Sentinel Lymph Node Identification in Post Neoadjuvant Chemotherapy Breast Cancer Patients Undergoing Surgical Excision Using Lymphosonography.

OBJECTIVES: This study evaluated the efficacy of lymphosonography in the identification of sentinel lymph nodes (SLNs) in post neoadjuvant chemotherapy patients with breast cancer scheduled to undergo surgical excision. METHODS: Seventy-nine subjects scheduled for breast cancer surgery with SLN excision completed this IRB-approved study, out of which 18 (23%) underwent neoadjuvant chemotherapy before surgery. Subjects underwent percutaneous Sonazoid (GE Healthcare) injections around the tumor area for a total of 1.0 mL. Lymphosonography was performed using CPS on an S3000 HELX scanner (Siemens Healthineers) with a linear probe. Subjects received blue dye and radioactive tracer as part of their standard of care. Excised SLNs were classified as positive or negative for the presence of blue dye, radioactive tracer and Sonazoid. The results were compared between methods and pathology findings. RESULTS: Seventy-two SLNs were surgically excised from 18 subjects, 29 were positive for blue dye, 63 were positive for radioactive tracer and 57 were positive for Sonazoid. Comparison with blue dye showed that both radioactive tracer and lymphosonography achieved an accuracy of 53% (P > .50). Comparison with radioactive tracer showed that blue dye had an accuracy of 53%, while lymphosonography achieved an accuracy of 67% (P < .01). Of the 72 SLNs, 15 were determined malignant by pathology; the detection rate was 47% for blue dye (7/15), 67% for radioactive tracer (10/15) and 100% for lymphosonography (15/15) (P < .001). CONCLUSIONS: Lymphosonography achieved similar accuracy as radioactive tracer and higher accuracy than blue dye for identifying SLNs. The 15 SLNs positive for malignancy were all identified by lymphosonography.

Omission of Radiation in Conservative Treatment for Breast Cancer: Opportunity for De-escalation of Care.

INTRODUCTION: De-escalation of breast cancer treatment aims to reduce patient and financial toxicity without compromising outcomes. Level I evidence and National Comprehensive Cancer Network guidelines support omission of adjuvant radiation in patients aged >70 y with hormone-sensitive, pT1N0M0 invasive breast cancer treated with endocrine therapy. We evaluated radiation use in patients eligible for guideline concordant omission of radiation. METHODS: Subgroup analysis of patients eligible for radiation omission from two pooled randomized controlled trials, which included stage 0-III breast cancer patients undergoing breast conserving surgery, was performed to evaluate factors associated with radiation use. RESULTS: Of 631 patients, 47 (7.4%) met radiation omission criteria and were treated by 14 surgeons at eight institutions. The mean age was 75.3 (standard deviation + 4.4) y. Majority of patients identified as White (n = 46; 97.9%) and non-Hispanic (n = 44; 93.6%). The mean tumor size was 1.0 cm; 37 patients (88.1%) had ductal, 4 patients (9.5%) had lobular, and 17 patients (40.5%) had low-grade disease. Among patients eligible for radiation omission, 34 (72.3%) patients received adjuvant radiation. Those who received radiation were significantly younger than those who did not (74 y, interquartile range = 4 y, versus 78 y, interquartile range = 11 y, P = 0.03). There was no difference in radiation use based on size (P = 0.4), histology (P = 0.5), grade (P = 0.7), race (P = 1), ethnicity (P = 0.6), institution (P = 0.1), gender of the surgeon (P = 0.7), or surgeon (P = 0.1). CONCLUSIONS: Fewer than 10% of patients undergoing breast conservation met criteria for radiation omission. Nearly three-quarters received radiation therapy with younger age being a driver of radiation use, suggesting ample opportunity for de-escalation, particularly among younger eligible patients.

Resection of Cavity Shave Margins in Stage 0-III Breast Cancer Patients Undergoing Breast Conserving Surgery: A Prospective Multicenter Randomized Controlled Trial.

