Postoperative Tumor Research Articles

Impact of combining photodynamic diagnosis with reflectance confocal microscopy, on tumor margin detection and surgical outcomes in patients with extramammary Paget disease.

Background The recurrence rate of extramammary Paget disease after surgical resection is high due to the lesions' poorly delineated and unclear margins. Aims To evaluate the impact of non-invasive tumour margin detection via photodynamic diagnosis plus reflectance confocal microscopy on the surgical outcomes of patients with extramammary Paget disease. Methods Thirty-six patients with histopathologically confirmed primary extramammary Paget disease between January 2017 and June 2018 were included in this study. The skin lesion margins were preoperatively observed using the naked eye, photodynamic diagnosis, and reflectance confocal microscopy. An incision was made 0.5-2 cm from the outermost non-invasive detection marker line. The incision depth was more significant than the follicle level or the deepest level affected by the tumour in the biopsy specimens. After the skin lesions were removed, a pathological examination of the specimens was conducted to ensure clear margins to prevent tumour recurrence and metastases. Results A total of 166 good-quality tissue sections were selected from 36 patients. The tumour surfaces and deep margins were within the scope of resection. Six patients (6/36, 15.4%) experienced local recurrence 2-12 months postoperatively. One patient (1/36, 2.8%) had lymph node metastasis without local recurrence 36 months postoperatively and died 50 months postoperatively (1/36, 2.8%). Limitations This study is limited by the small patient population, especially the number of patients with mucous membrane involvement. Conclusion Using photodynamic diagnosis plus reflectance confocal microscopy to detect the margins of extramammary Paget disease lesions non-invasively reduces the postoperative tumour recurrence rate and is a valuable guide for tumour treatment.

Dual-layer spectral-detector CT for predicting microsatellite instability status and prognosis in locally advanced gastric cancer

ObjectiveTo construct and validate a prediction model based on dual-layer detector spectral CT (DLCT) and clinico-radiologic features to predict the microsatellite instability (MSI) status of gastric cancer (GC) and to explore the relationship between the prediction results and patient prognosis.MethodsA total of 264 GC patients who underwent preoperative DLCT examination were randomly allocated into the training set (n = 187) and validation set (n = 80). Clinico-radiologic features and DLCT parameters were used to build the clinical and DLCT model through multivariate logistic regression analysis. A combined DLCT parameter (CDLCT) was constructed to predict MSI. A combined prediction model was constructed using multivariate logistic regression analysis by integrating the significant clinico-radiologic features and CDLCT. The Kaplan–Meier survival analysis was used to explore the prognostic significant of the prediction results of the combined model.ResultsIn this study, there were 70 (26.52%) MSI-high (MSI-H) GC patients. Tumor location and CT_N staging were independent risk factors for MSI-H. In the validation set, the area under the curve (AUC) of the clinical model and DLCT model for predicting MSI status was 0.721 and 0.837, respectively. The combined model achieved a high prediction efficacy in the validation set, with AUC, sensitivity, and specificity of 0.879, 78.95%, and 75.4%, respectively. Survival analysis demonstrated that the combined model could stratify GC patients according to recurrence-free survival (p = 0.010).ConclusionThe combined model provides an efficient tool for predicting the MSI status of GC noninvasively and tumor recurrence risk stratification after surgery.Critical relevance statementMSI is an important molecular subtype in gastric cancer (GC). But MSI can only be evaluated using biopsy or postoperative tumor tissues. Our study developed a combined model based on DLCT which could effectively predict MSI preoperatively. Our result also showed that the combined model could stratify patients according to recurrence-free survival. It may be valuable for clinicians in choosing appropriate treatment strategies to avoid tumor recurrence and predicting clinical prognosis in GC.Key points• Tumor location and CT_N staging were independent predictors for MSI-H in GC.• Quantitative DLCT parameters showed potential in predicting MSI status in GC.• The combined model integrating clinico-radiologic features and CDLCT could improve the predictive performance.• The prediction results could stratify the risk of tumor recurrence after surgery.Graphical

Combined Use of Tumor Markers in Gastric Cancer: A Novel Method with Promising Prognostic Accuracy and Practicality.

