Breast cancer staging

SAN ANTONIO -- Axillary staging by any method is inappropriate for ductal carcinoma in situ, Dr. David Brenin said at a breast cancer symposium sponsored by the San Antonio Cancer Institute.

Several studies have recently concluded that micrometastases are present upon sentinel node biopsy in as many as 6%-14% of ductal carcinoma in situ (DCIS) patients. But Dr. Brenin and others at the meeting presented data to suggest that the presence of such nonpalpable metastatic disease is unlikely to be of clinical significance in patients with DCIS.

He reported on 432 DCIS patients treated by breast-conserving therapy or simple mastectomy. None underwent axillary staging. Yet only two patients ultimately died of breast cancer without having an invasive local recurrence or an invasive second primary breast cancer.

This works out to an actuarial 5-year disease-specific survival of 98.2%. That's a rate so high it indicates that failure to detect lymph node metastases is unlikely to have any meaningful clinical impact, argued Dr. Brenin of Columbia University, New York.

Sentinel lymph node biopsy is the current craze among patients and physicians. They embrace it as a kinder, gentler alternative to axillary dissection. The rationale is that if a patient's first lymph node in the chain draining from the tumor site is cancer-free, there is no need to perform a complete axillary dissection in an effort to eradicate the malignancy.

But based on his findings, Dr. Brenin urged restraint in applying sentinel node biopsy to patients with DCIS.

This sentiment was seconded by Dr. Judy Ann Chapman of the University of Toronto, who rose from the audience to informally present a series of 124 DCIS patients who were treated without axillary dissection. Their 5-year breast cancer-specific survival was 100%.

Likewise, a study presented by Dr. Brenin's Columbia coinvestigator, Dr. Mahmoud el-Tamer, also backed the idea that axillary staging of DCIS doesn't impact survival.

He reported on 326 DCIS patients who underwent conventional axillary dissection. Only four were found to have positive nodes. The 5-year diseasespecific survival was 99.6%, and the 10-year rate was 97.6%--figures very similar to those reported by Dr. Brenin in the study of DCLS patients who didn't undergo axillary staging.