OBJECTIVE: Single-center studies have demonstrated that resection of cavity shave margins (CSM) halves the rate of positive margins and re-excision in breast cancer patients undergoing partial mastectomy (PM). We sought to determine if these findings were externally generalizable across practice settings. METHODS: In this multicenter randomized controlled trial occurring in 9 centers across the United States, stage 0-III breast cancer patients undergoing PM were randomly assigned to either have resection of CSM ("shave" group) or not ("no shave" group). Randomization occurred intraoperatively, after the surgeon had completed their standard PM. Primary outcome measures were positive margin and re-excision rates. RESULTS: Between July 28, 2016 and April 13, 2018, 400 patients were enrolled in this trial. Four patients (2 in each arm) did not meet inclusion criteria after randomization, leaving 396 patients for analysis: 196 in the "shave" group and 200 to the "no shave" group. Median patient age was 65 years (range; 29-94). Groups were well matched at baseline for demographic and clinicopathologic factors. Prior to randomization, positive margin rates were similar in the "shave" and "no shave" groups (76/196 (38.8%) vs. 72/200 (36.0%), respectively, P = 0.604). After randomization, those in the "shave" group were significantly less likely than those in the "no shave" group to have positive margins (19/196 (9.7%) vs. 72/200 (36.0%), P < 0.001), and to require re-excision or mastectomy for margin clearance (17/196 (8.7%) vs. 47/200 (23.5%), P < 0.001). CONCLUSION: Resection of CSM significantly reduces positive margin and re-excision rates in patients undergoing PM.

Nipple-sparing mastectomy: A review of outcomes at a single institution.

Nipple-sparing mastectomy (NSM) offers patients who are not candidates for breast-conserving treatment an aesthetically pleasing alternative to traditional mastectomy. Some studies have demonstrated its oncologic safety while others have demonstrated residual occult tumor cells at the nipple-areolar complex (NAC). These data prompt further review of oncologic outcomes after NSM.A single institution retrospective chart review was performed of all NSMs performed by 4 breast surgeons at Thomas Jefferson University Hospital over a span of 2012-2019. In this cohort, we review the reconstruction performed, axillary lymph node status, surgical margins, final pathology, loss of the NAC, recurrence rates, and follow-up. In our cohort, we reviewed 170 NSMs performed on 105 patients. All patients were female, and the average age was 46.9 years. Prophylactic procedures were performed on 43% of patients with 17.1% of patients being BRCA positive. Of those undergoing NSM for cancer (n = 94), the associated pathology was 28.8% DCIS, 32.9% IDC, and 3.5% ILC (this accounts for some patients with multiple diagnoses on final pathology). Sentinel lymph node biopsy (SLNB) was performed in 52.9% of cases with 10.6% of cases being positive for axillary disease. Margins were positive in 10.6% (n = 10) of cases performed for cancer with 8.5% (n = 8) of cases having positive margin at the NAC and the remainder being at the deep margin. Based on margin positivity, 2.4% (n = 4) of patients underwent redo surgery with 1 patient requiring re-resection at the NAC margin and 3 patients having total NAC resection. Total loss of NAC occurred in 5.9% (n = 10) of cases due to positive margins (n = 3) and necrosis (n = 7). Recurrence occurred in 7.2% (n = 7) of cases who underwent NSM for cancer. Locoregional recurrence in breast tissue, skin, or axilla occurred in 4.1% (n = 4) of cases with 0 recurrences at the NAC. Distant recurrence occurred in 4.1% (n = 4) of cases at both liver and bone. Average time to recurrence was 27.3 months. Of the 170 NSM performed, 98% had immediate tissue expander placement with 60% converting to permanent subpectoral implant reconstruction, 14% latissimus dorsi flap reconstruction, 0.6% delayed deep inferior epigastric artery perforator free-flap reconstruction, and 5.2% undergoing delayed free transversus abdominus muscle flap reconstruction. Of all the cases reviewed, there was only 1 death. Our average follow-up was 26.7 months. We demonstrate similar numbers in our analysis as other studies that have looked at oncologic outcomes after NSM. Although we demonstrate evidence of occult disease at the NAC margin when performing NSM, there was no evidence of recurrence at the NAC demonstrating its efficacy and safety. With proper patient selection, this procedure can be safely offered as an esthetically appealing alternative to traditional mastectomy.

