Non-contrast-enhanced breast MRI for evaluation of tumor volume change after neoadjuvant chemotherapy.

PURPOSE: Three-dimensional contrast-enhanced magnetic resonance imaging (3D-Ce-MRI) is a most powerful tool for evaluation of neoadjuvant chemotherapy (NAC). However, the use of contrast agent is invasive, expensive, and time consuming, Thus, contrast agent-free imaging is preferable. We aimed to investigate the tumor volume change after NAC using maximum intensity projection diffusion-weighted image (MIP-DWI) and 3D-Ce-MRI. METHOD: We finally enrolled 55 breast cancer patients who underwent NAC in 2018. All MRI analyses were performed using SYNAPSE VINCENT® medical imaging system (Fujifilm Medical, Tokyo, Japan). We evaluated the tumor volumes before, during, and after NAC. Tumor volume before NAC on 3D-Ce-MRI was termed Pre-CE and those during and after NAC were termed Post-CE. The observer raised the lower end of the window width until the tumor was clearly visible and then manually deleted the non-tumor tissues. A month thereafter, the same observer who was blinded to the 3D-Ce-MRI results randomly evaluated the tumor volumes (Pre-DWI and Post-DWI) using MIP-DWI with the same method. Tumor volume change between ΔCE (Pre-CE - Post-CE/Pre-CE) and ΔDWI (Pre-DWI - Post-DWI/Pre-DWI) and the processing time for both methods (Time-DWI and Time-CE) were compared. RESULTS: We enrolled 55 patients. Spearman's rho between ΔDWI and ΔCE for pure mass lesions, and non-mass enhancement (NME) was 0.89 (p < 0.01), 0.63(p < 0.01) respectively. Time-DWI was significantly shorter than Time-CE (41.3 ± 21.2 and 199.5 ± 98.3 respectively, p < 0.01). CONCLUSIONS: Non-contrast-enhanced Breast MRI enables appropriate and faster evaluation of tumor volume change after NAC than 3D-Ce-MRI especially for mass lesions.

Superficial Thoracic Artery Perforator Flap for Volume Replacement Oncoplastic Breast-conserving Surgery.

Lateral chest wall perforator flaps, such as the lateral intercostal artery perforator flap, lateral thoracic artery perforator flap, and thoracodorsal artery perforator flap, have been used for volume replacement oncoplastic breast-conserving surgery (VR-OPBCS) in the lateral and central breast. However, there are cases in which these perforators are missing or too thin, making it difficult to raise a flap for partial breast reconstruction. A 58-year-old woman underwent VR-OPBCS for breast cancer in the lower quadrant of the right breast. Preoperative imaging studies did not identify lateral thoracic artery perforator or thoracodorsal artery perforator but identified a well-developed superficial thoracic artery perforator (STAP). A flap based on the STAP was dissected, and partial breast reconstruction was performed. The flap survived with no complications. No deformity of the lower breast or displacement of the nipple-areola complex was observed 8 months after the completion of postoperative radiotherapy. The STAP flap can be used as an alternative to VR-OPBCS when other lateral chest wall perforator flaps are unavailable.

A case of extensively spreading acinic cell carcinoma of the breast with microglandular features.

Acinic cell carcinoma (ACC) is an exceptionally rare type of breast carcinoma with a low-grade morphology and a favorable prognosis. It is postulated to be a type of invasive carcinoma arising in microglandular adenosis (MGA). We report a case of extensively spreading ACC of the breast with MGA-like features. Macroscopically, yellowish nodules were widely distributed throughout the right breast, up to the axilla, without mass formation. Microscopically, the tumor consisted of two distinct carcinoma components: one was multiple nodular lesions showing invasive carcinoma with fused solid nests, and the other was a widely spreading lesion exhibiting MGA-like features with uniform small single glands. Immunohistochemically, both components were negative for ER, PR, and HER2, and expressed EMA, S100 and lysozyme. The distinct morphology and molecular expression indicated ACC. The single glands in the MGA-like area lacked myoepithelial cells but were linearly surrounded by type IV collagen, a basement membrane component. This case supports the hypothesis that ACC and MGA have the same lineage and indicates that ACC is not necessarily a low-grade malignancy and can be aggressive.

Can breast MRI and adjunctive Doppler ultrasound improve the accuracy of predicting pathological complete response after neoadjuvant chemotherapy?

