High Mitotic Index Research Articles

P3-01-08: In Vitro and In Vivo Antitumor Activity of the Aurora and Angiogenic Kinase Inhibitor ENMD-2076 in Triple-Negative Breast Cancer Models.

Abstract Background Triple-negative breast cancer (TNBC) is an aggressive biologic subtype which lacks effective targeted anti-cancer agents and is characterized by a high mitotic index and dependence on angiogenesis. ENMD-2076 is a novel orally bioavailable Aurora and angiogenic kinase inhibitor currently in clinical development with favorable pharmacokinetics and a manageable toxicity profile. The purpose of this study was to use TNBC cell line-based in vitro and in vivo models to demonstrate the antitumor activity of ENMD-2076 towards this breast cancer subtype compared to the luminal and HER2−amplified subtypes. Additionally, we used baseline gene expression profiling and pathway analysis to explore molecular predictors of responsiveness to ENMD-2076 in TNBC. Methods: Twenty-five breast cancer cell lines were exposed to ENMD-2076 and the effects on proliferation, apoptosis, and cell cycle distribution were evaluated. Proliferation was assessed using an SRB assay, apoptosis was analyzed using a caspase 3/7 assay and cell cycle was measured using flow cytometry. In vitro activity of ENMD-2076 was confirmed in 3-D cell culture and in MDA-MB-231 and MDA-MB-468 triple-negative breast cancer xenograft models and immunohistochemical analysis was performed for phosphor-histone H3 (pHH3). Gene array and gene set enrichment analysis (GSEA) was used to identify pathways differentially regulated in the sensitive and resistance cell lines, including within the triple-negative breast cancer subset. Results: In vitro exposure to ENMD-2076 resulted in robust inhibition of proliferation in TNBC cell lines which was associated with a G2 cell cycle arrest and induction of caspase-dependent apoptosis. Of the TNBC cell lines screened, 1 of 10 had a mean IC50 value > 5 μmol/L and 7 of 10 had a mean IC50 ≤ 1 μmol/L (Fisher's exact test, p-value = 0.009). In comparison, only 1 luminal (ER+) and one UER2-amplified breast cancer cell line had an IC50 value < 1, whereas 7 and 5 resistant lines were luminal and HER2−amplified, respectively (Fisher's exact test, p-values = 0.02 and 0.11 for ER and HER2 status, respectively). ENMD-2076 exhibited antitumor activity towards MDA-MD-231 and MDA-MB-468 xenograft models of TNBC with statistically significant tumor growth inhibition compared to vehicle control (p< 0.05 and p< 0.01, respectively). A trend towards an increase in pHH3 staining cells in the MDA-MB-231 ENMD-2076 treated group compared to the vehicle control group was observed; however, this was not statistically significant (104.7 ± 36.2 positive cells/mm2 in treated vs. 79.9 ± 34.5 in control). Using significance of analysis of microarrays (SAM) analysis and GSEA, we identified Ran, a member of the mitotic spindle regulation pathway as upregulated in sensitive TNBC cell lines (p = 0.017). Interestingly, AURKA, the main target of ENMD-2076, is a core gene in this pathway. Conclusions: ENMD-2076 exhibited robust anticancer activity towards preclinical models of TNBC, supporting future clinical investigations of this agent in TNBC with an emphasis on the continued development of biomarkers predictive of response in this breast cancer subset. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-01-08.

P4-09-11: Kinesin Family Member 2C (KIF2C) Is a New Surrogate Prognostic Marker in Breast Cancer (BC).

