Marcos Roberto Gonzalez

Dr. Marcos Roberto Gonzalez

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 January 2024 in Cancers
Verified
Journal Article
Open access
PDF file
FLFelipe Larios
Felipe Larios
MGMarcos Roberto Gonzalez
Marcos Roberto Gonzalez
KRKim Ruiz-Arellanos
Kim Ruiz-Arellanos
GSGeorge Aquilino E Silva
George Aquilino E Silva
JPJuan Pretell-Mazzini
Juan Pretell-Mazzini
Background: Soft tissue sarcomas are a group of rare neoplasms which can be mistaken for benign masses and be excised in a non-oncologic fashion (unplanned excision). Whether unplanned excision (UE) is associated with worse outcomes is highly debated due to conflicting evidence. Methods: We performed a systematic review and meta-analysis following PRISMA guidelines. Main outcomes analyzed were five-year overall survival (OS), five-year local recurrence-free survival (LRFS), amputation rate and plastic reconstruction surgery rate. Risk ratios were used to compare outcomes between patients treated with planned and unplanned excision. Results: We included 16,946 patients with STS, 6017 (35.5%) with UE. UE was associated with worse five-year LRFS (RR 1.35, p = 0.019). Residual tumor on the tumor bed was associated with lower five-year LRFS (RR = 2.59, p < 0.001). Local recurrence was associated with worse five-year OS (RR = 1.82, p < 0.001). UE was not associated with a worse five-year OS (RR = 0.90, p = 0.16), higher amputation rate (RR = 0.77, p = 0.134), or a worse plastic reconstruction surgery rate (RR = 1.25, p = 0.244). Conclusions: Unplanned excision of Soft Tissue Sarcomas and the presence of disease in tumor bed after one were associated with worse five-year LRFS. Tumor bed excision should remain the standard approach, with special consideration to the presence of residual disease.

25 January 2025 in Cancers
Verified
Journal Article
Open access
PDF file
MGMarcos Roberto Gonzalez
Marcos Roberto Gonzalez
CMCarolina Mendez-Guerra
Carolina Mendez-Guerra
MGMegan Goh
Megan Goh
JPJuan Pretell-Mazzini
Juan Pretell-Mazzini
Soft tissue sarcoma (STS) is a group of highly heterogeneous tumors of mesenchymal origin that have variable primary site locations and clinical behavior. Despite the broad diversity of STS, the standard of care involves surgical resection with or without radiation therapy (RT) to control local recurrence and systemic treatment in select cases. The complexities of STS require a critical understanding of the preoperative work-up process, surgical treatment, and postoperative management. Advanced imaging plays a vital role in the characterization of the soft tissue mass, preoperative biopsy planning, and disease staging. Surgical treatment prioritizes wide resection with negative margins, supported by newer margin classification systems for better prognosis. Further, advancements in surgical technique have enabled limb-salvage surgery to largely replace amputation in the management of these tumors. Additional surgical considerations, such as nerve preservation, vascular reconstruction, and complex tissue closure, further highlight the complexity of STS management. Lastly, postoperative follow-up is critical for the early detection of local or distant recurrences. For complex cases, such as unplanned excisions or invasive tumors, strategies like re-resection may be beneficial. Ongoing research into imaging, chemotherapy, and targeted therapies will further refine management strategies, especially in complex and recurrent cases. This review highlights the essential aspects of STS surgical management and underscores the need for coordinated, multidisciplinary care to enhance both survival and quality of life for affected patients.

1 May 2023 in JBJS Reviews
Verified
Journal Article
Closed access
MIMaria Lucia Inchaustegui
Maria Lucia Inchaustegui
KRKim Ruiz-Arellanos
Kim Ruiz-Arellanos
MGMarcos Roberto Gonzalez
Marcos Roberto Gonzalez
JPJuan Pretell-Mazzini
Juan Pretell-Mazzini
Background: Subtrochanteric pathological fractures (PFs) occur in approximately one-third of femur bone metastases. We seek to analyze surgical treatment strategies for subtrochanteric metastatic PFs and their revision rates. Methods: A systematic review was performed using the PubMed and Ovid databases. Reoperations as a result of complications were analyzed according to initial treatment modality, primary tumor site, and type of revision procedure. Results: We identified a total of 544 patients, 405 with PFs and 139 with impending fractures. The study population's mean age was 65.85 years with a male/female ratio of 0.9. Patients with subtrochanteric PFs who underwent an intramedullary nail (IMN) procedure (75%) presented a noninfectious revision rate of 7.2%. Patients treated with prosthesis reconstruction (21%) presented a noninfectious revision rate of 8.9% for standard endoprostheses and 2.5% for tumoral endoprostheses (p < 0.001). Revision rates because of infection were 2.2% for standard and 7.5% for tumoral endoprostheses. There were no infections within the IMN and plate/screws group (p = 0.407). Breast was the most common primary tumor site (41%) and had the highest revision rate (14.81%). Prosthetic reconstructions were the most common type of revision procedure. Conclusion: No consensus exists regarding the optimal surgical approach in patients with subtrochanteric PFs. IMN is a simpler, less invasive procedure, ideal for patients with a shorter survival. Tumoral prostheses may be better suited for patients with longer life expectancies. Treatment should be tailored considering revision rates, patient's life expectancy, and surgeon's expertise. Level of Evidence: Level III. See Instructions for Authors for a complete description of levels of evidence.

