Abstract P2-01-06: Patterns of axillary evaluation in older patients (pts) with breast cancer and impact on adjuvant therapy
Authors: Dominici LS , Sineshaw H , Jemal A , Lin A , King TA , Freedman RA 
Published: March 2017

Background:

Axillary lymph node status has traditionally been a key factor in informing adjuvant therapy recommendations for pts with breast cancer. With increased emphasis on tumor biology, this information may be less relevant, particularly in older populations where competing comorbidity frequently influences treatment decisions. We examined patterns of axillary surgery in older breast cancer pts and the impact axillary surgery has on treatment receipt.

Methods:

We identified women aged ≥65 with Stage I-III invasive breast cancer diagnosed during 2012-2013 from the National Cancer Data Base who did not have clinically positive nodes and underwent cancer-directed surgery. Nodal surgery type and receipt of adjuvant therapies were examined. Multivariable logistic regression was used to examine the associations of axillary surgery receipt with pt, clinical and facility factors.

Results:

Among 69,414 eligible women, 40% were aged 65-70, 42% aged 71-80 and 18% aged &gt;80. 91% had axillary surgery (67% sentinel lymph node biopsy, 11% axillary lymph node dissection, 13% unspecified axillary surgery), and 24% of pts had pathologically positive nodes. 10% of pts (stage IIB-III) received adjuvant chemotherapy, 81% (hormone receptor positive) received adjuvant hormonal therapy, 67% (breast conservation or stage III postmastectomy) received radiation. In adjusted analyses, increasing age and neoadjuvant hormonal therapy were strongly associated with lower odds of axillary surgery. Region and mastectomy were strongly associated with higher odds of axillary surgery. The table shows variables associated with axillary surgery.

VariableAdjusted OR (95% CI) for having any axillary surgery*Age (vs. 65-70) 71-75.64 (.58-.71)76-80.34 (.31-.37)&gt;80.08 (.07-.09)Diagnosed in 2013 (vs. 2012)1.08 (1.02-1.15)Stage (vs. II) I1.25 (1.13-1.38)III.73 (.60-.89)Grade (vs. 1) 21.22 (1.14-1.31)31.24 (1.13-1.37)HER2 status (vs. positive) Negative.83 (.73-.93)Tumor size (vs. ≤2 cm) &gt;2-5cm1 (.91-1.11)&gt;5cm.56 (.47-.67)Comorbidity score (vs. 0) 1.85 (.79-.92)&gt;/=2.62 (.56-.68)Region (vs. New England)Range 1.66-2.67 (1.42-3.12)Case volume (vs. high) Low.82 (.73-.93)Medium.98 (.91-1.06)Insurance (vs. private) Uninsured.69 (.44-1.09)Medicaid.67 (.52-.86)Medicare.84 (.77-.93)Median household income ($) (vs. &gt;46K) &lt;30,0001.06 (.95-1.18)30,000-34,9991.11 (1.01-1.21)35,000-45,9991.08 (1.01-1.16)Neoadjuvant hormonal therapy (vs. not).49 (.42-.59)Surgery (vs. BCS) Mastectomy, no recon3.37 (3.09-3.68)Mastectomy, +recon2.76 (2.16-3.51)  *Adjusted for table variables plus race, hormone receptor status, and facility type (none significantly associated with axillary surgery)

Axillary surgery and younger age were significantly associated with receipt of adjuvant chemotherapy, radiation, and hormonal therapy.

Conclusion:

Within the NCDB, 91% of pts age ≥65 with clinically node-negative breast cancer undergo surgical staging of the axilla, and axillary surgery was associated with adjuvant therapy receipt. The impact of routine node assessment on treatment and outcome has been questioned, and further study in this population of pts is warranted.

Citation Format: Dominici LS, Sineshaw H, Jemal A, Lin A, King TA, Freedman RA. Patterns of axillary evaluation in older patients (pts) with breast cancer and impact on adjuvant therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-06.