Is radial scar on core needle biopsy a risk factor for malignancy? A single-center retrospective review and implications for management.

INTRODUCTION: Reported upgrade rate to malignancy of radial scars (RS) ranges widely (0%-40%) making management controversial. METHODS: A retrospective chart review was performed on patients with RS on core needle biopsy (CNB). Upgrade rates to malignancy and atypia on surgical excision were evaluated. RESULTS: Of 127 patients with RS on CNB, 53 were excluded due to malignancy or missing records. Of 74 patients reviewed, 52 (70.3%) had surgical excision with four (7.7%) upgraded to malignancy. Eight patients (10.8%) had atypia with RS on CNB with two (25%) upgraded to malignancy. When isolated RS was on CNB, 2 of 44 (4.5%) upgraded to malignancy while 15 of 44 (34%) had atypia on excision. Of 22 patients (29.7%) who did not have excision, zero developed cancer. CONCLUSION: We found higher than expected upgrade rates of isolated RS to atypia which can alter management. Additionally, 25% of RS with atypia upgraded to malignancy suggesting these patients are at higher risk.

Intraductal Papilloma with Benign Pathology on Breast Core Biopsy: To Excise or Not?

BACKGROUND: The management of intraductal papillomas on core biopsy continues to be controversial. Papillomas with atypia are typically excised. However, it is unclear whether surgical excision is warranted for benign lesions. METHODS: A retrospective review of our institution's pathology and radiology databases from January 2009 through May 2014 identified 119 patients with a diagnosis of benign papilloma without atypia on core biopsy. We determined the rate of carcinoma identification on surgical excision. RESULTS: The average patient age was 52.8 years (range 24-84 years). Indication for core biopsy included: abnormal imaging (n = 106), nipple discharge (n = 21), or palpable mass (n = 24). Seventy-five patients underwent surgical excision after core biopsy. Sixteen patients (21.3 %) had atypia in the excision specimen (combination atypical ductal hyperplasia, n = 11; atypical lobular hyperplasia, n = 8; lobular carcinoma-in situ, n = 3), 15 (93.8 %) of which were in the surrounding breast tissue. Two patients (2.7 %) had malignancy (ductal carcinoma-in situ and micropapillary carcinoma-in situ). As a result of surgical findings, 12 % of patients had a change in management. In comparing those with benign findings on surgical pathology and those whose disease was upstaged, there was no statistically significant difference in family history of breast cancer, indication for core biopsy, mammographic findings, or location of papilloma. CONCLUSIONS: Benign papillomas diagnosed on core biopsy are rarely upstaged to malignancy on surgical excision. However, at least 21 % of patients may have atypical findings in the surrounding tissue, which could change clinical management. Surgical excision should be considered in patients with benign papillomas.

Novel Form of Breast Intraoperative Radiation Therapy with CT-Guided High-Dose-Rate Brachytherapy: Interim Results of a Prospective Phase-II Clinical Trial.