Abstract Introduction Gene expression microarrays, artificial neural network (ANN), tissue microarray and immunohistochemistry (IHC) techniques allow for the analysis of huge numbers of gene transcripts and their corresponding proteins and have been widely applied in predicting clinical outcome. Methods 1- In this study, we analysed 48,000 gene transcripts of 171 unselected series of BC using ANN and pathways analysis to identify genes that can be used to predict clinical outcome of BC. 2- The clinic-pathological outcome of candidate genes were validated by using IHC in 4 independent primary BC data sets: a) a series of 379 consecutive high risk BC (NPI>3.4) who treated with surgery (S)+ radiotherapy (RT) and did not received neither endocrine (ET) nor chemo-therapies (CT), b) A series of 1650 consecutive cases of BC who treated with S + RT and received adjuvant CMF and/or ET according to Nottingham prognostic index (NPI), menopausal and ER status, c) 250 locally advanced BC treated with anthracycline-based combination with or without Taxane followed by S + RT and d) 145 BC overexpressing HER-2 treated with S + RT followed by sequential adjuvant anthracycline combination CT + trastuzumab. Results Gene expression analysis ANN analysis revealed that KIF2C gene was the highest ranked gene that predicted clinical outcome and accurately differentiated between low and high grade BC based on a 10-fold external cross-validation analysis with an average classification accuracy of >98%. High KIF2C gene expression level was associated with shortest BC specific survival (BCSS), disease free (DFS) and distal metastasis free survivals (DM-FS); p<0.0001. In univariate analysis, high level of KIF2C gene expression was associated with large tumour size, higher lymph node stage, negative ER, positive p53 expression and HER2 overexpression. However in multivariate analysis, KIF2C gene expression level was only statistically associated with histological grade (p<00001) and mitosis (p<0.0001). Pathways analysis revealed that KIF2C is likely to play a significant role in cytokinesis, cell division and cell cycle regulations. Immunohistochemistry 75% of BC showed overexpression of KIF2C protein. KIF2C protein overexpression was associated with unfavourable clinic-pathological features including high grade, high mitotic index, basal like phenotype, triple negative phenotype, HER2 overexpression, TOP2A overexpression, p53 mutation, and loss of BRCA1 (adjusted p<0.0001). In univariate analysis, KIF2C protein overexpression was associated with patient's BCSS in both ER+/high risk patients (NPI > 3.4) who did not received ET (HR: 3.3, 95% CI: 1.2−9.3, p=0.02) and ER-/high risk patients who did not received CT (HR: 3.2, 95% CI: 1.1−8.8, p=0.025). In 1650 BC series, multivariate Cox regression model including validated prognostic factors, confirmed that KIF2C overexpression is an independent prognostic factor. KIF2C overexpression showed increase in the risk of death (HR: 1.5, 95% CI: 1.1−2.0, p=0.009), recurrence (HR: 1.4, 95% CI: 1.1−1.8, p=0.017) and DM (HR: 1.6, 95% CI: 1.2−2.3, p=0.005). In conclusion, our findings provide a new insight to a better understanding of mammary carcinogenesis and that KIF2C is a promising molecular prognostic factor and a potential therapeutic target. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-09-11.

P2-18-03: Systemic Adjuvant Treatment of T1a and T1b N0M0 HER2+ Breast Carcinomas; an AERIO/UNICANCER Study.

Abstract Background: Trials have shown benefit of adjuvant trastuzumab (TZM) for node-positive (N+) or T1c+ HER2−positive breast carcinomas. Methods: Retrospective series in 6 french cancer centers from 2000 to 2010 of T1abN0M0 HER2 positive breast carcinomas. Multifocal tumors were excluded. Results: Two hundred five N- cases were retrieved. Median size was 8 mm (range, 2 to 10 mm), 51 were T1a (25%), 152 tumors were T1b; 120 tumors (59 %) exhibited significant hormonal receptors (HR) expression. All patients had surgery, 65 % (n= 133) had a local irradiation. Ninety percent of HR+ patients (108/120) received hormonotherapy: 77 received aromatase inhibitors (AI) upfront or sequential; 23 received tamoxifen (TAM) alone 13 received LHRH agonists alone or in combination with TAM or AI. Forty-nine percent (n= 101) had chemotherapy (CT) (Anthracycline alone for 41 cases, taxane alone for 31 cases, sequential A/T for 28 cases and concurrent for 1 case), associated with TZM in 90 cases. TZM was administered without chemotherapy in 3 cases. Decision of adjuvant CT and/or TZM was associated with (all p<0.05) HR-negative status, Elston-Ellis grade 2/3 and high mitotic index (MI) while patients with HR+/ low MI tumors were rarely treated (p<0.01). With a 41 months median follow-up, there was a statistically significant difference in invasive recurrences between TZM treated patients and others (log-rank test p=0.04). Twelve of the 112 patients treated without TZM (11%) had a recurrent invasive disease including 6 metastatic cases and 3 fatal events. There was one invasive recurrence in TZM group. There were as much recurrences in T1a as in T1b tumors. Three of the 12 recurrences (25%) in the group without TZM occurred in T1a cases. Conclusion: T1abN0M0 HER2 positive tumors have a significant risk of recurrence which could be avoided by adjuvant chemotherapy associated with TZM. Interestingly, there were no differences in the risk of recurrence between T1a and T1b. Adjuvant chemotherapy associated with TZM should not only be discussed in T1bN0 HER2−positive tumors but also in T1aN0 HER2−positive cases. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-18-03.

