Tumour cell displacement after 14G breast biopsy

Breast fine-needle aspiration cytology in the era of core-needle biopsy: what is its role?

Fine-needle aspiration cytology (FNAC) has long been recognized as a minimally invasive, cost-effective, and reliable diagnostic tool for breast lesions. However, with the advent of core-needle biopsy (CNB), the role of FNAC has diminished in some clinical settings. This review aims to re-evaluate the diagnostic value of FNAC in the current era, focusing on its complementary use alongside CNB, the adoption of new approaches such as the International Academy of Cytology Yokohama System, and the implementation of rapid on-site evaluation to reduce inadequate sample rates. Advances in liquid-based cytology, receptor expression testing, molecular diagnostics, and artificial intelligence are discussed, highlighting their potential to enhance the diagnostic accuracy of FNAC. Despite challenges, FNAC remains a valuable diagnostic method, particularly in low-resource settings and specific clinical scenarios, and its role continues to evolve with technology.

Minimally invasive biopsy-based diagnostics in support of precision cancer medicine

Precision cancer medicine (PCM) to support the treatment of solid tumors requires minimally invasive diagnostics. Here, we describe the development of fine-needle aspiration biopsy-based (FNA) molecular cytology which will be increasingly important in diagnostics and adaptive treatment. We provide support for FNA-based molecular cytology having a significant potential to replace core needle biopsy (CNB) as a patient-friendly potent technique for tumor sampling for various tumor types. This is not only because CNB is a more traumatic procedure and may be associated with more complications compared to FNA-based sampling, but also due to the recently developed molecular methods used with FNA. Recent studies show that image-guided FNA in combination with ultrasensitive molecular methods also offers opportunities for characterization of the tumor microenvironment which can aid therapeutic decisions. Here we provide arguments for an increased implementation of molecular FNA-based sampling as a patient-friendly diagnostic method, which may, due to its repeatability, facilitate regular sampling that is needed during different treatment lines, to provide tumor information, supporting treatment decisions, shortening lead times in healthcare, and benefit healthcare economics.

Sustained delivery of celecoxib from nanoparticles embedded in hydrogel injected into the biopsy cavity to prevent biopsy-induced breast cancer metastasis

PURPOSE

We have previously reported that protracted Cyclooxygenase-2 (COX-2) activity in bone marrow-derived cells (BMDCs) infiltrating into biopsy wounds adjacent to the biopsy cavity of breast tumors in mice promotes M2-shift of macrophages and pro-metastatic changes in cancer cells, effects which were suppressed by oral administration of COX-2 inhibitors. Thus, local control of COX-2 activity in the biopsy wound may mitigate biopsy-induced pro-metastatic changes.

METHODS

A combinatorial delivery system-thermosensitive biodegradable poly(lactic acid) hydrogel (PLA-gel) incorporating celecoxib-encapsulated poly(lactic-co-glycolic acid) nanoparticles (Cx-NP/PLA-gel)-was injected into the biopsy cavity of Py230 murine breast tumors to achieve local control of COX-2 activity in the wound stroma.

RESULTS

A single intra-biopsy cavity injection of PLA-gel loaded with rhodamine-encapsulated nanoparticles (NPs) showed sustained local delivery of rhodamine preferentially to infiltrating BMDCs with minimal to no rhodamine uptake by the reticuloendothelial organs in mice. Moreover, significant reductions in M2-like macrophage density, cancer cell epithelial-to-mesenchymal transition, and blood vessel density were observed in response to a single intra-biopsy cavity injection of Cx-NP/PLA-gel compared to PLA-gel loaded with NPs containing no payload. Accordingly, intra-biopsy cavity injection of Cx-NP/PLA-gel led to significantly fewer metastatic cells in the lungs than control-treated mice.

CONCLUSION

This study provides evidence for the feasibility of sustained, local delivery of payload preferential to BMDCs in the wound stroma adjacent to the biopsy cavity using a combinatorial delivery system to reduce localized inflammation and effectively mitigate breast cancer cell dissemination.

Reducing the Risk of Needle Tract Seeding or Tumor Cell Dissemination during Needle Biopsy Procedures

PURPOSE

Many women fear that breast needle biopsies increase the risk of cancer spread. The purpose of this review article is to discuss the breast cancer literature regarding the risk of needle-biopsy-induced cancer cell displacement and its impact on local and regional recurrence and breast cancer survival.

METHODS

A literature review is performed to discuss the risks and mitigation of needle-biopsy-induced cancer cell displacement.

RESULTS

Needle-biopsy-induced cancer cell displacement is a common event. The risk is influenced by the biopsy technique and the breast cancer type. Evidence suggests that the risk of needle-biopsy-induced cancer cell displacement may potentially increase the odds of local recurrence but has no impact on regional recurrence and long-term survival.

CONCLUSIONS

Technical modifications of needle biopsy procedures can reduce the risk of breast needle-biopsy-induced cancer cell displacement and potentially reduce the risk of local recurrence, especially in patients for whom whole breast radiation is to be omitted.

Needle biopsy accelerates pro-metastatic changes and systemic dissemination in breast cancer: Implications for mortality by surgery delay

Increased breast cancer (BC) mortality risk posed by delayed surgical resection of tumor after diagnosis is a growing concern, yet the underlying mechanisms remain unknown. Our cohort analyses of early-stage BC patients reveal the emergence of a significantly rising mortality risk when the biopsy-to-surgery interval was extended beyond 53 days. Additionally, histology of post-biopsy tumors shows prolonged retention of a metastasis-permissive wound stroma dominated by M2-like macrophages capable of promoting cancer cell epithelial-to-mesenchymal transition and angiogenesis. We show that needle biopsy promotes systemic dissemination of cancer cells through a mechanism of sustained activation of the COX-2/PGE2/EP2 feedforward loop, which favors M2 polarization and its associated pro-metastatic changes but are abrogated by oral treatment with COX-2 or EP2 inhibitors in estrogen-receptor-positive (ER+) syngeneic mouse tumor models. Therefore, we conclude that needle biopsy of ER+ BC provokes progressive pro-metastatic changes, which may explain the mortality risk posed by surgery delay after diagnosis.

Increased breast cancer mortality due to treatment delay and needle biopsy type: a retrospective analysis of SEER-medicare

BACKGROUND

Substantial evidence indicates that delay of first treatment after diagnosis is associated with poorer survival outcomes in breast cancer. Accordingly, the Commission on Cancer introduced a quality measure for receipt of therapeutic surgery within 60 days of diagnostic biopsy for stage I-III breast cancer patients in the non-neoadjuvant setting. It is unknown, however, what may contribute to mortality associated with treatment delay. Therefore, we investigated whether biopsy type moderates the effect of the mortality risk posed by treatment delay.

