Severe Pseudomonas aeruginosa Pneumonia in a Breast Cancer Patient Despite Pegfilgrastim Administration.

Pegfilgrastim dramatically reduces febrile neutropenia (FN) caused by high-risk chemotherapy. This report details the presentation of a 72-year-old female who developed a fatal infection of Pseudomonas aeruginosa pneumonia that occurred during preoperative chemotherapy despite pegfilgrastim administration. She was brought to the hospital with symptoms of high fever and general fatigue during chemotherapy, but her respiratory symptoms were minimal, and a chest computed tomography (CT) showed no obvious signs of pneumonia. She had FN. After she was hospitalized, her breathing and consciousness worsened rapidly, and the chest CT showed prominent lobar pneumonia. Her blood cultures suggested P. aeruginosa, so she was quickly switched to meropenem. She was diagnosed with septic shock and acute respiratory distress syndrome due to severe P. aeruginosa pneumonia, and she was started on noninvasive positive pressure ventilation with immunoglobulin preparations. P. aeruginosa developed drug resistance, so it was necessary to change antibiotics. She was discharged without complications of pulmonary fibrosis on chest CT. It is crucial to always be aware that severe infections can occur even with pegfilgrastim administration, promptly identify the causative pathogen, and intervene with early treatment.

The Japanese Breast Cancer Society clinical practice guidelines for epidemiology and prevention of breast cancer, 2022 edition.

The Japanese Breast Cancer Society Clinical Practice Guidelines for Epidemiology and Prevention of Breast Cancer, 2022 Edition.

Immunohistological analysis of B7-H4, IDO1, and PD-L1 expression and tumor immune microenvironment based on triple-negative breast cancer subtypes.

BACKGROUND: B7 homolog 4 (B7-H4) and indoleamine 2,3-dioxygenase (IDO1) are factors involved in the inhibition of antitumor activity and are new therapeutic targets for immune checkpoint therapy. Our study aimed to simultaneously investigate the interrelationship among B7-H4, IDO1 and programmed cell death ligand 1 (PD-L1) expression in triple-negative breast cancer (TNBC), including tumor immune microenvironment (TIME) and TNBC subtypes. METHODS: Immunostaining for PD-L1, B7-H4, and IDO1 was performed on whole-slide sections of 119 cases of TNBC. The TIME was evaluated based on stromal tumor infiltrating lymphocytes (sTILs; %), pattern classification of TILs, tumor-stroma ratio (TSR), and tertiary lymphoid structure (TLS). TNBC subtypes were also determined by immunohistochemistry analysis of cytokeratin 5/6 and androgen receptor (AR) expression. RESULTS: B7-H4 expression was significantly higher in cases with a combined positive score cutoff of 5 for PD-L1 (clone 28-8; p = 0.021), inflamed TIL pattern (p = 0.007), and TLS ≥ 4 (p = 0.006). B7-H4 expression was higher in case of CK5/6 ≥ 10 (p = 0.035). The H-scores of AR and B7-H4 were inversely correlated (ρ = - 0.509, p < 0.001). B7-H4 and IDO1 expression levels were inversely correlated in cases with AR < 10 (ρ = - 0.354, p < 0.001). CONCLUSIONS: These results suggest that considering the TIL pattern and TLS and identifying the expression of PD-L1 and the basal-like type are useful for estimating B7-H4 expression. In addition, luminal androgen receptor (LAR)-type is frequently deficient in B7-H4 expression. In non-LAR types, B7-H4 and IDO1 expression are exclusive.

Alcohol consumption and breast cancer prognosis after breast cancer diagnosis: a systematic review and meta­analysis of the Japanese Breast Cancer Society Clinical Practice Guideline, 2022 edition.