Prognostic Factors for Survival post Surgery for Patients with Gastrointestinal Stromal Tumors

Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms located in the alimentary tract. Our aim was to assess the influence of prognostic factors on survival in patients surgically treated for GISTs. Study: One hundred and five patients treated between January 1989 and December 2008 were available for study. A retrospective analysis of prognostic factors (age, gender, mitotic index, tumor location, tumor size, risk of malignant behavior, and coexisting other neoplasm) was performed. Univariate and multivariate survival analyses were undertaken. Results: Univariate analyses revealed the importance of patient gender (p = 0.007), disease location (p = 0.055), mitotic index (p = 0.054) and coexistence with other neoplasms (p = 0.004). However, multivariate analysis showed 3 independently statistically significant factors: coexistence with other neoplasm (RR = 3.53, p = 0.004), male gender (RR = 2.60, p = 0.011) and mitotic index ≧10/50 HPF, (RR = 2.60, p = 0.042). Conclusions: Our study has shown that male gender, a high mitotic index ≧10/50 HPF, and coexistence with other malignant neoplasms were independent poor prognostic factors in patients with GIST. The presence of middle or lower gut disease location leads to an increased risk of mortality when compared with the upper gut.

Modified Natural Clinoptilolite Detoxifies Small Mammal’s Organism Loaded with Lead II: Genetic, Cell, and Physiological Effects

The detoxification capacity of the clinoptilolite modification KLS-10-MA used as food additive in small mammals, chronically lead-exposed, was proven for the first time. The modified clinoptilolite was prepared based on natural Bulgarian clinoptilolite deposits. As a powder, it was mechanically mixed at 12.5% concentration with the conventional forage for small rodents. Lead in the form of aqueous solution of Pb(NO(3))(2) was diluted in the drinking water. In the ecotoxicological experiment covering 90 days, imprinting control region laboratory mice were used. They were allocated into four groups: group 1, (control): animals fed with conventional food for small rodents and water; group 2: animals fed with conventional food + clinosorbent KLS-10-MA and water; group 3: animals fed with conventional food and water + Pb(NO(3))(2); and group 4: animals fed with conventional food + KLS-10-MA and water + Pb(NO(3))(2). A group of non-exposed healthy animals was fed with conventional forage mixed with KLS-10-MA to prove eventual toxicity of the sorbent and influence on growth performance. The changes in the chromosome structure, mitotic index, erythrocyte form, erythropoiesis, and body weight gain were recorded. On day 90, the following relations were established: Pb-exposed and clinoptilolite-supplemented mice exhibited 2.3-fold lower chromosome aberrations frequency, 2.5-fold higher mitotic index, and 1.5-fold higher percentage normal erythrocytes 1.3-fold higher body weight compared to Pb-exposed and unsupplemented animals. The obtained data showed that the sorbent is practically non-toxic. The results of the present study encourage a further elaboration of a reliable drug based on the tested substance in the cases of chronic lead intoxication.

Oncocytic Adrenocortical Tumors

The pathologic diagnosis of adrenocortical carcinoma (ACC) relies on microscopic features that are sometimes equivocal in special variants, including oncocytic adrenocortical tumors (OACTs). We report a series of 27 unpublished OACTs (15 pure and 12 mixed or focal) and assess for the first time in OACTs the diagnostic utility of an algorithm recently proposed by our group ("reticulin" algorithm) for conventional ACCs on the basis of a combination of reticulin staining and assessment of only 3 Weiss parameters. Overall, 12 cases were malignant according to the Lin-Weiss-Bisceglia (L-W-B) system for pure tumors and the original Weiss system for mixed or focal tumors; extensive or focal disruption of the reticulin network was found in 16 of 27 OACTs. This was associated with either a high mitotic index, presence of necrosis, and/or vascular invasion in 14 of these, which were thus considered malignant according to our algorithm. From a clinical standpoint, OACTs, at least in the pure form, are "low grade" lesions with a low mean Weiss score, mitotic and Ki-67 indices, and uncommon capsular or vascular invasion. They, including unequivocal morphologically malignant cases, generally pursue an indolent clinical course. In addition, the 4977 bp mitochondrial DNA "common deletion" was detected using real-time polymerase chain reaction in 54% of cases from this study and an additional validation series of 23 OACTs, with a heterogenous (heteroplasmic) intratissue and intracellular distribution (as detected by a modified FISH procedure) and a marked association with the presence of intact reticulin framework.

