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Dive into the research topics where Antonio Santillan is active.

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Featured researches published by Antonio Santillan.


Cancer | 2007

Secondary cytoreductive surgery for localized, recurrent epithelial ovarian cancer: analysis of prognostic factors and survival outcome.

Ritu Salani; Antonio Santillan; Marianna Zahurak; Robert L. Giuntoli; Ginger J. Gardner; Deborah K. Armstrong; Robert E. Bristow

The objective of this study was to evaluate the role of secondary cytoreductive surgery in the outcome of patients who had recurrent epithelial ovarian carcinoma that was limited to ≤5 recurrence sites within the abdomen or pelvis on preoperative imaging studies and attempt to define selection criteria associated with improved survival, with specific attention to the number of lesions suspicious for recurrent disease.


Gynecologic Oncology | 2011

Identification of patient groups at highest risk from traditional approach to ovarian cancer treatment

Giovanni D. Aletti; Eric L. Eisenhauer; Antonio Santillan; Allison E. Axtell; Giacomo Aletti; Christine H. Holschneider; Dennis S. Chi; Robert E. Bristow; William A. Cliby

OBJECTIVE Define subgroups of patients at highest risk for major morbidity and mortality after a traditional approach of maximal surgical efforts followed by chemotherapy for advanced ovarian cancer (AOC). METHODS Preoperative health, intra-operative findings and outcomes were assessed in consecutive patients with primary AOC from 4 centers. Initial tumor dissemination was stratified into 3 groups based on volume of disease. Surgery was categorized using a previously described surgical complexity score (SCS). Statistical analysis was directed toward validating a multivariable risk-adjusted model. RESULTS 576 patients with stage IIIC (N=447, 77.6%) or IV AOC (N=129, 22.4%) were analyzed. Age (HR (per year): 1.02; 95%CI: 1.01-1.03), high tumor dissemination (HTD) (HR: 1.73; 95%CI: 1.19-2.56), residual disease (RD) >1 cm (HR: 2.46; 95%CI: 1.74-3.53), and stage IV (HR: 1.93; 95% CI: 1.51-2.45), independently correlated with OS. We identified a small subgroup of patients who comprised a high-risk group (N=38, 6.6%) characterized by all of the following characteristics: high initial tumor dissemination (HTD) or stage IV plus poor performance or nutritional status plus age ≥ 75. In this group, high SCS to achieve low RD was associated with morbidity of 63.6% and limited survival benefit. CONCLUSIONS Optimal management of AOC requires accurate, risk-adjusted predictors of outcomes allowing a tailored approach starting with primary therapy. Complex surgical procedures to render low RD improve survival, and in the majority of cases, the benefits of such surgery appear to outweigh the morbidity. However careful analysis identifies a subgroup of patients in whom an alternative approach may be the better strategy.


Journal of Clinical Oncology | 2005

Risk of Epithelial Ovarian Cancer Recurrence in Patients With Rising Serum CA-125 Levels Within the Normal Range

Antonio Santillan; Ruchi Garg; Marianna Zahurak; Ginger J. Gardner; Robert L. Giuntoli; Deborah K. Armstrong; Robert E. Bristow

PURPOSE To evaluate the risk of epithelial ovarian cancer (EOC) recurrence in patients with rising serum cancer antigen 125 (CA-125) levels that remain below the upper limit of normal (< 35 U/mL). PATIENTS AND METHODS All patients treated for EOC between September 1997 and March 2003 were identified and screened retrospectively for the following: (1) elevated serum CA-125 at time of diagnosis, (2) complete clinical and radiographic response (CR) to initial treatment with normalization of serum CA-125, (3) at least three serial serum CA-125 determinations that remained within the normal range, and (4) clinical and/or radiographic determination of disease status at the time of last follow-up or recurrence. For statistical analyses, univariate regression models were used to compare absolute and relative changes in CA-125 levels among patients with recurrent disease and those without EOC recurrence. RESULTS A total of 39 patients satisfied study inclusion criteria; 22 patients manifested EOC recurrence at a median interval from complete response of 11 months. The median follow-up time from complete response to last contact was 32 months for the 17 patients in the no recurrence group. A relative increase in CA-125 of 100% (odds ratio [OR] = 23.7; 95% CI, 2.9 to 192.5; P = .003) was significantly predictive of recurrence. From baseline CA-125 nadir levels, an absolute increase in CA-125 of 5 U/mL (OR = 8.4; 95% CI, 2.2 to 32.6; P = .002) and 10 U/mL (OR = 71.2; 95% CI, 4.8 to > 999.9; P = .002) were also significantly associated with the likelihood of concurrent disease recurrence. CONCLUSION Among patients with EOC in complete clinical remission, a progressive low-level increase in serum CA-125 levels is strongly predictive of disease recurrence.