BACKGROUND: Precision breast intraoperative radiation therapy (PB-IORT) is a novel method of IORT that uses customized CT-based treatment plans and high-dose-rate (HDR) brachytherapy. We conducted a phase-II multi-institution trial to evaluate the efficacy of PB-IORT. STUDY DESIGN: Between 2015 and 2022, 3 centers enrolled women aged 45 years and older with invasive or in situ carcinoma measuring 3 cm or smaller and N0 status (n = 358). Breast-conserving surgery was performed, and a multilumen balloon catheter was placed in the lumpectomy bed. CT images were used to create customized HDR brachytherapy plans that delivered 12.5 Gy to the tumor bed. The primary outcome assessed was the 5-year rate of index quadrant tumor recurrence. An interim analysis was conducted after one-third of eligible participants completed 5 years of follow-up. This trial is registered with clinicaltrials.gov (NCT02400658). RESULTS: The cohort comprised 153 participants with a median age of 64 years and median follow-up time of 5.9 years. The estimated 5-year index quadrant tumor recurrence rate and overall survival were 5.08% (95% CI 2.23 to 9.68) and 95.1%, respectively. Locoregional (ipsilateral breast and axilla) and distant recurrence rates were each 1.96%. Seven deaths occurred during the first 5 years of follow-up, with only 1 attributable to breast cancer. Overall, 68.6% of patients experienced any adverse effects, and 4 cases of breast-related severe toxicities were observed. CONCLUSIONS: This study presents the results of a planned interim analysis of a phase-II trial investigating PB-IORT and demonstrates the efficacy and safety of single-fraction, CT-based, HDR brachytherapy after breast-conserving surgery. These findings provide valuable insights into the use of PB-IORT as a treatment modality.

Bracketed Localization in Breast-Conserving Surgery: Indications and Success Rates From a Single, High Volume, Academic Breast Cancer Center.

BACKGROUND: Bracketed localization is a technique used to help localize lesions for breast-conserving surgery (BCS). To date, there are no guidelines for when bracketed localization should be used in clinical practice. Based on our experience, we aim to provide criteria that should prompt surgeons to consider bracketing. METHODS: A single-institution retrospective chart review was performed on patients who underwent bracketed localization for BCS between 2015 and 2021. Lesion characteristics were recorded including lesion span, number of lesions, histology type on core needle biopsy and surgical specimen, margin status, and need for additional surgery. RESULTS: One hundred and thirteen cases were analyzed. Imaging showed an average lesion span of 5.0-cm. Multifocal lesions represented 45% of cases. Ductal carcinoma in situ (DCIS) was a histological component in 64% of core needle biopsies and 76% of surgical specimens. Negative margins were achieved in 82% of patients on the first excision. Additional surgery was performed in 17% of patients. Invasive lobular carcinoma had the highest additional surgery rate at 23%. Negative margins with BCS were achieved in 96% of cases, including those with successful re-excision. DISCUSSION: This descriptive study shows that bracketed localization was most often employed for patients with large lesion spans, multifocality, and a DCIS or invasive lobular component. While these characteristics are typically associated with higher rates of positive margins, our cohort's rate of additional surgery was comparable to the national average for all BCS operations. These results argue that surgeon utilization of bracketed localization may be beneficial in these clinical scenarios.

Sentinel Lymph Node Identification in Patients With Breast Cancer Using Lymphosonography.

The objective of the work described here was to evaluate the efficacy of lymphosonography in identifying sentinel lymph nodes (SLNs) in patients with breast cancer undergoing surgical excision. Of the 86 individuals enrolled, 79 completed this institutional review board-approved study. Participants received subcutaneous 1.0-mL injections of ultrasound contrast agent (UCA) around the tumor. An ultrasound scanner with contrast-enhanced ultrasound (CEUS) capabilities was used to identify SLNs. Participants were administered with blue dye and radioactive tracer to guide SLN excision as standard-of-care. Excised SLNs were classified as positive or negative for the presence of blue dye, radioactive tracer and UCA, and sent for pathology. Two hundred fifty-two SLNs were excised; 158 were positive for blue dye, 222 were positive for radioactive tracer and 223 were positive for UCA. Comparison with blue dye revealed accuracies of 96.2% for radioactive tracer and 99.4% for lymphosonography (p > 0.15). Relative to radioactive tracer, blue dye had an accuracy of 68.5%, and lymphosonography achieved 86.5% (p < 0.0001). Of 252 SLNs excised, 34 were determined to be malignant by pathology; 18 were positive for blue dye (detection rate = 53%), 23 for radioactive tracer (detection rate = 68%) and 34 for UCA (detection rate = 100%) (p < 0.0001). Lymphosonography was similar in accuracy to radioactive tracer and higher in accuracy than blue dye in identifying SLNs. All 34 malignant SLNs were identified by lymphosonography.