BACKGROUND: To examine the accuracy of MRI and Doppler ultrasound (US) for detecting residual tumor after neoadjuvant chemotherapy (NAC) for breast cancer and evaluate whether adjunctive Doppler US improves the MRI accuracy. METHODS: We reviewed 276 invasive breast cancer cases treated with NAC. Tumors were classified into four subtypes based on estrogen receptor and HER2 status. Response to NAC was evaluated using contrast-enhanced MRI and Doppler US. Residual Doppler flow was assumed to indicate a residual tumor. MRI and Doppler findings were compared with the histopathological findings of resected specimens. Pathological complete response (pCR) was defined as neither in situ nor invasive cancer left. RESULTS: Of the 276 tumors, imaging complete responses were observed using MRI and Doppler US in 62 (22%) and 111 (40%), respectively, whereas pCR was achieved in 44 (16%). MRI and Doppler US predicted residual tumor with 88% and 69% sensitivity, 80% and 91% specificity, 87% and 73% accuracy, 96% and 98% PPV, and 56% and 36% NPV, respectively. The accuracies of MRI and Doppler US were significantly higher for HER2-negative than HER2-positive tumors (p < 0.001 and p = 0.043, respectively). Seven (26%) of 27 false-negative cases identified by MRI were correctly diagnosed as positives with adjunctive Doppler US. CONCLUSIONS: Although MRI accurately detected residual tumor with 87% accuracy, this was still not sufficient to meet clinical demands and differed with tumor subtype. Adjunctive Doppler US in cases that appear to show a complete response on MRI might reduce chances of false negatives and increase the NPV of MRI for predicting residual tumor.

Evaluation of Breast Edema Findings at T2-weighted Breast MRI Is Useful for Diagnosing Occult Inflammatory Breast Cancer and Can Predict Prognosis after Neoadjuvant Chemotherapy.

Background Prediction of occult inflammatory breast cancer (IBC) and breast cancer prognosis based on breast edema findings on T2-weighted MRI scans, even for patients without clinical signs of IBC, would be useful in both pretreatment planning and prognosis and may elucidate the underlying biologic mechanisms. Purpose To evaluate whether classification of breast edema on T2-weighted MRI scans is useful for predicting the prognosis of patients with breast cancer treated with neoadjuvant chemotherapy (NAC). Materials and Methods A retrospective evaluation was performed of women with breast cancer who underwent breast MRI and were treated with NAC between January 2011 and December 2018. Breast edema on T2-weighted images was scored on a scale of 1 to 4, as follows: (a) breast edema score (BES) 1, no edema; (b) BES 2, peritumoral edema; (c) BES 3, prepectoral edema; and (d) BES 4, subcutaneous edema (suspicious for occult IBC). Clinically evident IBC was classified as BES 5 (without MRI). The log-rank test was performed, and hazard ratios were calculated using the Cox hazard model to evaluate associations between BES and progression-free survival (PFS) and overall survival (OS). PFS rate at 100 months after initiation of therapy was also evaluated. Results Of 408 patients (median age, 53 years; range, 28-80 years), 65 (16%) had a recurrence and 27 (7%) died. The log-rank test revealed differences in PFS for BES 4 versus 1, BES 5 versus 1, BES 5 versus 2, and BES 5 versus 3 (adjusted P < .05 for all). PFS rates for BES 1-5 were 0.92, 0.85, 0.80, 0.62, and 0.58, respectively, and the corresponding OS rates at 100 months were 0.98, 0.91, 0.92, 0.77, 0.86, respectively. Conclusion Classification of breast edema findings on T2-weighted MRI scans using a breast edema score was related to the prognosis of patients after neoadjuvant chemotherapy. © RSNA, 2021 Online supplemental material is available for this article.

Is the presence of edema and necrosis on T2WI pretreatment breast MRI the key to predict pCR of triple negative breast cancer?

