Prognosis according to the timing of recurrence in breast cancer

Purpose@#Clinically, breast cancer can be divided into 4 subtypes based on the presence of hormone receptors, human epidermal growth factor receptor 2 (HER2), and Ki-67. Because the pattern and time of recurrence vary according to the subtype, we evaluated whether there was a difference in overall survival (OS) among the subtypes according to the time and type of recurrence. @*Methods@#A total of 2,730 patients who underwent breast cancer surgery were analyzed. Early and late recurrence were defined as recurrence within and after 5 years of diagnosis, respectively. Recurrence type was categorized as locoregional recurrence or systemic recurrence. @*Results@#Hormone receptor-positive tumors were significantly more frequent in the late recurrence group than in the early recurrence group (estrogen receptor positive, 47.8% [early] vs. 78.7% [late]). However, there was no difference in the rate of HER2 overexpression (HER2+, 38.1% [early] vs.39.0% [late]). In subgroup analysis, early recurrence was a significant prognostic factor for OS in all subtypes. However, late recurrence was a significant prognostic factor for OS only in the luminal B subtype (hazard ratio of 4.30). In addition, the luminal B type had the highest proportion in late recurrence patients (63.2%). @*Conclusion@#The luminal B subtype had a high rate of late recurrence, and late recurrence was a poor prognostic factor for OS only in this subgroup. Therefore, further targeted treatments for luminal B breast cancer are needed and patients with this subtype require close long-term surveillance.

Differences in prognosis by p53 expression after neoadjuvant chemotherapy in triple-negative breast cancer

Purpose@#Our previous studies suggested that p53-positive triple-negative breast cancer (TNBC) should be more sensitive to chemotherapy than p53-negative TNBC. The aim of this study was to determine whether p53 expression in TNBC could predict response to neoadjuvant chemotherapy and the resulting prognosis. @*Methods@#From January 2009 to December 2017, TNBC patients who underwent neoadjuvant chemotherapy were reviewed, including a total of 31 TNBC patients who had clinical lymph node metastasis. The status of p53 expression in patients before and after chemotherapy was evaluated. @*Results@#Two patients (22.2%, 2 of 9) achieved pCR in p53(+) TNBC and 4 patients (50%, 5 of 10) achieved pCR in p53(-) TNBC. There was no correlation between pCR rate and p53 expression (P = 0.350). Based on prechemotherapy p53 expression, there was no significant difference in disease-free survival (DFS) between p53(+) TNBC and p53(-) TNBC (P = 0.335). However, after chemotherapy, p53(+) TNBC had shown higher DFS than p53(-) TBNC (P = 0.099). Based on prechemotherapy p53 expression, p53(+) TNBC had better overall survival (OS) than p53(-) TNBC, but the difference was not statistically significant (P = 0.082). After chemotherapy, p53(+) TNBC showed significantly better OS than p53(-) TNBC (P = 0.018). @*Conclusion@#Immunohistochemically detected p53 expression in TNBC could not predict the response to neoadjuvant chemotherapy. However, p53(+) TNBC had a better OS than p53(-) TNBC in patients who underwent neoadjuvant chemotherapy.

Differences in prognosis by p53 expression after neoadjuvant chemotherapy in triple-negative breast cancer

Purpose@#Our previous studies suggested that p53-positive triple-negative breast cancer (TNBC) should be more sensitive to chemotherapy than p53-negative TNBC. The aim of this study was to determine whether p53 expression in TNBC could predict response to neoadjuvant chemotherapy and the resulting prognosis. @*Methods@#From January 2009 to December 2017, TNBC patients who underwent neoadjuvant chemotherapy were reviewed, including a total of 31 TNBC patients who had clinical lymph node metastasis. The status of p53 expression in patients before and after chemotherapy was evaluated. @*Results@#Two patients (22.2%, 2 of 9) achieved pCR in p53(+) TNBC and 4 patients (50%, 5 of 10) achieved pCR in p53(-) TNBC. There was no correlation between pCR rate and p53 expression (P = 0.350). Based on prechemotherapy p53 expression, there was no significant difference in disease-free survival (DFS) between p53(+) TNBC and p53(-) TNBC (P = 0.335). However, after chemotherapy, p53(+) TNBC had shown higher DFS than p53(-) TBNC (P = 0.099). Based on prechemotherapy p53 expression, p53(+) TNBC had better overall survival (OS) than p53(-) TNBC, but the difference was not statistically significant (P = 0.082). After chemotherapy, p53(+) TNBC showed significantly better OS than p53(-) TNBC (P = 0.018). @*Conclusion@#Immunohistochemically detected p53 expression in TNBC could not predict the response to neoadjuvant chemotherapy. However, p53(+) TNBC had a better OS than p53(-) TNBC in patients who underwent neoadjuvant chemotherapy.

