Comparison of robotic and laparoscopic lateral transperitoneal adrenalectomies

Purpose@#This study aimed to compare the intraoperative and postoperative outcomes between robotic and laparoscopic transperitoneal adrenalectomies. @*Methods@#In this retrospective study, 93 patients underwent adrenalectomy using 2 surgical modalities: 45 patients underwent adrenalectomy using the da Vinci Xi system (robotic group), and 48 patients using laparoscopic devices (laparoscopic group). We compared the operation time, intraoperative bleeding, and hospital stay according to the surgical modality and tumor characteristics. @*Results@#There were no significant differences in the operative time (P = 0.827), hospital stay (P = 0.177), and intraoperative bleeding (P = 0.174) between the groups. However, the robotic group showed a lower coefficient of variation in total operative time than that of the laparoscopic group (100.6 ± 23.3 minutes vs. 101.9±32.7 minutes, 0.230 vs. 0.321). When divided into 2 subgroups based on the tumor size (3 cm had a shorter operative time than that of the laparoscopic group (P = 0.032). The robotic group also had fewer cases of intraoperative bleeding (P = 0.034). @*Conclusions@#Compared to the laparoscopic transperitoneal adrenalectomy, the robotic one achieved a lower deviation in total operative time and showed less bleeding and a shorter operative time, especially for tumors sized >3 cm.

Comparison of Single Incision Endoscopic Nipple-Sparing Mastectomy and Conventional NippleSparing Mastectomy for Breast Cancer Based on Initial Experience / 한국유방암학회지

Purpose@#Endoscopic breast surgery for patients with breast cancer was introduced for its superior cosmetic outcomes; it was initially studied in the field of breast-conserving surgery and, more recently, in robotic-assisted nipple-sparing mastectomy (NSM). The main purpose of this study was to investigate the feasibility and safety of endoscopic NSM (E-NSM) in patients with breast cancer by comparing E-NSM and conventional NSM (C-NSM). @*Methods@#Between May 2017 and October 2020, we retrieved the records of 45 patients who underwent NSM with permanent silicone implants and divided them into the E-NSM group (20 patients) and the C-NSM group (25 patients), depending on the use of the endoscopic device.We also analyzed demographic information, pathology, operative time, and complications. @*Results@#No significant differences were observed between the 2 groups based on demographic information, postoperative pathological data, mean length of hospital stay, and total number of complications. The mean preparation time for surgery was comparable between both groups. Compared to the C-NSM group, the E-NSM group had a significantly longer mean operative time and, subsequently, a significantly longer mean total operative time and number of complications. @*Conclusion@#The results showed that E-NSM was feasible and safe with a more inconspicuous incision in patients with breast cancer.

Comparison of Single Incision Endoscopic Nipple-Sparing Mastectomy and Conventional NippleSparing Mastectomy for Breast Cancer Based on Initial Experience / 한국유방암학회지

Purpose@#Endoscopic breast surgery for patients with breast cancer was introduced for its superior cosmetic outcomes; it was initially studied in the field of breast-conserving surgery and, more recently, in robotic-assisted nipple-sparing mastectomy (NSM). The main purpose of this study was to investigate the feasibility and safety of endoscopic NSM (E-NSM) in patients with breast cancer by comparing E-NSM and conventional NSM (C-NSM). @*Methods@#Between May 2017 and October 2020, we retrieved the records of 45 patients who underwent NSM with permanent silicone implants and divided them into the E-NSM group (20 patients) and the C-NSM group (25 patients), depending on the use of the endoscopic device.We also analyzed demographic information, pathology, operative time, and complications. @*Results@#No significant differences were observed between the 2 groups based on demographic information, postoperative pathological data, mean length of hospital stay, and total number of complications. The mean preparation time for surgery was comparable between both groups. Compared to the C-NSM group, the E-NSM group had a significantly longer mean operative time and, subsequently, a significantly longer mean total operative time and number of complications. @*Conclusion@#The results showed that E-NSM was feasible and safe with a more inconspicuous incision in patients with breast cancer.