Extraskeletal Osteosarcoma of the Hand

IntroductionExtraskeletal osteosarcoma (ESOS) is a rare tumour thatdoes not typically present in the hand. We describe a caseof ESOS, a rare soft tissue tumour, arising in the hand as arecurrent soft tissue lump. Establishing a histologicaldiagnosis can be difficult in this rare tumour. This casereport highlights the difficulty in the diagnosis andtreatment of this rare sarcoma.Case ReportA 56-year-old man presented with a swelling in his rightpalm that had increased in size for 3 months. He had fullfunction of his hand but complained of paraesthesia in hismiddle finger and radial half of his ring finger. There wasno history of injury or other comorbidity.On examination, there was a 3 cm, firm, non-tender,lobulated swelling in the centre of the right palm with noattachment to the skin or flexor tendons. His hand wasneurovascularly intact, with full range of movement, andthere was no axillary lymphadenopathy.Magnetic resonance imaging (MRI) showed a 3.9×2.9×2.5 cm mass in the superficial and deep compart-ments of the palm interposed between the flexortendons (Fig. 1). Ultrasound-guided needle core biopsyshowed no high-grade malignancy, but was non-diagnostic. He underwent function-preserving marginalexcision of the lesion. Histology showed a spindle celltumour of uncertain malignant potential with few mitoses,chondromyxoid areas and no osteoid (Fig.2), with clearexcision margins.Four months after excision, there was clinical and MRIevidence of local recurrence. Incisional biopsy showed ahighly cellular spindle cell neoplasm with a high mitoticindex, nuclear pleomorphism, areas of necrosis andosteochondroid foci. The diagnosis of high-grade ESOSwas confirmed by two musculoskeletal pathologists.No metastases were identified on computed tomography(CT) of the chest, abdomen and pelvis or radioisotope bonescan. He was commenced on doxorubicin and cisplatinchemotherapy. Clinical examination (Fig. 3)andMRI(Fig. 4) after completion of two cycles of chemotherapyshowed an increase in the size of the tumour. As the tumourwas non-responsive to chemotherapy and not amenable tolimb salvage, he underwent radical resection (below-elbowamputation). Resection histology confirmed ESOS withlittle necrosis. Following surgery, his chemotherapyregimen was changed to ifosfamide and etoposide.However, pulmonary metastases were detected onfollow-up chest imaging at 11 months, and he died ofadvanced metastatic disease.DiscussionESOS accounts for 1.2% of soft tissue sarcomas and 3.7–4.6% of osteosarcomas [2]. It is a tumour that arises in the

Exon 11 mutations, Ki67, and p16 INK4A as predictors of prognosis in patients with GIST

Prognostic biomarkers for GIST are under investigation. The aim of this study was to assess whether exon 11 mutations, Ki67, and p16 INK4A are predictors of prognosis in GIST. Consecutive GIST cases ( n = 84) had their specimens evaluated for exon 11 mutations and expression of Ki67 and p16 INK4A. Surgical cases were categorized according to NIH and Miettinen's classification, and survival was analyzed from hospital database. GISTs were predominately gastric (45%) and with spindle cell morphology (74%). The risk category was very low or low in 28%, intermediate in 23%, and high in 49%. Exon 11 mutation was identified in 29 (48%) out of 60 cases studied. There were 12 point mutations, 10 deletions, 4 duplications, and 3 double mutations. A third of GISTs had either high Ki67 index (>3%) or negativity for p16 INK4A. In multivariate analysis, independent predictors of mortality were Ki67 > 3% (HR = 7.3; P = 0.036) and high mitotic index (HR = 10.4; P = 0.043). There was no association between exon 11 mutations and survival. This study suggests that Ki67 > 3% is an independent predictor of poor prognosis in patients with GIST. Exon 11 mutations and negativity for p16 INK4A need further studies to address the prognostic value.

Fine‐needle aspiration cytology of triple‐negative basal‐like breast cancer

Invasive breast cancer is divided into luminal A, luminal B, HER2 overexpression, basal-like (BL) and normal-like subtypes, among which the BL subtype has the worst prognosis. The purpose of this study was to determine the clinicopathological and cytological characteristics of BL breast cancer (BLBC). Fine-needle aspiration cytology samples from 17 patients with consecutive BLBC were investigated, and the findings were compared with those of other subtypes (10 cases each) for the following cytomorphological features: necrosis; lymphocyte infiltration; mitotic index; apoptosis; naked nuclei; nuclear/cytoplasmic ratio; nuclear margin, size and pleomorphism; chromatin granularity and density; and nucleolar appearance. Histologically, the BLBCs were heterogeneous, and included medullary carcinoma and metaplastic carcinoma, in addition to invasive ductal carcinoma. Cytologically, high mitotic index, naked nuclei, and irregular nuclear margin were significantly observed when compared with both the luminal A and B subtypes. Large nuclei with nucleoli and lymphocyte infiltration were frequently seen compared with the luminal A and B subtypes, respectively. Squamous nodules were seen in all metaplastic cases, but not in the HER2 overexpression subtype. Lymphocyte infiltration, squamous metaplasia, and nuclear findings such as a high mitotic index, naked or large nuclei, an irregular nuclear margin and the presence of nucleoli, may be clues indicating BLBC.