Significance of micrometastases in the calculation of the lymph node ratio for papillary thyroid cancer

PURPOSE: The lymph node ratio (LNR) is an important prognostic factor in papillary thyroid carcinoma (PTC), but micrometastases in cervical lymph nodes (LNs) are not of great clinical importance. In this study, we analyzed the accuracy of prediction of the prognosis depending on whether micrometastases were included in the number of metastatic LNs when calculating LNR. METHODS: The study included 353 PTC patients who underwent total thyroidectomy with neck LN dissection, and calculated LNR by 2 methods according to whether micrometastases were included in the number of metastatic LNs: Method 1 did not and method 2 did include. To compare the predictive values of LNR by the 2 methods, correlation coefficients and receiver operating characteristic (ROC) curves were analyzed. RESULTS: Positive correlations were found between LNR and preablation stimulated thyroglobulin (sTg) levels in both methods, but the correlation between method 1 LNR and preablation sTg level was significantly stronger than that for method 2 (Fisher z = 1.7, P = 0.045). The areas under these 2 independent ROC curves were analyzed; the prognostic efficacy of method 1 LNR was more accurate than that of method 2 LNR, and the difference was statistically significant (P = 0.0001). CONCLUSION: Regional recurrence of PTC can be predicted more accurately by not including micrometastases in the number of metastatic LNs when calculating LNR.

Erratum: Validation of a Web-Based Tool to Predict the Ipsilateral Breast Tumor Recurrence (IBTR! 2.0) after Breast-Conserving Therapy for Korean Patients / 한국유방암학회지

This article was published with a misspelled the date of acceptance. The date of acceptance should be corrected as “March 7, 2013”.

Extensive silicone lymphadenopathy after breast implant insertion mimicking malignant lymphadenopathy

Silicone implants are widely used in aesthetic and reconstructive breast surgery. Silicone lymphadenopathy is a well-known rare complication of implant insertion. Silicone leakage from a rupture or silicone bleeding can accumulate in lymph nodes. Foreign body reactions in the affected lymph nodes may be misdiagnosed as metastasis or malignant lymphadeno pathy upon initial presentation if silicone lymphadenopathy is not considered in the initial diagnosis. We report a case of siliconoma with extensive involvement of multiple lymph nodes mimicking malignant features to emphasize that clinicians should carefully evaluate each patient's medical history and disease status during differential diagnosis.

Extensive silicone lymphadenopathy after breast implant insertion mimicking malignant lymphadenopathy

Silicone implants are widely used in aesthetic and reconstructive breast surgery. Silicone lymphadenopathy is a well-known rare complication of implant insertion. Silicone leakage from a rupture or silicone bleeding can accumulate in lymph nodes. Foreign body reactions in the affected lymph nodes may be misdiagnosed as metastasis or malignant lymphadeno pathy upon initial presentation if silicone lymphadenopathy is not considered in the initial diagnosis. We report a case of siliconoma with extensive involvement of multiple lymph nodes mimicking malignant features to emphasize that clinicians should carefully evaluate each patient's medical history and disease status during differential diagnosis.

Evaluation of Prognostic Factors and Validation of Tumor Response Ratios after Neoadjuvant Chemotherapy in Patients with Breast Cancer

PURPOSE: In the treatment of breast cancer, neoadjuvant chemotherapy (NAC) is useful to reduce breast cancer size before surgical intervention. Patients who achieve a pathologic complete response (pCR) to NAC have improved overall survival (OS). However, the relationship between prognosis and partial response is yet unclear. In this study, we evaluated prognostic factors and the tumor response ratio (TRR) method among patients who received NAC. METHODS: Clinicopathologic factors were evaluated to predict OS. The TRR was calculated by dividing pathologic tumor size by clinical tumor size. TRRs were then categorized into four groups, and the survival times for the different TRR groups were compared using statistical evaluation. RESULTS: Clinical N stage (p=0.02), overall stage (p=0.04), pathologic N stage (p=0.03), hormone receptor status (p=0.01), and lymphovascular invasion (p=0.02) were significantly associated with OS. Pathologic overall stage and TRR did not correlate with OS. Patients with a pCR exhibited the best survival rates using the current staging system and the TRR method. CONCLUSION: Clinicopathologic factors can be easily applied to predict OS, and clinicians could use these parameters until an accurate, simple, and highly discriminatory methods is developed to assess breast cancer patients with a partial.