A Prospective Study on the Value of Ultrasound Microflow Assessment to Distinguish Malignant from Benign Solid Breast Masses: Association between Ultrasound Parameters and Histologic Microvessel Densities

OBJECTIVE: To investigate the value of ultrasound (US) microflow assessment in distinguishing malignant from benign solid breast masses as well as the association between US parameters and histologic microvessel density (MVD). MATERIALS AND METHODS: Ninety-eight breast masses (57 benign and 41 malignant) were examined using Superb Microvascular Imaging (SMI) and contrast-enhanced US (CEUS) before biopsy. Two radiologists evaluated the quantitative and qualitative vascular parameters on SMI (vascular index, morphology, distribution, and penetration) and CEUS (time-intensity curve analysis and enhancement characteristics). US parameters were compared between benign and malignant masses and the diagnostic performance was compared between SMI and CEUS. Subgroup analysis was performed according to lesion size. The effect of vascular parameters on downgrading Breast Imaging Reporting and Data System (BI-RADS) category 4A masses was evaluated. The association between histologic MVD and US parameters was analyzed. RESULTS: Malignant masses were associated with a higher vascular index (15.1 ± 7.3 vs. 5.9 ± 5.6), complex vessel morphology (82.9% vs. 42.1%), central vascularity (95.1% vs. 59.6%), penetrating vessels (80.5% vs. 31.6%) on SMI (all, p < 0.001), as well as higher peak intensity (37.1 ± 25.7 vs. 17.0 ± 15.8, p < 0.001), slope (10.6 ± 11.2 vs. 3.9 ± 4.2, p = 0.001), area (1035.7 ± 726.9 vs. 458.2 ± 410.2, p < 0.001), hyperenhancement (95.1% vs. 70.2%, p = 0.005), centripetal enhancement (70.7% vs. 45.6%, p = 0.023), penetrating vessels (65.9% vs. 22.8%, p < 0.001), and perfusion defects (31.7% vs. 3.5%, p < 0.001) on CEUS (p ≤ 0.023). The areas under the receiver operating characteristic curve (AUCs) of SMI and CEUS were 0.853 and 0.841, respectively (p = 0.803). In 19 masses measuring < 10 mm, central vascularity on SMI was associated with malignancy (100% vs. 38.5%, p = 0.018). Considering all benign SMI parameters on the BI-RADS assessment, unnecessary biopsies could be avoided in 12 category 4A masses with improved AUCs (0.500 vs. 0.605, p < 0.001). US vascular parameters associated with malignancy showed higher MVD (p ≤ 0.016). MVD was higher in malignant masses than in benign masses, and malignant masses negative for estrogen receptor or positive for Ki67 had higher MVD (p < 0.05). CONCLUSION: US microflow assessment using SMI and CEUS is valuable in distinguishing malignant from benign solid breast masses, and US vascular parameters are associated with histologic MVD.

Extent of central lymph node dissection for papillary thyroid carcinoma in the isthmus

PURPOSE: The incidence of papillary thyroid carcinoma (PTC) arising from the isthmus is low; however, these tumors have aggressive clinical and pathological features. Moreover, the existing guidelines regarding the extent of surgery for this type of tumor are unclear. METHODS: This study enrolled 282 patients who underwent total thyroidectomy with bilateral central lymph node dissection. The patients were divided into 2 groups based on the location of the median line of the PTC. Group I included patients in whom the median line was located between the lateral margins of the trachea; group II included all others. We compared the 2 groups and conducted a multivariate analysis to assess risk factors for contralateral node metastasis from a PTC arising from the isthmus. RESULTS: Patients in group I had significantly higher frequencies of extrathyroidal extension and central lymph node metastasis. Group I also had a higher frequency of contralateral node metastasis, and a tumor size >1.0 cm was identified as an independent risk factor for contralateral node metastasis among patients in this group. CONCLUSION: Bilateral central lymph node dissection could be considered for patients with isthmic PTCs >1.0 cm in size who have clinically suspicious node metastasis.

Clinical features of recently diagnosed papillary thyroid carcinoma in elderly patients aged 65 and older based on 10 years of sonographic experience at a single institution in Korea

