not controlled and therefore can float to unknown values.
Second, there is little discussion in the newspapers about the fact that your or any metanalysis is no more a guarantee than any initial study, but merely a statistical evaluation of the likelihood of having detected (or not detected) a real effect.
— Dr. S, Valhalla, N.Y.
Second, there is little discussion in the newspapers about the fact that your or any metanalysis is no more a guarantee than any initial study, but merely a statistical evaluation of the likelihood of having detected (or not detected) a real effect.
— Dr. S, Valhalla, N.Y.
A.
The New York Times did not reach a conclusion. We are reporting the conclusion that the authors of a peer-reviewed journal article reached, that the editorialist in the journal supported, and that cancer centers are already putting into practice. We did ask two independent experts on medical statistics at two different universities to evaluate the study. They had some quibbles, but nothing serious enough to throw the findings into question. This was not the first study in this area; there have been others in the past, all pointing in the same direction — to the idea that at least some patients can be spared axillary dissection and the serious complications that it can cause.
Q.
I have not seen raised in this discussion the issue of genetic findings related to the familial propensity for breast cancer if that diagnosis is a part of the clinical picture. How are suspected lymphatic involvement and possible surgical intervention influenced by genetic findings? Thank you.
— MJM, Shenandoah Valley, Va.
— MJM, Shenandoah Valley, Va.
A.
We asked this question of Dr. Monica Morrow, an author of the study and chief of the breast service at Memorial Sloan-Kettering Cancer Center in Manhattan. Her reply:
Genetic breast cancer doesn’t influence how we treat the nodes. Due to the increased risk of second breast cancers, many of these women chose mastectomy. Women with mastectomy require axillary dissection if the nodes are involved.
Q.
Surgeons have been removing lymph nodes from the armpits of breast cancer patients for 100 years. Why has it taken so long to find out that not every patient needs this surgery?
A.
The procedure is a holdover from the era of the radical mastectomy, before radiation treatment and chemotherapy existed and when the only hope for controlling cancer was to try to cut it all out. Removing lymph nodes became part of the standard of care, because the nodes might harbor cancer cells that could spread around the body.
Before the sentinel node technique was developed, there was no way to find which nodes were most likely to be the ones where cancer cells would land; to be on the safe side, the only thing surgeons could do was to take out as many nodes as possible. Women suffered from side effects, like lymphedema, that could be severe, but the prospect of a cancer recurrence was worse, so doctors and patients alike were afraid of what would happen if the nodes were not removed. Only when it became apparent that the sentinel node biopsy was reliable did it become possible to ask the next question: If just one or two nodes are positive, do they all have to come out? The answer seems to be no.
Part of what makes it possible to leave the nodes alone is that there are now more effective combinations of chemotherapy and radiation, which can wipe out microscopic traces of disease that might be left behind.
Before the sentinel node technique was developed, there was no way to find which nodes were most likely to be the ones where cancer cells would land; to be on the safe side, the only thing surgeons could do was to take out as many nodes as possible. Women suffered from side effects, like lymphedema, that could be severe, but the prospect of a cancer recurrence was worse, so doctors and patients alike were afraid of what would happen if the nodes were not removed. Only when it became apparent that the sentinel node biopsy was reliable did it become possible to ask the next question: If just one or two nodes are positive, do they all have to come out? The answer seems to be no.
Part of what makes it possible to leave the nodes alone is that there are now more effective combinations of chemotherapy and radiation, which can wipe out microscopic traces of disease that might be left behind.
Q.
Which women still need to have their lymph nodes dissected?
A.
Surgeons say that the lymph nodes must come out if they are big enough to feel or show up as cancerous on imaging. Surgeons will also remove nodes if there are three or more positive sentinel lymph nodes (sentinel lymph node biopsy is described in the article).
Surprises can also turn up in the operating room, doctors say. Occasionally, the sentinel node biopsy will give a false-negative result, which means failing to find cancer even though it is present. That can happen if, for instance, the sentinel node is very cancerous and the lymphatic vessels that feed it are choked off and do not pick up the dye. Then, the dye may go to a different node, one that does not have cancer. Knowing this is possible — and knowing that the sentinel node biopsy, though highly reliable, is not infallible — surgeons look and feel around in the armpit carefully during the operation and make judgment calls about what to remove and what to leave alone.
Surprises can also turn up in the operating room, doctors say. Occasionally, the sentinel node biopsy will give a false-negative result, which means failing to find cancer even though it is present. That can happen if, for instance, the sentinel node is very cancerous and the lymphatic vessels that feed it are choked off and do not pick up the dye. Then, the dye may go to a different node, one that does not have cancer. Knowing this is possible — and knowing that the sentinel node biopsy, though highly reliable, is not infallible — surgeons look and feel around in the armpit carefully during the operation and make judgment calls about what to remove and what to leave alone.
Q.
Why are the study findings said to apply only to women who have whole-breast irradiation, and not partial breast irradiation?
A.
Whole-breast irradiation hits part of the armpit, and therefore some of the lymph nodes. This is what the women in the study received, and researchers think it may have wiped out any cancer in the nodes that were left behind. They say they are also unsure about whether the findings would apply to women who have irradiation while lying prone, on their stomachs. In that position, the radiation may not reach the armpit.
Q.
The study findings apply to 20 percent of patients — about 40,000 women a year in the United States, according to your article. What about the other 80 percent?
– Brandon, Berkeley, Calif.
– Brandon, Berkeley, Calif.
A.
Here is a further explanation: First of all, 20 percent (the estimate of the study’s lead author, Dr. Armando E. Giuliano) refers to 20 percent of all the newly diagnosed cases of invasive breast cancer each year. This does not include noninvasive breast cancer, or DCIS, ductal carcinoma in situ. The total is about 207,000, so 20 percent is roughly 40,000 women. That is about how many women would match those in the study, in terms of tumor status, affected lymph nodes and course of treatment.
To answer the question about the other 80 percent, we need to look at how many women get a breast cancer diagnosis at various stages. The figures from the American Cancer Society indicate that 60 percent of all patients have “localized” breast cancer. That means they do not have affected lymph nodes. They do not have to worry about extensive axillary dissection, as lymph node removal is known; their sentinel node will be clean. Another 33 percent of women have “regional” disease, meaning that the cancer has reached lymph nodes. These are the patients who might match those in the study.
By Dr. Giuliano’s estimate, about two-thirds of these women will match the study criteria, and one-third will not, so for that one-third, about 10 percent of breast cancer patients over all, node dissection may be needed. Another 5 percent of all patients have “distant” disease at the time of diagnosis, meaning the cancer has already spread to organs or bones. I don’t know if lymph node surgery is of use or benefit to women whose disease is already advanced. In the remaining 2 percent of cases, the stage of the disease at diagnosis is not known.
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