Primary Follicular Lymphoma in a Male Breast: A Case Report / Journal of the Korean Cancer Association, 대한암학회지

Primary breast lymphoma (PBL) is a rare disease, particularly in males. Diffuse large B cell lymphoma is the most common PBL, while follicular lymphoma is less common. Furthermore, primary follicular lymphoma of a male breast is rarely reported. We report a male patient with primary follicular lymphoma of the breast and hepatocellular carcinoma (HCC). A 46-year-old man was diagnosed with liver cirrhosis secondary to chronic hepatitis B infection. Ten years later, he underwent segmentectomy of the liver due to HCC. Another 5 months later, he presented with a painless mass in the right chest wall. The mass was diagnosed as follicular lymphoma of the breast. The stage was IEA and he did not receive adjuvant therapy. Although only a few cases have been reported, lymphoma should be considered as a possible cause of breast mass, even in male patients.

Primary Follicular Lymphoma in a Male Breast: A Case Report / Journal of the Korean Cancer Association, 대한암학회지

Primary breast lymphoma (PBL) is a rare disease, particularly in males. Diffuse large B cell lymphoma is the most common PBL, while follicular lymphoma is less common. Furthermore, primary follicular lymphoma of a male breast is rarely reported. We report a male patient with primary follicular lymphoma of the breast and hepatocellular carcinoma (HCC). A 46-year-old man was diagnosed with liver cirrhosis secondary to chronic hepatitis B infection. Ten years later, he underwent segmentectomy of the liver due to HCC. Another 5 months later, he presented with a painless mass in the right chest wall. The mass was diagnosed as follicular lymphoma of the breast. The stage was IEA and he did not receive adjuvant therapy. Although only a few cases have been reported, lymphoma should be considered as a possible cause of breast mass, even in male patients.

Achievement of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative: recommended serum calcium, phosphate and parathyroid hormone values with parathyroidectomy in patients with secondary hyperparathyroidism / 대한외과학회지

PURPOSE: The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF-K/DOQI) 2003 has established guidelines for the treatment of secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease - minerals and bone disorder (CKD-MBD). This study evaluated parathyroidectomy in SHPT patients for the achievement of the NKF-K/DOQI-recommended values of serum calcium, phosphate, and parathyroid hormone (PTH). METHODS: Between January 2005 and December 2010, parathyroidectomy was performed as recommended by the NKF-K/DOQI guidelines in 81 patients with SHPT and CKD-MBD. Serum PTH, calcium, and phosphate levels were measured prior to and 6, 12, 36, and 60 months after parathyroidectomy. RESULTS: Calcium, phosphate, and PTH levels dropped shortly after parathyroidectomy; however, a slight increase showed in the long term. Calcium levels increased for up to 60 months. Phosphate and PTH levels increased for up to 36 months but tended to decrease slightly at 60 months. The mean values were within the target ranges, except for PTH at 36 months. The target parameters of serum phosphate (42.9-61.1% of patients) and serum calcium (a peak of 61.1% of patients at 36 months, but only 28.6% at 60 months) were achieved the most. Less than 34% of patients achieved the recommended range for PTH. CONCLUSION: Parathyroidectomy was not an optimal procedure for achieving all the biochemical parameters recommended by the NKF-K/DOQI. Although it was helpful in attaining the recommended values for serum calcium and phosphate in SHPT patients resistant to medical therapy, the PTH levels did not fall within the recommended range.