PURPOSE: The aim of this study was to assess the characteristics of papillary thyroid carcinoma (PTC) in patients aged 65 and older in order to predict postoperative recurrence based on the results of ultrasonographic surveillance. METHODS: Among 1,494 patients (200 male and 1,294 female; mean age, 46.6±11.3 years) who underwent surgery for thyroid cancer at our institution between 2006 and 2015, we retrospectively enrolled 150 PTC patients (29 male and 121 female; mean age, 69.4±4.2 years). To identify the risk factors for recurrence, we analyzed age, gender, multiplicity, size, number, extrathyroidal extension (ETE) of the tumor, lymph node metastasis (LNM), type of surgery, and the dose of radioactive ablation using a Cox regression model to identify hazard ratios (HRs). RESULTS: Among the 115 asymptomatic patients with PTCs detected by screening ultrasonography (n=86), other cross-sectional imaging modalities (computed tomography or positron emission tomography-computed tomography, n=13), or incidentally through a surgical specimen (n=16), 78 patients were confirmed to have papillary thyroid microcarcinomas (PTMCs). The other 35 patients presented with palpable neck masses (n=25), vocal cord palsy (n=9) or blood-tinged sputum (n=1). During the follow-up period (mean, 43.6 months), 17 patients (12.5%) experienced recurrence in the neck. None of the patients died due to PTC-related recurrence or distant metastasis during the follow-up period. Cox regression analysis demonstrated that tumor size (HR, 2.12; P<0.001) and LNM (central LNM: HR, 9.08; P=0.004; lateral LNM: HR, 14.71; P=0.002; both central and lateral LNM: HR, 58.41; P<0.001) significantly increased the recurrence rate. ETE, LNM, and recurrence were significantly less frequent in PTMCs than in non-PTMC (all P<0.001). CONCLUSION: PTCs of small size and absent LNM showed significantly better prognoses in patients 65 years and older.

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.

Fulminant course in a case of malignant phyllodes tumor

We present the case of a 31-year-old woman with an inflammatory and ulcerative malignant phyllodes tumor in her right breast. A right modified radical mastectomy and transverse rectus abdominis myocutaneous (TRAM) flap were performed. A month after the initial operation, several masses recurred at the superior margin and deep margin of the TRAM flap. Wide excision was performed, but masses recurred at the inferior margin and in both lung fields 2 weeks after the second operation. Six weeks after the second operation, the patient died due to progression of dyspnea and respiratory failure.

Invasive Lobular Carcinoma Mimicking Fat Necrosis in Breast: A Case Report

Invasive lobular carcinoma is the second most common breast malignancy. Mammographic finding of invasive lobular carcinoma is often subtle or negative due to its histological feature showing infiltration of tumor cells into surrounding tissue with scanty fibrotic reaction. Thus, ultrasound plays an important role in detection of invasive lobular carcinoma. We report here on our experience with a 70-year-old female who had invasive lobular carcinoma of the breast with unique ultrasound findings; a mixed hyper- and hypoechoic mass at the fatty layer mimicking fat necrosis.

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.

Lymphoma Affecting the Breast: A Pictorial Review of Multimodal Imaging Findings / 한국유방암학회지

Hematological malignancies rarely affect the breast, and the majority of those that do are lymphomas. In this review, we describe the clinical aspects and multimodal imaging findings of breast lymphoma. We also illustrate the key clinical and radiological findings that allow it to be distinguished from various other malignant and benign diseases of the breast. Breast lymphoma manifests as a breast mass, a change in the subcutaneous tissue or the skin, or enlargement of the associated lymph node on radiological examination. Radiological findings associated with other breast malignancies, such as calcifications, spiculations, or architectural distortions are extremely rare. Skin and subcutaneous changes frequently accompany T-cell lymphoma. Multimodal breast imaging characteristics may aid in the diagnosis of breast lymphoma.

Non-amputative Surgical Management of Subungal Melanoma in Situ / 대한피부과학회지

Subungual melanoma is a variant of acral lentiginous melanoma and is thought to carry a poor prognosis due to difficulties in early diagnosis. Classical management of subungual melanoma is based on the radical surgery of distal phalanx amputation. Instead, conservative treatment with non-amputative wide excision of the nail unit followed by reconstruction has been insufficiently reported, especially in Korea. A 71-year-old woman presented with dark brownish longitudinal bands on her right thumbnail. Punch biopsies from the nail matrix and nail bed showed proliferation of atypical melanocytes without dermal involvement. We describe a case of subungual melanoma in situ of the right thumb, and a non-amputative surgical management which aims to provide adequate clearance of the lesion with minimal morbidity and satisfactory preservation of function for the patient.

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.

The Anatomical Variations of DIEA (Deep Inferior Epigastric Artery) in Microsurgical Breast Reconstruction: Clinical Report

Autologous breast reconstruction after mastectomy in breast cancer patient is now increasing. The deep inferior epigastric artery (DIEA) free flap is well known as an ideal donor site for the microsurgical breast reconstruction. The branching pattern of the DIEA was well described in the literature. In that study, DIEA has three branching patterns near the arcuate line. We describe a case in which branching variation of the DIEA before entering the posterior surface of the rectus abdominis muscle. In three cases, DIEA originated from the external iliac artery ascended as a double trunk at 1cm, 2cm, and 4cm above the originating point, respectively. In one case, DIEA ascended as a single trunk along the linea alba toward to the umbilicus until it supply overlying subcutaneous tissue. Preoperative 3D computed tomographic angiography to identify the anomaly is recommended and meticulous dissection to the originating point of DIEA is needed.

