Clipping a Positive Lymph Node Improves Accuracy of Nodal Staging After Neoadjuvant Chemotherapy for Breast Cancer Patients, but Does It Drive Management Changes?

BACKGROUND

Sentinel lymph node (SLN) biopsy for cN+ breast cancer patients after neoadjuvant chemotherapy (NAC) is controversial because the false-negative rate (FNR) is high. Identification of three or more SLNs with a dual tracer improves these results, and inclusion of a clipped lymph node (CLN) (targeted axillary dissection [TAD]) may be even more effective.

METHODS

A retrospective, single-institution analysis of consecutive cN+ patients undergoing NAC from 2019 to 2021 was performed. Patients routinely underwent placement of a clip in the positive lymph node before NAC, and TAD was performed after completion of therapy.

RESULTS

The study analyzed 73 patients, and the identification rate for CLN was 98.6% (72/73). A complete response in the lymph nodes was achieved for 43 (59%) of the 73 patients. Overall, the CLN was not a SLN in 18 (25%) of 73 cases, and for women who had one or two and those who had three or more SLNs identified, this occurred in 11 (32%) and 7 (21%) of 34 cases, respectively. Failure of SLN or TAD to identify a positive residual lymph node status after NAC occurred in 10 (15%) of 69 and 2 (3%) of 73 cases, respectively (p = 0.01). In four cases, a SLN was not retrieved (5.5%), and two of these cases had a positive CLN. In three cases, the CLN was the only positive node and did not match with a SLN, directing lymphadenectomy and oncologic management change in two cases. Therefore, 7 (10%) of 73 cases had a change in surgical or oncologic management with TAD.

CONCLUSIONS

For a conservative axillary treatment in this setting, TAD is an effective method. It is more accurate than SLN alone and allows management changes. Further studies are warranted.

Intraoperative Examination of Retro-Areolar Margin is not Routinely Necessary During Nipple-Sparing Mastectomy for Cancer

BACKGROUND

Intraoperative examination of retro-areolar margin (IERM) often is used during nipple-sparing mastectomy (NSM) for cancer, but there is no robust data regarding its real advantage.

METHODS

Consecutive patients undergoing NSM for cancer with omission of IERM according to institutional protocols from 2016 to 2021 were retrospectively analyzed. The decision to maintain or remove the Nipple-Areola Complex (NAC) after definitive pathology was taken at the multidisciplinary meeting.

RESULTS

Among 162 women operated in the study period, the presence of neoplastic cells within 2 mm from the inked retroareolar margin (RAM) was detected at permanent pathology in 17 cases (10.5%). Nipple-Areola-Complex (NAC) was removed postoperatively in five patients (3%) for margins <1 mm, the other 12 were observed, whereas postoperative NAC necrosis required surgical removal in additional five cases (3%). The NAC was thus preserved in 152 of 162 patients (94%). At multivariate analysis, RAM ≤2 mm was associated with radiological tumor-to-nipple distance less than or equal to 1 cm (p = 0.04) and Ki67 label index ≥ 20 (p = 0.04), whereas multifocality/multicentricity showed a trend towards significance (p = 0.07). At a median follow-up of 46 months, five locoregional relapses occurred (3%), only one of them involving the NAC (0, 6%). Locoregional relapse and overall survival for patients with RAM > or < 2 mm were not different.

CONCLUSIONS

IERM is not routinely necessary during NSM for cancer, because its omission is associated with a very low return to the operating room, it is oncologically safe, and associated pitfalls are avoided. Further studies are necessary to confirm these findings.

Nipple-Sparing Mastectomy After Neoadjuvant Chemotherapy: Definitive Results with a Long-Term Follow-Up Evaluation

BACKGROUND

Nipple-sparing mastectomy (NSM) is increasingly used for women with breast cancer who are not candidates for conservative surgery. The authors previously reported satisfying results with NSM after neoadjuvant chemotherapy (NACT).

METHODS

From 2010 to 2020, 1072 women underwent mastectomy at the authors' institution. In this group, 433 NSMs were performed (40%). The only contraindications to NSM were close proximity to the nipple-areola complex (NAC), bloody discharge, and Paget disease.