Primary breast lymphoma: a single institution's experience / 대한외과학회지

PURPOSE: Primary breast lymphoma is a very rare disease, accounting for 0.4-0.5% of all breast malignancies. Due to the rarity, there are only limited reports of this disease in Korean women. In this reason, we report the experience of a single institution in Korea with primary breast lymphoma (PBL). METHODS: We retrospectively reviewed the medical records of 9 patients with PBL and evaluated the clinicopathologic characteristics and treatment outcomes. RESULTS: All nine patients were female and had diffuse large B-cell lymphoma (DLBL). The median age at diagnosis was 47.9 years and the median tumor size was 3.8 cm in diameter. The most common symptom was a painless palpable mass. Five patients were classified as stage IEA and four patients were IIEA according to the Ann Arbor staging system. Four patients underwent excisional biopsy and one patient underwent a lumpectomy with sentinel lymph node biopsy due to uncertain histology of the preoperative core needle biopsy. Nine patients received anthracycline containing combined chemotherapy; among them, five patients were treated with a rituximab containing regimen. Four patients received radiotherapy combined with chemotherapy. A complete response was achieved in eight patients. During the 44 months of the median follow-up period, three cases of relapse occurred, and among them, two patients died due to disease progression. CONCLUSION: Most PBLs are B-cell origin, with DLBL being the most common histologic type. A combined treatment modality has been known to have positive effects on prognosis, and surgery should be limited to a diagnostic purpose.

Breast Metastasis from Rhabdomyosarcoma of the Anus in an Adolescent Female / 한국유방암학회지

Rhabdomyosarcoma (RMS) of the breast is rare and there is scant information about the clinical behavior and treatment strategies. We report an adolescent female patient with metastatic RMS of the breast from the anus. An 18-year-old female patient was referred to our clinic due to palpable mass in the left breast. At age seven, she was diagnosed with acute lymphoblastic leukemia and treated with chemoradiation therapy. After 10 years of complete remission state, she presented with anal mass which was diagnosed as RMS and she received chemoradiation therapy. After 1 year of complete remission state, she noticed a palpable mass in her left breast. The breast mass was diagnosed as metastatic RMS based on core needle biopsy specimen. The RMS in breast was excised for the decreasing tumor burden despite of another metastatic lesion. Although rarely reported, metastasis of RMS should be considered as a cause of breast mass. Tissue biopsy is recommended when clinically suspected lesion is detected.

Validation of a Web-Based Tool to Predict the Ipsilateral Breast Tumor Recurrence (IBTR! 2.0) after Breast-Conserving Therapy for Korean Patients / 한국유방암학회지

PURPOSE: IBTR! 2.0 is a web-based nomogram that predicts the 10-year ipsilateral breast tumor recurrence (IBTR) rate after breast-conserving therapy. We validated this nomogram in Korean patients. METHODS: The nomogram was tested for 520 Korean patients, who underwent breast-conserving surgery followed by radiation therapy. Predicted and observed 10-year outcomes were compared for the entire cohort and for each group, predefined by nomogram-predicted risks: group 1, 10%. RESULTS: In overall patients, the overall 10 year predicted and observed estimates of IBTR were 5.22% and 5.70% (p=0.68). In group 1, (n=124), the predicted and observed estimates were 2.25% and 1.80% (p=0.73), in group 2 (n=177), 3.95% and 3.90% (p=0.97), in group 3 (n=181), 7.14% and 8.80% (p=0.42), and in group 4 (n=38), 11.66% and 14.90% (p=0.73), respectively. CONCLUSION: In a previous validation of this nomogram based on American patients, nomogram-predicted IBTR rates were overestimated in the high-risk subgroup. However, our results based on Korean patients showed that the observed IBTR was higher than the predicted estimates in groups 3 and 4. This difference may arise from ethnic differences, as well as from the methods used to detect IBTR and the healthcare environment. IBTR! 2.0 may be considered as an acceptable nomogram in Korean patients with low- to moderate-risk of in-breast recurrence. Before widespread use of this nomogram, the IBTR! 2.0 needs a larger validation study and continuous modification.

The Role of the CDH1 Promoter Hypermethylation in the Axillary Lymph Node Metastasis and Prognosis / 한국유방암학회지

PURPOSE: Hypermethylation of the tumor suppressor genes is frequently observed in the tumor development and progression. However, the correlation between the hypermethylation of the tumor suppressor genes, CDH1 and the axillary lymph node (ALN) metastasis is not fully elucidated. To verify the role of the CDH1 promoter hypermethylation in the ALN metastasis and prognosis, we compared the methylation status of the CDH1 genes in the primary lesion and the paired metastatic ALNs. METHODS: We selected a total of 122 paraffin-embedded specimens of the primary and paired metastatic lymph node from 61 breast cancer patients and analyzed the frequency of hypermethylation in the primary and metastatic lymph node using the methylation-specific polymerase chain reaction. In addition, the methylation status of CDH1 was analyzed with the clinicopathologic characteristics, the disease-free survival and disease-specific survival. RESULTS: The hypermethylation of CDH1 gene was identified in 54 (88.5%) of the 61 patients who had axillary metastasis. The hypermethylation status of the CDH1 gene was significantly increased in the metastatic ALNs compared with that in the primary tumors (60.7% vs. 45.9%, p<0.001). The hypermethylation status of the CDH1 genes in the metastatic ALNs was associated with a poor histologic grade (p=0.041) and the patients who had methylated tumor in the primary lesion showed worse disease-free survival than the patients who did not have methylated tumor (p=0.046). CONCLUSION: This study suggests that hypermethylation of the CDH1 gene may play a pivotal role in the metastasis of the axillary lymph node and the breast cancer recurrence.

