Complete Excision Of Tumor Research Articles

Efficacy of endoscopic versus microscopic removal of pituitary noninvasive adenoma

Purpose: The purpose of this study was to compare the effectiveness of endoscopic vs microscopic excision of pituitary noninvasive adenoma.Materials and Methods: The current prospective comparison study was carried out at the Department of Neurology, Apex Hospital, Jaipur, Rajasthan, India among 40 patients who had been diagnosed with noninvasive pituitary adenoma Group I (n=22) had endoscopic trans-sphenoidal surgery performed on them. Group II (n=18) had trans-sphenoidal surgery using a microscopic approach.Results: An overall total of 40 individuals with pituitary nodules had transsphenoidal surgery as a result of this study. Endonasal endoscopic trans-sphenoidal surgery (Group I) was performed on 22 patients, whereas microscopic trans-sphenoidal surgery (Group II) was performed on 18 patients (group II). Complete tumour excision was accomplished in 14 (63.6 percent) of the patients in group I, while it was achieved in 10 (55.6 percent) of the patients in group II.Conclusion: Both techniques are valid for the treatment of pituitary noninvasive adenomas. However, endoscopy proves to be superior for resection followed by less post-operative complication in comparison to microscopic technique.

Treading Toward Anterolateral Skull Base by Unlocking the Frontotemporal Dural Fold Along with Extradural Clinoidectomy: Translation from A Cadaver to Clinical Scenario.

Unlocking of the frontotemporal dural fold (FTDF) and extradural removal of the anterior clinoid process (EACP) are challenging but mandatory skills for micro-neurosurgeons. Despite the presence of an extensive body of literature on this subject, the translation of this cadaveric and 3D simulation to a real patient turns out to be a very demanding and difficult task. This video is aimed to address the surgical nuances and major adjustments necessary in the unlocking of the FTDF and extradural ACP removal in an actual case for an early-career neurosurgeon. A 40-year lady presented with features of acromegaly with radiological evidence of significant component of the tumor in the right cavernous sinus along with sellar suprasellar component. To achieve a good hormonal control, a complete tumor excision was required, which was achieved with FTDF and EACP removal. The cavernous sinus was approached through the Parkinson's triangle. The patient had uneventful recovery and good hormonal control at the 3-month follow-up. FTDF unlocking and EACP are elegant procedures and need to be learned by all neurosurgeons. This article will provide excellent teaching material for young neurosurgeons.

Role of pre-operative percutaneous embolization in orbital alveolar soft part sarcoma - An experience from a tertiary eye-care center.

Purpose:To describe the clinic-radiological, pathological profile, and management outcomes of primary alveolar soft-part sarcoma (ASPS) of the orbit.Methods:A retrospective analysis of all histopathologically proven cases of orbital ASPS that presented between May 2016 and September 2019 was done. Data collected included demographics, clinical features, imaging characteristics, metastatic workup, management, and follow-up.Results:Five patients, of which four were males, presented to us during the study period. The mean age of presentation was 12.6 years (range 3–22 years). The most common presenting features were abaxial proptosis (n = 4) and diminished vision (n = 4). Imaging showed a well-defined orbital mass in all patients with internal flow voids in three. Preoperative percutaneous embolization with cyanoacrylate glue was done in these three patients owing to high vascularity. Four patients underwent complete tumor excision. One patient underwent exenteration. Histopathology showed polygonal tumor cells arranged in a pseudo-alveolar pattern and Periodic Acid-Schiff (PAS) positive crystals in the cytoplasm in all patients. One patient had systemic metastasis at presentation and developed a local recurrence after 3 months. No recurrence or metastasis was noted in the remaining four patients at a mean final follow-up of 11.2 months (range 5–15 months).Conclusion:ASPS is a rare orbital neoplasm that poses a diagnostic and therapeutic challenge. Imaging might show a soft-tissue tumor with high vascularity. Multidisciplinary management with interventional radiologists for preoperative embolization of vascular lesions helps minimize intraoperative bleeding and aids in complete tumor resection. A localized orbital disease carries a better prognosis.