Alcohol consumption is internationally recognized as one of the compelling risk factors for breast cancer, but it does not necessarily correlate with the prognosis of breast cancer patients. Alcohol consumption in breast cancer patients was addressed in the 2022 Breast Cancer Clinical Practice Guidelines. A systematic review and meta-analysis of epidemiological studies on alcohol consumption and breast cancer recurrence, breast cancer-related mortality, all-cause mortality, and cardiovascular disease mortality in breast cancer patients was performed. The PubMed, Cochrane Library, and Ichushi-Web databases were searched for relevant publications reporting cohort or case-control studies published until March 2021. A total of 33 studies (32 cohort studies and 1 case-control study) met the eligibility criteria; 4638 cases of recurrence, 12,209 cases of breast cancer-specific mortality, and 21,945 cases of all-cause mortality were observed. With regard to breast cancer recurrence, 7 studies assessed pre-diagnosis alcohol consumption (relative risk (RR) 1.02, 95% confidence interval (95% CI) 0.77-1.37, p = 0.88) and 3 studies assessed post-diagnosis alcohol consumption (RR 0.96, 95% CI 0.85-1.10, p = 0.57), and no significant increase or decrease in risk was observed. With regard to breast cancer-related mortality, 19 studies assessed pre-diagnosis alcohol consumption (RR 1.02, 95% CI 0.93-1.11, p = 0.69), 9 studies assessed post-diagnosis alcohol consumption (RR 0.96, 95% CI 0.77-1.19, p = 0.70), and no significant increase or decrease in risk was observed. With regard to all-cause mortality, 18 studies assessed pre-diagnosis alcohol consumption (RR 0.90, 95% CI 0.82-0.99, p = 0.02), 8 studies assessed post-diagnosis alcohol consumption (RR 0.88, 95% CI 0.74-1.02, p = 0.08), and pre-diagnosis alcohol consumption was associated with a significantly decreased risk. With regard to cardiovascular disease mortality and alcohol consumption, 2 studies assessed it, and the RRwas 0.47 (95% CI 0.28-0.79, p = 0.005), showing that alcohol consumption was associated with a significantly decreased risk. The limitations of this study are that drinking status was mainly based on a questionnaire survey, which is somewhat inaccurate and has many confounding factors, and the cut-off value for the maximum alcohol intake in many studies was low, and it is possible that the actual intake was only an appropriate amount. In many countries, a standard drinking amount is set, and wise decisions are required.

An extremely rare case of nonfunctioning parathyroid carcinoma occurring in a parathyroid adenoma.

A 53-year-old woman with a 4-month history of fatigue and somnolence was referred to her local doctor because of the worsening of her symptoms. Marked increases in her serum calcium (13.0 mg/dl) and intact-parathyroid hormone (175 pg/ml) were found, she was referred to our hospital. On physical examination, there was a palpable 3 cm mass in her right neck. Ultrasonography showed a 1.9 × 3.6 cm circumscribed hypoechoic lesion in the caudal right lobe of the thyroid gland. There was very mild 99mTc-sestamibi scintigraphic accumulation. Her preoperative diagnosis was primary hyperparathyroidism due to parathyroid carcinoma, and surgery was performed. The tumor weighed 6300 mg and did not invade the surrounding area. The pathology showed a mixture of small cells thought to be parathyroid adenomas and large, pleomorphic nuclei and fissionable carcinomas. Immunostaining showed that the adenoma portion was PTH-positive, chromogranin A-positive, p53-negative, PAX8-positive, PGP 9.5-negative with a Ki 67 labeling index (LI) of 2.2%. Whereas the carcinoma portion was PTH-negative, chromogranin A-negative, p53-positive, PAX8-positive, PGP 9.5-positive with a Ki67 LI of 39.6%, showing a nonfunctioning aspect and highly malignant. Postoperatively, the patient is alive without recurrence 9 years later without hypercalcemia or recurrence. A case of nonfunctioning parathyroid carcinoma in an extremely rare parathyroid adenoma is reported.

[Neoadjuvant Epirubicin-Cyclophosphamide Therapy followed by Nab-Paclitaxel in Patients with Operable Breast Cancer-A Single-Center Phase â ¡ Trial].