Robotic Adrenalectomy Using a Lateral Transperitoneal Approach: Initial Experience of Fifteen Consecutive Cases / 대한내분비외과학회지

PURPOSE: In this study, we report on our initial experience using the da Vinci-S® robotic surgical system in performance of laparoscopic adrenalectomy. METHODS: Fifteen patients, 11 with left adrenal tumors and four with right adrenal tumors, underwent robotic adrenalectomies using the lateral transperitoneal approach with the da Vinci-S® surgical system at the Korea University Anam Hospital, Seoul, Korea, between October 2009 and May 2012. RESULTS: The mean age of the patients was 45.5 (22~61) years, and the mean body mass index was 23.81 (18.0~28.57) kg/m². Eleven left adrenalectomies, four for primary aldosteronisms, four for pheochromocytomas, two for primary adrenal Cushing's adenoma, and one for myelolipoma, and four right adrenalectomies, two for the primary adrenal Cushing's adenomas, one for pheochromocytoma, and one for primary aldosteronism, were performed robotically. There was no conversion to traditional laparoscopic or open surgery. The mean size of the tumor was 2.54 (1.0~5.5) cm. The mean operative time was 208.2 (120~320) minutes, and the mean console time was 127.6 (75~212) minutes. No major postoperative morbidity was observed, and the mean length of hospital stay was 5.86 days. CONCLUSION: We found that the robotic systems, with magnified stereoscopic three-dimensional vision, elimination of tremor, and the ability to articulate and rotate the instruments, were ideal surgical tools for operation of adrenal lesion. Robotic adrenalectomy may be a safe and effective alternative to traditional laparoscopic adrenalectomy.

Circulating Tumor Cells Detected by RT-PCR for CK-20 before Surgery Indicate Worse Prognostic Impact in Triple-Negative and HER2 Subtype Breast Cancer / 한국유방암학회지

PURPOSE: Circulating tumor cells (CTC) clearly correlate with unfavorable outcomes for patients with metastatic breast cancer, but the long-term prognostic implications of CTC for molecular subtypes of operable breast cancer are not yet known. We explored the relationships between previously established prognostic factors and CTC in operable breast cancer, and the significance of CTC by breast cancer molecular subtype. METHODS: We retrospectively evaluated 166 patients with operable breast cancer (stage I-IIIA) diagnosed from April 1997 to May 2003. CTC were detected using cytokeratin-20 (CK-20) mRNA expression in peripheral blood samples that were collected just prior to surgery under general anesthesia. Clinicopathological characteristics of the cancer were analyzed according to CTC status. Metastasis-free survival (MFS) and overall survival (OS) were analyzed according to CTC status and breast cancer molecular subtype. RESULTS: CK-20 mRNA-positive CTC was detected in 37 of 166 patients (22.3%) and was not correlated with any previous clinical factors in univariate analysis (p>0.05). After a median follow-up of 100 months, the patients with CK-20 mRNA-positive CTC had less favorable outcomes in terms of MFS and OS than those without detectable CTC (log-rank p<0.05). Among molecular subtypes of operable breast cancer, the patients with CK-20 mRNA-positive CTC had shorter MFS and OS in triple negative and human epidermal growth factor 2 (HER2) breast cancer subtype (log-rank, p<0.05). CONCLUSION: CK-20 mRNA-positive CTC may lend insight into tumor progression as a prognostic indicator especially in the triple negative and HER2 subtypes of operable breast cancer.