METHODS

Retrospective analysis of 31,306 women with stage I-III breast cancer diagnosed between 2003 and 2013 selected from the SEER-Medicare database was performed to determine whether needle biopsy type [core needle biopsy (CNB) or vacuum-assisted biopsy (VAB)] impacts time to treatment (TTT)-associated survival outcomes. Multivariable Fine-Gray competing risk survival models, adjusted for inverse propensity score weights, were used to determine the association between biopsy type, TTT, and breast cancer-specific mortality (BCSM).

RESULTS

TTT ≥ 60 days was associated with 45% higher risk of BCSM (sHR = 1.45, 95% CI 1.24-1.69) compared to those with TTT < 60 days in stage I-III cases. Independent of TTT, CNB was associated with 28% higher risk of BCSM compared to VAB in stage II-III cases (sHR = 1.28, 95% CI 1.11-1.36), translating to a 2.7% and 4.0% absolute difference in BCSM at 5 and 10 years, respectively. However, in stage I cases, the BCSM risk was not associated with type of biopsy.

CONCLUSIONS

Our results suggest that treatment delay ≥ 60 days is independently associated with poorer survival outcomes in breast cancer patients. In stage II-III, CNB is associated with higher BCSM than VAB. However, type of biopsy does not underlie TTT-associated breast cancer mortality risk.

Local recurrence of breast cancer histologically resembling Paget disease presumably due to needle tract seeding: a case report

Seeding of cancer cells along the needle tract during core needle biopsy is a well-known phenomenon, with a reported frequency of between 22 and 50% [Hoorntje et al. in Eur J Surg Oncol 30:520-525, 2004;Liebens et al. in Maturitas 62:113-123, 2009;Diaz et al. in AJR Am J Roentgenol 173:1303-1313, 1999;]. Local recurrence due to needle tract seeding is rare because the immune system eliminates the cancer cells in most cases. In addition, most local recurrences due to needle tract seeding occur as invasive carcinoma after diagnosis of invasive ductal carcinoma of the breast or mucinous carcinoma, and needle tract seeding due to noninvasive carcinoma is uncommon. We herein report a rare case of local breast cancer recurrence histologically resembling Paget disease, presumably due to needle tract seeding after core needle biopsy for diagnosis of ductal carcinoma in situ of the breast. After receiving a diagnosis of ductal carcinoma in situ, the patient underwent skin-sparing mastectomy and breast reconstruction with a latissimus dorsi musculocutaneous flap. The pathological study showed ER/PgR-negative ductal carcinoma in situ, and no postoperative radiation therapy or systemic therapy was administered. Six months after the surgery, the patient had a breast cancer recurrence histologically resembling Paget disease, presumably in the scar of her core needle biopsy. The pathological study showed Paget disease localized in the epidermis, no invasive carcinoma, and no lymph node metastasis. It was morphologically similar to the primary lesion and was diagnosed as a local recurrence due to needle tract seeding.

Survival Outcomes of Patients With Breast Cancer Diagnosed Using Vacuum-Assisted Biopsy: A Nationwide Study From the Korean Breast Cancer Society

PURPOSE

Breast cancer is mainly diagnosed using core needle biopsy (CNB), although other biopsy methods, including vacuum-assisted biopsy (VAB), may also be used. We compared differences in clinical characteristics and prognoses of patients with breast cancer according to biopsy methods used for diagnosis.

METHODS

A total of 98,457 patients who underwent various biopsy methods (CNB, fine-needle aspiration [FNA], VAB, and excisional biopsy) for diagnosing breast cancer were recruited. Using CNB as a reference, related clinicopathological factors and prognostic differences between biopsy methods were analyzed retrospectively using large-scale data from the Korean Breast Cancer Society Registration System. The associations between biopsy methods and clinicopathological factors were compared using multinomial logistic regression analysis, and the prognoses of patients undergoing the different biopsy methods, as breast cancer-specific survival (BCSS) and overall survival (OS), were compared using the Kaplan-Meier method and Cox proportional hazard model.

RESULTS

Univariate and multivariate analyses showed that unlike FNA, both VAB and excisional biopsy were significantly associated with tumor size, palpability, tumor stage, and histologic grade as relatively good prognostic factors compared to CNB. In particular, VAB showed lower odds ratios for these factors than excisional biopsy. In the univariate analysis, the prognosis of patients undergoing VAB was better than that of those undergoing CNB with respect to BCSS (hazard ratio [HR], 0.188, p < 0.001) and OS (HR, 0.359; p < 0.001). However, in the multivariate analysis, there were no significant prognostic differences from CNB in both BCSS and OS; differences were only evident for FNA.

CONCLUSION

In this study, we showed that the characteristics of breast cancer differed according to various biopsy methods. Although VAB is not a standard method for breast cancer diagnosis, it showed no prognostic differences to CNB.

The significance of biopsy scar excision at the time of skin- or nipple-sparing mastectomy with immediate breast reconstruction

BACKGROUND

Neoplastic seeding (NS) can occur after tissue biopsy, which is a clinical issue especially in mastectomy with immediate reconstruction. This is because postoperative radiation is not usually given and local recurrence of preserved skin flap may increase. The purpose of this study is to investigate the importance of preoperative evaluation of NS and the validity of biopsy scar excision.

PATIENTS AND METHODS

We retrospectively analysed 174 cases of mastectomy with immediate breast reconstruction. The primary endpoint is the frequency of clinical and pathological NS and the secondary endpoint is the problem of excision of needle biopsy site.

RESULTS

Three cases (1.7%) had preoperative clinical findings of NS. Pathological examination revealed NS in all three cases. Biopsy scars could be excised in 115 cases among 171 cases without clinical NS. Pathological NS was found in 1 of 66 (1.5%) cases of which pathological examination was performed. Biopsy scars could not be excised in the remaining 56 cases: the biopsy scar could not be identified in 41 cases, and there was concern about a decrease in flap blood flow after excision in 15 cases. In 12 of these 15 cases, the scars were close to the skin incision; excision of these scars might have triggered skin necrosis between the incision and the biopsy scar excision site. No postoperative complications were observed.