Are we choosing wisely? Drivers of preoperative MRI use in breast cancer patients.

INTRODUCTION: Factors contributing to the use of preoperative MRI remain poorly understood. METHODS: Data from a randomized controlled trial of stage 0-3 breast cancer patients undergoing breast conserving surgery between 2016 and 2018 were analyzed. RESULTS: Of the 396 patients in this trial, 32.6% had a preoperative MRI. Patient age, race, ethnicity, tumor histology, and use of neoadjuvant therapy were significant predictors of MRI use. On multivariate analysis, younger patients with invasive lobular tumors were more likely to have a preoperative MRI. Rates also varied significantly by individual surgeon (p < 0.001); in particular, female surgeons (39.9% vs. 24.0% for male surgeons, p = 0.001) and those in community practice (58.9% vs. 14.2% for academic, p < 0.001) were more likely to order preoperative MRI. Rates declined over the two years of the study, particularly among female surgeons. CONCLUSIONS: Preoperative MRI varies with patient age and tumor histology; however, there remains variability by individual surgeon.

Extended Prophylactic Antibiotics for Mastectomy with Immediate Breast Reconstruction: A Meta-analysis.

The risk of surgical site infection (SSI) for breast surgery in patients without additional risk factors is low, below 5%. Evidence shows the risk of SSI is significantly elevated in patients undergoing immediate breast reconstruction (IBR). However, there is no consensus regarding the use of extended antibiotic prophylaxis. We aim to determine the effect of extended antibiotic prophylaxis on the incidence of SSI after IBR. METHODS: PubMed and Scopus were searched by 2 independent reviewers. Data abstracted included types of study, basic characteristics, detailed antibiotic prophylaxis information, SSI event, and other secondary outcomes. We calculated the risk ratio (RR) and 95% confidence interval (CI) for each study and used a random-effects model to estimate the results. Study quality, bias, and heterogeneity were also analyzed. RESULTS: A total of 11 studies (15,966 mastectomy procedures) were included. We found an overall 5.99% SSI rate in our population. Three studies comparing topical antibiotics with no topical antibiotics demonstrated statistical significance (RR = 0.26, 95% CI: 0.12-0.60, P = 0.001), whereas 8 studies comparing extended systemic antibiotics with standard of care found no statistical significance (RR = 0.80, 95% CI: 0.60-1.08, P = 0.13). CONCLUSIONS: In the setting of IBR following mastectomy, there is insufficient evidence for the use of extended prophylactic antibiotics to reduce SSI rates. Well-designed randomized controlled trials in patients undergoing IBR should be conducted to determine the appropriate regimen and/or duration of prophylactic antibiotics on SSI outcomes.

Toxicity and cosmetic outcomes after treatment with a novel form of breast IORT.