PURPOSE: Given that a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) is an important prognostic factor, evaluating pretreatment imaging findings is important. Outcomes for triple negative breast cancer (TNBC) vary with the histological classification, indicating that this classification is clinically significant. In this study, we focus on the most common histological subtype of TNBC, invasive carcinoma of no special type (NST), to evaluate whether intramammary edema (intra-E) and intratumoral necrosis (intra-N) on T2-weighted magnetic resonance imaging (T2WI) is a useful predictor of pCR. METHOD: We retrospectively included patients with biopsy-diagnosed TNBC-NST who received NAC between January 2014 and December 2017. Intra-E and intra-N were evaluated on T2WI before NAC. We grouped intra-E into no edema, peritumoral edema, prepectoral edema, and subcutaneous edema, and we defined intra-N as water-like signal intensity without enhancement on T2WI. We also evaluated tumor size, Ki-67 expression, and histological/nuclear grade, as well as their correlation with intra-E and intra-N. RESULTS: Fifty-seven patients with TNBC-NST were enrolled. There was no correlation with the rate of pCR and the presence of either intra-E or intra-N before NAC. Only intra-E and tumor size showed a positive correlation. CONCLUSIONS: In patients with TNBC-NST, intra-E and intra-N did not correlate with pCR, but intra-E did positively correlate with tumor size. NST may exhibit a greater response to NAC, regardless of whether intra-E or intra-N is present or not on the pretreatment MRI. KEY POINTS: • Pathological complete response in TNBC-NST had no correlation with intramammary edema or intratumoral necrosis. • NAC may be justified in TNBC-NST even in the presence of edema or necrosis. • The extension of edema correlated with tumor size of TNBC-NST.

Imaging features of breast cancer with marked hemosiderin deposition: A case report.

A 63-year-old woman was referred to our hospital for breast cancer treatment. She had a large HER2-positive breast tumor on her left breast, and received neoadjuvant chemotherapy. After treatment, a shrunk spiculated mass with calcification-like high density was detected on mammography, and MRI revealed a large strong susceptibility artifact. Surgical specimen analysis attributed these imaging features to a large marked hemosiderin deposition. This case is herein reported due to its rarity and to the importance of acknowledging that this large marked hemosiderin depositions can present as a calcification-like high density on mammography and shows large susceptibility artifact on MRI imaging.

MRI-detected breast lesions: clinical implications and evaluation based on MRI/ultrasonography fusion technology.

Magnetic resonance imaging (MRI) is a highly sensitive imaging modality that frequently reveals additional breast lesions that are occult on mammography and ultrasonography (US) and are thus difficult to diagnose. It is important to investigate these MRI-detected suspicious lesions, which are associated with a fairly high rate of malignancy. In this review, we have discussed MRI/US fusion technology, a magnetic position tracking system that synchronizes real-time US and MRI to improve lesion detection and enables comparisons of MRI and US findings of the detected lesions. This combination increases the precision of second-look US. We hope that our review underscores the importance of understanding the US findings and histopathology of MRI-detected breast lesions, as this will enable radiologists to perform appropriate assessments.

Does breast cancer growth rate really depend on tumor subtype? Measurement of tumor doubling time using serial ultrasonography between diagnosis and surgery.

BACKGROUND: Breast cancer growth is generally expected to differ between tumor subtypes. We aimed to evaluate tumor doubling time (DT) using ultrasonography and verify whether each tumor subtype has a unique DT. METHODS: This retrospective study included 265 patients with invasive breast cancer who received serial ultrasonography between diagnosis and surgery. Tumor diameters were measured in three directions and DTs were calculated according to an exponential growth model using the volume change during serial ultrasonography. We investigated the relationships between DT, tumor subtype, and histopathological factors. RESULTS: Volumes did not change in 95 (36%) of 265 tumors and increased in 170 (64%) tumors during serial ultrasonography (mean interval, 56.9 days). The mean volume increases of all tumors and volume-increased tumors were 22.1% and 34.5%, respectively. Triple-negative tumors had greater volume increases (40% vs. 20%, p = 0.001) and shorter DT (124 vs. 185 days, p = 0.027) than estrogen receptor (ER)+/human epidermal growth factor receptor 2 (HER2)- tumors. Volume-increased tumors had higher Ki-67 indices than those of volume-stable tumors in ER+/HER2- (p = 0.002) and ER+/HER2+ tumors (p = 0.011) and higher histological grades in all tumors except triple-negative tumors (p < 0.001). Triple-negative tumors with DTs < 90 days (short-DT) showed higher Ki-67 indices than those with DTs > 90 days (long-DT) (p = 0.008). In ER+/HER2- tumors, histological grades were higher for short-DT than for long-DT tumors (p = 0.022). CONCLUSION: Differences in tumor DT depending on breast cancer subtype, Ki-67 index, and histological grade were confirmed using serial ultrasonography even during preoperative short interval.

T2-hypointense rim of breast mass lesions on magnetic resonance images: Radiologic-pathologic correlation.

