AVOIDING ALND IN SLN+ BREAST CANCER HIGHLY DEBATABLE

The American Society of Clinical Oncology's (ASCO's) new recommendation that that some women with early-stage breast cancer and minimal lymph node involvement can forgo extensive lymph node surgery has been questioned separately by two sets of clinicians.

The guidelines were originally published in May 1 in the Journal of Clinical Oncology (JCO), the flagship journal of ASCO.

Now, in letters to the journal published on September 22, critics are saying that there is not enough evidence to support the recommendation.

But the investigators of the trial on which the recommendation is based argue back, saying it is time to skip the surgery in certain patients.

The guidance is based on findings from the widely publicized American College of Surgeons Oncology Group Z0011 trial.

The Z0011 investigators reported previously that overall survival was highly similar at 6 years among early-stage breast cancer patients with minimal disease in their axilla who were treated with either sentinel lymph node biopsy alone or completion axillary lymph node dissection (ALND).

Thus ASCO now advises that women with clinical T1/T2 invasive breast cancer and 1 or 2 sentinel lymph nodes (SLNs) do not need to undergo ALND.

This procedure should not be routine in these women, who will receive treatment with breast-conserving surgery, whole-breast irradiation, and, in most cases, adjuvant systemic therapy, according to ASCO.

The recommendation is "premature," say four clinicians from the United Kingdom in their letter: Dr Amit Goyal, of Royal Derby Hospital, Dr David Dowell, of St James Hospital in Leeds, and Dr Malcolm Reed and Dr Robert Coleman, of the University of Sheffield.

That is because the recommendation is "based entirely on the results" of the Z0011 trial, they write.

That's not so, counter the Z0011 investigators in their own letter, which was also published online September 22 in JCO.

"The Z0011 study is not the only randomized trial examining axillary treatment. At least four others have examined axillary dissection versus other means of treating the axilla, including no axillary therapy," write the study authors, led by Dr Armando Giuliano, from the Cedars-Sinai Medical Center, Los Angeles, California.

"The other studies have similarly shown no impact of axillary treatment on survival," they write.

However, the Z0011 investigators are mostly conciliatory toward their critics and acknowledge the trial's limitations, such as a lack of quality assurance of radiation therapy performed at different centers participating in the trial.

They also agree with a criticism in a letter from Dr Ioannis Vouttsadakis and Dr Sylvana Spadafora, from the Sault Area Hospital in Sault Ste Marie, Canada.

The pair argue that the tumor burden of the Z0011 patients was "low."

Dr Guiliano and colleagues emphatically agree that the results apply only to patients with a low tumor burden.

The Canadians have a laundry list of objections about the trial, including the fact that 6 years may be too short a time for overall survival differences to emerge because the population studied mainly had estrogen-receptor-positive disease, which is often indolent in postmenopausal women (the study population).

The two sets of critics share a major concern about Z0011: the trial results are not "generalizable" to all subtypes of breast cancers, such as HER2+ disease. (The testing for  HER2 disease was not standard at the time.)

For that reason, the British clinicians have begun their own study, the POSNOC (Positive Sentinel Node: Adjuvant Therapy Alone Versus Adjuvant Therapy Plus Clearance or Axillary Radiotherapy) trial.

The new trial "will provide a more solid evidence base to inform clinical practice," they write.

Agreed, say the Z0011 respondents.

"We are pleased the POSNOC have chosen to repeat the Z0011 study," write Dr Guiliano and colleagues, who also argue that there is "no reason to believe" that various subtypes of breast cancer have increased nodal recurrences.

But they also assert that Z0011 is very valuable now.

The results have "forced us to realistically examine our indiscriminate use of axillary dissection," write Dr Guiliano and colleagues.

Business as usual is not advisable, they argue now, as they have in the past.

They state that in small breast tumors with minimal (1 or 2) lymph node involvement, ALND and its considerable complications, such as edema, can be avoided without a compromise of survival.

"We do not recommend waiting another decade before lifting this burden from the large number of women to whom these recommendations directly apply," they conclude.

None of the parties have indicated any relevant financial relationships.