The Clinicopathological Characteristics of Palpable and Non-palpable Breast Cancer

ABSTRACT

Purpose@#Palpability is known to be a poor prognostic factor for breast cancer. The present study analyzed the clinicopathological characteristics and outcomes of palpable and nonpalpable breast cancers using big data. @*Methods@#Between January 2005 and May 2019, a total of 15,141 patients were enrolled. All patients were diagnosed with invasive ductal carcinomas. Patients with unclear medical records, multiple tumors, bilateral breast cancers, inflammatory breast cancers, inoperable breast cancers and distant metastasis were excluded. Patients were divided into the palpable and nonpalpable breast cancer groups based on physicians’ clinical examinations. The clinicopathological characteristics and disease-specific survivals (DSS) were analyzed. @*Results@#Patients with palpable breast cancers were younger, had larger tumors, and higher tumor-node-metastasis stage (p<0.001) than patients with nonpalpable breast cancers. Palpable breast cancer cases had higher rates of lympho-vascular invasion, higher histologic and nuclear grades than nonpalpable breast cancer cases (p<0.001). The positive proportion of hormone receptor was higher in the nonpalpable breast cancer group than in the palpable breast cancer group, but that of human epidermal growth factor receptor 2 was higher in the palpable breast cancer group than in the nonpalpable breast cancer group (p<0.001). The Ki-67 index was higher in the palpable breast cancer group than in the nonpalpable breast cancer group (p<0.001). Total mastectomy and axillary dissection were performed more frequently in the palpable breast cancer group than in the nonpalpable breast cancer group (p<0.001). Adjuvant chemotherapy was administered more frequently in the palpable breast cancer group than in the nonpalpable breast cancer group. However, radiotherapy and hormonal therapy were performed more frequently in nonpalpable breast cancer group than in the nonpalpable breast cancer group (p<0.001). According to a multivariate analysis, younger age, lower body mass index, larger tumor size, tumor location, higher stage, higher histologic grade and higher Ki-67 index were associated with palpability (p<0.001). DSS was significantly lower in the palpable breast cancer group than in the nonpalpable breast cancer group (p<0.001). @*Conclusion@#Palpable breast cancers tend to be triple negative breast cancers and have higher histologic grade and, Ki-67 index and worse prognosis than nonpalpable breast cancers. Therefore, based on the results of the present study, treating palpable breast cancers requires careful attention.