CONCLUSIONS

It is important to preoperatively evaluate clinical NS, and biopsy scars should be excised in clinical NS cases. Even in cases without clinical NS, biopsy scar excision should be considered. It is also important to perform a biopsy in consideration of the incision design for reconstructive surgery.

MRI Diagnosis of Needle Tract Tumor Seeding Following Core Biopsy of Mucinous Carcinoma of the Breast

Displacement or seeding of malignant cells into the needle tract following percutaneous biopsy is a known phenomenon, although it does not affect disease recurrence or overall survival of patients with breast cancer. It has, however, been previously hypothesized that needle tract seeding may occasionally progress to clinical tumor recurrence, and there have been case reports of breast cancer recurrence that are likely to be related to needle tract seeding. We are presenting a case of invasive mucinous carcinoma of the breast with associated malignant cell seeding within the biopsy tract, which was diagnosed preoperatively on contrast-enhanced MR imaging. A needle tract can often be visualized on contrast-enhanced MRI post biopsy and these changes may reflect tissue damage and regeneration only. In our case, an unusual nodular enhancement pattern was demonstrated along the biopsy needle tract, which was consistent with the histopathological finding of tumor seeding.

Application of preoperative computed tomographic lymphography for precise sentinel lymph node biopsy in breast cancer patients

Background

In light of the extensive application of sentinel lymph node biopsy (SLNB) in clinically node-negative breast cancer patients and the recently investigated failure of SLNB after lumpectomy, it has become important to explore methods for preoperative mapping of sentinel lymph nodes (SLNs) and their lymphatics to direct precise SLNB and improve the identification rate of SLNs.

Methods

Twenty-seven patients with suspected breast cancer based on the results of the clinical examination and imaging were enrolled in the study. Computed tomographic lymphography (CTLG) followed by CT three-dimensional reconstruction was performed to determine the localization of SLNs and lymphatics on the body surface preoperatively. Intraoperatively combined staining with methylene blue and indocyanine green was used to evaluate the accuracy and feasibility of CTLG.

Results

SLNs and lymphatics from the breast were identified using CTLG in all patients, and preoperative SLNs and lymphatics localization on the body surface showed a significant role in the selection of operative incision and injection points. The accuracy rate of SLN and lymphatic detection by CTLG was 92.6% compared with intraoperatively combined staining. Moreover, preoperative CTLG performed well in SLN number detection, and the accuracy rate was 95.2%.

Conclusion

We evaluate the procedure and application of preoperative CTLG in the superficial localization of SLNs and lymphatics, which may lead to a decreased incidence of cutting off the lymphatics of SLNs and consequently more rapid and accurate SLN detection. This method promotes personalized SLN mapping, providing detailed information about the number and anatomical location of SLNs and lymphatics for adequate surgical planning for breast cancer patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01190-7.

The influence of preoperative biopsy on the surgical method in breast cancer patients: a single-center experience of 3,966 cases in China

Background

The National Surgical Adjuvant Breast and Bowel Project (NSABP) B32 trial reported that the detection rate of sentinel lymph nodes by core needle biopsy (CNB) is higher than that by segmental resection. However, there are few reports regarding the detection rate of sentinel lymph nodes by vacuum-assisted breast biopsy (VABB). Therefore, we analyzed the impact of preoperative biopsy methods on the surgical modes of 3,966 patients with breast cancer in our center.

Methods

In total, 3,966 female breast cancer patients [clinical tumor node metastasis (TNM) stage I-III] were enrolled in this study. Preoperative pathological diagnosis methods included fine needle aspiration (FNA) biopsy, CNB, excision biopsy, and VABB. According to the time of diagnosis. The data were analysis by chi square test, variance analysis and the Kaplan-Meier time series in SPSS 22.0.

Results

There was a decrease in the number of patients that underwent excision biopsy (7.3% to 2.7%) and intraoperative freezing (89.4% to 28.9%) over time, while CNB exhibited an increasing trend (1.6% to 55.3%). The positive rates of VABB, CNB, excision biopsy, and FNA were 99.5%, 97.1%, 97.9%, and 82.2%, respectively, and the false negative rates were 0%, 1.8%, 0.34%, and 8.9%, respectively. The overall breast-conserving rate was 36.7%, while the breast-conserving rate for VABB was 57.1%. The axillary sentinel lymph node biopsy rate of cN0 patients was 48.3%, and the intraoperative frozen group (36.7%) and excision biopsy group (39.5%) were lower than the CNB (57.1%) and VABB (77.9%) groups. Until December 2019, there were 350 cases with tumor recurrence or metastasis. The methods of biopsy were not correlated to the cumulative survival time.

Conclusions

Changes to the diagnosis and treatment of breast cancer has a profound impact on the method of tumor biopsy. VABB biopsy offers advantages such as accurate diagnosis, a greater volume of tissue taken at one time, minimally invasive and repeatable, and does not affect the surgical approach and prognosis of patients. It will gradually become the primary method of preoperative pathological evaluation of breast cancer.

The association between methods of biopsy and survival following breast cancer: A hospital registry based cohort study

Percutaneous biopsy in breast cancer has been associated with an increased risk of malignant cell seeding. However, the importance of these observations remains obscure due to lack of corroborating evidence from clinical studies. We determined whether method of biopsy is associated with breast cancer survival. This hospital registry-based cohort study included 3416 non-metastatic breast cancer patients diagnosed from 1993 to 2011 in a tertiary setting. Factors associated with biopsy methods were assessed. Multivariable Cox regression analysis was used to determine the independent prognostic impact of method of biopsy. Overall, 990 patients were diagnosed by core needle biopsy (CNB), 1364 by fine needle aspiration cytology (FNAC), and 1062 by excision biopsy. Excision biopsy was significantly associated with more favorable tumor characteristics. Radiotherapy modified the prognostic impact of biopsy method (Pinteraction < .001). Following multivariable analysis, excision biopsy was consistently associated with lower risk of mortality compared to FNAC in women receiving adjuvant radiotherapy (adjusted hazard ratio: 0.81, 95%CI: 0.66-0.99), but not in those who did not receive adjuvant radiotherapy (adjusted hazard ratio: 0.87, 95%CI: 0.65-1.17). While the risk of mortality was not different between patients undergoing FNAC and CNB when radiotherapy is administered, in the absence of radiotherapy, CNB was associated with higher risk of mortality than FNAC (adjusted hazard ratio: 1.57, 95%CI: 1.16-2.12). Given that our results contradict with findings of previous clinical studies assessing the prognostic impact of method of biopsy in women with breast cancer, further studies are warranted.