Cancer Research | 2006

Ubiquitin-Proteasome System Stress Sensitizes Ovarian Cancer to Proteasome Inhibitor–Induced Apoptosis

Martina Bazzaro; Michael K. Lee; Alessia Zoso; Wanda Stirling; Antonio Santillan; Ie Ming Shih; Richard Roden

The ubiquitin-proteasome system (UPS) mediates targeted protein degradation. Notably, the UPS determines levels of key checkpoint proteins controlling apoptosis and proliferation by controlling protein half-life. Herein, we show that ovarian carcinoma manifests an overstressed UPS by comparison with normal tissues by accumulation of ubiquitinated proteins despite elevated proteasome levels. Elevated levels of total ubiquitinated proteins and 19S and 20S proteasome subunits are evident in both low-grade and high-grade ovarian carcinoma tissues relative to benign ovarian tumors and in ovarian carcinoma cell lines relative to immortalized surface epithelium. We find that ovarian carcinoma cell lines exhibit greater sensitivity to apoptosis in response to proteasome inhibitors than immortalized ovarian surface epithelial cells. This sensitivity correlates with increased cellular proliferation rate and UPS stress rather than absolute proteasome levels. Proteasomal inhibition in vitro induces cell cycle arrest and the accumulation of p21 and p27 and triggers apoptosis via activation of caspase-3. Furthermore, treatment with the licensed proteasome inhibitor PS-341 slows the growth of ES-2 ovarian carcinoma xenograft in immunodeficient mice. In sum, elevated proliferation and metabolic rate resulting from malignant transformation of the epithelium stresses the UPS and renders ovarian carcinoma more sensitive to apoptosis in response to proteasomal inhibition.


Proceedings of the National Academy of Sciences of the United States of America | 2006

A BTB/POZ protein, NAC-1, is related to tumor recurrence and is essential for tumor growth and survival

Kentaro Nakayama; Naomi Nakayama; Ben Davidson; Jim Jinn Chyuan Sheu; Natini Jinawath; Antonio Santillan; Ritu Salani; Robert E. Bristow; Patrice J. Morin; Robert J. Kurman; Tian Li Wang; Ie Ming Shih

Recent studies have suggested an oncogenic role of the BTB/POZ-domain genes in hematopoietic malignancy. The aim of this study is to identify and characterize BTB/POZ-domain genes in the development of human epithelial cancers, i.e., carcinomas. In this study, we focused on ovarian carcinoma and analyzed gene expression levels using the serial analysis of gene expression (SAGE) data in all 130 deduced BTB/POZ genes. Our analysis reveals that NAC-1 is significantly overexpressed in ovarian serous carcinomas and several other types of carcinomas. Immunohistochemistry studies in ovarian serous carcinomas demonstrate that NAC-1 is localized in discrete nuclear bodies (tentatively named NAC-1 bodies), and the levels of NAC-1 expression correlate with tumor recurrence. Furthermore, intense NAC-1 immunoreactivity in primary tumors predicts early recurrence in ovarian cancer. Both coimmunoprecipitation and double immunofluorescence staining demonstrate that NAC-1 molecules homooligomerize through the BTB/POZ domain. Induced expression of the NAC-1 mutant containing only the BTB/POZ domain disrupts NAC-1 bodies, prevents tumor formation, and promotes tumor cell apoptosis in established tumors in a mouse xenograft model. Overexpression of full-length NAC-1 enhanced tumorigenicity of ovarian surface epithelial cells and NIH 3T3 cells in athymic nu/nu mice. In summary, NAC-1 is a tumor recurrence-associated gene with oncogenic potential, and the interaction between BTB/POZ domains of NAC-1 proteins is critical to form the discrete NAC-1 nuclear bodies and essential for tumor cell proliferation and survival.