RESULTS

In 112 cases involving 111 women, NSM followed NACT (group 1), whereas it was performed as primary surgery in 321 instances involving 306 women (group 2). At 5 years, local relapse was 7% in group 1 and 2% in group 2, although in the multivariate analysis, locoregional relapses (LRRs) did not differ between the two groups. An increased incidence of local relapse was associated with higher tumor stage (stage III; p = 0.046) and age younger than 51 years (p = 0.038). For 34 (30.3%) of the 111 women in group 1 with a pathologic complete response (pCR), no LRRs were recorded. Only one NAC recurrence was observed. Overall survival with each tumor stage did not differ between the two groups. No differences in complications were observed. Cosmetic results were satisfying in 83.8% of the cases and did not get worse after NACT.

CONCLUSIONS

The study data definitively confirm that NSM is safe even after NACT, with good cosmetic results and complications comparable with those in the primary surgery setting. Tumor stage and age were the only independent factors for local relapse. Patients with pCR enjoyed optimal locoregional control.

Abstract P4-07-27: Clipped lymph nodes for cN+ patients decrease false negative rate and lead to potential changes in surgical and oncological management after clinical complete response following neoadjuvant chemotherapy

Introduction Targeted axillary dissection (TAD) after neoadjuvant chemotherapy (NAC) is a new axillary staging technique that consists of surgical removal of biopsy-proven, positive, clipped axillary nodes (CLN) in addition to the sentinel lymph node biopsy (SLNB), and provides for more conservative axillary surgery1. A question was recently raised whether clipping a positive node for later assessment indeed leads to a management change2. The purpose of our study is to report the feasibility of TAD and to evaluate false negative rate (FNR), impact on surgical ad oncological management.

Materials and methods This retrospective, single-institution, study included 73 consecutive women operated between 2019 and 2021 after NAC for cN+ disease confirmed by citology or histology, whose diseased lymph-node was marked with a clip before therapy. At surgery, in case of clinical-radiological complete response, patients underwent TAD (dual mapping with radiocolloid and blue dye + CLN) (n=43), or TAD plus ALND if any residual disease (n=30). The chemoterapeutsic regimen were antracycline/taxane based, with trastuzumab in case of HER2+ tumors. Patients were routinely evaluated with a breast MRI both before and after NAC.

Results Clinical and pathological details of the 73 enrolled patients are listed in Table 1. The mean age at diagnosis was 49.53±10 years. Pathologic complete response was achievied in 32 out 73 patients (43.8%) with the greatest rate in HR-/HER2+ tumors (n=10/12; 83.3%). The identification rate of the CLN was 91.8% (68/73), and it was one of SLNs in 68.5% (50/73) of the cases. In cases in which one, two or three or more SLNs were identified, the CLN was in the SLN specimen in 42.9%, 77.8% and 81.8% of cases, respectively. The FNR of the SLN was 18.5% (CI: 4.9-38.1). In 18 cases the CLN was not in the SLN specimen; eleven out of 18 CLNs were positive, leading to ALND, and three of them had additional positive LNs. Only in one case the CLN was negative and the SLN was positive. In 3 cases (4.1%), the CLN was positive in the absence of residual tumour in the breast leading a potential change in the oncological management.

Conclusions Removal of CLN after NAC is feasible, allowing de-escalation of surgical management of cN+ women in case of clinical-radiological complete response, as 59% of women avoided a formal ALND. The CLN coincides with SLN in about 70% of cases (more than 80% if three or more SLNs are identified) and reflects the overall status of the axilla in 97.3% of the cases. Adding CLN to SLNB contributes to reduce significantly the FNR of the latter from 18% to 0% (FNR for SLNB =18.5% vs FNR for TAD=0%). Potential changes in surgical (CLN+/SLNs-) and oncological management (CLN+/SLNs- and absence of residual tumor in breast) occurs in 15.1% (11/73) and 4.1% (3/73) of cases, respectively.

References

1. Swarnkar PK et al. The Evolving Role of Marked Lymph Node Biopsy (MLNB) and Targeted Axillary Dissection (TAD) after Neoadjuvant Chemotherapy (NACT) for Node-Positive Breast Cancer: Systematic Review and Pooled Analysis. Cancers (Basel) 2021 Mar 26;13(7):1539.

