Palpable vs non-palpable breast cancers in screened populations: Clinicopathological features and prognostic implications

Abstract

BACKGROUND

Despite widespread mammographic screening, a substantial proportion of breast cancers are still diagnosed as palpable lesions, frequently self-detected by the patient. Prior studies have investigated palpability as a prognostic factor, but few have incorporated contemporary staging systems or focused on clinically homogeneous, screening-eligible populations. In high-resource settings with equal access to screening, it remains unclear whether palpability reflects intrinsic tumor aggressiveness rather than delayed detection. This study evaluates whether palpable tumors exhibit distinct clinicopathological characteristics and worse outcomes in a screening-eligible population, hypothesizing that palpability may reflect aggressive tumor biology and potentially influence prognosis even when screening programs are accessible.

AIM

To compare clinicopathological features and survival outcomes of palpable vs non-palpable breast cancers in a screened population.

METHODS

We retrospectively analyzed 2110 women with clinically node-negative, localized breast cancer treated surgically between 2004 and 2024. Palpability at diagnosis was used to classify tumors as palpable (n = 1234) or non-palpable (n = 876). Endpoints included tumor size, grade, subtype, Ki-67 index, nodal status, overall survival, and breast cancer-specific survival. Statistical analyses included χ² and t-tests and Kaplan-Meier estimates, with significance set at P < 0.05.

RESULTS

Palpable tumors were significantly larger (17.5 mm ± 8.6 vs 11.0 ± 6.7 mm, P < 0.001), more often high-grade (G3: 33% vs 16.3%, P < 0.001), and more frequently of luminal B or triple-negative subtype (37.1% vs 20.6%, P < 0.001). Ki-67 proliferation index was markedly higher in palpable tumors (24.7% ± 11.9% vs 15.1% ± 9.4%, P < 0.001). Sentinel lymph node positivity was increased (27.6% vs 16.7%, P < 0.001). While 10-year overall survival was similar (92% palpable vs 95% non-palpable, P = 0.56), breast cancer-specific survival showed a trend toward worse survival in palpable cases (96% vs 99%, P = 0.1).

CONCLUSION

Palpable tumors display faster growth kinetics and aggressive features, potentially shortening the preclinical window. Palpability may indicate biologically aggressive disease, warranting individualized management despite access to routine screening.

Keywords: Breast cancer; Palpable tumor; Tumor aggressiveness; Mammographic screening; Clinicopathological features; Survival outcomes; Ki-67 index; Tumor biology; Prognostic factors; Screening-detected cancer

Core Tip: Despite widespread mammographic screening, many breast cancers still present as palpable masses. This large cohort study (n = 2110) reveals that palpable tumors exhibit aggressive biology-larger size (17.5 mm vs 11.0 mm, P < 0.001), higher grade (G3) (33% vs 16%), elevated Ki-67 (24.7% vs 15.1%), and more frequent luminal B/TN subtypes (P < 0.001). While 10-year survival remained excellent (> 90%) for both groups, palpability served as a clinical marker of rapid tumor growth, underscoring its utility in risk stratification. Findings highlight that even in screened populations, palpable presentation may signal biologically aggressive disease warranting tailored management.