We investigated the radiologic-pathologic correlation of a strong hypointense rim on T2-weighted images (T2-hypo-rim) surrounding breast mass lesions and evaluated its clinical significance. We retrospectively reviewed 3503 consecutive breast magnetic resonance imaging (MRI) examinations. The T2-hypo-rim was defined as a border of strong hypointensity compared with the fat signal on fat-suppressed T2-weighted images. Detected lesions with T2-hypo-rim were classified as a solid or cystic mass with MRI and correlated with histopathologic findings. Sixty-two masses (2%; 34 solid, 28 cystic) with T2-hypo-rim were detected [44 breast cancers, 18 benign lesions, including 15 (24%) papillary tumors]. Patients with cancer were significantly older than those with benign lesions (P = .002). Breast cancers were significantly larger than benign masses (P = .023). In 49 of 62 lesions (24 solid and 16 cystic cancers; three solid and six cystic benign masses), the rims were accurately correlated with the histopathologic findings. All malignant and benign cystic masses exhibited hemosiderin deposits in the cyst walls. However, 22 of 24 solid cancers and no solid benign masses exhibited hemosiderin at the tumor periphery (92% and 0%, respectively, P < .001). In addition, a thick fibrous capsule was present in nine (38%) of 24 solid cancers and none of the solid benign lesions. Strong T2-hypo-rims mostly correlated with hemosiderin deposits and/or sometimes fibrous capsules. Although the rims could not distinguish malignant from benign cystic lesions, they indicated malignancy in solid mass lesions on MRI. Additionally, the rims often indicated papillary tumors.

Thirty percent of ductal carcinoma in situ of the breast in Japan is extremely low-grade ER(+)/HER2(-) type without comedo necrosis.

Background Overdiagnosis in mammography (MMG) is a problem. Combination of MMG and ultrasonography for breast cancer screening may increase overdiagnosis. Most cases of overdiagnosis are low-grade ductal carcinoma in situ (LGD), but no reports have focused on them. Materials and methods We immunostained 169 ductal carcinoma in situ (DCIS) cases for ER, PgR, HER2 and Ki67 and classified them into 4 subtypes: ER(+)/HER2(-), ER(+)/HER2(+), ER(-)/HER2(-) and ER(-)/HER2(+). The Ki67 index was used to evaluate the grade of malignancy and examined for correlations with each ER/HER2 subtype and the nuclear grade (NG), with/without comedo necrosis. Results The Ki67 index correlated significantly with NG, both with/without comedo necrosis, and reliably evaluated the grade of malignancy. The index for ER(+)/HER2(-) (n=117, 69.2%) was 7.45±7.10, which was significantly lower than for each of the other types. The index was 5.71±6.94 for ER(+)/HER2(-) without comedo necrosis (n=52, 30.8%), which was significantly lower than with comedo necrosis. This was considered LGD, characterized by absence of microcalcification in MMG and either presence of a solid mass or cystic lesion or absence of hypoechoic areas in ultrasound. Conclusion In Japan, ER(+)/HER2(-) without comedo necrosis accounts for about 30% of DCIS and is LGD. This may be being overdiagnosed. J. Med. Invest. 63: 192-198, August, 2016.

Triple assessment of sentinel lymph node metastasis in early breast cancer using preoperative CTLG, intraoperative fluorescence navigation and OSNA.

BACKGROUND: Sentinel lymph node biopsy (SLNB) became a standard surgical procedure for patients with early breast cancer; however, the optimal method of sentinel lymph node (SLN) identification remains controversial. The current study presents the protocol of our institution for preoperative and intraoperative SLN detection. METHODS: Fifty female patients with early breast cancer and clinically node-negative axilla were enrolled in this study. All patients underwent preoperative CT lymphography (CTLG), intraoperative SLNB using fluorescence navigation, intraoperative one-step nucleic acid amplification (OSNA) and postoperative hematoxylin and eosin histopathological analysis. Prediction of metastasis by CTLG and detection of metastasis by OSNA were compared to results of histopathology as standard reference. RESULTS: SLN were identified by preoperative CTLG and intraoperative SLNB with fluorescence navigation in all patients, the identification rate was 100 %. SLN metastases were detected as positive by OSNA in 9 patients (18 %), 4 were (++), 4 were (+) and 1 was (+I). SLN metastases were detected as positive by histopathology in 10 patients (20 %). The concordance rate between OSNA and permanent sections was 90 %. The negative predictive value of CTLG was 80 %. CONCLUSION: Use of CTLG and fluorescence navigation made performing SLNB with high accuracy possible in institutions that cannot use the radioisotope method. OSNA provided accurate intraoperative method, allowing for completion of axillary node dissection during surgery and avoidance of second surgical procedure in patients with positive SLNs, thereby reducing patient distress and, finally, saving hospital costs.