Breast cancer neoplastic seeding in the setting of image-guided needle biopsies of the breast

PURPOSE

To identify clinicopathologic, technical, and imaging features associated with neoplastic seeding (NS) following image-guided needle breast biopsy.

METHODS

We performed an institutional review board-approved retrospective review of patients presenting with a new diagnosis of breast cancer or suspicious breast findings requiring biopsy with subsequent diagnosis of NS. The time from biopsy to NS diagnosis was calculated. Histology, grade, estrogen receptor (ER) status, progesterone receptor (PR) status, HER2 status, T category, and N category were recorded. Biopsy guidance method, needle gauge, and number of passes were reviewed in addition to the mammographic and sonographic features of the primary tumors and the NS.

RESULTS

Eight cases of NS were identified in 4010 patients. The mean time from biopsy to NS diagnosis was 60.8 days. The most frequent histology was invasive ductal carcinoma (7/8). Six cases were grade 3 (75.0%). Five primary breast cancers were ER, PR, and HER2 negative (62.5%). Seven patients underwent biopsy with ultrasound guidance. Multiple-insertion, non-coaxial ultrasound-guided core-needle biopsy was done in 6 cases. Mammographic presentation of NS was focal asymmetry (3/7 cases), mass (1/7), calcifications only (1/7), or occult (2/7). Sonographic presentation of NS was most often a mass (7/8) with irregular shape (5/7) and without circumscribed margins (6/7) and was occult in 1 case (1/8). NS distribution was subdermal and intradermal.

CONCLUSION

High-grade, triple-negative breast cancers and multiple-insertion, non-coaxial biopsies may be risk factors for NS. NS should be suspected on the basis of the superficial and linear pattern of disease progression in these patients.

Validation of a Novel Diagnostic Kit Using the Semidry Dot-Blot Method to Detect Metastatic Lymph Nodes in Breast Cancer: Distinguishing Macrometastases From Nonmacrometastases

BACKGROUND

The semidry dot-blot method is a diagnostic procedure for detecting lymph node (LN) metastases using the presence of cytokeratin (CK) in lavage fluid from sectioned LNs. We evaluated 2 novel kits that use newly developed anti-CK-19 antibodies to diagnose LN metastases in breast cancer.

PATIENTS AND METHODS

We examined 159 LNs dissected that we sliced at 2-mm intervals and washed with phosphate-buffered saline. The suspended cells in the lavage were centrifuged and lysed to extract protein. This extracted protein was used with a low-power and a high-power kit to diagnose LN metastasis. Diagnoses on the basis of the kits were compared with pathological diagnoses.

RESULTS

Of the 159 LNs, 68 were assessed as positive and 91 as negative in permanent section examination. Sensitivity, specificity, and accuracy of the low-power kit for detecting LN metastases was 83.8%, 100%, and 93.1%, respectively. Those of the high-power kit were 92.6%, 92.3%, and 92.5%, respectively. Combining the low- and high-power kit results, those for distinguishing macrometastases were 94.5%, 95.2%, and 95.0%, respectively. Diagnosis was achieved in approximately 20 minutes, at a cost of less than $30 USD.

CONCLUSION

The kits were accurate, fast, and cost-effective in diagnosing LN metastases without the loss of LN tissue.

Human breast cancer biopsies induce eosinophil recruitment and enhance adjacent cancer cell proliferation

Chronic inflammation is known to facilitate cancer progression and metastasis. Less is known about the effect of acute inflammation within the tumor microenvironment, resulting from standard invasive procedures. Recent studies in mouse models have shown that the acute inflammatory response triggered by a biopsy in mammary cancer increases the frequency of distal metastases. Although tumor biopsies are part of the standard clinical practice in breast cancer diagnosis, no studies have reported their effect on inflammatory response. The objective of this study is to (1) determine whether core needle biopsies in breast cancer patients trigger an inflammatory response, (2) characterize the type of inflammatory response present, and (3) evaluate the potential effect of any acute inflammatory response on residual tumor cells. The biopsy wound site was identified in the primary tumor resection tissue samples from breast cancer patients. The inflammatory response in areas adjacent (i.e., immediately around previous biopsy site) and distant to the wound biopsy was investigated by histology and immunohistochemistry analysis. Proliferation of tumor cells was also assayed. We demonstrate that diagnostic core needle biopsies trigger a selective recruitment of inflammatory cells at the site of the biopsy, and they persist for extended periods of time. While macrophages were part of the inflammatory response, an unexpected accumulation of eosinophils at the edge of the biopsy wound was also identified. Importantly, we show that biopsy causes an increase in the proliferation rate of tumor cells located in the area adjacent to the biopsy wound. Diagnostic core needle biopsies in breast cancer patients do induce a unique acute inflammatory response within the tumor microenvironment and have an effect on the surrounding tumor cells. Therefore, biopsy-induced inflammation could have an impact on residual tumor cell progression and/or metastasis in human breast cancer. These findings may carry relevance in the clinical management of breast cancer.

Is Sentinel Lymph Node Dissection Warranted for Patients with a Diagnosis of Ductal Carcinoma In Situ?

BACKGROUND

Positive sentinel lymph node (SLN) findings in ductal carcinoma in situ (DCIS) range from 1 to 22 % but have unknown biologic significance. This study sought to identify predictors of positive SLNs and to assess their clinical significance for patients with an initial diagnosis of DCIS.

METHODS

The study identified 1234 patients with an initial diagnosis of DCIS who underwent SLN dissection (SLND) at our institution from 1997 through 2011. Positive SLN findings were categorized as isolated tumor cells (ITCs) (≤0.2 mm), micrometastases (>0.2-2 mm), or macrometastases (>2 mm). Predictors of positive SLNs were analyzed, and survival outcomes were examined.

RESULTS

Positive SLN findings were identified in 132 patients (10.7 %): 66 patients with ITCs (5.4 %), 36 patients with micrometastases (2.9 %), and 30 patients with macrometastases (2.4 %). Upstaging to microinvasive (n = 68, 5.5 %) or invasive (n = 259, 21.0 %) cancer occurred for 327 patients (26.5 %). Factors predicting positive SLNs included diagnosis by excisional biopsy (odds ratio [OR] 1.90; P = 0.007), papillary histology (OR 1.77; P = 0.006), DCIS larger than 2 cm (OR 1.55; P = 0.030), more than three interventions before SLND (4 interventions: OR 2.04; P = 0.022; ≥5 interventions: OR 3.87; P < 0.001), and occult invasion (microinvasive: OR 3.44; P = 0.001; invasive: OR 6.21; P < 0.001). The median follow-up period was 61.7 months. Patients who had pure DCIS with and without positive SLNs had equivalent survival rates (100.0 vs 99.7 %; P = 0.679). Patients with occult invasion and positive SLNs had the worst survival rate (91.7 %; P < 0.001).