Clinical Cancer Research | 2008

Ubiquitin Proteasome System Stress Underlies Synergistic Killing of Ovarian Cancer Cells by Bortezomib and a Novel HDAC6 Inhibitor

Martina Bazzaro; Zhenhua Lin; Antonio Santillan; Michael K. Lee; Mei Cheng Wang; Kwun Chuen Gary Chan; Robert E. Bristow; Ralph Mazitschek; James E. Bradner; Richard Roden

Purpose: Elevated metabolic activity of ovarian cancer cells causes increased ubiquitin-proteasome-system (UPS) stress, resulting in their greater sensitivity to the toxic effects of proteasomal inhibition. The proteasomes and a potentially compensatory histone deacetylase 6 (HDAC6)-dependent lysosomal pathway mediate eukaryotic protein turnover. We hypothesized that up-regulation of the HDAC6-dependent lysosomal pathway occurs in response to UPS stress and proteasomal inhibition, and thus, ovarian cancer cell death can be triggered most effectively by coinhibition of both the proteasome- and HDAC6-dependent protein degradation pathways. Experimental Design: To address this hypothesis, we examined HDAC6 expression patterns in normal and cancerous ovarian tissues and used a novel HDAC6-specific inhibitor, NK84, to address HDAC6 function in ovarian cancer. Results: Abnormally high levels of HDAC6 are expressed by ovarian cancer cells in situ and in culture relative to benign epithelium and immortalized ovarian surface epithelium, respectively. Specific HDAC6 inhibition acts in synergy with the proteasome inhibitor Bortezomib (PS-341) to cause selective apoptotic cell death of ovarian cancer cells at doses that do not cause significant toxicity when used individually. Levels of UPS stress regulate the sensitivity of ovarian cancer cells to proteasome/HDAC6 inhibition. Pharmacologic inhibition of HDAC6 also reduces ovarian cancer cell spreading and migration consistent with its known function in regulating microtubule polymerization via deacetylation of α-tubulin. Conclusion: Our results suggest the elevation of both the proteasomal and alternate HDAC6-dependent proteolytic pathways in ovarian cancer and the potential of combined inhibition of proteasome and HDAC6 as a therapy for ovarian cancer.


Cancer | 2007

Centralization of care for patients with advanced-stage ovarian cancer: a cost-effectiveness analysis.

Robert E. Bristow; Antonio Santillan; Teresa P. Díaz-Montes; Ginger J. Gardner; Robert L. Giuntoli; Benjamin C. Meisner; Kevin D. Frick; Deborah K. Armstrong

The objective of this study was to evaluate the cost‐effectiveness of centralized referral of patients with advanced‐stage epithelial ovarian cancer who underwent primary cytoreductive surgery and adjuvant chemotherapy.


Gynecologic Oncology | 2010

Surveillance for the detection of recurrent ovarian cancer: Survival impact or lead-time bias?

Edward J. Tanner; Dennis S. Chi; Eric L. Eisenhauer; Teresa P. Díaz-Montes; Antonio Santillan; Robert E. Bristow

OBJECTIVE To compare the survival impact of diagnosing recurrent disease by routine surveillance testing versus clinical symptomatology in patients with recurrent epithelial ovarian cancer (EOC) who have achieved a complete response following primary therapy. METHODS We identified all patients who underwent primary surgery for EOC at two institutions between 1/1997 and 12/2004 and were diagnosed with recurrent disease following a complete clinical response to primary chemotherapy. Survival and post-recurrence management were compared between asymptomatic patients in which recurrent disease was diagnosed at a scheduled visit by routine surveillance testing and symptomatic patients in which recurrent disease was diagnosed based on clinical symptomatology at an unscheduled office visit or hospitalization. RESULTS Of the 121 patients that met inclusion criteria, 22 (18.2%) were diagnosed with a symptomatic recurrence. Median primary PFS was similar for asymptomatic and symptomatic patients (24.8 versus 22.6 months, P = 0.36); however, post-recurrence survival was significantly greater in asymptomatic patients (45.0 versus 29.4 months, P = 0.006). Secondary cytoreductive surgery (SCRS) was attempted equally in both groups (41% versus 32%, P = NS); however, optimal residual disease (<or=5mm) was more often achieved in asymptomatic patients (90% versus 57%, P = 0.053). On multivariate analysis, detection of asymptomatic recurrence was a significant and independent predictor of improved overall survival (P = 0.001). Median OS was significantly greater for asymptomatic patients (71.9 versus 50.7 months, P = 0.004). CONCLUSIONS In patients with platinum-sensitive EOC, detection of asymptomatic recurrences by routine surveillance testing was associated with a high likelihood of optimal SCRS in operative candidates and extended overall survival.