Immunocytochemical results for HER2 and Ki67 in breast cancer touch-smear cell specimens are reliable.

BACKGROUND: Re-evaluation of the subtype of recurrent breast cancer is necessary for deciding the treatment approach, but it is often not performed due to the difficulty of obtaining tissue specimens from a recurrent lesion, etc. However, when a recurrent lesion is close to the body surface, fine-needle aspiration cells (FNA cells) can be easily obtained, and immunocytochemical (ICC) analysis of hormone receptors expression in FNA cells is said to be highly reliable. However, there is no consensus regarding ICC analysis of human epidermal growth factor receptor type 2 (HER2) expression and the Ki67 index using FNA cells. METHODS: Touch-smear cells (TSC) were prepared from resected specimens from 36 patients with primary invasive ductal carcinoma of the breast. The TSC were fixed in 95 % ethanol and subjected to ICC analysis for HER2 using HercepTest™ (Dako) and Ki67 using MIB-1™ (Dako). HER2 expression and the Ki67 index for the TSC were compared with the results of immunohistochemical analysis of histological section (HS). Statistical analyses used the kappa test and Pearson's correlation coefficients. RESULTS: HER2 and Ki67 were analyzed in TSC from 36 and 28 patients, respectively. The HER2 expression scores in the TSC and HS groups showed good agreement (kappa value =0.640) and significant correlation (correlation coefficient =0.860, p < 0.001). The Ki67 indexes in the TSC and HS groups also showed significant correlation (correlation coefficient =0.861, p < 0.001). CONCLUSIONS: The reliability of ICC analysis of HER2 expression and the Ki67 index using TSC were recognized.

Preoperative diagnosis of sentinel lymph node (SLN) metastasis using 3D CT lymphography (CTLG).

BACKGROUND: Sentinel lymph node biopsy (SLNB) became a standard procedure for patients with early breast cancer, however, an indication of SLN navigation to metastatic disease may lead to misdiagnosis for staging. Preoperative CTLG with a water-soluble iodinated contrast medium visualizes the correct primary SLNs and its afferent lymphatic channels surrounding detailed anatomy, therefore it can predict LN metastasis by visualizing the lymph vessel obstruction or stain defect of the SLN by tumor. The current study presents the value of CTLG for preoperative prediction for SLN status. METHODS: A total of 228 patients with Tis-T2 breast cancer who did not receive primary chemotherapy were studied. SLN metastasis was diagnosed according to the following staining patterns of SLNs and afferent lymphatic vessels: stain defect of SLN, obstruction, stagnation, dilation, and detour of the lymphatic vessels by tumor occupation. The diagnosis was compared with the pathological results to evaluate the accuracy of prediction for SLN metastasis using CTLG. RESULTS: Twenty-seven of 228 patients had metastatic SLN pathologically. Twenty-five of these were diagnosed as metastatic preoperatively. The accuracy for metastatic diagnosis using CTLG was 89.0%, sensitivity was 92.6%, and specificity was 88.6%. The positive predictive value was 52.1% and negative predictive value was 98.8%. CONCLUSION: CTLG can select the candidate with truly node negative cases in early breast cancer patients, because it predicts lymph node metastasis preoperatively from natural status of the lymphographic image. It also might omit the SLN biopsy itself.

Metastatic breast carcinoma of the abdominal wall muscle: a case report.

Metastasis from breast carcinoma is an uncommon occurrence in skeletal muscle, compared to local invasion into muscle from direct tumor spread. A 49-year-old woman was referred to our hospital with an 8.5-cm mass in the right breast. Core needle biopsy revealed metaplastic carcinoma with squamous metaplasia. The mass was rapidly growing and metaplastic, so mastectomy with dissection of axillary lymph nodes was performed. Pathological examination showed metaplastic carcinoma, histological grade 3, triple negative, and a MIB-1 labeling index of 80%. Six months postoperatively, during adjuvant chemotherapy treatment, she reported numbness and pain in the right lateral thigh and a mass in the right lower abdomen. Computed tomography revealed multiple lined masses in the abdominal wall and iliac muscle. Core needle biopsy showed metastatic breast carcinoma. Radio- and chemotherapy were administered, but the mass in the muscle became enlarged. To control her pain, a combined treatment with morphine, fentanyl, ketamine, antiepilepsy drug, and NSAIDs was administered. Liver metastasis appeared 9 months (15 months postoperatively) after recognition of muscle metastasis, and the patient died 16 months postoperatively. Skeletal muscle metastasis is uncommon, and therapeutic intervention is mainly palliative. The most common symptom of skeletal muscle metastasis is pain; thus, pain control is a pivotal goal of treatment.