Leiomiossarcoma cutâneo no tronco

Cutaneous leiomyosarcoma is a relatively uncommon tumor that accounts for 7% of all soft tissue sarcomas. It occurs more frequently in males between 50-70 years and only 10-15% of cases are located on the trunk. Radiotherapy and previous trauma have been implied as risk factors. We report the case of a 57 year-old male with an eight-month history of a hard painless erythematous-violaceous tumor on the presternal region. Histopathology evidenced a malignant spindle cell tumor, "cigar" shaped, with pleomorphic nuclei and a high mitotic index that occupied the entire dermal thickness. Immunohistochemical staining of the tumor cells was positive for smooth muscle actin, desmin and vimentin and negative for S-100 protein and pan-cytokeratin, which supported the diagnosis of dermal leiomyosarcoma. Radical surgery was performed to remove the tumor.

Clinical Pathologic Conference Case 3: Nodular Fasciitis

Intraoral nodular nodular fasciitis is a rare entity that is important to recognize because it may simulate a malignancy clinically and histologically. The rapid growth and high mitotic index seen in nodular fasciitis may suggest a malignant neoplastic process, but it is generally considered to be a benign reactive proliferation. Recognizing the unique histologic features of nodular fasciitis is important to avoid a possible misdiagnosis as a malignancy, leading to unnecessary further treatment.

Clinicopathologic features and prognostic factors of endometrial stromal sarcoma: a study of 55 cases

To investigate the clinicopathologic features and the prognostic factors of endometrial stromal sarcoma (ESS). 55 cases of endometrial stromal sarcoma were reviewed and categorized into 3 pathologic types based on the related literatures, i.e., low grade endometrial stromal sarcoma (LGESS), undifferentiated endometrial sarcoma with nuclear uniformity (UES-U) and undifferentiated endometrial sarcoma with nuclear pleomorphism (UES-P). Meanwhile, the pathologic features were reviewed, including fibroid, myoid, mucoid, and epithelioid differentiation and mitotic index. Clinical and follow-up data were collected. In endometrial stromal sarcoma, two or three pathologic types co-existed in one case, including 12.8% (5/39) of LGESS, 5/9 of UES-U, and 5/7 of UES-P. Mitotic index varied in different regions of one tumor from rare to high. Multi-differentiation was also commonly seen in ESS. The numbers of cases in LGESS, UES-U and UES-P were 39, 9 and 7, with recurrence rate of 51.6% (16/31), 5/6 and 2/3, respectively. There was no death case in LGESS, and 2 cases were died in UES-U and UES-P, respectively. In the 2 death cases of UES-U, both had focus of UES-P. There was a significant difference in the recurrence rate between cases with different mitotic index (≥ 10/10 HPF and < 10/10 HPF, P = 0.009), especially in LGESS group. All death cases had high mitotic index (> 30/10 HPF). It is a common phenomenon in ESS that two or three pathologic types may exist in one case, especially in UES-U and UES-P. And multi-differentiation is also commonly seen in ESS. So adequate pathologic sampling is important for pathologists to make a correct diagnosis of ESS in daily work. The recurrence rates are significantly higher in cases with high mitotic index, especially in LGESS. In addition, the presence of UES-P and high mitotic index may increase the risk of death in the patients.

Microenvironmental Influence on Pre-Clinical Activity of Polo-Like Kinase Inhibition in Multiple Myeloma: Implications for Clinical Translation

