Paz‐Fumagalli, Ricardo

Introduction: Individuals receiving systemic anticancer therapies for advanced solid tumors routinely undergo imaging studies to assess the efficacy of the treatment. Mixed response (MR) to cancer therapy is a common but poorly described phenomenon. There is a paucity of data regarding both the incidence and possible mechanisms of this clinical quandary. Potential etiologies include tumor heterogeneity, differences in tumor microenvironment, and discrepancies in drug delivery to different tumor deposits. It is also possible that MR simply reflects differences in the rate of resistance emerging. MR represents a therapeutic dilemma for the clinician. Methods: Mixed tumor response was defined as: One tumor decreasing in size; one tumor increasing in size (classified as RECIST response/progressions), One tumor stable; another tumor progressing, One tumor stable; another tumor responding, New tumor; another tumor responding or remaining stable. Between 2015 and 2017, 120 restaging CT scans were reviewed of patients who had received at least 1 line of therapy for advanced cancer diagnosis which showed MR; hematologic malignancies were excluded. Charts were reviewed to determine the clinical decision that was made at the time of the MR. Results: A total of 120 scans with MR were reviewed from various solid tumor diagnoses. 38 scans were excluded due to loss of follow-up or death. Of the remaining 82 scans, therapy was switched in 30, the same therapy was continued in 50, and an additional agent was added to the current treatment in 2 cases (Table). Of the patients in which treatment was switched, 20% (6/30) showed response to treatment on the following scan. Of the cases that were kept on current treatment, none showed response on the following restaging scan which was done 6–8 weeks later. There were 4 (10%) deaths prior to the next scan in the group that had treatment switched and similarly 5 deaths (10%) prior to the next scan in the group in which treatment remained the same. Conclusion: MR is associated with a poor prognosis, irrespective of treatment decisions. These data are retrospective and our sample size is small, so definitive conclusions cannot be drawn. However, changing therapy when a MR is observed may be of benefit to some patients. A prospective evaluation to more accurately describe and understand the MR phenomenon is warranted.

AbstractBackgroundHepatic artery stenosis (HAS) after liver transplant (LT) is a source of significant morbidity. Some reports have suggested higher arterial complications in patients who receive donation after cardiac death (DCD) livers.MethodsA total of 2860 consecutive LT were reviewed from a prospectively collected database. All angiograms performed in LT recipients were reviewed and primary patency rates determined by need for further intervention or graft loss due to HAT.ResultsHepatic artery stenosis was seen in 4.6% of DCD and donation after brain death (DBD) recipients. Recipient male gender, age at transplant, complex donor hepatic artery anatomy, and prolonged operative time were all associated with HAS, but not DCD status. While HAS in recipients of DCD grafts required more stents (1.7% vs 0.6%, P = 0.04) and had worse primary patency rates (logrank, P = 0.02), outcomes as defined by HAT, patient and graft survival were not significantly different between the recipients of DCD or DBD grafts.ConclusionWe observed no significant difference in the incidence of hepatic artery complications, patient survival, or graft survival in recipients of DCD or DBD grafts. However, HAS in DCD recipients had worse primary patency and a higher need for stent placement.

Intraoperative localization of nonpalpable recurrent thyroid cancer has been reported using needle localization, intraoperative ultrasound (US), dye injection, and radio‐guided surgery. We describe the alternative technique of radioactive seed localization (RSL) in 3 patients with residual or recurrent papillary thyroid cancer. This technique has been used for many years in the setting of nonpalpable breast cancer, where it has been shown to be safe and has been associated with greater surgeon satisfaction as well as improved patient tolerability, cosmesis, and outcomes compared to needle localization. In addition, RSL allows complete decoupling of the radiology and surgery schedules. RSL was successful in our 3 patients with regard to safety, patient tolerability, and scheduling.

Increasingly, endovenous ablation of the greater saphenous vein (GSV) is used for the treatment of symptomatic varicose veins. The propagation of thrombus can result in a “tail of thrombus” within the common femoral vein (CFV). In two cases, patients were treated with low molecular weight heparin and re-imaged within 1 week. In both cases, complete resolution of the thrombus was confirmed, and anticoagulation was discontinued. Thrombus extension into the CFV after endovenous ablation may be safely treated with short-term anticoagulation and followed by duplex ultrasound. If unresolved, standard deep vein thrombosis anticoagulation is indicated.

