Vacuum-assisted core biopsy (VACB) is a minimally invasive method used in the diagnosis and treatment of focal breast lesions [1]. Various advantages of VACB have made it a commonly used procedure to diagnose breast lesions. VACB allows removal of multiple tissue samples at a single attempt in a relatively short time, and the patient is able to patients are discharged from the hospital soon [2]. VACB is primarily a diagnostic method for focal breast lesions. Focal lesions in the breast requiring histopathological examination are the primary indications for this procedure [3]. In some cases, VACB can be used therapeutically. It is not used to treat malignant lesions because the samples obtained in this procedure are fragmented, which make it impossible to precisely establish the margin of the removed tissue [4]. However, for treating small benign lesions, VACB is currently used as a minimally invasive alternative to open surgical biopsy [5]. Benign breast disease (BBD) is a heterogeneous condition consisting of many histological entities, including ductal proliferation with or without atypia, fibroadenomas, and intraductal papillomas [6]. Some of these lesions are thought to represent progressive changes in the stepwise sequence of histological changes leading to the development of breast cancer. Specifically, it has been hypothesized that nonatypical proliferative forms of BBD, proliferative diseases with atypia, and in situ cancer represent successive steps preceding the development of invasive breast carcinoma [7]. We have occasionally encountered tumor regrowth in sites where VACB was previously performed or in adjacent tissues. Hence, we aimed to evaluate the factors that influence tumor regrowth at post-biopsy sites or at adjacent tissues.

A total of 647 women who underwent VACB were identified from the patient report of Kosin University Hospital. In this cohort, the median age at diagnosis was 56 years (range, 20–95 years), and 36% of patients were aged 50 and over. Patients’ demographics and BBD data are presented in Table 1. A majority of patients (86.7%) had a normal body mass index (BMI). Among them, 562 patients (86.9%) were categorized as group A (post-VACB without recurrence). Group A was more likely to have proliferative lesions without atypia, sclerosing adenosis, and microcalcification. According to the post-VACB pathology report, most BBDs were heterogeneous. Fibrocystic changes were found in 579 tumors (89.5%), intraductal papillomas in 99 tumors (15.3%), proliferative lesions in 103 tumors (15.9%), sclerosing adenosis in 49 tumors (7.6%), radial scars in 41 tumors (6.3%), apocrine metaplasia in 34 tumors (5.3%), and ADH in 37 tumors (5.7%). Reoperation was done in 37 patients with ADH due to safety concerns about surgical margins. Furthermore, patients were followed up for 6 months intervals. During the follow-up periods, 85 patients were diagnosed as group B, and biopsies were taken. According to the second pathology reports, fibrocystic diseases were found in 77 (90.6%), intraductal papillomas in 19 (22.4%), proliferative diseases without atypia in 22 (25.9%), sclerosing adenosis in 13 (15.3%), radial scars in two (2.3%), and apocrine metaplasia in six (7.0%) tumors (Table 2). For analysis accounting for various confounding factors, group B was significantly associated with proliferative diseases without atypia, sclerosing adenosis, and microcalcification compared to group A (p=0.008, p=0.007, and p=0.001, respectively). After adjustment for confounding variables, group B was associated more with proliferative breast diseases than group A (HR, 0.558; 95% CI, 0.343–0.907; p=0.018). Furthermore, group B was associated with intraductal papilloma (HR, 0.571; 95% CI, 0.342–0.953; p=0.032). However, group B was not associated with high BMI (HR, 0.511; 95% CI, 0.219–1.193; p=0.286) (Table 3).

Breast tumors can recur at the original site (called local recurrence). Local recurrence is usually found on breast ultrasound during a follow-up examination by a health care provider or if a morphologic change is observed. Recurrence is usually found when breast ultrasound is reported as BI-RADS C4 during follow-up. When a local recurrence is observed, it is diagnosed in a similar manner as that used for the diagnosis of the first breast tumor. The tumor is biopsied by the surgeon and examined by the pathologist. Tests are done to ensure that there is no sign of malignancy. In our study, there was no evidence of malignancy on pathology reports. Hence, most cases were diagnosed as BI-RADS C4 on breast ultrasonography during follow-up. Post-VACB scar formation was believed to have influenced the diagnosis of BI-RADS C4 on breast ultrasound. Developments in imaging diagnostics and relatively good availability of devices for performing mammography and ultrasound has increased the detection of breast focal lesions at the preclinical stages [6]. The differential diagnosis of small, impalpable focal lesions suspected of a malignant process is especially difficult [8,9]. Until recently, the gold standard treatment for such cases was an open surgical biopsy. However, the possibility of developing complications, the length of the procedure, high costs, formation of scars, and frequent occurrence of breast deformation have led to a search for less invasive and less expensive methods [10]. VACB proves to be a method that eliminates or to a large extent limits these disadvantages [11]. It is an efficient, minimally invasive, relatively inexpensive procedure with a good cosmetic effect, and has a low complication rate [12]. Similar to minimally invasive techniques used in the treatment of other organs, VACB, in some cases, can be an alternative to a more extended surgical procedure [13]. This procedure is gradually replacing the commonly used procedure: fine needle aspiration biopsy, whose main disadvantage is a high rate of nondiagnostic results (4%–35.4%), as well as false negative findings (2.6%–20%). VACB provides multiple quality samples from a single procedure compared to a traditional core biopsy [14]. The diagnostic accuracy of the Mammotome biopsy is 98% to 100% for breast lumps [15]. Open surgical biopsy yields similar results, but is more invasive and expensive. In our patients, a sufficient number of samples for histopathological examination were obtained in the first biopsy from 647 patients (99.2%) [16]. VACB can have therapeutic value, while being well tolerated and associated with low complication rates compared to surgery [17]. In our study, we entirely removed lesions with a low-risk of malignancy using VACB in imaging examinations with an incision diameter up to 15 mm in 94.5% of women. This is similar to Plantade, who excised entire lesions in 98.1% of his patients [18]. However, if cases are diagnosed as benign lesions by biopsy, and the lesions are classified as BI-RADS 4a, 4b, 5 by imaging examinations, it is necessary to repeat the biopsy or perform open surgical biopsy as there is a high risk that the cancer may not be completely treated [19]. In conclusion, lesions previously diagnosed as proliferative diseases without atypia or microcalcification during the first VACB were significantly associated with recurrent benign breast tumors. Intraductal papilloma was also significantly associated with tumor regrowth. Therefore, close follow-up is needed for such diagnosis on VACB samples.