Clinical studies have confirmed that nab-paclitaxel(nab-PTX)therapy is effective and safe in patients with metastatic breast cancer. Neoadjuvant chemotherapy(NAC) with nab-PTX has resulted in a pathological complete response (pCR) rate of 29% in all cases and 58% in HER2-positive cases. However, these data were obtained from an overseas study, and the effectiveness and safety of NAC with nab-PTX remain unclear in Japan. Thus, the present study was conducted to investigate these aspects. In patients with T1-3, N0-2, M0 breast cancer, 4 cycles of 260 mg/m2 nab-PTX were administered every 3 weeks after 4 cycles of EC therapy(100 mg/m2 of epirubicin and 600 mg/m2 of cyclophosphamide)as NAC. In HER2- positive patients, trastuzumab was used in combination with nab-PTX. Overall, 14 patients were registered between October 2014 and October 2018. One patient who had requested for another drug after providing informed consent was excluded, and the remaining 13 patients were analyzed. The primary endpoint was pCR rate. The median age of the subjects was 57 years, and the median tumor diameter was 35 mm. There were 7 cases of Stage Ⅱ disease and 6 cases of Stage Ⅲ disease. As for tumor subtype, there were 7 cases of Luminal-type, 2 cases of Luminal- HER2-type, 4 cases of HER2-type, and no triple negative-type tumors(the cut-off values for estrogen receptor [ER] and progesterone receptor were both 1%). The objective response rate to NAC was 77%(10/13 cases), and no PD was observed. The pCR rate was 54%(7/13 cases): 2 patients had Luminal-type tumors, 1 had a Luminal-HER2-type tumor, and 4 had HER2-type tumors. Predictive factors for pCR were ER negativity and HER2 positivity. Common adverse events of chemotherapy were hair loss, pain, malaise, anemia, dysgeusia, constipation, itchiness, and numbness, but their severity was modest, and they were manageable. This study suggests the efficacy and safety of nab-PTX after EC therapy in Japanese patients with operable breast cancer.

A Case of Rare Matrix-producing Triple-negative Breast Carcinoma for Which Drug Response in a Patient-derived Orthotopic Xenograft Mouse Model Was Correlated With Patient Response.

BACKGROUND: Matrix-producing breast carcinoma (MPBC) is a very rare and usually aggressive triple-negative breast cancer. We successfully established a patient-derived orthotopic xenograft (PDOX) model from a patient with MPBC and used it to study tumor sensitivity to various agents. CASE REPORT: A 40-year-old woman was diagnosed with MPBC with a triple-negative phenotype. Due to axillary lymph-node metastases found during radical mastectomy, the patient was subsequently treated with epirubicin, cyclophosphamide and paclitaxel. In addition, radiotherapy was directed to the chest wall and subclavicular fossa. A portion of the cancer tissue from the mastectomy was used to establish a PDOX nude-mouse model. The PDOX model was resistant to paclitaxel, bevacizumab, vinorelbine, cisplatinum and olaparib, and sensitive to eribulin. Metastases in mediastinal lymph nodes and the right ovary were observed in the patient 14 months after mastectomy. Thoracoscopic mediastinal lymph-node biopsy and laparoscopic oophorectomy were performed, and both confirmed breast-cancer metastasis. The patient was then treated with paclitaxel and bevacizumab but no response was observed, which correlated with the inability of these drugs to arrest tumor growth in the PDOX models of the patient's tumor. The patient was then given eribulin based on the PDOX-model result, but treatment had to be stopped because of rapid progression of metastasis into the cervical lymph nodes and thyroid gland. The patient was subsequently treated with atezolizumab and nab-paclitaxel. Unfortunately, the patient died of her cancer 8 months after recurrence. CONCLUSION: The present study demonstrates that the PDOX model of a patient's triple-negative MPBC accurately predicted that paclitaxel and bevacizumab would not arrest the patient's tumor growth. Eribulin may have been effective if administered at an earlier stage of the patient's cancer course. Drug-screening results from PDOX models should be used as early as possible in order to improve patient outcome.

Automated assessment of Ki-67 in breast cancer: the utility of digital image analysis using virtual triple staining and whole slide imaging.

AIMS: Precise evaluation of proliferative activity is essential for the stratified treatment of luminal-type breast cancer (BC). Immunohistochemical staining of Ki-67 has been widely used to determine proliferative activity and is recognised to be a useful prognostic marker. However, there remains discussion concerning the methodology. We aimed to develop an automated and reliable Ki-67 assessment approach for invasive BC. MATERIALS AND RESULTS: A retrospective study was designed to include two cohorts consisting of 152 and 261 consecutive patients with luminal-type BC. Representative tissue blocks following surgery were collected, and three serial sections were stained automatically with Ki-67, pan-cytokeratin and p63. The whole slides were scanned digitally and aligned using VirtualTripleStaining - an extension to the VirtualDoubleStaining™ technique provided by Visiopharm software. The aligned files underwent automated invasive cancer detection, hot-spot identification and Ki-67 counting. The automated scores showed a significant positive correlation with the pathologists' scores (r = 0.82, P < 0.0001). Among selected patients with curative surgery and standard adjuvant therapies (n = 130), the digitally assessed low Ki-67 group (<20%) demonstrated a significantly better prognosis (breast cancer-specific survival, P = 0.030; hazard ratio = 0.038) than the high Ki-67 group. CONCLUSIONS: Digital image analysis yielded similar results to the scores determined by experienced pathologists. The prognostic utility was verified in our cohort, and an automated process is expected to have high reproducibility. Although some pitfalls were confirmed and thus need to be monitored by laboratory staff, the application could be utilised for the assessment of BC.