Circulating Tumor Cells Detected by RT-PCR for CK-20 before Surgery Indicate Worse Prognostic Impact in Triple-Negative and HER2 Subtype Breast Cancer / 한국유방암학회지

PURPOSE: Circulating tumor cells (CTC) clearly correlate with unfavorable outcomes for patients with metastatic breast cancer, but the long-term prognostic implications of CTC for molecular subtypes of operable breast cancer are not yet known. We explored the relationships between previously established prognostic factors and CTC in operable breast cancer, and the significance of CTC by breast cancer molecular subtype. METHODS: We retrospectively evaluated 166 patients with operable breast cancer (stage I-IIIA) diagnosed from April 1997 to May 2003. CTC were detected using cytokeratin-20 (CK-20) mRNA expression in peripheral blood samples that were collected just prior to surgery under general anesthesia. Clinicopathological characteristics of the cancer were analyzed according to CTC status. Metastasis-free survival (MFS) and overall survival (OS) were analyzed according to CTC status and breast cancer molecular subtype. RESULTS: CK-20 mRNA-positive CTC was detected in 37 of 166 patients (22.3%) and was not correlated with any previous clinical factors in univariate analysis (p>0.05). After a median follow-up of 100 months, the patients with CK-20 mRNA-positive CTC had less favorable outcomes in terms of MFS and OS than those without detectable CTC (log-rank p<0.05). Among molecular subtypes of operable breast cancer, the patients with CK-20 mRNA-positive CTC had shorter MFS and OS in triple negative and human epidermal growth factor 2 (HER2) breast cancer subtype (log-rank, p<0.05). CONCLUSION: CK-20 mRNA-positive CTC may lend insight into tumor progression as a prognostic indicator especially in the triple negative and HER2 subtypes of operable breast cancer.

D2-40, Podoplanin, and CD31 as a Prognostic Predictor in Invasive Ductal Carcinomas of the Breast / 한국유방암학회지

PURPOSE: Distant metastasis and recurrence are major prognostic factors associated with breast cancer. Both lymphovascular invasion (LVI) and blood vessel invasion (BVI) are important routes for metastasis to regional lymph nodes and for systemic metastasis. Despite the importance of vascular invasion as a prognostic factor, application of vascular invasion as a histopathological criterion is controversial. The aim of this study was to distinguish LVI from BVI in prognosis and recurrence of breast cancer using an endothelial subtype specific immunohistochemical stain (podoplanin, D2-40, and CD31). METHODS: Sections from 80 paraffin-embedded archival specimens of invasive breast cancer were stained for podoplanin, D2-40, or CD31 expression. Immunohistochemical staining results were correlated with clinicopathological features, such as tumor size, status of lymph node metastases, estrogen receptor status, progesterone receptor status, human epidermal growth factor receptor-2 expression, and recurrence. Patients with ductal carcinoma in situ and stage IV breast cancer were excluded. RESULTS: A significant correlation was found between D2-40 LVI positivity and lymph node metastasis (p=0.022). We found a significant correlation between D2-40 LVI positivity and recurrence of breast cancer (p=0.014). However, no significant correlation was found between BVI and recurrence. A poorer disease free survival was shown for D2-40 positive LVI (p=0.003). In a multivariate analysis, the presence of D2-40 LVI positivity revealed a significant association with decreased disease-free survival. CONCLUSION: D2-40 LVI positivity was a more prognostic predictor of breast cancer than BVI.

Prognostic Implications of MicroRNA-21 Overexpression in Invasive Ductal Carcinomas of the Breast / 한국유방암학회지

PURPOSE: Among more than 500 microRNAs, microRNA-21 (miR-21) is known to act as an oncogene. The aim of this study was to investigate the significance of miR-21 expression level in relation with clinicopathological factors and prognosis in breast cancer. METHODS: MicroRNA was extracted from cancer and normal breast tissue of 109 breast cancer patients who underwent surgery from 2002 to 2004 using the Taqman(R) MicroRNA Assay. The correlation between miR-21 expression and clinicopathologic features was analyzed and the significance of miR-21 as a prognostic factor and its relationship with survival was determined. RESULTS: MiR-21 expression was higher in cancer tissues than in normal tissues (p<0.0001). High miR-21 expression was associated with mastectomy, larger tumor size, higher stage, higher grade, estrogen receptor (ER) negative, human epidermal growth factor receptor 2 (HER2) positive, HER2 positive breast cancer subtype, high Ki-67 expression, and death. On multivariate analysis, prognostic factors for overall survival were ER and miR-21. High miR-21 expression was significantly related to lower overall survival (p=0.031). CONCLUSION: This study supports the role of miR-21 as an oncogene and a biomarker for breast cancer with its high expression in cancer tissues and its relationship with other prognostic factors and survival.