238 Background: To compare post-transplant recurrence rates of hepatocellular carcinoma (HCC) and differences in percent tumor necrosis in patients with pre-operative superselective chemoembolization (CE) vs. non-superselective CE. Methods: Retrospective review of 147 patients with liver transplant (LT) for HCC treated with pre-operative CE. Those transplanted less than 24 hours after CE and those who had other concomitant treatments were excluded. The angiographic studies and written reports were reviewed to categorize patients into superselective and non-superselective groups. CE was done with an emulsion of lipiodol, cisplatin, doxorubicin, mitomycin C, and contrast, with or without embolization particles. Superselective CE was defined as treatment directly into the vessel(s) feeding the tumor. Treatment from more proximal vessels was considered non-superselective. Data gathered included age, gender, date of CE, date of LT, tumor size and number, tumor stage, MELD score, Child-Pugh class, alpha fetoprotein, percent tumor necrosis at explant, date of recurrence, date and cause of death, and date of last follow-up. Patient and disease characteristics and percent tumor necrosis were analyzed with a Wilcoxon rank sum test or Fisher’s exact test. The Kaplan-Meier method was used to estimate the cumulative incidences of death due to recurrent disease after LT. Results: 99 patients were included, 53 had superselective CE and 46 non-superselective. HCC recurrence rates at 1, 3, 5, and 8 years were all significantly less for superselective CE compared to non-superselective CE (p = 0.039 single, p = 0.011 multivariable). Using multivariable analysis, superselective CE had a lower risk of death due to recurrent HCC at 1, 3, 5, and 8 years (p = 0.046). There was a trend toward more percent tumor necrosis after superselective CE, but it did not reach significance (p = 0.057). Conclusions: This study provides evidence that HCC recurrence after LT and death due to recurrent HCC is lower after pre-LT superselective CE versus non-superselective CE. The strong trend for greater percent tumor necrosis with superselective CE may explain the differences in recurrence rate.

190 Background: It is not known if biopsy of CRPC stage metastases alters CTC results. We evaluated pre & post biopsy CTC counts in a prospective cohort undergoing pre-chemotherapy abiraterone acetate/prednisone (AA/P). Methods: CTC enumeration was performed on 7.5mL blood using the FDA cleared immunomagnetic/immunofluorescence assay (CellSearch). Time of blood draw for CTC counts pre/post biopsy was recorded for each biopsy. Biopsies were performed using 11/13 gauge core biopsy device for bone lesions and 18 gauge core needle biopsy device for soft tissue/nodal metastases. All patients (pts) underwent two serial biopsies 3 months apart. Change in CTC counts pre/post biopsy for visits 1 and 2 were evaluated using Wilcoxon signed rank test (significance at p<0.05). Differences in CTC count change (visit1) pre/post biopsy based on metastatic site (skeletal vs. non-skeletal) was compared using Wilcoxon rank-sum test. Results: Median age of the cohort was 74 years (IQR: 68-78); median PSA at V1 was 16.4 ng/ml (IQR: 6.4-87.6); at V2 was 11.5 ng/ml (IQR: 1.8-23.7). Of 59 pts undergoing biopsies 42 were in bone and 17 in nodal/soft tissue masses. At V1, pre/post biopsy CTC counts were measured on 50 and 49 pts, respectively; at V2, pre/post CTC counts were measured on 43 and 36 pts. High volume metastatic disease at V1 was observed in 67.8 % of all pts. Table lists CTC counts and time of collection pre/post biopsy for both visits. Mean change in pre/post biopsy CTC counts for skeletal sites was 0.7 (range: -12 to 64) compared to 12.1 (range: -21 to 13) for non-skeletal sites (p=0.23). Conclusions: An increase in mean CTC counts after biopsy of CRPC metastases was observed. No significant differences in change of CTC counts based on site biopsied (skeletal versus non-skeletal) was noted. Correlation with clinical outcomes is on-going. Clinical trial information: NCT# 01953640. [Table: see text]

AbstractBackground and AimThe aim of this study was to assess the effectiveness of yttrium‐90 (90Y) microspheres for the treatment of unresectable metastatic liver neuroendocrine tumors (NET).MethodsFrom February 2006 to September 2015, 36 patients (19 male and 17 female, age 63.6 ± 9.4 years) who underwent 90Y therapy for unresectable liver metastases of NET were included and analyzed retrospectively. All patients received a variety of treatments before 90Y therapy. The radiological response, symptoms improvement of carcinoid syndrome, tumor marker changes, complications, side effects/toxicity, survival, and factors related to survival were evaluated and analyzed.ResultsOf the 36 patients, the mean delivered dose of 90Y was 1.8 ± 0.7 GBq with a total of 40 treatments. Overall disease control rate was 88.9% (32/36) at 3 months following therapy. In 16 patients with carcinoid syndrome, 15 (93.8%) patients had symptomatic improvement. Tumor marker response (5‐hydroxyindoleacetic acid [n = 7] and chromogranin A [n = 13]) at 3 months after treatment were as follows: none (n = 0, 4), partial (n = 6, 7), and complete (n = 1, 2). Radiation‐induced gastrointestinal ulcers (n = 2, 5.6%) were identified. Side effects included fatigue (n = 31, 86.1%), anorexia (n = 26, 72.2%), nausea (n = 15, 41.7%), vomiting (n = 14, 38.9%), abdominal pain (n = 10, 27.8%), and fever (n = 8, 22.2%). The mean follow‐up was 27.0 ± 16.4 months, with a median survival of 41.0 months. Child–Pugh classification (P = 0.008) and lymph node metastases (P = 0.045) had statistically significant influence on overall survival.ConclusionsYttrium‐90 radioembolization can be effective in the treatment of unresectable liver metastases of NET who failed to respond to other treatments.