ASCO 2013

Axillary radiotherapy provides alternative to invasive early stage breast cancer surgery

Dr Emiel J. Rutgers - Netherlands Cancer Institute, Amsterdam

For the patients with operable early breast cancer up to 5cm and clinically node negative axilla, so no palpable nodes and these patients were eligible for this study. This is the vast majority of our current daily practice patient population. These patients got the sentinel node procedure to identify those who have lymphatic spread to the lymph nodes in the axilla and those who had spread to the lymph node in the axilla, the sentinel lymph node, those were randomised between either the standard axillary clearance, complete axillary lymph node dissection, or the radiotherapy to the axilla together with the radiotherapy of the breast. This was done in a period of about ten years and we entered 4,800 patients in this trial and 1,400 were randomised, either 700 between radiotherapy and surgery. And at the end of the show, one, oncologically cancer care is extremely safe – the risk of relapse in the axilla after either radiotherapy or surgery in those sentinel node positive patients is extremely low, 4 out of 700, 7 out of 700. But more interestingly the side effects, and one of the most important side effects of axillary treatment, axillary surgery, is lymphoedema, obstruction of the lymph flow from the arm. And what we have seen is that in the patients who had surgery, 28%, more than one in four, had after five years still treatment and garments for those lymphoedema.

How was the quality of life?

The quality of life measurements were good, that’s a fact. There were no significant differences. But you may wonder whether the questionnaires we applied sorted out well this problem.

How do you describe axillary clearance?

It is for a long, long, long time, since Halstead, axillary clearance is the dogma in optimal local regional treatment in breast cancer. Of course we have shifted away from a complete axillary clearance in every patient thanks to the sentinel node procedure but now the next step is if the sentinel node is positive how can we spare an unnecessary side effect of that treatment.

What is the data from this study?

Approximately 700 patients in both study groups. The risk of recurrence after five years, of cancer in lymph nodes after five years, is less than 1% in both groups. It’s extremely low; in absolute figures it’s 4 and 7 patients. So for cancer cure both treatments are excellent.

What is the downside of using radiotherapy?

In the long run the downside of using radiotherapy could be the damage to the nerves to the arm, what we call a difficult word – plexopathy, and induced sarcomas, radiation induced sarcomas. So far at five years there is no signal whatsoever on nerve damage caused by the radiotherapy. It’s a little bit short but at most it is at ten years in the range of 1% of the serious damage. But the other way around, lymphoedema in the long run is associated with serious side effects and very rare but serious sarcoma of the arm. If you prevent lymphoedema you may prevent that serious side effect in the long run.

What is the incidence of lymphoedema after surgery?

You get to 28% even. Lymphoedema related problems, treatment necessitating problems after five years after the complete surgery, yes.

What is your recommendation to doctors at this point?

The recommendation is quite clear – first do a sentinel node. Second, think what you do with the outcome. If it’s negative do nothing. If it’s positive, if it contains a small tumour, a small primary tumour, you can refrain from any axillary treatment. If there is more involved tumour then radiotherapy is now the standard of care instead of an axillary clearance.

Where do we go from here in terms of getting this accepted?

I don’t think it’s that difficult to get it accepted because many patients do get radiotherapy anyway because of the breast conservation so they go to the radiation oncologist anyway. And adding a small field of radiotherapy to the axillary region is not that difficult and not a problem and patients are going anyway. So I feel that acceptance will be quite easy.

What are you doing to test long term toxicity?

We will follow the patients for at least ten years and hopefully, and most likely, for fifteen years. EORTC has a very strong record in long term follow-ups in breast cancer trials and we will pursue this for this trial as well. So we will get the long term toxicity data in the future.

Is there a risk of long term toxicity?

It’s small because if you see the risk of lymphoedema now it’s diminishing over time. After three years it’s less than after one year and after five years less than after three years. So it’s not very likely that after five years the risk of lymphoedema will increase further. So we are not that afraid of long-term side effects.

How would you sum all of this up?

The bottom line message is that in early breast cancer axillary clearance, complete axillary dissection, is obsolete.