Polo-like kinases (PLKs) play an important role in cell cycle progression, checkpoint control and mitosis. The high mitotic index and chromosomal instability of advanced cancers suggest that PLK inhibitors may be an attractive therapeutic option for presently incurable advanced neoplasias with systemic involvement, such as multiple myeloma (MM). We studied the PLK 1, 2, 3 inhibitor BI 2536 and observed potent (IC50<40 nM) and rapid (commitment to cell death <24 hrs) in vitro activity against MM cells in isolation, as well as in vivo activity against a traditional subcutaneous xenograft mouse model. Tumor cells in MM patients, however, don't exist in isolation, but reside in and interact with the bone microenvironment. Therefore conventional in vitro and in vivo preclinical assays don't take into account how interactions between MM cells and the bone microenvironment can potentially confer drug resistance. To probe this question, we performed tumor cell compartment-specific bioluminescence imaging assays to compare the preclinical anti-MM activity of BI 2536 in vitro in the presence vs. absence of stromal cells or osteoclasts. We observed that the presence of these bone marrow non-malignant cells led to decreased anti-MM activity of BI 2536. We further validated these results in an orthotopic in vivo mouse model of diffuse MM bone lesions where tumor cells interact with non-malignant cells of the bone microenvironment. We again observed that BI 2536 had decreased activity in this in vivo model of tumor-bone microenvironment interactions highlighting that, despite BI 2536's promising activity in conventional assays, its lack of activity in microenvironmental models raises concerns for its clinical development for MM. More broadly, preclinical drug testing in the absence of relevant tumor microenvironment interactions may overestimate potential clinical activity, thus explaining at least in part the gap between preclinical vs. clinical efficacy in MM and other cancers.

Complicações Orais em Pacientes em Tratamento Quimioterápico na Unacon, no Município de Itajaí/SC

Chemotherapy affects cells with high mitotic index. Lesions in the oral cavity are the most frequent complication of antineoplastic chemotherapy, because of the high sensitivity of oral tissues and structures to the toxic effects of the chemotherapics. The objective of this work was to register the most common oral complications found in patients undergoing to cancer chemotherapy, determining the frequency of the lesion and the possible interaction with the medication in use. This work was conducted at CEPON (Oncological Center Care), in Itajai (SC), Brazil. Patients’ reports were analyzed and personal data, therapeutic plan and the type of the tumor information were registered. An oral clinical examination was performed to detect buccal manifestations. The data were registered by the distributing the frequency of each episode in accordance with age, gender, and therapeutic modality. The results showed that the most frequent gender was female (60%); in both genders, the age was over 50 years (57,8%); breast cancer was the most incident tumor (11 episodes); oral manifestations found were xerostomy (46 episodes), aphtha (2 episodes), herpes simplex (2 episodes) and candidiases (1 episode). In conclusion the females older than 50 years were the most affected. Most patients had some oral manifestation with a highest incidence of oral dryness, and it was related with many different chemotherapics, being a xerostomy-induced medication.

KI 67 in patients (pts) with breast cancer (BC) younger than age 35: A comparison with older patients treated in a single institution.

e21003 Background: The prognosis of pts 35 years of age or less is very poor. We studied a cohort of pts treated in the same institution for primary breast cancer. The aim of the study was to compare KI67 as well as histoprognostic grading (SBR), mitotic index (MI), estradiol, progesterone receptors (ER, PR) and HER2 according to age. Methods: 43 pts less than 35 years old were treated between January 1, 2006 and December 31, 2008 and 359 pts more than 35 years treated in 2006. Biomarker studies were performed on surgical specimens or tumor biopsy if neoadjuvant chemotherapy was performed. All pathological studies were performed in the same laboratory. Results: Young pts have a higher median value of KI67 (30% [3-95] vs 10% [0-90], p< 0.0001), more frequent grade 3 carcinoma (44% versus 28%, p=0.04) and higher grade 3 MI (35% vs 13%, p<0.001). Positive ER was observed in 56% of tumors in young pts vs 87% (p< 0.001), Positive PR in 38% vs 68% (p<0.001). Moreover, the Immunohistochemistry intensity was lower in young ptrs: 50% of high intensity for the ER vs 74% in older pts (p=0.02). Intensity was similar for PR :60% vs 62% respectively (p=0.87). HER2 wa more frequently amplified in young pts (24% vs 10%, p=0.007). Finally, young pts had more frequently a triple negative tumor (31% vs 8%, p<0.001). In this subgroup, young pts had a higher median Ki67 (70 [10-95] vs 38 [2-80], p=0.06) but grade 3 and MI were similar (67% of grading 3 vs 81%, p=0.34 and 50% of MI 3 in the two populations). Conclusions: Pts less than 35 years have more frequently high KI 67 values, grade 3 tumors, high MI, negative or poorly positive hormone receptors. Furthermore, they are more frequently HER2 positive.