Eribulin Regresses a Cisplatinum-resistant Rare-type Triple-negative Matrix-producing Breast Carcinoma Patient-derived Orthotopic Xenograft Mouse Model.

BACKGROUND/AIM: Matrix-producing breast carcinoma (MPBC) is a rare and usually aggressive triple-negative breast cancer (TNBC). In the present report, we determined the drug sensitivity for a triple-negative MPBC using a patient-derived orthotopic xenograft (PDOX) model. MATERIALS AND METHODS: The PDOX model was established in the left 2nd mammary by surgical orthotopic implantation (SOI). MPBC PDOX models were randomized into 4 groups (6 mice per group) when the tumor volume became 80 mm3: G1, control group; G2, cisplatinum group [intraperitoneal (i.p.) injection, weekly, for 2 weeks]; G3, paclitaxel group (i.p., weekly, for 2 weeks); G4, eribulin group [intravenous (i.v.) injection, weekly, for 2 weeks]. All mice were sacrificed on day 15. Tumor volume and body weight were measured one time per week. RESULTS: The MPBC PDOX model was resistant to cisplatinum (p=0.800). Paclitaxel suppressed tumor growth compared to the control group (p=0.009). However, only eribulin regressed the tumor (p=0.001). CONCLUSION: Eribulin has clinical potential for triple-negative MPBC patients.

A Triple-negative Matrix-producing Breast Carcinoma Patient-derived Orthotopic Xenograft (PDOX) Mouse Model Is Sensitive to Bevacizumab and Vinorelbine, Regressed by Eribulin and Resistant to Olaparib.

BACKGROUND/AIM: Matrix-producing breast carcinoma (MPBC) is a rare and usually aggressive triple-negative breast cancer (TNBC). In this study, we determined drug sensitivity for a triple-negative MPBC, without BRCA mutations, in a patient-derived orthotopic xenograft (PDOX) model. MATERIALS AND METHODS: The MPBC PDOX model was established in the left 2nd mammary gland of nude mouse by implantation of the patient tumor using surgical orthotopic implantation (SOI). We randomized MPBC PDOX mice into 5 groups (n=5 mice/per treatment group) when the tumor volume reached 80 mm3: G1, control-no treatment; G2, bevacizumab [intra-peritoneal (i.p.), weekly, for 2 weeks]; G3, vinorelbine (i.p., weekly, for 2 weeks); G4, olaparib (oral., daily, for 2 weeks); G5, eribulin [intravenous (i.v.), weekly, for 2 weeks]. The mice in each treatment group were sacrificed on day 15. Tumor volume and body weight were measured once/week. RESULTS: The MPBC PDOX model was resistant to olaparib (p=0.22). The MPBC PDOX model treated with bevacizumab and vinorelbine showed significantly suppressed tumor growth compared to the untreated group (p=0.005 and 0.002, respectively). However, only eribulin regressed the tumor (p=0.0001). Eribulin was more effective than olaparib (p=0.0001), bevacizumab (p=0.0025) and vinorelbine (p=0.0061). CONCLUSION: Eribulin has clinical potential as treatment for triple-negative MPBC patients that are resistant to a PARP inhibitor such as olaparib.

[Two Cases of Endobronchial Metastases from Breast Cancer].

Endobronchialmetastasis(EBM)is a rare complication in breast cancer patients. Herein, we report 2 cases of EBM in breast cancer patients. Patient 1 had pulmonary metastases that were treated with hormone therapy and showed long survival after achieving a CR, while patient 2 had multi-organ metastases and died 42 months after the diagnosis of EBM. If bronchial obstruction is observed in a breast cancer patient, early diagnosis of EBM via a bronchoscopic examination is recommended. EBM may not indicate a poor prognosis, and appropriate anti-cancer therapy with palliative intrabronchial therapies can prolong the survival in selected EBM patients.

[Three Cases of Intrathecal Chemotherapy with Ventricular Catheter for the Treatment of Leptomeningeal Metastasis from Breast Cancer].