PURPOSE: Intraoperative radiation therapy (IORT), a form of accelerated partial breast irradiation (APBI), is an appealing alternative to postoperative whole breast irradiation for early-stage breast cancer. The purpose of this study was to examine the toxicity and cosmetic outcomes of patients treated with a novel form of breast IORT (precision breast IORT; PB-IORT), that delivers a targeted, higher dose of radiation than conventional IORT. METHODS AND MATERIALS: The first 204 patients treated with PB-IORT in a Phase II clinical trial (NCT02400658) with 12 months of followup were included. Trial inclusion criteria were age ≥45 years, invasive or in situ breast cancer, tumor size ≤3 cm, and node negative. Toxicity and cosmetic scoring were performed at 6 and 12 months. RESULTS: 98 patients (48%; 95% CI, 41-55%) experienced toxicity. Seven Grade 3 toxicities occurred (3.4%; 95% CI, 1.4-6.9%). Most patients (95%) had excellent or good cosmetic outcomes (95% CI, 91-98%) at 12 months. Most patients (94%) had little or no pigmentation change (95% CI, 90-97%), 88% little to no size change (95% CI, 82-92%), and 87% experienced minimal shape change (95% CI, 82-92%). CONCLUSIONS: Overall, Grade 3+ toxicity was rare and cosmetic outcomes were excellent. Severe toxicity with PB-IORT is similar to that reported in the TARGIT trial (3.3% rate of major toxicity) but lower than APBI (NSABP-39, 10.1% Grade 3/4 toxicities). We propose that the toxicity of PB-IORT compared with TARGIT and NSABP-39 is related to the radiation dose and delivery schedule. PB-IORT offers low-toxicity and good cosmetic outcomes when compared with other forms of APBI.

Algernon Brashear Jackson, M.D.: A Pioneer for Community and Minority Advocacy.

A historical vignette regarding Dr. Algernon Brashear Jackson, the first Black male graduate from Jefferson Medical College. It details his early life, medical school years, surgical training, and contributions to his local community and beyond as he paved the way for future doctors of color.

Pilot study demonstrating metabolic and anti-proliferative effects of in vivo anti-oxidant supplementation with N-Acetylcysteine in Breast Cancer.

BACKGROUND: High oxidative stress as defined by hydroxyl and peroxyl activity is often found in the stroma of human breast cancers. Oxidative stress induces stromal catabolism, which promotes cancer aggressiveness. Stromal cells exposed to oxidative stress release catabolites such as lactate, which are up-taken by cancer cells to support mitochondrial oxidative phosphorylation. The transfer of catabolites between stromal and cancer cells leads to metabolic heterogeneity between these cells and increased cancer cell proliferation and reduced apoptosis in preclinical models. N-Acetylcysteine (NAC) is an antioxidant that reduces oxidative stress and reverses stromal catabolism and stromal-carcinoma cell metabolic heterogeneity, resulting in reduced proliferation and increased apoptosis of cancer cells in experimental models of breast cancer. The purpose of this clinical trial was to determine if NAC could reduce markers of stromal-cancer metabolic heterogeneity and markers of cancer cell aggressiveness in human breast cancer. METHODS: Subjects with newly diagnosed stage 0 and I breast cancer who were not going to receive neoadjuvant therapy prior to surgical resection were treated with NAC before definitive surgery to assess intra-tumoral metabolic markers. NAC was administered once a week intravenously at a dose of 150 mg/kg and 600 mg twice daily orally on the days not receiving intravenous NAC. Histochemistry for the stromal metabolic markers monocarboxylate transporter 4 (MCT4) and caveolin-1 (CAV1) and the Ki67 proliferation assay and TUNEL apoptosis assay in carcinoma cells were performed in pre- and post-NAC specimens. RESULTS: The range of days on NAC was 14-27 and the mean was 19 days. Post-treatment biopsies showed significant decrease in stromal MCT4 and reduced Ki67 in carcinoma cells. NAC did not significantly change stromal CAV1 and carcinoma TUNEL staining. NAC was well tolerated. CONCLUSIONS: NAC as a single agent reduces MCT4 stromal expression, which is a marker of glycolysis in breast cancer with reduced carcinoma cell proliferation. This study suggests that modulating metabolism in the tumor microenvironment has the potential to impact breast cancer proliferation.

Clinical-pathological features and treatment modalities associated with recurrence in DCIS and micro-invasive carcinoma: Who to treat more and who to treat less.