2. Weiss A et al. How Often Does Retrieval of a Clipped Lymph Node Change Adjuvant Therapy Recommendations? A Prospective, Consecutive, Patient Cohort Study. 2022 Jun. Ann Surg Oncol 2022; 29(6): 3764-3771.

Table 1: Clinicopathologic characteristics in the cN+ breast cancer patients NAC and clipped Lymph Node NAC

Citation Format: Francesca Arienzo, Domenico Campagna, Paola Scavinia, Laura Broglia, Laura Broglia, Alessandra Ascarelli, Helena Colavito, Mirko Montanari, Elena Manna, Tiziana Mastropietro, Emanuele Zarba Meli, Massimo La Pinta, Daniela Musio, Mauro Minelli, Paola Scavina, Michelina Maria Carla Amato, Leopoldo Costarelli. Clipped lymph nodes for cN+ patients decrease false negative rate and lead to potential changes in surgical and oncological management after clinical complete response following neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-27.

AB0836 Micronutrients deficiencies in Enteropathic Spondyloarthritis: the interplay with metabolism and HLA-B27 in disease phenotype

Background

Micronutrients play immunomodulatory roles through interactions with innate and adaptive immunity influencing the pro/anti-inflammatory balance. Serum levels depend on multiple factors such as gender, nutrition, and gut microbiome. Micronutrient deficiencies (MNDs) are associated with a pro-inflammatory status and co-morbidities in patients with chronic inflammatory diseases. No studies focused on potential interplay between MNDs and disease phenotype in Enteropathic Spondyloarthritis (ESpA) in which the combination of SpA with inflammatory bowel diseases (IBD) might dramatically affect micronutrients status.

Objectives

We analysed the occurrence of anemia (Hb ≤12 g/dl) and deficiencies of ferritin (Fe, ≤15 ng/dL), vitamin D [25(OH)D, ≤20 ng/ml], vitamin B12 (VB12, ≤200 pg/ml), and folic acid (FA, ≤ 4ng/mL) in ESpA patients. The interplay of MNDs with gender, metabolic parameters, HLA-B27 susceptibility, type of SpA and IBD, disease activity, and treatments was also explored.

Methods

Selection criteria of this cross-sectional descriptive study consisted of having a diagnosis of ESpA, regardless of its type, in an age of ESpA onset ≥18 and ≤80 years, among patients who were admitted to a combined Gastro-Intestinal and RHEumatologic “GI–Rhe” clinic (Tor Vergata University Hospital, Rome, Italy). Exclusion criteria were represented by active IBD, pregnancy or lactation, kidney and/or liver failure, alcohol abuse, neoplasia, ongoing supplementations. SpA disease activity was assessed by ASDAS-CRP and functional status by HAQ-S. All the enrolled patients underwent blood chemistry analysis to determine parameters including CRP, uric acid (SUA), Fe, 25(OH)D, VB12, FA, and HLA-B27 typing.

Results

We included 164 patients comprising 109 females and 55 age-matched males. A diagnosis of Crohn’s Disease (CD) occurred in 70% of patients while Ulcerative Colitis (UC) represented a third of the cohort. Peripheral (per) and axial (ax) SpA were equally distributed (50%vs50%). Patients with ax-SpA displayed a greater prevalence of CD than UC (p=0.02) while UC was prevalent in per-SpA (p=0.02). B27+ was revealed in 19% of our cohort: B27+ patients had a higher prevalence of ax-SpA (p=0.016) and a more severe disease activity (p=0.02) than B27-. Moreover, B27 positivity and uveitis were prevalent in ax-SpA compared to per-SpA (p=0.009 and p=0.01, respectively). According to univariate analysis, males showed higher SUA (P=0.004) and BMI (p=0.03) than females. Conversely, females showed a higher prevalence of anemia than males (p=0.002). A third of ESpA cohort showed FA (31.6%) and 25(OH)D (27.8%) deficiency while VB12 defect was less frequent (18.2%) and was registered almost entirely in B27- ESpA (p=0.02). CD-ESpA showed a lower mean VB12 (p=0.04) and a higher prevalence of ocular/skin co-morbidities (p=0.02) and ax-SpA (p=0.04) than UC-ESpA. Accordingly, CD-ESpA were on bDMARDs more than UC-ESpA (p=0.04).