CONCLUSIONS

Occult invasion and more than three total interventions were the strongest predictors of positive SLN findings in patients with an initial diagnosis of DCIS. This supports the theory of benign mechanical transport of breast epithelial cells. Except for patients at high risk for invasive disease, routine use of SLND in DCIS is not warranted.

Breast cancer prognosis and isolated tumor cell findings in axillary lymph nodes after core needle biopsy and fine needle aspiration cytology: Biopsy method and breast cancer outcome

BACKGROUND

It is unknown whether performing a core needle biopsy (CNB) to diagnose breast cancer increases the incidence of isolated tumor cells (ITC) in the axillary sentinel lymph nodes.

METHODS

Patients diagnosed with unilateral invasive pT1 breast cancer (≤2 cm in diameter, n = 1525) at a single center between February 2001 and August 2005 were included in this prospective observational cohort study. The patients were categorized into two groups according to the type of the preoperative breast needle biopsy performed, the CNB and the fine needle aspiration cytology (FNAC) groups, and followed up for a median of 9.5 years after breast surgery.

RESULTS

868 (56.9%) patients had FNAC and 657 (43.2%) CNB. In the subset of patients with no axillary metastases (pN0, n = 1005) 70 patients had ITC, 37 (4.3%) out of the 546 patients in FNAC group and 33 (5.0%) out of the 459 patients in the CNB group (p = 0.798). The type of tumor biopsy did not influence breast cancer-specific survival (p = 0.461) or local recurrence-free survival (p = 0.814) in univariable survival analyses. Overall, survival favored the CNB group in a univariable analysis, but no difference in survival emerged in a multivariable analysis (p = 0.718).

CONCLUSIONS

CNB was not associated with a greater incidence of ITC in axillary lymph nodes as compared with FNAC, and did not have an adverse effect on survival outcomes in a patient population treated with modern adjuvant therapies.

Comparison of Sonography versus Digital Breast Tomosynthesis to Locate Intramammary Marker Clips

Introduction: This study aimed to compare the accuracy of sonography versus digital breast tomosynthesis to locate intramammary marker clips placed under ultrasound guidance. Patients and Methods: Fifty patients with suspicion of breast cancer (lesion diameter less than 2 cm [cT1]) had ultrasound-guided core needle biopsy with placement of a marker clip in the center of the tumor. Intramammary marker clips were subsequently located with both sonography and digital breast tomosynthesis. Results: Sonography detected no dislocation of intrammammary marker clips in 42 of 50 patients (84 %); dislocation was reported in 8 patients (16 %) with a maximum dislocation of 7 mm along the x-, y- or z-axis. Digital breast tomosynthesis showed accurate placement without dislocation of the intramammary marker clip in 48 patients (96 %); 2 patients (4 %) had a maximum clip dislocation of 3 mm along the x-, y- or z-axis (p < 0.05). Conclusion: The use of digital breast tomosynthesis could improve the accuracy when locating intramammary marker clips compared to sonography and could, in future, be used to complement or even completely replace sonography.

Risk of tumor cell seeding through biopsy and aspiration cytology

Cancer cells, besides reproducing uncontrollably, lose cohesiveness and orderliness of normal tissue, invade and get detached from the primary tumor to travel and set up colonies elsewhere. Dislodging neoplastically altered cells from a tumor during biopsy or surgical intervention or during simple procedure like needle aspiration is a possibility because they lack cohesiveness, and they attain the capacity to migrate and colonize. Considering the fact that, every tumor cell, is bathed in interstitial fluid, which drains into the lymphatic system and has an individualized arterial blood supply and venous drainage like any other normal cell in our body, inserting a needle or a knife into a tumor, there is a jeopardy of dislodging a loose tumor cell into either the circulation or into the tissue fluid. Tumor cells are easier to dislodge due to lower cell-to-cell adhesion. This theory with the possibility of seeding of tumor cells is supported by several case studies that have shown that after diagnostic biopsy of a tumor, many patients developed cancer at multiple sites and showed the presence of circulating cancer cells in the blood stream on examination. In this review, we evaluate the risk of exposure to seeding of tumor cells by biopsy and aspiration cytology and provide some suggested practices to prevent tumor cell seeding.

Biopsy trauma dislodges thymocytes from a thymoma to fill regional lymph node sinusoids

We present a case of an incisional thymoma biopsy causing dissemination of thymocytes to a regional lymph node. Lymphatic seeding from circulating tumor cells is a distinct mechanism of tumor spread. We review the literature relevant to operative trauma as a cause of tumor cell migration to nearby lymph nodes. Summarized are case reports wherein metastasis of benign tumors has been related to operative trauma.

Evaluation of Newly Adapted Clip Marker System in Ultrasound-Guided Core Needle Biopsy for Suspicion of Breast Cancer

Introduction: A newly adapted clip system for intramammary marking during ultrasound-guided core needle biopsy for suspicion of breast cancer is described and evaluated here. Material and Method: Fifty patients with suspicion of breast cancer (cT2) had ultrasound-guided core needle biopsy using a newly adapted clip marker system (HistoCore™ and O-Twist Marker™). Subsequently, ultrasound follow-up and tomosynthesis scans were done to determine the location of the marker clips. Results: No dislocation of the marker clip was detected on ultrasound in 45 of 50 patients (90 %), and 5 patients (10 %) had a maximum dislocation of 5 mm along the x-, y- or z-axis. Tomosynthesis scans demonstrated precise placement without dislocation of the clip markers in 48 patients (96 %); 2 patients (4 %) had a maximum dislocation of 3 mm along the x-, y- or z-axis. Conclusion: The newly developed clip marker system, a combination of a single-use breast biopsy needle and a precise, length-adapted intramammary marker clip, represents a further improvement in oncological therapy. This is of particular importance for patients requiring subsequent neoadjuvant chemotherapy, as in cases with complete tumour remission, there is no target point for preoperative, ultrasound-guided wire marking.