IgG4-related sclerosing disease of the breast successfully treated by steroid therapy.

IgG4-related sclerosing disease was first identified and defined in the twenty-first century. In this pathology, the serum IgG4 level increases and IgG4-positive plasma cells and lymphocytes infiltrate organs such as the pancreas, salivary glands, lacrimal glands, kidneys, and the retroperitoneum. Presented in this report is a case of IgG4-related sclerosing disease that occurred in the breast and was treated successfully with steroid therapy. A 51-year-old woman presented with bilaterally swollen eyelids and an elevated serum IgG4 concentration. Screening CT revealed a lesion in her right breast but no other lesions. Mammography, ultrasonography, and MRI could not rule out malignancy, so a core needle biopsy was performed. Histologically, the lesion was composed of papilloma with fibrosis, adenosis, and severe lymphoplasmacytic infiltration. No malignant features were observed. Many plasma cells within the lesion were immunohistochemically positive for IgG4. IgG4-related sclerosing disease of the breast was diagnosed, and steroid therapy was initiated. During 4 weeks of steroid treatment the lesion became smaller in size, and at 7-months follow-up the lesion showed no new growth. Since steroid therapy is effective for this disease, IgG4-related sclerosing disease should be considered in the differential diagnosis of breast lesions in order to avoid unnecessary surgery.

Clip placement after an 11-gauge vacuum-assisted stereotactic breast biopsy: correlation between breast thickness and clip movement.

PURPOSE: To retrospectively evaluate the accuracy of clip placement on the basis of measurements obtained on pre- and post-vacuum-assisted 11-gauge stereotactic biopsy mammograms and to analyze the factors that can predict which patients will experience a significant movement of the clip. MATERIALS AND METHODS: The pre- and post-vacuum-assisted 11-guage stereotactic biopsy mammographic findings in 204 cases undergoing clip placement were reviewed. The clip-to-lesion distance was measured. The correlations between the clinical-mammographic findings and the likelihood of clip movement were evaluated. RESULTS: Target mammographic lesion types of the 204 cases were characterized as calcification in all but one case, which was a distortion lesion. The clip-to-lesion distance was within 5 mm on both the craniocaudal and mediolateral oblique projections in 119 (58%) cases, within 6-10 mm in 28 (14%), within 11-19 mm in 25 (12%), and was > 20 mm in 32 (16%). The variability of the clip-to-lesion distance was greatest in the plane orthogonal to the compression plane used for stereotactic biopsy. Breast thickness was the only factor that was predictive of a significant movement of the clip, and thin breasts tended to exhibit greater clip movement. CONCLUSION: Breast thickness may be a useful factor for predicting the degree of clip movement after 11-gauge vacuum-assisted stereotactic biopsy.

Is lymphovascular invasion degree one of the important factors to predict neoadjuvant chemotherapy efficacy in breast cancer?

BACKGROUND: Patients who achieve pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) have favorable disease-free survival rates. A few studies have suggested that lymphovascular invasion degree may play an important role in predicting pCR. This study aims to confirm the role of lymphatic invasion degree in predicting pCR in breast cancer patients after NAC. METHODS: We retrospectively analyzed 120 patients treated with NAC and surgery. The following pathological features were evaluated on surgical specimens after NAC: histological grade, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), lymphovascular invasion degree, intratumoral necrosis positivity, and axillary lymph node positivity. RESULTS: pCR and marked response were achieved in 12% (14/120) and 35% (42/120), respectively, of 120 breast cancers in 120 women. Breast cancers with pCR or marked response were classified as chemosensitive. The remaining 64 breast cancers (53%) were classified as chemoresistant. Severe lymphovascular invasion (P = .003), large tumor size (P = .029), ER positivity (P = .001), and PR positivity (P = .006) were significantly associated with chemoresistant breast cancer. Invasive ductal carcinoma (P = .028) and HER-2 positivity (P < .0001) were significantly associated with chemosensitive breast cancer. On multivariate analysis, HER-2 positivity (P < .0001), invasive ductal carcinoma (P = .047), and marked/moderate lymphovascular invasion (P = .023) were the three factors that remained statistically significant in the model to predict histological therapeutic effect. CONCLUSION: Lymphovascular invasion degree is one of the important factors to predict NAC efficacy for breast cancer.