Tumor Characteristics Associated With Mammographic Detection of Breast Cancer in the Ontario Breast Screening Program

Few studies have compared the prognostic value of tumor characteristics by type of breast cancer diagnosed in the interval between mammographic screenings with screen-detected breast cancers. We conducted a case-case study within the cohort of women (n = 431 480) in the Ontario Breast Screening Program who were aged 50 years and older and were screened between January 1, 1994, and December 31, 2002. Interval cancers, defined as breast cancers diagnosed within 24 months after a negative screening mammogram, were designated as true interval cancers (n = 288) or missed interval cancers (n = 87) if they were not identified at the time of screening but were identified in retrospect. Screen-detected breast cancers (n = 450) were selected to match interval cancers. Tumors were evaluated for stage, grade, mitotic index, histology, and expression of hormone receptors and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by conditional logistic regression. Both true and missed interval cancers were of higher stage and grade than matched screen-detected breast cancers. However, true interval cancers had a higher mitotic index (OR = 3.13, 95% CI = 1.81 to 5.42), a higher percentage of nonductal histology (OR = 1.94, 95% CI = 1.05 to 3.59), and were more likely to be both estrogen receptor-negative (OR = 2.09, 95% CI = 1.32 to 3.30) and progesterone receptor-negative (OR = 2.49, 95% CI = 1.68 to 3.70) compared with matched screen-detected tumors. In this study, interval cancers were of higher stage and grade compared with screen-detected cancers. True interval cancers were more likely to have additional adverse prognostic features of estrogen and progesterone receptor negativity and nonductal morphology. The findings suggest a need for more sensitive screening modalities to detect true interval breast cancers and different approaches for early detection of fast-growing tumors.

Abstract LB-58: Spontaneous Epstein Barr virus-associated lymphomagenesis in primary human solid tumor xenografts

Abstract Xenotransplantation of primary human solid tumors into immunodeficient mice is widely utilized as a tool for the study of human cancer biology. We have generated subcutaneous xenografts from a large number of human hepatocellular carcinoma (HCC) resection specimens, and have observed that subcutaneous implantation of tumor fragments or bulk cell suspensions results in a much higher rate of primary engraftment than implantation of cells sorted to exclude CD45+ leukocytes in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice. While the majority of xenografts arising from tumor fragments or bulk tumor cells retain typical characteristics of parent HCCs, we have noted the frequent development of very rapidly-growing tumors that do not share these attributes, and sought to further characterize these tumors. Histopathological analysis of these tumors revealed monomorphic populations of lymphoid cells demonstrating nuclear atypia, high mitotic index, and invasion into surrounding tissues. Flow cytometry and immunohistochemistry revealed that these tumors consisted almost completely of cells expressing the human leukocyte antigen CD45 and the human B-cell antigen CD20. In situ hybridization demonstrated strong expression of the Epstein-Barr virus (EBV)-encoded small RNA (EBER) in all tumors. Staining of tumors for mouse H2K expression was negative in all cases. These findings suggest that the originally implanted human HCC tumor fragments or bulk tumor cells were replaced by human B-cell lymphomas. No lymphomas arose from the implantation of human HCC cells that were sorted to exclude human CD45+ leukocytes. Histopathological re-examination of the parent tumors in all cases confirmed a diagnosis of HCC with no evidence of lymphoma. Analogous to post-transplant lymphoproliferative disorder (PTLD) in humans, our data suggest that these lymphomas spontaneously developed in xenografts through EBV-mediated transformation of EBV-infected passenger lymphocytes harbored in patient tumors in the permissive context of an immunodeficient host environment. Recognition of this phenomenon is important for those utilizing primary human tumor tissue in xenotransplantation assays, because the development of lymphomas may confound accurate analysis of tumor biology and may out-compete the tumor type of interest resulting in the loss of valuable experimental samples. Our observations highlight an important potential pitfall of human solid tumor xenotransplantation assays in models where primary engraftment requires the implantation of bulk cells or tumor fragments which may contain passenger lymphocytes. In such circumstances, our observations underscore the critical importance of routinely quantifying the degree of human lymphocyte “contamination” in xenograft-derived data and implementing strategies to deplete or eliminate human lymphocytes from these assays. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-58. doi:10.1158/1538-7445.AM2011-LB-58