26 December 2023 in Antibiotics
Verified
Journal Article
Open access
PDF file
MGMarcos Roberto Gonzalez
Marcos Roberto Gonzalez
JPJuan Pretell-Mazzini
Juan Pretell-Mazzini
SLSantiago A Lozano-Calderón
Santiago A Lozano-Calderón
Prosthetic joint infection (PJI) is the most common mode of failure of megaprostheses, yet the literature on the topic is scarce, and studies report conflicting data regarding the optimal treatment strategy. Patients with megaprostheses PJI are often immunosuppressed, and surgeons must balance the trade-off between treatment efficacy and morbidity associated with the surgery aiming for infection eradication. Our review on megaprostheses PJI focuses on two axes: (1) risk factors and preventative strategies; and (2) surgical strategies to manage this condition. Risk factors were classified as either unmodifiable or modifiable. Attempts to decrease the risk of PJI should target the latter group. Strategies to prevent PJI include the use of silver-coated implants, timely discontinuation of perioperative antibiotic prophylaxis, and adequate soft tissue coverage to diminish the amount of dead space. Regarding surgical treatment, main strategies include debridement, antibiotics, implant retention (DAIR), DAIR with modular component exchange, stem retention (DAIR plus), one-stage, and two-stage revision. Two-stage revision is the “gold standard” for PJI in conventional implants; however, its success hinges on adequate soft tissue coverage and willingness of patients to tolerate a spacer for a minimum of 6 weeks. DAIR plus and one-stage revisions may be appropriate for a select group of patients who cannot endure the morbidity of two surgeries. Moreover, whenever DAIR is considered, exchange of the modular components should be performed (DAIR plus). Due to the low volume of megaprostheses implanted, studies assessing PJI should be conducted in a multi-institutional fashion. This would allow for more meaningful comparison of groups, with sufficient statistical power. Level of evidence: IV.

25 November 2023 in Cancers
Verified
Journal Article
Open access
PDF file
MIMaria Lucia Inchaustegui
Maria Lucia Inchaustegui
KKKelly Kon-Liao
Kelly Kon-Liao
KRKim Ruiz-Arellanos
Kim Ruiz-Arellanos
GSGeorge Aquilino E Silva
George Aquilino E Silva
MGMarcos Roberto Gonzalez
Marcos Roberto Gonzalez
JPJuan Pretell-Mazzini
Juan Pretell-Mazzini
Introduction: Radiation-induced soft tissue sarcomas (RISs) are rare secondary malignancies with a dire prognosis. The literature on the management of these tumors remains scarce due to their low incidence. Our systematic review sought to assess the treatment alternatives and outcomes of patients with RIS. Methods: A systematic review was conducted following the PRISMA guidelines. Our study was registered in PROSPERO (ID: CRD42023438415). Quality assessment was performed using the STROBE checklist. Weighted means for both continuous and categorical values were calculated. Results: Twenty-one studies comprising 1371 patients with RIS were included. The mean latency period from radiation to RIS diagnosis was 14 years, and the mean radiation dose delivered to the primary malignancy was 29.2 Gy. The most common histological type was undifferentiated pleomorphic sarcoma (42.2%), and 64% of all tumors were high-grade. The trunk was the most common location (59%), followed by extremities (21%) and pelvis (11%). Surgery was performed in 68% of patients and, among those with an appendicular tumor, the majority (74%) underwent limb-salvage surgery. Negative margins were attained in 58% of patients. Chemotherapy and radiotherapy were administered in 29% and 15% of patients, respectively. The mean 5-year overall survival was 45%, and the local recurrence and metastasis rates were 39% and 27%, respectively. Conclusions: In our study, the most common treatment was surgical resection, with RT and chemotherapy being administered in less than one third of patients. Patients with RIS exhibited poor oncologic outcomes. Future studies should compare RIS with de novo STS while controlling for confounders.

24 November 2022 in Cancer Treatment and Research Communications
Verified
Journal Article
Open access
MGMarcos Roberto Gonzalez
Marcos Roberto Gonzalez
MBMayte Bryce-Alberti
Mayte Bryce-Alberti
APArianna Portmann-Baracco
Arianna Portmann-Baracco
SCSamy Castillo-Flores
Samy Castillo-Flores
JPJuan Pretell-Mazzini
Juan Pretell-Mazzini
Merkel cell carcinoma (MCC) is an aggressive cutaneous cancer that frequently compromises the lymph nodes (LN) and distal organs. We sought to describe clinical and demographic characteristics of affected patients, analyze risk factors for LN compromise, metastasis, and death, and evaluate their impact on survival. Patients with MCC were retrieved from the SEER database. Demographic, clinical and treatment data were analyzed. Logistic and Cox proportional hazard regression were used to analyze risk factors. Survival analysis was done with the Kaplan-Meier method. A total of 2010 patients were included, among which 288 (14.33%) had distant metastases at diagnosis. LN involvement occurred in 45.8% and 20.1% of patients with and without distant metastasis, respectively. Males were more likely to present LN compromise (OR = 1.33, p10 mm showed a significantly higher risk for LN involvement and distant metastasis, with those >20 mm showing the highest risk (OR = 2.76 p<0.001 and OR = 8.88 p<0.001 respectively). Location of the tumor in the trunk was a protective factor for overall death (OR = 0.27), while LN compromise was a risk factor (OR = 3.12). Only history of previous malignancy significantly affected disease-specific death (OR = 0.32, p = 0.01). One-year survival was 79.7% and 38.2% for patients with regional LN disease and distant metastasis, respectively. MCC is an aggressive cancer with high rates of LN involvement and distant metastases. Male gender and tumor size were risk factors for regional LN and metastatic disease. Tumor location in the trunk decrease the risk of overall death, while LN involvement increased it.