Leptomeningeal metastasis(LM)is a rare complication in patients with breast cancer. We report 3 cases of LMs in patients with breast cancer who were treated with intrathecal methotrexate via an Ommaya reservoir. In 2 patients, a significant neurological improvement was observed, whereas in 1 patient there was no response. The overall survivals for the patients who experienced improvements were 22 and 9 months. Although we have no evidence for the efficacy of intrathecal chemotherapy for LMs in patients with breast cancer, its effects for some patients could be promising, after reservoir management and drug selection establishment.

[A Case Report of Surgery and Chemotherapy for a Patient with Rapidly Progressing Breast Cancer during Pregnancy].

A 33-year-old woman became aware of a right breast mass at her 28th week of pregnancy. From the biopsy results, we diagnosed her with right breast cancer. At her 33rd week of pregnancy, she underwent modified radical mastectomy (pT2N3aM0, Stage III C, ER-negative, PR-negative, HER2-positive), and she elected to receive adjuvant therapy after the surgery during her pregnancy. She received the first course of EC (epirubicin plus cyclophosphamide) therapy on the 13th postoperative day (35 weeks of gestation) and gave a natural, vaginal delivery at 36 weeks and 5 days of gestation. On the 4th day after birth, the patient noticed a contralateral left breast mass and was diagnosed with left breast cancer, after core needle biopsy. She received 4 courses of EC therapy and is currently undergoing PTX plus HER (paclitaxel plus trastuzumab) therapy. Regarding chemotherapy during pregnancy, we recommend that there is no need to perform artificial preterm birth, because chemotherapy has little influence on children after their second-trimester. After the second-trimester, chemotherapy can be safely performed.

Correction: Preparation of a novel antiserum to aromatase with high affinity and specificity: Its clinicopathological significance on breast cancer tissue.

[This corrects the article DOI: 10.1371/journal.pone.0177439.].

Preparation of a novel antiserum to aromatase with high affinity and specificity: Its clinicopathological significance on breast cancer tissue.

Aromatase inhibitors have been widely used for the endocrine treatment of estrogen-dependent breast cancer in postmenopausal patients. However, clinicopathological studies of aromatase have been limited due to unsatisfactory specificity and/or restricted availability of anti-aromatase antibodies. Here, we have generated a polyclonal antiserum with high affinity and specificity for human aromatase using a monoclonal antibody tagged immunoaffinity chromatography on an industrial production scale. Our preliminary immunohistochemical analysis of 221 invasive breast cancer cases indicated that 87.3% (193/221) had at least 5% aromatase positive cells. The histoscore for aromatase was inversely correlated with pT (p = 0.019), pN (p = 0.001), stage (p < 0.001), histologic grade (p = 0.003), lymphatic infiltration (p < 0.001), venous infiltration (p < 0.001), and Ki-67 index (p < 0.001). However, cancer aromatase expression was independent of estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 statuses. This antiserum will be applicable to clinicopathological examination of aromatase in addition to ER and PgR for an appropriate use of aromatase inhibitor on the treatment of breast cancer. Further studies on the relationship between Aromatase inhibitors have been widely used for the endocrine treatment of estrogen-dependent breast cancer in postmenopausal patients. However, clinicopathological studies of aromatase have been limited due to unsatisfactory specificity and/or restricted availability of anti-aromatase antibodies. Here, we have generated a polyclonal antiserum with high affinity and specificity for human aromatase using a monoclonal antibody tagged immunoaffinity chromatography on an industrial production scale. Our preliminary immunohistochemical analysis of 221 invasive breast cancer cases indicated that 87.3% (193/221) had at least 5% aromatase positive cells. The histoscore for aromatase was inversely correlated with pT (p = 0.019), pN (p = 0.001), stage (p < 0.001), histologic grade (p = 0.003), lymphatic infiltration (p < 0.001), venous infiltration (p < 0.001), and Ki-67 index (p < 0.001). However, cancer aromatase expression was independent of estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 statuses. This antiserum will be applicable to clinicopathological examination of aromatase in addition to ER and PgR for an appropriate use of aromatase inhibitor on the treatment of breast cancer. Further studies on the relationship between aromatase expression and aromatase inhibitors are warranted.

Impact of modifiable lifestyle factors on outcomes after breast cancer diagnosis: the Setouchi Breast Cancer Cohort Study.