Abstract 5364: AURA kinases as markers and targets in GIST

Abstract Mitotic index has been found to be an important prognostic factor in primary gastrointestinal stromal tumor (GIST). By using gene sets related to cell cycle (Proc Natl Acad Sci U S A. 2008; 22;105(3):955-60), we can stratify a group of patients with advanced GIST (J Clin Oncol 2008;26:4100-4108.) into two risk groups with distinct survival. So it is interesting to explore whether genes involved in regulation of cell cycle could be used as a target in treating GIST. Aurora kinase A (AURKA) and B (AURKB) were two important genes in cell cycle regulation. In the same cohort of patients, expression levels of both AURKA and AURKB were found higher in high risk group patients than those in low risk group. By using MTT assay, GIST882, an imatinib-sensitive GIST cell line, was relatively resistant to both AURKA inhibitor MLN8237 and AURKB inhibitor ZM447439 than GIST 48IM, an imatinib-resistant GIST cell line. MLN8237 could induce significant cell cycle arrest in both GIST cell lines, but apoptosis could only be seen in GIST48IM. On the other hand, after ZM447439 treatment, cell cycle inhibition could only be found in GIST48IM, and none of them had apoptosis. Instead, ZM447439 could induce autophagy in both cell lines. We then used immunohistochemistry (IHC) to examine 76 primary GIST patients. High expression of AURKA but not AURKB was more often seen in non-gastric GIST. In univariate analysis, patients with tumors having strong AURKA IHC staining, as well as large tumor size, high mitotic index and NIH high risk group, had significant lower survival than comparative groups. However, in the multivariate analysis, only high mitotic count and high AURKA expression were independent adverse prognostic factors. In conclusion, cell cycle-related genes could be used in predicting prognosis in advanced GIST, and cell cycle regulated genes such as AURKA and AURKB could be used as treatment targets. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5364. doi:10.1158/1538-7445.AM2011-5364

Low-density lipoprotein receptor–related protein 1 is associated with proliferation and invasiveness in Her-2/ neu and triple-negative breast carcinomas

Low-density lipoprotein receptor-related protein 1, a member of the low-density lipoprotein cholesterol receptor family, has been implicated in the progression of certain tumors; but it remains unclear whether it plays a role in infiltrating ductal breast carcinomas. We studied a series of 81 ductal breast tumors to determine the correlation of low-density lipoprotein receptor-related protein 1 overexpression with clinicopathologic and immunohistochemical characteristics associated with prognosis. Low-density lipoprotein receptor-related protein 1 overexpression was identified in 14% (11/81) of tumors and was correlated with a high nuclear grade (P = .043), high mitotic index (P = .006), and Ki-67 greater than 20% (P = .047). Furthermore, low-density lipoprotein receptor-related protein 1 expression was associated with aggressive carcinomas (triple-negative tumors [21%, 7/33] and Her-2/neu tumors [17%, 4/24]) but not with hormone-dependent carcinomas (0%, 0/24) (P = .040). There was no correlation between low-density lipoprotein receptor-related protein 1 expression and survival, but a trend was found between low-density lipoprotein receptor-related protein 1 overexpression and tumor recurrence. Low-density lipoprotein receptor-related protein 1 overexpression was related to proliferation and invasiveness in Her-2/neu and triple-negative breast carcinoma. Moreover, patients with low-density lipoprotein receptor-related protein 1-positive tumors had higher cholesterol levels (62.5%, 5/8) than those with low-density lipoprotein receptor-related protein 1-negative tumors (40%, 19/47). Nevertheless, the correlation between low-density lipoprotein receptor-related protein 1 and hypercholesterolemia was not statistically significant; but cholesterol levels were higher in patients with triple-negative breast carcinoma (60%, 15/25) and Her-2/neu carcinomas (40%, 6/15) than in luminal-A carcinomas (20%, 3/15) (P = .046). These findings suggest a relationship between hypercholesterolemia and aggressiveness of ductal breast carcinomas.

Surgical outcomes of gastrointestinal stromal tumors of the stomach: a single unit experience in the era of targeted drug therapy

The stomach is the most common site of gastrointestinal stromal tumors (GISTs), but the surgical outcomes of gastric GISTs in the era of targeted drug therapy are unclear. This study aimed to assess factors associated with adverse outcomes and to analyze the effects of targeted drug therapy on gastric GISTs. The surgical outcomes and follow-up records of consecutive patients with gastric GISTs treated at Tianjin Medical University Cancer Institute & Hospital between June 2002 and December 2008 were reviewed. Eighty-five patients were included. Surgery was undertaken in all patients with curative intent. Imatinib mesylate was administered preoperatively to 6 (7%) patients (neoadjuvant therapy), and the median durations of therapy were 6 months (range 3-17 months). Imatinib mesylate was administered postoperatively to 18 (21%) patients with high-risk lesions (adjuvant therapy) and 19 (22%) patients with recurrent disease, and the median durations of therapy were 22 months (range 6-24 months) and 25 months (range 1-64 months), respectively. Tumor size greater than 10 cm (P = 0.015), high mitotic index (P = 0.021), and no adjuvant imatinib therapy (P = 0.046) were the only significant factors associated with higher recurrence-free survival in multivariate analysis. Large tumors, high mitotic index, and the absence of imatinib treatment are associated with high recurrence-free survival. Adjuvant imatinib therapy of 2 years appears to decrease the recurrence of gastric GISTs.