Characterization of Cystic Breast Masses on Ultrasound: Comparative Study among Conventional, Tissue Harmonic, Compound, and a Combination of Tissue Harmonic and Compound Imaging

PURPOSE: This prospective study was to compare the image quality and diagnostic performance of breast cystic masses by conventional and advanced ultrasound (US) techniques including tissue harmonic, compound, and the combination of these techniques. MATERIALS AND METHODS: All 91 patients, collectively having 109 breast cystic masses were scanned using four US techniques (complicated cysts in 36, septated cysts in 33, and complex cysts in 40). Two breast radiologists independently assessed the image quality and possibility of malignancy. Image quality was evaluated in terms of contrast and clarity of the wall and internal echo pattern and then graded on a scale of 1 (poor) to grade 3 (satisfactory). The possibility of malignancy was graded on a scale of 1 (suggestive of benignancy) to 5 (suggestive of malignancy) using US images. The histopathological results and follow-up images were used as the reference standard for the assessment of diagnostic performance. Results were evaluated by Friedman's test and receiver operating characteristic (ROC) analyses. RESULTS: In terms of image quality, a grade of 3 was significantly more frequent in the three advanced US techniques than conventional US (p < 0.05). For assessment of diagnostic performance, areas under the ROC curves in three advanced techniques were significantly higher than in conventional US (p < 0.05). CONCLUSION: Advanced US techniques including compound and tissue harmonic US techniques provide a better image quality in breast cystic masses and also improve the diagnostic performance compared with conventional US.

The Clinical Outcome of Flap Coverage for the Treatment of Malignant Melanoma

In surgical treatment of the malignant melanoma, radical resection and a sentinel lymph node biopsy are essential procedures to eradicate the tumor and to minimize the risk of local recurrence. For the reconstruction of skin defect after tumor resection, a skin graft has been generally performed procedure. However, if tendon or bone is exposed after tumor resection, simple skin graft is not enough for the coverage of the defect and additional procedure is mandatory. In this study, we reviewed the clinical results of 16 patients, who had been diagnosed with malignant melanoma of the limb and underwent surgical resection and reconstruction of the defect with various methods. The sentinel lymph node dissection was performed in all patients combined with radical excision of the tumor. In 11 cases of positive sentinel lymph nodes, further elective lymph node dissections were performed. The mean tumor invasion depth was 4.54 mm (2~10 mm), and AJCC stage II was most common (9 cases). The pedicled flaps were performed in 10 cases for the reconstruction of defects. All flaps were successfully survived without significant complications until the last follow up. In conclusion, a pedicled flap coverage is very useful reconstruction strategy for the soft tissue defects after radical resection of malignant melanoma.

Preoperative Thyroid-stimulating Hormone Levels as a Predictor of Thyroid Carcinoma / 대한내분비외과학회지

PURPOSE: This study investigated the effects of serum thyroid-stimulating hormone (TSH) levels in predicting malignancy-associated differentiated thyroid cancer (DTC) and benign thyroid nodules. METHODS: Between January 2005 and December 2007, 346 patients underwent thyroid surgery at one hospital. Their records were retrospectively reviewed. RESULTS: Sixty-nine percent (237 of 346) of the patients had DTC. The mean preoperative TSH level was higher than in the malignant group (5 uIU/ml vs 0.4 uIU/ml). The rate of malignancy was the 71% in patients with TSH levels >5 uIU/ml. The TSH level of DTC with metastasis of the lymph node was higher than that with non-metastasis (3.08 uIU/ml vs 2.09 uIU/ml, P<0.01) CONCLUSION: The likelihood of DTC increases with higher serum TSH concentration. Serum TSH level might be useful in predicting malignant nodular thyroid lesion.