Seeding of tumour cells following breast biopsy: a literature review

Needle biopsy of the breast is widely practised. Image guidance ensures a high degree of accuracy. However, sporadic cases of disease recurrence suggest that in some cases the procedure itself may contribute to this complication. This article reviews evidence relating to needle biopsy of the breast and the potential for tumour cell migration into adjacent tissues following the procedure. A literature search was undertaken using Medline, Embase and the Cochrane Library. Results are grouped under three categories: histological evidence of spread, clinical evidence of recurrent disease and the likelihood of seeding dependent upon tumour type. There is histological evidence of seeding of tumour cells from the primary neoplastic site into adjacent breast tissue following biopsy. However, as the interval between biopsy and surgery lengthens then the incidence of seeding declines, which suggests that displaced tumour cells are not viable. Clinical recurrence at the site of a needle biopsy is uncommon and the relationship between biopsy and later recurrence is difficult to confirm. There is some evidence to suggest that cell seeding may be reduced when vacuum biopsy devices are deployed.

Prognostic impact of isolated tumor cells in breast cancer axillary nodes: single tumor cell(s) versus tumor cell cluster(s) and microanatomic location

In breast cancer, it has been shown that pN0(i+) and pN1mi have a comparable negative impact on disease-free survival, compared with pN0. However, pN0(i+) is considered to be a heterogeneous group. We determined the effect of metastatic size and microanatomic location within the pN0(i+) group on breast cancer recurrence. We included all Dutch breast cancer patients diagnosed in 1998-2005 with favorable primary tumor characteristics and a final nodal status of pN0(i+). For this analysis, only patients without adjuvant systemic therapy were eligible (n = 513). Presence of single tumor cells versus cell clusters, metastatic size and microanatomic location were recorded. Primary endpoint was disease-free survival. Analyses were adjusted for age at diagnosis, tumor size, tumor grade, axillary treatment and hormone receptor status. The 5-year disease-free survival of patients with single tumor cell(s) (n = 93) was 78.6% and with tumor cell cluster(s) (n = 404) 77.1%. The hazard ratio for disease events was 1.05 (95% CI 0.63-1.76) for cell cluster(s) compared with single cell(s). In a Cox regression model, doubling of metastatic tumor size corresponded to a hazard ratio of 1.21 (95% CI 1.02-1.43). The adjusted hazard ratio was 0.90 (95% CI 0.54-1.50) for parenchymal (n = 112) versus sinusoidal location (n = 395). Single tumor cells bear similar prognostic information as small tumor cell clusters, even though results do suggest that within the pN0(i+) group, increasing size of nodal involvement is associated with reduced survival. Microanatomic location does not seem to have prognostic relevance.

Preoperative cytological and histological diagnosis of breast lesions: A critical review

BACKGROUND

Non-operative pathology diagnoses constitute an essential part of the work-up of breast lesions. With fine needle aspiration (FNA) and core needle biopsy (CNB) both having unique advantages, there is an increasing acceptance of CNB. This paper aims to outline the scientific basis of this trend. Additionally, we provide an update on novel techniques that derive cytological specimens from CNB (i.e., touch imprint (TI) and core wash (CW) cytology) in an attempt to get the best of both worlds.

METHODS

In addition to using the authors' experience, we performed a search of the Medline database combining the search terms "breast cancer diagnosis", "core needle biopsy", "fine needle aspiration", "touch imprint cytology", "core wash cytology" and "complications". We defined a conclusive non-operative diagnosis as "malignant" in lesions that were malignant on follow-up and "benign" in lesions that were benign on follow-up.

RESULTS

CNB was more often conclusive than FNA in benign and malignant lesions in 4 prospective studies. Although the more rapid diagnoses by FNA result in less patient anxiety during diagnostic work-up, CNB allows for fairly reliable estimation of invasion, histological type, grade, and receptor expression. CW and TI cytology seem promising techniques with conclusiveness rates that are roughly comparable to that of FNA.

CONCLUSIONS

All new suspicious breast lesions require careful non-operative investigation by CNB. However, additional cytological assessment by FNA can still be useful as a same-day diagnosis decreases patient anxiety and facilitates surgical treatment planning. TI and CW cytology techniques are promising same-day diagnosis modalities.

Image-guided breast biopsy: state-of-the-art

Percutaneous image-guided breast biopsy is widely practised to evaluate predominantly non-palpable breast lesions. There has been steady development in percutaneous biopsy techniques. Fine-needle aspiration cytology was the original method of sampling, followed in the early 1990s by large core needle biopsy. The accuracy of both has been improved by ultrasound and stereotactic guidance. Larger bore vacuum-assisted biopsy devices became available in the late 1990s and are now commonplace in most breast units. We review the different types of breast biopsy devices currently available together with various localization techniques used, focusing on their advantages, limitations and current controversial clinical management issues.

The use of positive core wash cytology to estimate potential risk of needle tract seeding of breast cancer: directional vacuum-assisted biopsy versus automated core needle biopsy

BACKGROUND

A disadvantage of the image-guided core needle biopsy is that needle tract seeding may occur and affect the local recurrence and overall survival rates of patients after breast-conserving surgery, although the chance is small. The purpose of this study was to compare the potential risk of needle tract seeding of breast cancer from ultrasonographically guided needle biopsies that were performed with a directional vacuum-assisted device and an automated core needle gun.

METHODS

The study compared the biopsies of 148 breast cancers performed using ultrasonographically guided core needle biopsy with the biopsies of 105 breast cancers performed using the vacuum suction probe. The potential risk of needle tract seeding of the breast cancer was defined by the cytological results derived from the needle wash material. The atypical/indeterminate, suspicious/probably malignant, and malignant categories were considered to represent positive cases.

RESULTS

There were significantly fewer positive cytological findings derived from the needle wash material with the directional vacuum-assisted device (33%) than with the automated core needle gun (69%) (P < 0.0001).

CONCLUSION

The use of the directional vacuum-assisted device significantly decreases the potential risk of needle tract seeding of breast cancer after an ultrasonographically guided needle biopsy.