Endovideosurgical removal of ectopic thymoma

A clinical case of endovascular surgical removal of ectopic thymoma in the hospital surgery clinic of S. M. Kirov Military Medical Academy performed a planned surgical intervention - thymomtectomy from left-side thoracoscopic access. 4 thoracoports used. The time of surgical intervention was 125 minutes, the volume of intraoperative blood loss was less than 50 ml. The postoperative period was uneventful. Drainage removed the next day. There were no postoperative complications. Discharged on the 5th day of the postoperative period in satisfactory condition. It is believed that ectopic thymomas arise from scattered ectopic thymus tissue, which could not migrate to the anteroposterior mediastinum. Currently, the surgical method is the «gold standard» in the treatment of patients with thymus neoplasms. Complete surgical removal of the thymus gland is a prerequisite for the effective treatment of thymic tumors. The basic principle of radicalism is the complete excision of the tumor surrounding the tissue with the lymph nodes. Particular care should be exercised when removing the spurs of the gland, which often go high on the neck, as the left tissue can cause a relapse of the disease. To remove the thymus, various «open» (transcervical, full, partial and oblique partial transsternal, right-, left- and bilateral transpleural), video-assisted (thoracoscopic, transcervical and subciphoidal, transoral) and robot-assisted surgical approaches are proposed. In this case, the choice of surgical access should be approached individually in each case.

MBCL-02. ROLE OF PREOPERATIVE CHEMOTHERAPY IN METASTATIC MEDULLOBLASTOMA: A COMPARATIVE STUDY IN 92 CHILDREN

BACKGROUNDPrevious pilot studies have shown the feasibility of preoperative chemotherapy in patients with medulloblastoma, but benefits and risks compared with initial surgery have not been assessed.METHODSTwo therapeutic strategies were retrospectively compared in 92 patients with metastatic medulloblastoma treated at Gustave Roussy, France, between 2002 and 2015: surgery at diagnosis (n=54; group A) and surgery delayed after carboplatin and etoposide-based preoperative therapy (n=38; group B). Treatment strategies were similar in both groups.RESULTSThe rate of complete tumor excision was significantly higher in group B than in group A (93.3% versus 57.4%, p=0.0013). Post-operative complications, chemotherapy-associated side effects and local progressions were not increased in group B. Preoperative chemotherapy led to a decrease in the primary tumor size in all patients, 4/38 patients experiencing meanwhile a distant progression. The histological review of 19 matched tumor pairs (before and after chemotherapy) showed that proliferation was reduced and histological diagnosis feasible and accurate even after preoperative chemotherapy. The 5-year progression-free and overall survival rates were comparable between groups. Comparison of the longitudinal neuropsychological data showed that intellectual outcome tended to be better in group B (the mean predicted intellectual quotient value was 6 points higher throughout the follow-up).CONCLUSIONPreoperative chemotherapy is a safe and efficient strategy for metastatic medulloblastoma. It increases the rate of complete tumor excision and may improve the neuropsychological outcome without jeopardizing survival.

Revising the Indications of Transtemporal Surgical Approaches in the Modern Endoscopic Era of Skull Base Surgery: A Dying Art.

Objectives The aim of the study is to emphasize and explore the possible transtemporal approaches for spectrum of complicated lateral skull base pathologies. Design Retrospective analysis of complicated lateral skull base pathologies was managed in our institute between January 2017 and December 2019. Setting The study was conducted in a tertiary care referral center. Main Outcome Measures The study focused on the selection of approach based on site and extent of the pathology, the surgical nuances for each approach, and the associated complications. Results A total of 10 different pathologies of the lateral skull base were managed by different transtemporal approaches. The most common complication encountered was facial nerve palsy (43%, n = 6). Other complications included cerebrospinal fluid (CSF) collection (15%, n = 2), cosmetic deformity (24%, n = 4), petrous internal carotid artery injury (7%, n = 1), and hypoglossal nerve palsy (7%, n = 1). The cosmetic deformity included flap necrosis ( n = 2) and postoperative bony defects leading to contour defects of the scalp ( n = 2). Conclusion Surgical approach should be tailored based on the individual basis, to obtain adequate exposure and complete excision. Selection of appropriate surgical approach should also be based on the training and preference of the operating surgeon. Whenever necessary, combined surgical approaches facilitating full tumor exposure are recommended so that complete tumor excision is feasible. This requires a multidisciplinary team comprising neurosurgeons, neuro-otologist, neuroanesthetist, and plastic surgeons. The surgeon must know precise microsurgical anatomy to preserve the adjacent nerves and vessels, which is necessary for better surgical outcomes.

Experience of treating pediatric hepatoblastoma at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia - Timely surgical intervention playing a key role.