The primary aim in the management of DCIS is the prevention of recurrence and contralateral tumor. Risk factors for DCIS recurrence and appropriate treatments are still widely debated. Adjuvant therapies after surgical resection reduce recurrences and contralateral disease, but these treatments have significant financial costs, side effects and there is a group of low-risk patients who would not gain additional benefit. The aim of our analysis was to identify clinical-pathological features and treatment modalities associated with recurrence in DCIS and microinvasive carcinoma. In the Thomas Jefferson University Cancer Registry of Philadelphia, we identified 865 patients with DCIS or micro-invasive carcinoma treated between 2003 and 2013. Associations between recurrence and demographic factors (age at diagnosis, ethnicity), biological features (ER, PR and HER2) and treatment modalities (surgery, radiotherapy and endocrine treatment) were assessed. Our single institution register-based study showed that distribution of age at diagnosis and biological features did not significantly differ among ethnic groups. Younger women and micro-invasive carcinoma patients were more likely to undergo mastectomy, while African Americans were more likely to take endocrine therapy and undergo radiotherapy. In our sample only ER/PR negative DCIS were associated with significantly higher recurrence rate. Moreover, we reported a high rate of HER2 positive recurrences, suggesting that expression of this oncogene may represent a potential biomarker for DCIS at high risk of recurrence. To better define the molecular profile of the subgroup at worse prognosis might help to identify biomarkers predictive of recurrence or second tumors, identifying patients candidates for more appropriate treatments.

Tumor-specific expression and alternative splicing of the COL6A3 gene in pancreatic cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDA) is a highly lethal disease; a prominent desmoplastic reaction is a defining characteristic. Fibrillar collagens, such as collagen I and to a lesser extent, collagens III and V, comprise the majority of this stromal fibrosis. Type VI collagen (COL6) forms a microfibrillar network associated with type I collagen fibrils. The expression of COL6 has been linked with inflammation and survival. Importantly, tumor-specific alternative splicing in COL6A3 has been identified in several cancers by genome exon arrays. We evaluated the expression and localization of COL6A3 in PDA and premalignant lesions and explored the presence of alternative splicing events. METHODS: We analyzed paired PDA-normal (n = 18), intraductal papillary mucinous neoplasms (IPMN; n = 5), pancreatic cystadenoma (n = 5), and 8 PDA cell lines with reverse transcriptase polymerase chain reaction, using unique primers that identify total COL6A3 gene and alternative splicing sites in several of its exons. Western blot analysis and immunohistochemistry were used to analyze the expression levels and localization of COL6A3 protein in the different lesions, and in 2 animal models of PDA. RESULTS: COL6A3 protein levels were significantly upregulated in 77% of the paired PDA-adjacent tissue examined. COL6A3 was mainly present in the desmoplastic stroma of PDA, with high deposition around the malignant ducts and in between the sites of stromal fatty infiltration. Analysis of the COL6A3 splice variants showed tumor-specific consistent inclusion of exons 3 and 6 in 17 of the 18 (94%) paired PDA-adjacent tissues. Inclusion of exon 4 was exclusively tumor specific, with barely detectable expression in the adjacent tissues. IPMN and pancreatic cystadenomas showed no expression of any of the examined exons. Total COL6A3 mRNA and exon 6 were identified in 6 PDA cell lines, but only 2 cell lines (MIA PACA-2 and ASPC-1) expressed exons 3 and 4. In both the xenograft and transgenic models of PDA, COL6A3 immunoreactivity was present in the stroma and some PDA cells. CONCLUSION: We have described, for the first time, a dynamic process of tumor-specific alternative splicing in several exons of stromal COL6A3. Alternatively spliced proteins may contribute to the etiology or progression of cancer and may serve as markers for cancer diagnosis. Identification of COL6A3 isoforms as PDA-specific provides the basis for future studies to explore the oncogenic and diagnostic potential of these alternative splicing events.

Induction of monocyte chemoattractant protein-1 by nicotine in pancreatic ductal adenocarcinoma cells: role of osteopontin.