Accuracy of ultrasound-guided, large-core needle breast biopsy

Ultrasound-guided, large-core needle biopsy (US-LCNB) of suspicious breast lesions is acknowledged as less invasive and less expensive and less time consuming than surgical biopsy, and provides a histologic diagnosis with a comparable high degree. US-LCNB has been proven to help reduce the number of unnecessary surgeries for benign disease. Its limitations, however, are false-negative results and underestimation of disease. Thus, the demand for breast teams is to carefully adhere to the principles of triple assessment and imaging-histologic correlation, and follow-up of lesions with a specific benign histology after biopsy. Also, the acceptance of guidelines and rigorous quality controls help to reliably minimize the delay in the diagnosis of breast cancer in patients with false-negative biopsies. This paper aims to summarize the equipment and methods as well as the benefits and limitations of US-LCNB. Also, guidelines of quality assessment are suggested. Finally, recent developments which may help to overcome the limitations of US-LCNB will be discussed, i.e., directional vacuum-assisted biopsy (VAB), three-dimensional (3D) US-guided biopsy, as well as the use of tissue harmonic imaging (THI) and compound imaging (CI) during biopsy.

Enhanced protein expression by internal ribosomal entry site-driven mRNA translation as a novel approach for in vitro loading of dendritic cells with antigens

Transfection of dendritic cells (DCs) with messenger RNAs (mRNAs) of tumor-associated antigens (TAAs) is a promising strategy for cancer vaccines. TAA mRNA can be generated by in vitro transcription using DNA encoding the TAA gene as a template. A cap analog is usually added upon in vitro transcription to stabilize mRNA and enhance the efficiency of mRNA translation. However, the inclusion of the cap analog correlates with significantly lower-yield mRNA transcription, potentially leading to an expensive vaccine manufacturing process. To solve this problem, we present a novel approach in which DNA templates are modified with an internal ribosomal entry site (IRES) sequence inserted upstream of the gene of interest to replace the use of the cap analog. The presence of IRES greatly enhanced transcription for the mRNA in vitro compared with the cap analog. Also, higher transgene expression was achieved using luciferase (Luc) mRNA with IRES than using capped Luc mRNA to transfect DCs. Immunization of mice with DCs transfected with IRES-containing mRNA encoding chicken ovalbumin (OVA) induced significant levels of antigen-specific interferon gamma-producing CD8(+) T cells and in vivo killing of antigen-bearing cells. Consistently, mice immunized with IRES-containing OVA mRNA-transfected DCs were protected from pulmonary metastasis of melanoma cells injected intravenously. We suggest that IRES can be used for the production of larger quantities of mRNA and that such IRES-containing mRNAs may be useful for DC-based antitumor immunotherapy.

Risk of needle tract seeding of breast cancer: cytological results derived from core wash material

Needle track seeding has been recognized as a possible, albeit rare, complication of breast core needle biopsy. The purpose of this study was to assess the risk of needle tract seeding of breast cancer from cytological results derived from core needle wash material. The study included biopsies of 207 breast cancers performed using ultrasonographically guided 18-gauge core needles. Each core needle without exposed sample notch was washed in saline solution immediately after removing the needles. Cytology derived from core wash material was performed by saline solution lavage of the fragments using a cytocentrifuge. The cytological diagnoses were divided into five categories: benign, atypical/indeterminate, suspicious/probably malignant, malignant and unsatisfactory. Atypical/indeterminate, suspicious/probably malignant and malignant categories were considered to represent positive cases of needle track seeding of breast cancer, whereas benign and unsatisfactory categories were counted as negative cases. Cytological diagnoses of the 207 lesions were as follows: 26 lesions (12%) were benign, 18 lesions (9%) were atypical/indeterminate, 37 lesions (18%) were suspicious/probably malignant, 79 lesions (38%) were malignant, and 47 lesions (23%) were unsatisfactory. The incidence of positive cases of cytology derived from core wash material was 65% (134/207). The 25% frequency of positive cases of invasive lobular carcinoma was significantly lower than the frequencies of DCIS (74%) and invasive ductal carcinoma (69%) (P = 0.001 and P < 0.01). The frequency of positive cases in the multiple passes group was 75%, which was slightly, although not significantly, higher than the 66% frequency in the single pass group (P = 0.3). In conclusion, the incidence of positive cases of cytology derived from ultrasonographically guided breast core needles' wash material was 65%. The clinical significance is debatable; however, there may be a theoretical risk of local recurrence if the tract is not excised or radiotherapy not given.

Preoperative core needle biopsy does not increase local recurrence rate in breast cancer patients

OBJECTIVE

Several case reports and clinical studies in the literature demonstrate needle track seeding after core needle biopsy in patients with breast cancer in up to 50% of cases. The impact of this observation on local recurrence and overall survival rate is, however, not fully investigated.

PATIENTS AND DESIGN

We retrospectively analysed 719 patients after breast conserving surgery and postoperative radiotherapy for stage I and II breast cancer. We divided this group into patients with (189) and without (530) preoperative core needle biopsy. Demographic data, local recurrence and overall survival rate were compared between these two groups.

RESULT

Preoperative core needle biopsy did not significantly influence the local free recurrence rate (median follow-up time of 78 and 71 months, respectively). The prognostic factors and the postoperative therapy did not differ significantly between the two groups.

CONCLUSION

Preoperative core needle biopsy seems to have no detrimental impact on local recurrence and overall survival after breast conserving surgery and postoperative radiotherapy.

Axillary sentinel lymph nodes can be falsely positive due to iatrogenic displacement and transport of benign epithelial cells in patients with breast carcinoma

PURPOSE

Immunohistochemical (IHC) staining for cytokeratins (CK) is common practice in evaluating sentinel lymph nodes (SLNs) in patients with breast carcinoma. IHC positivity typically indicates metastasis. SLN procedures are increasingly common in patients with pure intraductal carcinoma (DCIS). Iatrogenic epithelial cell displacement and benign transport of breast epithelial cells into axillary lymph nodes are recently described phenomena. We report 25 cases in which these factors probably resulted in benign epithelial cells in axillary SLNs (ie, false positivity).

METHODS

We reviewed 25 cases of CK-positive SLNs in which the epithelial cells had histologic and IHC characteristics different from their respective patients' underlying breast carcinomas.

RESULTS

In all cases, the cytologic features of the epithelial cells in the SLNs were benign, and 22 matched those of corresponding intraductal papillomas that were involved by or were separate from the DCIS in the original cores or surgical biopsies. Fifteen cases were pure DCIS; most invasive tumors were smaller than 1.0 cm. In six carcinomas (DCIS) showing strong Her-2/neu staining, the corresponding epithelial cells in the SLNs were negative. In 13 tumors that were strongly and uniformly positive for estrogen receptor (ER), the cytokeratin-positive cells in the SLNs were negative for ER. Nineteen cases showed benign epithelial cell displacement at the biopsy site.