BackgroundMany studies have demonstrated that outcome in patients with hepatoblastoma is determined by tumor resectability and the presence or absence of metastatic disease.PurposeTo evaluate and disseminate information on diagnosis, treatment, and outcome of hepatoblastoma patients at a tertiary care hospital in Saudi Arabia.Patients and methodsTwenty-four pediatric patients with hepatoblastoma were treated at our institution between January 2005 and December 2012. The majority of our patients were stage III and above, while one-third of them presented with metastatic disease. Four (16.7%) had vascular invasion. Two-thirds of our patients (n = 16, 66.7%) had alpha-fetoprotein (AFP) level above 100,000 ng/mL. Twenty-one patients underwent surgery; two had upfront surgery before getting any chemotherapy, and 15 had surgery on schedule after pre-operative chemotherapy. Four patients had delayed surgery as the tumor was not resectable and received extra cycles of chemotherapy. Chemotherapy regimens used were based on SIOPEL study protocols until 2011 and Children’s Oncology Group (COG) protocol from 2012 onwards. Relapse, progressive disease, or death from any cause were defined as events.ResultsFive-year overall survival (OS) of the cohort over a median follow-up time of 56.1 months was 70.6% ± 9.4% with seven (29.2%) events of mortality. No significant difference was found for age at diagnosis (less than 2 years vs. more), stage of disease, AFP levels (less than 100,000 vs. more), vascular invasion, or presence of metastatic disease at presentation in terms of OS. However, children receiving upfront or scheduled as-per-protocol surgery fared better than those who had delayed surgery (as the tumor was not resectable and they received extra cycles of chemotherapy) or did not undergo any surgery (P-Value .001).ConclusionFavorable survival outcome could be achieved with complete tumor excision and adjuvant chemotherapy. Inability to perform surgical excision was the single most important predictor of mortality in our patients.

A prelacrimal approach technique to overcome the limitation of the narrow lacrimal recess.

The distance between the anterior wall of the maxillary sinus and the nasolacrimal duct has been classified into three types by Simmen, in which type I (< 3mm) is the least feasible for a prelacrimal approach. The aim of our study is to present a surgical technique which overcomes the anatomical limitation of the narrow lacrimal recess (type I) in the management of inverted papilloma in the maxillary sinus. Case series. Eight patients with type I lacrimal recess underwent surgical resection for inverted papilloma in the maxillary sinus via a prelacrimal approach. The technique is described in detail in the article and essentially involves exposure of the nasolacrimal duct using a diamond burr. Complete tumor excision was achieved in all cases through this access, with no significant intra-operative complications. This prelacrimal approach technique is safe and effective for the management of inverted papilloma in maxillary sinuses with a type I lacrimal recess configuration.

Transanal endoscopic microsurgery under spinal anaesthesia.

Background:Transanal endoscopic microsurgery (TEM) is considered the procedure of choice for rectal adenomas non-amendable for endoscopic excision and for early rectal cancer. TEM may gain more importance in patients who are considered unfit for major surgery. The option of spinal anaesthesia may offer many advantages for patients undergoing TEM while maintaining the principles of complete tumour excision. The aim of this study is to report the outcome of patients undergoing TEM under spinal anaesthesia.Methods:Demographic and clinical data pertaining patients undergoing TEM under spinal anaesthesia between 2004 and 2015 were retrospectively collected.Results:A total of 158 TEM procedures were recorded in the study period. Twenty-three patients (15%) underwent the procedure under spinal anaesthesia and were included in the study; 13 of them were male and ten were female. The mean age of the patients was 69.1 ± 10.6 years. Seventeen (74%) rectal lesions were adenomas, two (9%) were adenocarcinoma and four (17%) had involved margins after polypectomy. The mean tumour size was 2.1 cm (range, 0.5–3). Distance from the anal verge was 7.7 ± 2.2 cm. Seventeen (74%) lesions were in the posterior wall. The operative time was 73 min (range, 46–108) No adverse anaesthesia-related events were recorded, and the post-operative pain was reduced. The median time of hospitalisation was 2 days (range, 1–4). No major complications were noted, and the minor complications were treated conservatively. The surgical margins were free of tumour in all cases.Conclusion:TEM under spinal anaesthesia had short duration of surgery, no increase in operative and post-operative complications or hospital length of stay. Avoiding the use of general anaesthesia, in such challenging procedure, may open new opportunities for patients determined to be unfit for general anaesthesia.

