The Presence of Extensive Lymphovascular Invasion (LVI) is Associated with Higher Risk of Recurrence in Curatively Treated Breast Cancer Patients

PURPOSE/OBJECTIVE(S)

Lymphovascular invasion (LVI) is a pathological feature seen in breast cancer that may be an important step in cancer metastasis. Multiple datasets have demonstrated a correlation between LVI and local-regional recurrence (LRR). Whether the extent of LVI is an incremental determinant of LRR risk is unknown. We describe clinical outcomes in women with invasive breast cancer stratified by: 1) absence of LVI (neg), 2) LVI focal or suspicious (FS-LVI), 3) usual (non-extensive) LVI (LVI) and 4) extensive LVI (E-LVI).

MATERIALS/METHODS

Between December 2009 and August 2021, there were 8,837 patients with early-stage breast cancer (T1-2 and N0-2a) were treated with curative intent and were evaluable. Clinical-pathological details were abstracted by retrospective review. The description of LVI was abstracted from pathology reports. Recurrence and survival outcomes were compared based on the extent of LVI.

RESULTS

Of the 8837 patients studied, 5584 were neg, 461 had FS-LVI, 2315 had LVI, and 477 had E-LVI. The E-LVI cohort had baseline characteristics suggestive of higher risk such as younger median age, higher proportion of grade 3, more nodal positivity, more mastectomy (67% vs 48%), and higher use of chemotherapy compared to LVI. The cumulative incidence of LRR and DM was highest in the E-LVI group. Using LVI as the reference, the presence of E-LVI, age, tumor size, ER status, grade, mastectomy, and close/positive margins were independent variables for LRR on Cox multivariable regression (Table 1). To assess the effect with an alternate statistical method, we created propensity matched cohorts (matched for age, size, receptors, grade, surgery type, margins and chemotherapy/RT use); a statistical difference in OS was noted between groups with LVI vs E-LVI (HR 1.44 (CI 1.06-1.96, p = 0.018), but not in LRR (HR 1.31 (CI 0.87-1.97, p = 0.2) or DM (HR 1.16 (CI 0.88-1.53, p = 0.3).

CONCLUSION

Our work suggests that patients with E-LVI are at a higher risk for LRR compared to patients with usual LVI, despite maximal standard of care treatment. This is important because E-LVI can be determined from breast specimens, and may help define indications for RNI/PMRT when nodal information is not available.

Oncotype Recurrence Score (RS) at the Extremes of Tumor Size: Which Drives Clinical Outcomes?

PURPOSE/OBJECTIVE(S)

Tumor size is an established and independent risk factor for local-regional recurrence (LRR) and distant recurrence (DM). More recently, the recurrence score calculated from a 21-gene expression assay (Oncotype DXTM, Exact Sciences) has also been correlated with LRR and DM. We sought to determine the impact of the interaction between tumor size and Oncotype RS, particularly when the variables are in discrepancy with each other. More specifically, we evaluated clinical outcomes in patients with small tumors (≤1 cm) and high RS (≥26) and, separately, in patients with large tumors (>5 cm) with low RS.

MATERIALS/METHODS

Between 2008 and 2020, 310 patients were identified retrospectively as having been treated for early-stage, hormone-receptor positive, Her2-negative breast cancers with tumor size ≤1 cm that were node-negative and had RS ≥ 26 at our institution. In addition, 64 patients were identified with tumor size >5 cm and RS < 26 (irrespective of nodal status). Locoregional recurrence rates (LRR) and invasive recurrence rates (composite of LRR and distant recurrence) were estimated using the Kaplan-Meier method.

RESULTS

Patient characteristics are shown in Table 1. In the group of patients with small tumors and high RS, the 5- and 10-year invasive recurrence rates with 95% CI were 8% (4.2-12) and 17% (8.2-26). The 5- and 10-year locoregional recurrence rates with 95% CI were 5.8% (2.7-8.8) and 15% (6.2-23). In the group of patients with large tumors and low RS, 10-year rates could not be estimated with the available data. The 5- and 8-year invasive recurrence rates with 95% CI were 3.2% (0-7.5) and 3.2% (0-7.5). The 5- and 8-year locoregional recurrence rates with 95% CI were 1.6% (0-4.7) and 1.6% (0-4.7).

CONCLUSION

Our findings suggest that patients with small tumors and high RS are at a higher risk for LRR compared to the average ≤1 cm node-negative breast cancer based on published data on the effect of tumor size on LRR and DM. Similarly, tumors larger than 5 cm with low RS appear to behave indolently and in a manner consistent with more favorable risk (despite their large size). These findings may have important implications for the tailoring of local-regional treatment strategies.

SOME STEAM-VOLATILE COMPONENTS OF THE EXTRACTIVES FROM POPULUS TREMULOÏDES HEARTWOOD

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