A Study Regarding Predictive Factors for Malignancy of Papillary Lesions on Core Needle Biopsy of the Breast / 한국유방암학회지

PURPOSE: Diagnosing benign or malignant papillary lesions of the breast through core needle biopsy (CNB) is often difficult. The purpose of this study was to identify the predictive factors of malignancy. METHODS: We retrospectively reviewed the pathology database and found 80 consecutive patients who had been diagnosed with breast papillary lesions prior to surgery at two medical centers from May 2004 through May 2009. Those patients who had undergone CNB and had been diagnosed with either intraductal papilloma or malignant lesions following surgical excision were included. RESULTS: Forty-five cases were diagnosed as intraductal papilloma and 24 cases as malignant lesions. Malignancy was found to be related to being older than 60 years (p<0.01), having bloody nipple discharge (p=0.05), and a tumor size of more than 1 cm (p<0.01). Further, irregular shape (p<0.01) and uncircumscribed margin (p<0.01) on mammogram and irregular shape (p=0.04), calcification (p<0.01), and isoechoic pattern (p<0.01) on ultrasonogram were significantly related to malignancy. CONCLUSION: Our study revealed that particular clinical factors and imaging findings correlated with malignant lesions. However, larger prospective studies are still necessary to establish treatment plans for patients diagnosed with papillary lesions on CNB.

The Clinical Use of Low-Dose Multidetector Row Computed Tomography for Breast Cancer Patients in the Prone Position / 한국유방암학회지

PURPOSE: To investigate the clinical use of low-dose multidetector row computed tomography (MDCT) for staging of invasive breast cancers with patients in the prone position. METHODS: Three hundred twenty-two patients with 334 pathologically-verified breast cancers had low-dose MDCT breast imaging in the prone position for tumor staging before treatment between May 2006 and June 2010. We designed an additional computed tomography table pad with a hole for prone positioning. Patients lay prone on the table pad and the breasts were positioned within the rectangular hole. We obtained dynamic breast imaging from the lower neck to the lung base with the following parameters: 120 kVp, 50 mAs, and 3-mm reconstruction intervals. We evaluated the extent of the primary tumor, lymph nodal status, and distant metastasis in lung or bone, then assessed tumor staging based on the TNM classification of breast cancer. The assessed staging compared to the pathologic results for diagnostic accuracy. RESULTS: Among the 334 invasive breast cancers, the overall diagnostic accuracy of tumor staging was 88.3% and the accuracy values of each tumor stage were 89.6% in T1, 90.8% in T2, 81.0% in T3, and 89.3% in T4. The overall diagnostic accuracy of lymph nodal staging was 86.3% and the accuracy values in each nodal stage were 82.9% in N0, 88.0% in N1, 89.7% in N2, and 93.3% in N3. Based on breast computed tomography scans, we detected distant metastases in 30 cases (7 lungs, 10 bones, 7 lungs and bones, and 6 livers). CONCLUSION: Low-dose MDCT scanning for invasive breast cancer patients in the prone position is a feasible imaging technique for tumor staging before treatment to evaluate primary breast tumors, lymph nodes, lungs, or thoracic bones with reduced radiation doses.

Cancer Vaccines Targeting HER2/neu for Early Breast Cancer / 한국유방암학회지

Recent studies of immune responses to pathogens have identified pathogen-associated molecular patterns recognized by the innate immune system through specialized receptors called toll-like receptors (TLRs). Signaling through these receptors initiates robust immune responses. By exploiting TLR signaling pathways, immunity to tumor-associated antigens may be generated. Many tumor-associated antigens are involved in the regulation of tumor phenotype or carcinogenesis. Immune targeting of these antigens may either alter the tumor phenotype, yielding a more treatable tumor, or eradicate early tumor stem cells preventing tumor formation. The oncoprotein HER2/neu, which is often overexpressed in ductal carcinoma in situ (DCIS), may provide such a target. Immune responses directed against HER2/neu may eliminate the disease, make tumors more amenable to anti-estrogen therapy, or prevent escape of hormone-resistant tumor phenotypes. Effective breast cancer prevention in preclinical studies utilizing murine HER2/neu transgenic models has stimulated interest in, and optimism regarding, protective breast cancer vaccines in humans. Induction of anti-HER2 neu T cell (CD4+ and CD8+) and B cell responses has been demonstrated in an ongoing clinical study targeting HER2/neu using a TLR agonist-primed dendritic cell vaccine. Moreover, these vaccinations lead to reductions in both HER2/neu expression and extent of DCIS. HER2/neu expression and aromatase activity have recently been linked through the intermediary cyclooxygenase 2 (COX-2). This convergence between growth factor and hormone mediated pathways provides additional support for the notion that a significant number of breast cancers may be prevented through effective immune targeting of HER2/neu. As progress is made towards the development of vaccines for breast cancer prevention, the contributions of immune-mediated effecter and inhibitory mechanisms to the pathogenesis of HER2/neu overexpressing breast cancer will need to be better understood.