Primary aneurysmal bone cyst of sacrum for adolescent: Eleven cases experience and literature review

The present study is aiming to describe clinical characteristics, surgical flowchart and treatment results of eleven adolescent patients with primary aneurysmal bone cyst (ABC) of sacrum and review in the literature. We retrospectively reviewed eleven young patients with sacral primary ABC, which had the intact clinical and follow-up information at our bone tumor center from 2001 to 2018. The literature review was based on Google Scholar, Medline, EMBASE and Pubmed databases. The search was performed using terms of “aneurysmal bone cyst”, “sacral tumor”, “sacrum tumor” “spine tumor” and “spinal tumor” for the literature review from 1998 to 2019. There were six male and five female with a mean age of 13 years old at the presentation. The mean follow-up duration was 6.5 years. No patient died of disease and had the pulmonary metastasis. Two patients had wound complications, including onesurgical site infection and one wound dehiscence. No patient had the local recurrence and neurologic deficit. In the literature review, 11 articles were reviewed and 45 cases with sacral primary ABC were included. The rate of local recurrence may be higher than that in our cohort. We proposed our flow chart for preparation of surgery for patients. Preoperative selective arterial embolization and intraoperative aortic balloon occlusion could provide the clear surgical vision and guarantee complete tumor excision by intralesional curettage. Preoperative selective arterial embolization, intraoperative aortic balloon occlusion and complete tumor excision by intralesional curettage can yield satisfactory results with a low rate of recurrence in adolescent patients with a sacral primary ABC.

Congenital myofibroma of the pericranium

Abstract We report a case of a healthy male newborn with a congenital tumor of the pericranium. Imaging procedures were inconclusive concerning dignity and intracranial tumor infiltration and slow tumor growth was observed. MRI Scan raised suspicion of an intracranial tumor. Only via ultrasound, integrity of the scull could be confirmed and intracranial expansion was ruled out. Complete tumor excision was performed. Histopathological evaluation of the tumor showed a myofibroma that was resected in toto with negative resection margins.

Undifferentiated sarcoma of the liver: Multicenter international experience of the Cooperative Soft-Tissue Sarcoma Group and Polish Paediatric Solid Tumor Group.

Undifferentiated embryonal sarcomas of the liver (UESL) are extremely rare and continue to pose a diagnostic and therapeutic challenge. The aim of the study was to present a multicenter experience of the German CWS and Polish PPSTG groups in the treatment of UESL in children. Twenty-five patients were treated according to the CWS-96, CWS-2002, and CYVADIC protocols. Distant metastases were observed in four cases (16%). In four cases, an initial disease presentation mimicked other entities. A pure cystic appearance of liver mass led to misdiagnosis of hydatid cyst in three cases. In one case, laparotomy was performed due to the signs of appendicitis, and bleeding from ruptured liver tumor was found. All these patients were finally diagnosed as UESL. Thirteen patients received preoperative chemotherapy. Partial response was observed in 10 cases. Tumor resection was performed in 20 patients (primary resections, 12; delayed resections-, 8). In five patients, the primary tumor never became operable. The macroscopically complete resection rate was 95% (19/20). Postoperative chemotherapy was given to 20 children. Local radiotherapy was used in three children. After a median follow-up time of 136 months, 17 patients (68%) were alive with no evidence of disease. All children with unresectable tumor and three out of four patients with distant metastases died. The five-year overall survival (OS) rate was 72%. In summary, a complete tumor excision plays the central role in the treatment of UESL. A cystic presentation of the liver lesion on imaging does not exclude the diagnosis of malignant tumor.

Vascular Tumors of the Neck in Adults: 10-Year Experience in a Tertiary Center.

The diagnosis and management of vascular lesions of the neck is a challenging task that requires a multidisciplinary approach. This retrospective study assesses the single center experience of vascular tumors of the neck. Patients diagnosed with a vascular tumor and/or a mass in close proximity to the carotid artery were identified from our records over a 10-year period. The demographic characteristics, clinical features, surgical approach, and outcomes were reviewed. Surgical excision of 17 vascular lesions were performed in 16 patients with a mean age of 51.56 ± 17.35 years at the time of operation. Intra- and/or postoperative clinical and histological assessment revealed unilateral glomus caroticum (N = 11), glomus vagale (N = 2), bilateral glomus caroticum (N = 1), cavernous hemangioma (N = 1), and carotid sheath tumor (N = 1). In three patients, internal carotid artery, common carotid artery and vagal nerve were sacrificed to facilitate complete tumor excision. During the follow-up period, no tumor recurrences were observed, and the morbidity and mortality were minimal. Preoperative evaluation concerning the size, extent, and anatomical relationships of the tumor thoroughly should be investigated. Multidisciplinary approach involving vascular surgery, otolaryngology, and radiology is preferred to treat these patients for better outcomes. Preoperative embolization in selected cases may decrease estimated blood loss and operative time.

