Impact of Treatment Modalities Upon Survival Outcomes in Skull Base and Clival Chordoma: An NCDB Analysis

Objectives: Skull base chordomas are locally aggressive malignant tumors derived from the notochord remnant. There are limited large-scale studies examining the role and extent of surgery and radiation therapy. Design: Analysis of the National Cancer Database (NCDB) was performed to evaluate the survival outcomes of various treatments, and to assess for predictors of overall survival (OS). Participants: Retrospective, population-based cohort study of patients diagnosed with a clival/skull base chordoma between 2004-2015 in the NCDB. Main Outcome Measures: The primary outcome was overall survival (OS). Results: 468 cases were identified. 49% of patients received surgery and 20.7% had positive margins. Mean age at diagnosis was 48.4 years in the surgical cohort, and 55% were male. Of the surgical cohort, 33.8% had negative margins, 20.7% had positive margins, and 45.5% had unknown margin status. Age ≥ 65 (HR 3.07, 95% CI 1.63-5.76, p<0.001), diagnosis between 2010-2015 (HR 0.49, 95% CI 0.26-0.90, p=0.022), tumor size >5 cm (HR 2.29, 95% CI 1.26-4.15, p=0.007) and government insurance (HR 2.28, 95% CI 1.24-4.2, p=0.008) were independent predictors of OS. When comparing surgery with or without adjuvant radiation, no survival differences were found, regardless of margin status (P=0.66). Conclusions: Surgery remains the mainstay of therapy. Advanced age over 65, large tumor size, and government insurance were predictors of worse OS. While negative margins and the use of adjuvant radiation did not appear to impact OS, these may very well reduce local recurrences. A multidisciplinary approach is critical in achieving optimal outcomes in this challenging disease.

Radical or Not-So-Radical Prostatectomy: Do Surgical Margins Matter?

Prostate cancer is the second most common malignancy in men, and prostatectomy is the treatment of choice for most patients with at least low risk of progression. The presence of positive margins in the radical prostatectomy specimen is considered an adverse pathologic feature, and may prompt additional therapeutic intervention in the patients. The absence of a distinct capsule around the prostate and intraoperative manipulations that aim to minimize postoperative adverse effects, complicate its wide removal. Proper handling of the specimen during the gross processing is essential for accurate determination of the status of margins or resection. Positive margins, defined as the presence of neoplastic glands in the highlighted-with-ink margin of resection, range from 6–38%. The surgical technique, surgeon’s expertise and tumor (i.e., grade and stage) and patients’ (i.e., BMI) characteristics affect the rate of margin positivity. Extensive or multifocal and nonanterior/nonapical positive margins are linked with higher recurrence rates, especially in organ-confined disease, underscoring the need for treating these patients more aggressively. In summary, detailed description of the status of the margins should be performed in every pathology report to determine patients’ prognosis and the most appropriate therapeutic plan.

Does conventional specimen radiography after neoadjuvant chemotherapy of breast cancer help to reduce the rate of second surgeries?

Purpose This is the first study to systematically evaluate the diagnostic accuracy of intraoperative specimen radiography on margin level and its potential to reduce second surgeries in patients treated with neoadjuvant chemotherapy. Methods This retrospective study included 174 cases receiving breast conserving surgery (BCS) after neoadjuvant chemotherapy (NACT) of primary breast cancer. Conventional specimen radiography (CSR) was performed to assess potential margin infiltration and recommend an intraoperative re-excision of any radiologically positive margin. The histological workup of the specimen served as gold standard for the evaluation of the accuracy of CSR and the potential reduction of second surgeries by CSR-guided re-excisions. Results 1044 margins were assessed. Of 47 (4.5%) histopathological positive margins, CSR identified 9 correctly (true positive). 38 infiltrated margins were missed (false negative). This resulted in a sensitivity of 19.2%, a specificity of 89.2%, a positive predictive value (PPV) of 7.7%, and a negative predictive value (NPV) of 95.9%. The rate of secondary procedures was reduced from 23 to 16 with a number needed to treat (NNT) of CSR-guided intraoperative re-excisions of 25. In the subgroup of patients with cCR, the prevalence of positive margins was 10/510 (2.0%), PPV was 1.9%, and the NNT was 85. Conclusion Positive margins after NACT are rare and CSR has only a low sensitivity to detect them. Thus, the rate of secondary surgeries cannot be significantly reduced by recommending targeted re-excisions, especially in cases with cCR. In summary, CSR after NACT is inadequate for intraoperative margin assessment but remains useful to document removal of the biopsy site clip.

