Locoregional failure of postmastectomy patients with 1-3 positive axillary lymph nodes without adjuvant radiotherapy.

PURPOSE

To analyze the incidence and risk factors for locoregional recurrence (LRR) in patients with breast cancer who had T1 or T2 primary tumor and 1-3 histologically involved axillary lymph nodes treated with modified radical mastectomy without adjuvant radiotherapy (RT).

MATERIALS AND METHODS

Between April 1991 and December 1998, 125 patients with invasive breast cancer were treated with modified radical mastectomy and were found to have 1-3 positive axillary nodes. The median number of nodes examined was 17 (range 7-33). Of the 125 patients, 110, who had no adjuvant RT and had a minimum follow-up of 25 months, were included in this study. Sixty-nine patients received adjuvant chemotherapy and 84 received adjuvant hormonal therapy with tamoxifen. Patient-related characteristics (age, menopausal status, medial/lateral quadrant of tumor location, T stage, tumor size, estrogen/progesterone receptor protein status, nuclear grade, extracapsular extension, lymphovascular invasion, and number of involved axillary nodes) and treatment-related factors (chemotherapy and hormonal therapy) were analyzed for their impact on LRR. The median follow-up was 54 months.

RESULTS

Of 110 patients without RT, 17 had LRR during follow-up. The 4-year LRR rate was 16.1% (95% confidence interval [CI] 9.1-23.1%). All but one LRR were isolated LRR without preceding or simultaneous distant metastasis. According to univariate analysis, age <40 years (p = 0.006), T2 classification (p = 0.04), tumor size >==3 cm (p = 0.002), negative estrogen receptor protein status (p = 0.02), presence of lymphovascular invasion (p = 0.02), and no tamoxifen therapy (p = 0.0006) were associated with a significantly higher rate of LRR. Tumor size (p = 0.006) was the only risk factor for LRR with statistical significance in the multivariate analysis. On the basis of the 4 patient-related factors (age <40 years, tumor >==3 cm, negative estrogen receptor protein, and lymphovascular invasion), the high-risk group (with 3 or 4 factors) had a 4-year LRR rate of 66.7% (95% CI 42.8-90.5%) compared with 7.8% (95% CI 2.2-13.3%) for the low-risk group (with 0-2 factors; p = 0.0001). For the 110 patients who received no adjuvant RT, LRR was associated with a 4-year distant metastasis rate of 49.0% (9 of 17, 95% CI 24.6-73.4%). For patients without LRR, it was 13.3% (15 of 93, 95% CI 6.3-20.3%; p = 0.0001). The 4-year survival rate for patients with and without LRR was 75.1% (95% CI 53.8-96.4%) and 88.7% (95% CI 82.1-95.4%; p = 0.049), respectively. LRR was independently associated with a higher risk of distant metastasis and worse survival in multivariate analysis.

CONCLUSION

LRR after mastectomy is not only a substantial clinical problem, but has a significant impact on the outcome of patients with T1 or T2 primary tumor and 1-3 positive axillary nodes. Patients with risk factors for LRR may need adjuvant RT. Randomized trials are warranted to determine the potential benefit of postmastectomy RT on the survival of patients with a T1 or T2 primary tumor and 1-3 positive nodes.