Complete Excision of Intradural-Extraforaminal Spinal Tumors Using a Minimally Invasive 2-Incision Technique With Fixed Tubular Retractors.

Spinal tumors are rare, of which intradural-extramedullary lesions form the majority of primary spinal tumors. Occasionally these may even be large, dumbbell shaped, with both intraspinal and extraspinal components. Complete gross total resection is the gold standard in the removal of these tumors since most are benign in nature. Traditionally this has been achieved using large open midline approaches that involve significant muscle dissection, extensive laminectomy, and even facetectomy. This may lead to instability, requiring stabilization to prevent deformity. Minimally invasive surgical approaches using fixed tubular retractors may obviate this need by minimizing the amount of muscle stripping and bony resection required for complete tumor excision. By utilizing facet sparing corridors, the authors describe a novel 2-incision minimally invasive surgical technique that combines a paramedian and a far-lateral approach to access both the intraspinal and extraforaminal, paraspinal portions of the tumor for achieving complete excision. Three illustrative cases are discussed with tumors in 2 different spinal locations that highlights the versatility of this technique-1 in the cervical region and the other 2 in the thoracolumbar region.

EFFICACY OF ENDOSCOPIC VERSUS MICROSCOPIC REMOVAL OF PITUITARY NONINVASIVE ADENOMA: A PROSPECTIVE COMPARATIVE STUDY.

Aim: to evaluate the efficacy of endoscopic versus microscopic removal of pituitary noninvasive adenoma.&#x0D; Materials and methods: The present prospective comparative was conducted in the Department of Neurosurgery, SKMCH, Muzaffarpur, Bihar, India among 40 patients diagnosed of noninvasive pituitary Adenoma. Group I (n=22); underwent endoscopic transsphenoidal surgery. Group II (n=18): underwent microscopic transsphenoidal surgery.&#x0D; Results: A total of 40 patients with pituitary noninvasive adenoma were operated transsphenoidally. Endonasal endoscopic transsphenoidal surgery (group I) was carried out among 22 patients and 18 patients were operated by microscopic transsphenoidal surgery (group II). In group I, complete tumor excision was achieved in 14 (63.6%) patients, and in group II, it was achieved in 10 (55.6%) patients.&#x0D; Conclusion: Both techniques are valid for the treatment of pituitary noninvasive adenomas. However, endoscopy proves to be superior for resection followed by less post-operative complication in comparison to microscopic technique.&#x0D; Keywords: endoscopy, microscopy, pituitary adenoma

Intra-Operative Gross Margin Evaluation in Breast Conservation Surgery: Assessing the Minimum Adequate Gross Margin Required to Achieve Microscopic Tumor-Free Margins

The aim of a breast conservation surgery (BCS) is to achieve complete excision of the tumor with clear surgical margins while preserving the normal breast as much as possible. Intra-operative margin assessment helps to achieve negative margins, decreasing the need for re-excision. Intra-operative gross margin evaluation is a cost-effective and easy technique; however, data available regarding its adequacy are limited. We aim to find the minimum adequate gross margin required to achieve microscopic tumor-free margins and assess the relation if any of margin status with the tumor type, grade, nodal status and immunohistochemical (IHC) markers. A total of 178 patients who underwent BCS from the years 2013–2018 in our tertiary care center were selected, excluding the ones who underwent prior neoadjuvant chemotherapy and excision biopsy. A retrospective chart review was done, and the minimum adequate cutoff of gross margins required to achieve negative margins, without any positive or close margins, was evaluated. Ten exceptional cases were excluded. Among the 168 cases, 147 (87.5%) had negative and 21 (12.5%) had close or positive margins. On evaluation, maintaining an average gross margin of 5.5 mm gave a positive predictive value of 95.45%. The sensitivity and specificity were 71.43% and 76.19%, respectively, with an accuracy of 72%. No correlation was obtained between gross margin status and tumor characteristics. Gross margin evaluation is a fast and cost-effective method which can be easily set up in any hospital setting with limited resources to ensure negative margins during BCS.

