Selected Pathological Criteria That Predict Low Rates of Axillary Lymph Node Metastases Regardless of Patient Age: A Single Institution Study.

BACKGROUND AND AIMS: Omission of sentinel node biopsy is increasingly offered to selected older women with cN0 low-risk breast cancer (BC). We hypothesized that some younger women might exhibit a low enough incidence of lymph node metastases to possibly justify excluding axillary surgery.

METHODS

We statistically analyzed, using parametric and nonparametric tests as appropriate, multiple demographic and clinicopathologic variables in cT1-2 N0 M0 BC patients of all ages undergoing axillary LN excisional surgery from a long-term, prospectively maintained database.

RESULTS

Patients with (816) and without (3617) LN metastases were compared. Although older patients were significantly (p < 0.0001) less likely to have LN metastases compared to younger patients, 3/61 (4.92%) of those < 50 years old with grade 1 tumors ≤ 1 cm in size (T1a and b) and no lymphovascular invasion had LN metastases compared to 30/504 (5.95%) ≥ 50. Patients aged 50 or older with Grade 2/3, < 1 cm, LVI-negative tumors had only 53/774 (6.85%) LN positive, compared to 19/131 (14.5%) in women < 50 with the same pathology.

CONCLUSIONS

Women with grade 1, ≤ 1 cm invasive BCs, and no LVI had < 6% incidence of LN metastases regardless of age. Instead of excluding younger women from axillary node surgery de-escalation strategies, this study suggests that any woman with a tumor size ≤ 1 cm, Grade 1, and no LVI could be evaluated in prospective studies whose objective is to safely avoid axillary LN surgery.