Gynecologic Oncology | 2009

p53 autoantibodies, cytokine levels and ovarian carcinogenesis

Miyun Tsai-Turton; Antonio Santillan; Dan Lu; Robert E. Bristow; Kwun Chuen Gary Chan; Ie Ming Shih; Richard B. S. Roden

OBJECTIVE To address the hypothesis that type II ovarian carcinoma, mutation of p53 and plasma levels of particular cytokines are associated with the generation of p53-specific serum autoantibody (AAb) responses in patients. METHODS Levels of CA125, 17 cytokines and AAbs to tumor-associated antigens including p53 were measured in plasma of 130 gynecologic tumor patients and 84 healthy controls. TP53 exons 4-9 were sequenced in tumor specimens. RESULTS p53 AAbs are associated with high grade, but not low grade ovarian carcinoma. Seropositivity for p53 AAb occurred only in those ovarian carcinoma patients whose tumors contained mutated TP53, regardless of the exon targeted. Higher p53 AAb levels were detected in ovarian carcinoma patients who had higher stage disease, but p53 AAb levels were not correlated with CA125 levels. Among high-grade carcinoma patients, there was no relationship between p53 AAb seropositivity and seropositivity to other tumor-associated antigens tested, CA125 level or survival outcome. Both high and low grade ovarian carcinoma patients exhibited elevated levels of IL6, IL8 and IL10 as compared to healthy volunteers, although increased levels of IL5, MCP1, MIP1 and TNFalpha were associated only with high grade and advanced disease. Higher levels of p53AAb responses were correlated with elevated circulating IL4 and IL12, but reduced IL8 levels. CONCLUSION Type II, but not type I, ovarian carcinoma patients had elevated serum levels of p53 AAb. P53 AAb is associated with mutation of TP53, higher plasma IL4 and IL12 but lower plasma IL8 levels and no survival advantage.


Nature Reviews Clinical Oncology | 2006

Paraneoplastic cerebellar degeneration in a woman with ovarian cancer

Antonio Santillan; Robert E. Bristow

Background A 52-year-old white female presented with sudden onset of light-headedness followed by diplopia, horizontal vertigo and severe nystagmus with oscillopsia. She had previously been in good health. MRI of the brain was normal. Lumbar puncture revealed monocytic pleocytosis. During her initial admission, the patient improved to some degree and was discharged with a possible diagnosis of viral meningitis. After a few weeks, the patients condition worsened and further evaluation was initiated. Examination revealed an unsteady widespread gait, severe nystagmus and mild dysarthria. A general and gynecological examination was otherwise unremarkable.Investigations General physical and gynecological examinations, MRI of the brain, lumbar punctures, electroencephalogram, transvaginal ultrasound, mammogram, tumor markers, anti-neuronal antibodies, colonoscopy, whole-body positron emission tomography scan, laparoscopy and biopsies.Diagnosis Stage IIIC endometrioid adenocarcinoma of the ovary with paraneoplastic cerebellar degeneration.Management Tumor cytoreduction, plasmapheresis, total abdominal hysterectomy, bilateral salpingo-oophorectomy, bilateral pelvic and para-aortic lymph-node dissection, total omentectomy, carboplatin and paclitaxel chemotherapy, rehabilitation, and speech therapy.

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Ginger J. Gardner

Memorial Sloan Kettering Cancer Center

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Ie Ming Shih

Johns Hopkins University

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Ritu Salani

Johns Hopkins University

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Dennis S. Chi

Memorial Sloan Kettering Cancer Center

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