Conclusion

Our findings document that FA and 25(OH)D deficiencies represent the main MNDs among ESpA patients while VB12 seems to be deficient mostly in patients with CD and almost exclusively in B27- patients. Otherwise, B27+ in ESpA results to be associated mainly with disease phenotype and treatments. In ESpA, the gender of patients appears to impact principally on dysmetabolism highlighting the role for nutritional interventions particularly in males. The interplay of MNDs with B27 and dysmetabolism in ESpA deserves further investigations also taking into account CD/UC localization and behavior.

References

[1]Park YE, et al. Incidence and risk factors of micronutrient deficiency in patients with IBD and intestinal Behçet’s disease: folate, vitamin B12, 25-OH-vitamin D, and ferritin. BMC Gastroenterol. 2021;21(1):32.doi: 10.1186/s12876-021-01609-8.

[2]Conigliaro P, et al. Impact of a multidisciplinary approach in enteropathic spondyloarthritis patients. Autoimmun Rev. 2016;15(2):184-90.doi: 10.1016/j.autrev.2015.11.002.

Disclosure of Interests

None declared

Immediate Breast Reconstruction after mastectomy with polyurethane implants versus textured implants: A retrospective study with focus on capsular contracture

BACKGROUND

Capsular contracture (CC) is the most common complication following Immediate Breast Reconstruction (IBR) with breast implants. Different implant surfaces were developed aiming to reduce the incidence of CC. We evaluated the incidence and degree of CC after Direct-to-Implant (DTI) IBR with insertion of textured (TE) or polyurethane (PU) covered implants.

METHODS

A retrospective review of consecutive patients treated at our Institution with mastectomy and one-stage IBR and implant reconstruction between 2013 and 2018, with or without post mastectomy radiation therapy (PMRT), was conducted. Immediate breast reconstruction was performed by implanting 186 PU covered implants and 172 TE implants.

RESULTS

Three-hundred-twelve women underwent 358 DTI IBR with PU or TE implants, were analyzed with a median follow-up time of 2.3 years (range 1.0-3.0). The overall rate of CC Baker grade III and IV was 11.8% (95%CI: 8.4-16.3), while, after PU and TE implant placement it was 8.1% (95% CI: 4.1-15.7) and 15.8% (95% CI: 4.1-15.7) [p = 0.009]), respectively. Irradiated breasts developed CC more frequently rather than non-irradiated breasts (HR = 12.5, p < 0.001), and the relative risk was higher in the TE group compared with the PU group (HR = 0.3, p = 0.003).

CONCLUSIONS

After mastectomy and one-stage IBR, the use of PU covered implants is associated with a lower incidence of CC compared to TE implants. This advantage is amplified several folds for patients who necessitate PMRT. Footnote: Capsular contracture (CC); Immediate Breast Reconstruction (IBR); Directto- Implant (DTI); Textured (TE); Polyurethane (PU); Post mastectomy radiation therapy (PMRT); Nipple Sparing mastectomy (NSM).

Surgical delay may extend the indications for nipple-sparing mastectomy: A multicentric study

INTRODUCTION

Nipple-sparing mastectomy (NSM) is considered an oncologically sound procedure but necrosis of the nipple-areola complex (NAC) or skin flaps is a concern, particularly in the presence of risk factors. To increase the indications for NSM and decrease such complications, different procedures of "surgical delay" (SD) have been described.

MATERIALS AND METHODS

A retrospective analysis of patients who underwent SD for NSM at four Italian Breast Centers from 2014 to 2017 was performed. SD generally consisted of a periareolar or "hemi-batwing" incision, dissecting the skin and the NAC from the underlying breast tissue. NSM was scheduled after 2-3 weeks.

RESULTS

Eighty-eight procedures were analyzed. Mild complications of SD were registered in 7.9% of cases. NSM was performed in 85 cases, whereas in three cases (3.4%) a "skin-sparing" mastectomy was necessary due to positivity of the retroareolar biopsy for cancer at SD. A direct-to- implant (DTI) reconstruction was performed in 42 cases (49.4%), while in 43 (50.6%) a tissue-expander (TE) was inserted. After NSM, eight complications (9.4%) were recorded: one total necrosis (1.2%), one partial necrosis (1.2%) and four minimal ischemia (4.7%) of NAC, one skin flap necrosis (1.2%), one haematoma (1.2%). In only two cases (2.3%) prosthesis removal was needed. Aesthetic outcome was evaluated excellent or good in 92.9% of cases. At a median follow-up of 24 months no local recurrences were seen.