CONCLUSION

Epithelial cells in SLNs may result from transport of displaced cells, usually originating in intraductal papillomas. Positive immunohistochemical results in SLNs should be interpreted with extreme caution to avoid automatically concluding that such cells represent metastasis. Sentinel lymph nodes in breast carcinoma can be falsely positive.

Rationale for a diagnostic chain in gestational breast tumor diagnosis

Due to the physiological tissue alterations of the breast during pregnancy and lactation the diagnosis of a breast tumor by palpation, imaging and fine-needle biopsy is difficult and often unreliable. The purpose of our study was to review the value of imaging (mammography and ultrasonography) and biopsy techniques in order to work out a reliable protocol for evaluating gestational tumors. We performed a retrospective analysis of 25 patients with clinical diagnosis of gestational breast tumors during a 4-year period from 1995 to 1999. Specimens were obtained by core biopsy for histological examination. Invasive breast cancer was diagnosed in five patients, malignant lymphoma of the skin in one patient. The tumors in the remaining 19 patients proved benign. The overall accuracy was 0.91 for conventional mammography, 0.76 for conventional and panoramic ultrasound and 0.48 for color-coded sonography. Mammography as the most reliable imaging method should be used to evaluate all patients in whom ultrasonographic findings are suspicious for tumor. Radiation phobia should not prevent the performance of mammography under these circumstances. Nevertheless, all pre-operative methods of diagnosing gestational breast tumors other than core biopsy are unreliable.

Pathological aspects of core needle biopsy for non-palpable breast lesions

Recently, the incidence of non-palpable or noninvasive breast cancer has increased. Consequently, criteria for choosing procedures to obtain pathological materials had changed. Fine needle aspiration biopsy cytology (FNA) and core needle biopsy (CNB) are both reliable procedures for detecting breast cancer. However, for non-palpable lesions, the diagnostic accuracy of CNB is higher. The main limits of FNA are the high rate of insufficient sampling and inability to determine invasiveness. CNB is an established alternative to surgical biopsy, and CNB can avoid excess surgical biopsies in a large number of patients. In addition to accurate histological diagnosis, there is interest in obtaining prognostic information from CNB, especially for patients being considered for preoperative (neoadjuvant) therapy. CNB provides useful information about histologic type and grade. However, an unavoidable problem of CNB is underestimation of invasion. On the other hand, there is good concordance in particular for estrogen receptor (ER) and progesterone receptor (PR) between CNB and surgical excision. Several aspects of CNB remains controversial, such as diagnosing papillary lesions by CNB, problems regarding tumor cell displacement after CNB, and management of lobular neoplasia (LN) on CNB.

Biopsy type does not influence sentinel lymph node status

BACKGROUND

This study sought to determine whether the type of biopsy examination independently affects sentinel lymph node (SLN) status in breast cancer patients.

METHODS

A prospective multicenter study of patients who had SLN biopsy examination followed by axillary node dissection was analyzed to determine whether the type of biopsy examination influenced SLN status.

RESULTS

Of the 3853 patients studied, 32% had a positive SLN. Patients were diagnosed by fine-needle (N = 293), core-needle (N = 2154), excisional (N = 1386), or incisional (N = 20) biopsy procedures. The rates of SLN positivity for these groups were 45%, 32%, 29%, and 65%, respectively (P < .001). Other factors predictive of SLN status included: patient age (P < .001), tumor size (P < .001), tumor palpability (P < .001), number of SLN removed (P < .001), type of surgery (mastectomy vs. lumpectomy) (P < .001), histologic subtype (P = .048), and the use of immunohistochemistry (P < .001). All of these factors remained significant in the multivariate model except for histologic subtype and biopsy examination type.

CONCLUSIONS

Biopsy examination type does not independently influence the risk for nodal metastasis.

Use of radiology for the pathologist in the management of breast lesions

Today radiology is an essential step in the pathological analysis of breast biopsies. It is determinant at each stage of the management of non palpable lesions, clusters of microcalcifications and opacities, whether this concerns the needle biopsy or the surgical excision. Firstly, an X-ray is necessary to ensure that the core needle biopsy specimen has been adequately sampled and when samples with microcalcifications are selected by the radiologist, management can be more specific and accurate. In the case of surgical specimens, the X-ray confirms the presence of the radiographic abnormality or the clip indicating the site of the surgical excision which guides sampling. Some radiographic features also provide information on underlying pathologies allowing management to be adapted accordingly. Radiographs are also important to ensure that microscopically detected microcalcifications or lesions exactly correspond to the radiographic abnormality in size and location. The paraffin block can also be X-rayed to select those containing microcalcifications for additional slicing. It is also important to identify the presence of modifications caused by the core needle biopsy (fibrosis, haemorrhage and inflammation) and to carefully recognize displacement of epithelial cells and pseudo-emboli resulting from the needle procedure. Such correlation between radiology and pathology is essential so that appropriate management of the specimen can be adapted and to avoid pitfalls arising from pre-operative procedures.

Contrast-aided diagnostic ultrasound does not enhance lung metastasis in a mouse melanoma tumor model

OBJECTIVE

The purpose of this research was to test the hypothesis that contrast-aided diagnostic ultrasound (CADUS) could exacerbate the metastatic spread of mouse melanoma tumor cells to the lungs.

METHODS

The melanoma cell lines B16 and B16-D5 (metastatic specifically to lung) were implanted on a hind leg of female C57/bl6 mice. Growing tumors were scanned by 1.5-MHz diagnostic ultrasound in a 37 degrees C water bath. Four hundred image frames were triggered at a 1-Hz rate with 4 retro-orbital injections of an ultrasonographic contrast agent at dosage of 10 microL/kg at 100-second intervals. Sham-treated mice received 400 frames of ultrasonography followed by the contrast agent with the ultrasound off. The primary tumor was surgically removed 1 day after ultrasound administration. Lungs were removed and evaluated blind after 2 weeks of bleaching in Fekete solution.

RESULTS

Three experiments were performed. The first experiment involved scanning sham and CADUS groups of 20 mice each with B16 tumors; B16 metastasis was not enhanced. The second experiment repeated this test with the D5 cell line; the metastasis enhancement was marginally significant for average number (0.3 and 3.2; P = .06) and incidence (3 and 9 of 19; P = .08) in mice without tumor recurrence. Finally, a third experiment was performed to clarify ambiguous results in the second experiment and consisted of 2 groups of 40 mice each. In this larger experiment, the results were essentially equal for the sham and CADUS groups.

CONCLUSIONS

Overall, the results do not support the hypothesis of CADUS-enhanced metastasis.