Aural Polyp with Chronic Suppurative Otitis Media Dissembling Glomus Tympanicum

Glomus tumors are benign, slow-growing tumors of the temporal bone and most commonly present as hearing loss and tinnitus with an intact tympanic membrane. Most of the time, the diagnosis is delayed and sometimes missed as it is associated with chronic suppurative otitis media (CSOM). History of the disease and proper clinical examination followed by radiological investigations are required for diagnosis and management. Surgery is the treatment of choice, but larger tumors may require other modalities of treatment. Histopathology with immunohistochemistry confirms the diagnosis. We report a case of 63-year-old female patient with glomus tympanicum associated with CSOM. She had symptoms for the last 10 years, but the diagnosis was missed because of coexisting CSOM. She was diagnosed with the help of radiological investigative modalities. She underwent mastoidectomy with complete excision of tumor. She was managed successfully without recurrence. Glomus tumor is an uncommon disease in the middle ear, and sometimes, its diagnosis is missed because of the presence of other diseases. Radiology helps in diagnosis and management of the tumor. Complete surgical excision with regular follow-up prevents recurrence.

Zyxin (ZYX) promotes invasion and acts as a biomarker for aggressive phenotypes of human glioblastoma multiforme

Glioblastoma multiforme (GBM) is characterized by highly invasive growth, which leads to extensive infiltration and makes complete tumor excision difficult. Since cytoskeleton proteins are related to leading processes and cell motility, and through analysis of public GBM databases, we determined that an actin-interacting protein, zyxin (ZYX), may involved in GBM invasion. Our own glioma cohort as well as the cancer genome atlas (TCGA), Rembrandt, and Gravendeel databases consistently showed that increased ZYX expression was related to tumor progression and poor prognosis of glioma patients. In vitro and in vivo experiments further confirmed the oncogenic roles of ZYX and demonstrated the role of ZYX in GBM invasive growth. Moreover, RNA-seq and mass-spectrum data from GBM cells with or without ZYX revealed that stathmin 1 (STMN1) was a potential target of ZYX. Subsequently, we found that both mRNA and protein levels of STMN1 were positively regulated by ZYX. Functionally, STMN1 not only promoted invasion of GBM cells but also rescued the invasion repression caused by ZYX loss. Taken together, our results indicate that high ZYX expression was associated with worse prognosis and highlighted that the ZYX-STMN1 axis might be a potential therapeutic target for GBM.

A case of von Hippel-Lindau disease with multi-organ involvement: a rare case report

Von Hippel-Lindau (VHL) disease is a rare autosomal dominant syndrome manifested by a spectrum of tumours in the central nervous system (CNS) and other visceral organs. We herein report a case of 35 years aged newly diagnosed diabetic female patient presented with headache, gait instability, loss of vision in both eyes, left sided hearing impairment and subsequently diagnosed to have VHL disease. The pathophysiology involves the inactivation of the VHL tumour suppressor gene. Early recognition and treatment remains the mainstay of management. Even many years after the complete tumour excision, newer neoplasms may develop. Increasing knowledge about the molecular enabled us to investigate the role of anti-angiogenic drugs. Continuous surveillance at regular interval must be conducted in patients with VHL disease.

Multimodality treatment including ONCEPT for canine oral melanoma: A retrospective analysis of 131 dogs.

Canine oral melanoma (OM) is an aggressive cancer with a high rate of metastasis. Surgery and/or radiotherapy (RT) are effective local treatments, yet many dogs succumb to distant metastasis. Immunotherapy represents an attractive strategy for this potentially immunogenic tumor. The objective of this multi-institutional retrospective study was to examine the clinical outcome of dogs with OM treated with ONCEPT melanoma vaccine. Most dogs also underwent surgery and/or RT (8Gy×four weekly fractions). Dogs with distant metastasis at diagnosis and those receiving concurrent chemotherapy were excluded. One hundred thirty-one dogs treated with ONCEPT were included: 62 had adequate local tumor control defined as complete tumor excision or irradiation of residual microscopic disease; 15 were treated in the microscopic disease setting following an incomplete excision without adjuvant RT; and 54 had gross disease. Median time to progression, median progression-free survival, and median tumor-specific overall survival were 304, 260, and 510 days, respectively. In multivariable analysis, presence of gross disease correlated negatively with all measures of clinical outcome. Other negative prognostic indicators were primary tumor ≥2cm, higher clinical stage (stages 2 and 3), presence of lymph node metastasis at diagnosis, and caudal location in the oral cavity. Radiotherapy had a protective effect against tumor progression. To date, this is the largest reported series of dogs with OM treated with ONCEPT. Several previously reported prognostic indicators were confirmed.