CONCLUSION

This is the largest series of SD with NSM presented so far in the literature. In our experience, SD extends indications for NSM in high-risk women.

Pleomorphic lobular carcinoma: is it more similar to a classic lobular cancer or to a high-grade ductal cancer?

Background

Pleomorphic invasive lobular carcinoma (P-ILC) is an uncommon variety of invasive lobular carcinoma with aggressive clinical features. Little is described in the literature regarding this topic.

Materials and methods

We reviewed our experiences from 2010 to 2015 and compared 40 patients with P-ILC, 126 patients with classic-ILC (C-ILC) and 574 cases of high-grade invasive ductal carcinoma (HG-IDC). We studied the histologic and immunohistochemical features, clinical presentation and surgical treatment.

Results

P-ILC is diagnosed at the same age and tumor diameter as those of the other two histologic types. It is associated more frequently with multiple lymph node metastases and high proliferative index, and HER2/neu is amplified in 10% of cases. In spite of sharing some histologic characteristics with C-ILC (same growth pattern, loss of E-cadherin expression, same genetic pathway), its clinical and pathologic features define an autonomous entity. Its surgical treatment is similar to those of C-ILC and HG-IDC.

Conclusion

This is the first review comparing these three pathologic entities. Our findings may be useful in understanding this variety of invasive lobular carcinoma, and further studies are certainly needed in this field.

A rare cause of acute gastrointestinal hemorrhage: ileal lipoma Case report

Primary small bowel tumors account for 1-6% of all Gastrointestinal (G.I.) tract malignancies. Among these pedunculated lipomas are unusual. We report a case of a 66-year-old male with a history of G.I. hemorrhage and acute anemia, negative upper and lower endoscopies and a pedunculated lipoma in distal ileum, revealed by CT enterography. The patient was successfully treated by open surgery. Patients with G.I. hemorrhage and negative upper and lower endoscopies need an accurate evaluation of small bowel. Multislice CT enterography or Magnetic Resonance enteroclysis/ enterography represent the fastest and more accurate tools to obtain an exhaustive evaluation of small bowel. In case of small bowel tumors this diagnostic procedures can show site and stage and can even suggest histological type of such neoplasms, with a significant impact in the surgical planning, avoiding time consuming surgical exploration. In this patient multislice TC enterography allowed a correct diagnosis of benign lipoma due to its radiological density and absence of infiltration of the intestinal wall and surrounding tissues.

KEY WORDS

CT enterography, Gastrointestinal hemorrhage, Lipoma, Small bowel.

Neoadjuvant chemotherapy is not a contraindication for nipple sparing mastectomy

BACKGROUND

Nipple-sparing mastectomy (NSM) has been recently implemented to improve cosmetic outcome after mastectomy, but it is rarely considered today after neoadjuvant chemotherapy (NCH).

PATIENTS AND METHODS

Among 275 NSMs performed from January 2007 to January 2015, 186 cases, with a minimum follow-up of 12 months, were carried out for invasive or intraductal carcinoma. Patients were considered for NSM if there were no clinical and radiological evidence of invasion or close proximity (<1 cm) to the nipple-areola complex (NAC). We compared patients operated with NSM after NCH (Group I N = 51) with those who underwent primary surgery (Group II, N = 135).

RESULTS

At a median follow-up of 35 months, 166/186 patients were alive and disease-free (89.7%). Three local relapses (1.6%) were observed, all in the skin flap outside the NAC in Group I: (6%; p < 0.01). No NAC recurrences have been recorded, in either group. Nipple loss due to full thickness necrosis or resection for insufficient margins was recorded in 31 cases (17%); 12 in Group I (24%) and 19 in Group II (14%) (P = 0.1). This event decreased by half in the second part of the study (21/93 vs 10/93) (P = 0.03).

