Locoregional Failure of Post-Mastectomy Patients Who Had 1-3 Positive Axillary Lymph Nodes without Adjuvant Radiotherapy

Ryan Smith, MD
University of Pennsylvania Cancer Center
Last Modified: November 6, 2001

Presenter: C. Cheng
Presenter's Affiliation: Sun Yat-Sen Cancer Center
Type of Session: Scientific

Background

Post-mastectomy radiation is routinely given for patients with 4 or more positive lymph nodes to reduce locoregional failure. However, optimal adjuvant treatment for those with 1-3 positive lymph nodes is debated.

This study was completed to determine the incidence and risk factors for the development of locoregional recurrence (LRR) in post-mastectomy patients with 1-3 positive lymph nodes.

Materials and Methods

This is a retrospective study of 110 patients with T1-2 primary tumors and 1-3 positive lymph nodes via pathologic analysis

90 patients were > 40 years old

41% had pT1 tumors and 59% had pT2 tumors

63% received adjuvant chemotherapy

84% received adjuvant Tamoxifen (68% were ER (+))

40% of patients had >20 nodes examined, 52% had 10-19 nodes examined, and only 8% had 7-9 lymph nodes examined

46% had 1 lymph node involved, 34% had 2 lymph nodes involved, and 20% had 3 lymph nodes involved

Data reported are 4 year results

Results

OS for the entire group was 86.6%

LRR was seen in 16.1% (17 patients). Sixteen of these patients had isolated LRR and 1 patient had concurrent metastatic disease. Fourteen of these had recurrence in the chest wall.

Distant metastatic rate was 18.9% (24 patients)

Four risk factors were identified: age <40, ER (-) status, tumor >3 cm, and lymphovascular invasion. If patients had 3-4 of these risk factors, their LRR rate was 66.7% compared to those with 0-2 risk factors, who had a LRR rate of 7.8%.

LRR was associated with the development of distant metastases. Those with LRR developed distant metastases at a rate of 49% compared to 13% for those who did not.

Author's Conclusions

LRR at 4 years was 16.1%, which was comparable to ECOG data (12.9%) and MDACC data (10%), but lower than the Danish trials (30%) and the British Columbia trial (33%).

Occurrence of LRR adversely impacts systemic disease control and survival

Prognostic factors (as above) need to be considered in determining therapeutic options

Clinical/Scientific Implications
As stated previously, there is no consensus on standard of treatment (adjuvant radiotherapy or not) for post-mastectomy patients with 1-3 positive lymph nodes. This presentation points out a fairly significant LRR rate in this group of patients. Also, in these patients that do develop LRR, their risk of developing distant metastases and risk of death from breast cancer seems to be much higher. Whether this is from tumor seeding or simply points to the aggressiveness of disease in these patients is unknown. In this presentation, a number of risk factors were identified which may indicate a higher risk of recurrence. While these may hold, the number of patients with these various risk factors are small (e.g., patients age <40 (20 patients)). Therefore, these risk factors should not be strictly adhered to until they are verified by a larger, prospective study. This data, again, should compel physicians to enroll patients in a newly opening intergroup study randomizing postmastectomy patients with 1-3 lymph nodes to +/- adjuvant radiation.

Oncolink's ASTRO Coverage made possible by an unrestricted Educational Grant from Bristol-Myers Squibb Oncology and Pharmacia Oncology.