BACKGROUND: Cigarette smoke and nicotine are among the leading environmental risk factors for developing pancreatic ductal adenocarcinoma (PDA). We showed recently that nicotine induces osteopontin (OPN), a protein that plays critical roles in inflammation and tumor metastasis. We identified an OPN isoform, OPNc, that is selectively inducible by nicotine and highly expressed in PDA tissue from smokers. In this study, we explored the potential proinflammatory role of nicotine in PDA through studying its effect on the expression of monocyte chemoattractant protein (MCP)-1 and evaluated the role of OPN in mediating these effects. METHODS: MCP-1 mRNA and protein in PDA cells treated with or without nicotine (3-300 nmol/L) or OPN (0.15-15 nmol/L) were analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Luciferase-labeled promoter studies evaluated the effects of nicotine and OPN on MCP-1 transcription. Intracellular and tissue colocalization of OPN and MCP-1 were examined by immunofluorescence and immunohistochemistry. RESULTS: Nicotine treatment significantly increased MCP-1 expression in PDA cells. Interestingly, blocking OPN with siRNA or OPN antibody abolished these effects. Transient transfection of the OPNc gene in PDA cells or their treatment with recombinant OPN protein significantly (P < .05) increased MCP-1 mRNA and protein and induced its promoter activity. MCP-1 was found in 60% of invasive PDA lesions, of whom 66% were smokers. MCP-1 colocalized with OPN in PDA cells and in the malignant ducts, and correlated well with higher expression levels of OPN in the tissue from patients with invasive PDA. CONCLUSION: Our data suggest that cigarette smoking and nicotine may contribute to PDA inflammation by inducing MCP-1 and provide a novel insight into a unique role for OPN in mediating these effects.

Involvement of osteopontin in the matrix-degrading and proangiogenic changes mediated by nicotine in pancreatic cancer cells.

BACKGROUND: Substantial evidence indicates that exposure to cigarette smoke is associated with an elevated risk of pancreatic ductal adenocarcinoma (PDA). However, the mechanisms underlying the effects of nicotine on the development or progression of PDA remain to be investigated. Previously, we showed that nicotine promotes the expression of osteopontin c (OPNc), an isoform of OPN protein that confers on cancer cells a migratory phenotype. In this study, we explored the potential prometastatic role of nicotine in PDA through studying its effect on the expression of matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) and evaluated the role of OPN in mediating these effects. MATERIALS AND METHODS: MMP-9 and VEGF mRNA and protein were analyzed in PDA cells treated with or without nicotine (3-300 nM). Transient transfection and luciferase-labeled promoter studies evaluated the effects of OPNc and OPN protein on the transcription and translation of MMP-9 and VEGF. Real-time PCR and immunohistochemistry were used to analyze the mRNA expression levels and localization of OPN, MMP-9, and VEGF proteins in matched invasive human PDA and surrounding nonmalignant tissues. RESULTS AND DISCUSSION: Nicotine significantly enhanced the expression of MMP-9 and VEGF mRNA and protein in PDA cells. Blocking OPN with siRNA or OPN antibody prevented the nicotine-mediated increase of both MMP-9 and VEGF. Transient transfection of OPNc gene in PDA cells or their treatment with recombinant OPN protein significantly (p < 0.05) increased MMP-9 and VEGF mRNA expression levels and induced their promoter activities. In invasive PDA lesions, MMP-9 mRNA levels were significantly (p < 0.005) higher in smokers vs. nonsmokers. VEGF protein co-localized with MMP-9 and OPN in the malignant ducts and correlated well with their higher levels in invasive PDA lesions. CONCLUSIONS: Our data show for the first time that cigarette smoking and nicotine may contribute to PDA metastasis through inducing MMP-9 and VEGF and suggest that OPN plays a central role in mediating these effects. The presence of OPN as a downstream effector of nicotine that is capable of mediating its prometastatic effects in PDA cells is novel and could provide a unique therapeutic target to control pancreatic cancer aggressiveness, especially in the cigarette-smoking population.