CONCLUSIONS

NSM after NCH is not associated with a statistically significant difference in terms of post-operative complications, total nipple loss for necrosis or margins, and results improve with experience. The loco-regional relapse rate was higher after NCH, yet it was consistent with traditional mastectomy in the high-risk setting. There is no need to avoid NSM after NCH for locally advanced cancers, if the retro-areolar margins of resection are clear at the time of surgery.

[The surgical tratment of the subperitoneal rectal cancer]

AIM

To value the results of "open" surgery with sphincter preservation, TME nerve-sparing, fast-track, without a protective stoma in a consecutive series of patients with subperitoneal rectal cancer (s.p.r.c.).

MATERIALS AND METHODS

In January 1989, we started a prospective, non-randomized study designed to assess when a primary derivative stoma was warranted in a series of consecutive patients electively treated with open low and ultralow AR. The inclusion criteria were: all patients with middle and low rectal cancer who underwent elective low and ultralow AR, including those treated with neoadjuvant therapy. The exclusion criteria were: urgent surgery, incomplete rings in the stapler, a positive hydropneumatic test, preoperative involvement of the external sphincter and/or surrounding structures by the tumor as demonstrated by CT-scan and endorectal MR and/or transrectal ultrasound. Anastomoses between 7 cm and 4 cm from the pectinate line were defined as low colo-rectal anastomoses, while anastomoses lower than 4 cm from the pectinate line were defined as ultralow anastomoses. A fistula or anastomotic dehiscence was suspected when pelvic and/or peritoneal pain, fever, leucocytosis, fecaloid liquid in the drainage and/or perianal erythematosus swelling were present. An anastomotic leak was confirmed by means of angio-CT and/or endoscopy and/or contrast enema depending on the procedure available most promptly. Signs of peritoneal reaction were considered to be indicative of a major dehiscence, regardless of the diameter of the fistula; when diagnosed, a transverse colostomy was immediately performed. Clinically less serious cases were defined as minor dehiscences, for which a "wait and see" strategy or a transcutaneous CT or ultrasound guided drainage of an abscess were used. Sixty-five patients were treated according to a fast-track postoperative protocol.

RESULTS

Between 1998 and 2007, 89 patients with s.p.r.c. were treated according to a prospective protocol. One hundred and nineteen patients (69.6%) underwent low anastomoses and 52 patients (30.4%) underwent ultra low anastomoses. Forty-two (24.6%) were treated with traditional AR, 129 (75.4%) with AR and nerve-sparing TME. Forty-six (26.9%) patients underwent neoadjuvant therapy. One hundred and two patients underwent a mechanical end-to-end anastomosis, 67 a double stapled anastomosis, and 2 a colo-anal anastomosis at the pectinate line performed according to our technique. All 6 patients with major dehiscences underwent a protective colostomy within hours of the onset of clinical symptoms immediately after the radiologically- or endoscopically-confirmed diagnosis. The 7 minor dehiscences were successfully treated with conservative therapy (antibiotic and enteral feeding) using an out-patient regimen. Two (28.6%) required percutaneous drainage: one pelvic CT-guided drainage and the other (an ultralow dehiscence) perineal drainage. The 72.6% of the patients survived at 5-years follow-up. The incidence of local recurrences in 2-years followup was 3.2% (on 124 patients). We had no deaths in patients treated with fast-track protocol.

CONCLUSION

Open, TME nerve-sparing A.R. with selective use of neoadjuvant therapy, can be successfully performed without a protective stoma in more than 80% of the patients. Fast-track protocol seems to increase quality of p.o. period and decrease hospital stay

A new enrichment model for high sensitivity detection and downstream analyses of circulating tumor cells in breast cancer patients