The primary purpose of this large cohort study is to investigate the effects on breast cancer outcomes of modifiable lifestyle factors after breast cancer diagnosis. These factors include physical activity, smoking, alcohol consumption, obesity and weight gain after diagnosis, alternative medicine and dietary factors. Women diagnosed with Stage 0 to III breast cancer are eligible for participation to this study. Lifestyle, use of alternative medicine, psychosocial factors, reproductive factors and health-related quality of life will be assessed using a questionnaire at the time of breast cancer diagnosis (baseline), and 1, 2, 3 and 5 years after diagnosis. Clinical information and breast cancer outcomes will be obtained from a breast cancer database. The primary endpoint will be disease-free survival. Secondary endpoints are overall survival, health-related quality of life, breast cancer-related symptoms and adverse events. Patient recruitment commenced in February 2013. Enrollment of 2000 breast cancer patients is planned during the 5-year recruitment period. The concept of the study is described in this article.

[Effectiveness of skin icing for reducing pain associated with luteinizing hormone-releasing hormone agonist injection].

We evaluated the effect of using the cooling method on pain at the site of luteinizing hormone-releasing hormone(LH-RH) agonist injection in 181 prostate cancer or premenopausal breast cancer patients by using a numerical rating scale(NRS)and a questionnaire survey with open-ended questions. According to the NRS, 38.1% of the patients experienced a reduction in pain, 37.5% experienced no change, and 24.4% experienced an increase in pain. Therefore, use of the cooling method did not have a statistically significant effect in terms of pain reduction(p=0.123). However, on analyzing pain reduction according to the answers in the questionnaire survey, 53.2% of the patients experienced a reduction in pain, 38.5% experienced no change, and 8.3% experienced an increase in pain. These findings were different from those obtained on using the NRS. In addition, irrespective of using the cooling method, needle thickness and patient obesity strongly influenced the pain experienced. The skin icing method was effective in reducing pain at the site of LH-RH agonist injection. This method is simple, inexpensive, and safe, and is hence recommended.

[A pilot study of the reduced effects of adverse events caused by oral morphine and oxycodone after rotating to fentanyl patch in patients with metastatic breast cancer].

BACKGROUND: It has been confirmed by several clinical trials that the fentanyl patch causes less adverse events than sustained-release oral morphine, and after rotation. However, there has been no evidence comparing the fentanyl patch with controlled-release oral oxycodone in terms of adverse events. PURPOSE: We prospectively investigated the reduced effects of adverse events caused by sustained-release oral morphine and controlled-release oxycodone after rotating to the fentanyl patch in patients with metastatic breast cancer. METHOD: Metastatic breast cancer patients requiring sustained-release oral morphine or controlled-release oral oxycodone(n=9, 2 taking oral morphine, 7 taking oral oxycodone, mean age, 57. 5 years)were recruited. Those experiencing adverse events from oral morphine or oral oxycodone were administered a fentanyl patch. RESULTS: The pain score was reduced significantly at the 4th week. The fentanyl patch was associated with significantly less nausea, vomiting, constipation, sleepiness and dizziness over the study period. CONCLUSION: This study suggested that the fentanyl patch can reduce adverse events caused by sustained-release oral morphine as well as controlled-release oral oxycodone.

New diagnostic method for breast cancer based on clinical mammographic data and its clinical validation.

BACKGROUND: Recently, the numbers of patients with breast cancer have increased rapidly in Japan, and about 40,000 people contract the disease annually today. Therefore, secondary prevention by breast cancer screening has become an important issue. Presently, mammography is used frequently for the diagnosis of breast cancer, but the reading of mammograms is difficult, and physicians must attend training classes specified by the Central Committee on Quality Control of Mammographic Screening and obtain a license to perform screening. Assessment categories are used for the evaluation of mammograms. Although they provide a scale for the diagnosis of breast cancer, the interpretation of mammograms is dependent on the physician's subjective judgment, and the advent of an objective evaluation method is awaited. METHODS: We scored the size, shape, density, margin, border, and internal structure of mammographic images and evaluated the relationships of these scores with lesion categorization. RESULTS: Since lesions could not be categorized by the analysis of any single item of mammographic images, the items were paired, and a new diagnostic system for breast cancer was prepared. When this system was applied, the diagnostic accuracy was very satisfactory, with a sensitivity of 100% (37/37) and a specificity of 92.9% (65/70) for category 5; 83.6% (51/61) and 97.8% (45/46), respectively, for category 4; and 88.9% (8/9) and 94.9% (93/98), respectively, for category 3. CONCLUSION: In this study, findings concerning the margin and internal structure were important for the discrimination of category 5, and those concerning the size, shape, and density made major contributions to the discrimination of category 3.