Clinical effects of cervical conization with positive margins in cervical cancer

Radical surgery after cervical conization is a common approach for the treatment of cervical cancer. In some cases, disease progression is observed after positive margins at conization, but the effect of conization on disease progression remains unclear. Thus, the aim of this study was to investigate the clinical outcomes of positive margins at conization in cervical cancer. A total of 101 patients who underwent cervical conization before radical hysterectomy and pelvic lymph node dissection were considered eligible by reviewing medical records. The association between the positive margins and patient outcomes, including subsequent lymph node metastasis, was evaluated. The rate of lymphovascular space invasion (LVSI) positivity at radical surgery was significantly higher in patients with positive margins (p = 0.017) than in those with negative margins, although there was no significant difference in the rate of pelvic lymph node metastasis (p = 0.155). Moreover, there was no significant difference in the overall survival or progression-free survival between the two groups (p = 0.332 and 0.200, respectively). A positive margin at conization presented no significant prognostic disadvantage; thus, diagnostic conization is one of the most suitable treatment options for early-stage cervical cancer that is difficult to accurately assess.

109. Evaluating Predictive Value of Surgical Resected Proximal Bone Margins in Diabetic Foot Osteomyelitis with Clinical Outcomes at One Year

Background Diabetic foot osteomyelitis (DFO) remains a significant comorbidity in diabetes and often requires both surgical and medical interventions. Surgical bone resection with proximal margins is performed for treatment at our institution to guide antimicrobial therapy. Optimal antibiotic duration often remains unclear, along with clinical outcomes with negative margins. We evaluate if negative bone margins predict outcomes of DFO at one year in our county hospital. Methods A retrospectively cohort study assessed adult patients undergoing DFO amputations between 9/2016 to 9/2019. Patient data collected included demographics, smoking history, hemoglobin A1c (HbA1c), basic labs, microbiology, antibiotic duration, bone margin pathology. Physician review of records determined if intervention was successful. Primary outcome was met if no further amputation at the same site was required in the following 12 months. Results Of 92 patients, 57 had negative margins and 35 had positive margins for pathology confirmed osteomyelitis. Smoking history was significant in positive margins (35.1% vs 57.1%; p=0.038). Patients with negative margins had a successful outcome at 12 months compared to positive margins (86% vs 66%; p=0.003), but no significant differences in outcome at 6 months. Antibiotic days was reduced in negative margin individuals (mean 18 vs 30 days; p=0.001). Negative margins also demonstrated significant lower rates of readmission at 12 months (p=0.015). Staphylococcus aureus was notable in positive vs negative margins (57.1% vs 29.8%; p=0.017). MSSA was significantly noted in positive margins (45.7% vs 14%; p=0.001). MRSA was similar regardless of margin results (15.8% vs 11.4%; p=0.399). Initial ESR, CRP and HbA1c were similar between groups. Conclusion Our study noted that negative proximal bone margins resulted in more successful outcomes at 12 months and less days of antimicrobial therapy. Patients with negative margins had lower rates of readmission at 12 months for surgical site complications. Negative proximal bone margins results can guide antibiotic therapy and improve outcomes of resections. Presence of S. aureus was significant in positive margins and likely warrant consideration for further aggressive intervention. Clinical Characteristics of Patients with Diabetic Foot Osteomyelitis Clinical demographics, antibiotic usage, microbiology and results of patients presenting for diabetic foot osteomyelitis needing surgical amputation intervention. Abbreviations: HbA1c - Hemoglobin A1c; MSSA - methicillin-susceptible Staphylococcus aureus; MRSA - methicillin-resistant Staphylococcus aureus; CRP -C-reactive protein; ESR - erythrocyte sedimentation rate Disclosures All Authors: No reported disclosures