Abstract #4162

The detection of circulating tumor cells (CTCs) in breast cancer patients have the potential to improve prognostication and the monitoring of response to treatment. Most CTC enrichment technologies are based on binding to anti-EpCAM antibodies. The sensitivity of such assays is limited by tumors that express no or undetectable levels of EpCAM. Improvements in CTC detection coupled with the development of systems to interrogate CTCs for therapeutic target expression could lead to novel applications for patient monitoring, clinical diagnosis and treatment. In this study, we describe a sensitive and reproducible enrichment method for CTCs. We defined cells as circulating tumor cells with three criteria: Positive for cytokeratin (CK+) and DAPI (nuclear) (DAPI+) and negative staining for CD45 (CD45-). We have previously reported that this system has a higher sensitivity for circulating tumor cell detection and provides a better platform for CTC downstream analyses compare to the methods currently available in the market. Herein, we describe the use of this platform for the evaluation of breast cancer biomarkers in CTCs. Blood samples from patients with metastatic breast cancer were used for CellSearch™ assay (Veridex , LLC ) and our CTC assay (A1000 CTC enrichment and detection kit, Genetix). We performed the CTC enrichment assay using the combination of anti-CK and anti-EpCAM antibodies. CTCs were identified with brightfield and fluorescence labeled anti-CK, anti-CD45 and DAPI (nuclear stain) images. The Ariol® system (Applied Imaging Corporation) was employed for automated cell image capture and analysis of CTCs on glass slides. CTCs enriched on the glass slides were used for CTC downstream analysis. Our CTC enrichment model is designed to have the capability to enrich all the three types of CTCs including CK+ & EpCAM+, CK+ & EpCAM-/low and CK-/low & EpCAM+ cells. Compared to the enrichment methods using anti-EpCAM or anti-cytokeratin antibody alone, a higher CTC detection rate and a larger dynamic CTC detected range were obtained with our new enrichment model. Interestingly there were clear CTC number differences with enrichment methods in the higher CTC count patient samples which indicate that the different enrichment methods may enrich different types of CTCs from patient blood samples.&#x2028; Results of DNA and RNA FISH analyses on enriched CTCs indicate that the CTCs on glass slides can be used for its downstream analyses directly or indirectly. Our method may have better performance on enrichment of heterogeneous CTCs and provide a better platform for CTCs profiling for biomarker evaluations and CTC downstream analyses.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4162.

Effect of MT1 melatonin receptor deletion on melatonin-mediated phase shift of circadian rhythms in the C57BL/6 mouse

In the mouse suprachiasmatic nucleus (SCN), melatonin activates MT1 and MT2 G-protein coupled receptors, which are involved primarily in inhibition of neuronal firing and phase shift of circadian rhythms. This study investigated the ability of melatonin to phase shift circadian rhythms in wild type (WT) and MT1 melatonin receptor knockout (KO) C57BL/6 mice. In WT mice, melatonin (90 microg/mouse, s.c.) administered at circadian time 10 (CT10; CT12 onset of activity) significantly phase advanced the onset of the circadian activity rhythm (0.60 +/- 0.09 hr, n = 41) when compared with vehicle treated controls (-0.02 +/- 0.07 hr, n = 28) (P < 0.001). In contrast, C57 MT1KO mice treated with melatonin did not phase shift circadian activity rhythms (-0.10 +/- 0.12 hr, n = 42) when compared with vehicle treated mice (-0.12 +/- 0.07 hr, n = 43). Similarly, in the C57 MT1KO mouse melatonin did not accelerate re-entrainment to a new dark onset after an abrupt advance of the dark cycle. In contrast, melatonin (3 and 10 pm) significantly phase advanced circadian rhythm of neuronal firing in SCN brain slices independent of genotype with an identical maximal shift at 10 pm (C57 WT: 3.61 +/- 0.38 hr, n = 3; C57 MT(1)KO: 3.45 +/- 0.11 hr, n = 4). Taken together, these results suggest that melatonin-mediated phase advances of circadian rhythms of neuronal firing in the SCN in vitro may involve activation of the MT2 receptor while in vivo activation of the MT1 and possibly the MT2 receptor may be necessary for the expression of melatonin-mediated phase shifts of overt circadian activity rhythms.

Primary and secondary structure of 26S ribosomal RNA of Oenothera mitochondria

The primary structure of 26S ribosomal RNA from mitochondria of the dicotyledoneous plant Oenothera berteriana is inferred from the sequence of a cloned rDNA restriction fragment. A tentative secondary structure model valid for Oenothera and for the major part of maize mitochondrial 26S rRNA has been constructed in analogy to the refined german model for E. coli L-rRNA (Maly and Brimacombe 1983). The derived structure generally matches the eubacterial model providing further support to the E. coli consensus structure. Some structural features however show eukaryotic characteristics. Possible interactions between L-rRNA, 5S rRNA and initiator-tRNA are discussed.