The elderly breast cancer patient: Association of age, tumor size, and grade with sentinel lymph node status.

Abstract

15 Background: Nodal evaluation of the elderly breast cancer patient remains controversial, and some have suggested that selected older women with breast cancer may not require sentinel lymph node biopsy (SLNB). Methods: An IRB-approved database was queried for patients undergoing SLNB for invasive breast cancer from 2000-2006. We compared 8 cohorts: age <40 years, 40-44, 45-49, 50-54, 55-59, 60-64, 65-69, and >70 years. Logistic regression and chi-square test were used. Results: Procedure success rate was above 95% for all groups in a total sample size of 1268 patients. Patients >70 years had lower grade tumors than patients <40 years (Grade 1: 25% vs. 7%; Grade 2: 53% vs. 47%; Grade 3: 17% vs. 40%, p<0.0001) and higher ER expression (ER+: 83% vs. 59%, p<0.0005). Patients <40 years also had a higher proportion of multifocal disease (21% vs. 9%, p<0.002), lymphovascular invasion (20% vs. 10%, p<0.007), and number of positive sentinel lymph nodes (PSLN) removed (mean: 3.7 vs. 2.7, p<0.028). Upon multivariate analysis, the odds of a PSLN decrease 9% for every 5-year increase in age (OR 0.91, p<0.003), but increase significantly with certain tumor characteristics (ER+ vs. ER-: OR 1.7, p=0.002), larger size (0.5 cm increase: OR 1.26, p<0.0001), and higher grade (Grades 2-3: OR 1.99, p<0.0007). The predicted probability of a PSLN for patients age 35, 55, and 70 years is 27%, 22%, and 16%, assuming each had a ER+, low grade, 2 cm tumor. Conclusions: Older breast cancer patients have more favorable pathology, and the chance of a PSLN decreases as age increases. However, the odds of a PSLN are significantly higher in patients with certain tumor characteristics, which are known prior to definitive surgery. Given recent reports that older patients are less likely to receive standard treatment for breast cancer and prognosis may worsen as a result, tumor size and characteristics rather than age should dictate the decision to perform SLNB, and we should continue appropriate, aggressive staging of the older breast cancer patient.