The effect of a single tumor marker on the prognosis of gastric cancer patients is not ideal. This study explored a novel prognostic assessment method for gastric cancer (GC) patients using a combination of three important tumor markers (CEA, CA72-4, and CA19-9). Data from 1966 GC patients who underwent curative gastrectomy at Sun Yat-Sen University Cancer Center (Guangzhou, China) were included. Hazard ratios (HR) for all factors for overall survival (OS) were analyzed by Cox regression. A nomogram and calibration curve were used to establish the survival prediction model. The prediction accuracy was evaluated with the concordance index (C-index). All patients were divided into four groups (C0-C3) according to the number of elevated tumor markers. The 5-year OS rates of the patients in preoperative groups C0-C3 were 83.8% (81.3-86.4%), 72.8% (68.5-77.4%), 58.9% (50.4-68.9%), and 18.5% (4.0-33.0%), respectively, and those in postoperative groups C0-C3 were 82.1% (79.4-84.8%), 76.1% (72.2-80.3%), 57.6% (48.4-68.5%), and 16.8% (5.1-28.5%), respectively, with significant differences between each C0-C3 subgroup in both preoperative and postoperative cohorts. Multivariate analysis showed that preoperative (HR: 6.001, 95% CI: 3.523-10.221) and postoperative (HR: 8.149, 95% CI: 4.962-13.528) elevated tumor markers were independent risk factors for GC patients. The C-index for the combined use of tumor markers was 0.65-0.66, which was higher than that for using a single tumor marker (0.53-0.56). The combined use of tumor markers significantly improved the prognostic value compared with using a single tumor marker. The survival prediction model including the combined tumor markers was accurate and effective.

Investigation of the Relationship between Adenoma Volume and Perioperative Hormone Levels in Patients with Acromegaly

Objective: Current pituitary adenomas classifications and surgical treatment results are made only with two-dimensional radiological sections and hormonal measurements. This study investigated the relationship between hormone levels and volumetric tumor burden by measuring tumor volumes before and after surgery in patients with acromegaly. Methods: In a retrospective clinical study, clinical and radiologically measured volumetric, hormonal and surgical results of 52 patients who were operated on with the diagnosis of acromegaly due to pituitary adenoma were examined. Radiological measurements were obtained using the ImageJ software package version 1.47 and the measure-stack plug-in. In statistical analysis, the relationship between tumor volumes, growth horomone (GH) and insulin-like growth factor (IGF-I) levels was analyzed during and after surgery. Results: Of the 52 cases, 22 (42.3%) were male, 30 (57.7%) were female, and the mean age of the patients was 43.40±11.40 years. 45 cases (86.53%) were macroadenoma, 7 cases (13.47%) were microadenoma. All patients were operated by the transnasal-transseptal-transsphenoidal route. When the early preoperative and postoperative hormone results of the patients were compared, significant decreases were observed in GH (82.1%), volume (67%), and IGF-1 (50%) levels in the postoperative period. While there was a significant positive correlation between preoperative GH levels and tumor volumes (r: 0.516, p<0.05), there was also a significant positive correlation between postoperative GH levels and tumor volumes (r: 0.755, p<0.05). No correlation was observed between IGF-I levels and volume in the preoperative and postoperative period (r:-0.051, p>0.05) (r:0.259, p>0.05). A significant positive correlation was found between postoperative GH levels and IGF-1 levels (r: 0.303, p<0.05). Conclusion: Both GH and IGF-I levels increase significantly as tumor volume increases in patients with pituitary adenoma before and after surgical treatment. Volumetric measurements may be necessary for classifying patients with acromegaly before and after surgery and in the more objective and quantitative determination of postoperative residual and/or recurrence. For this reason, we believe that it is more accurate to evaluate tumor tissues occupying a 3-dimensional volume with volumetric measurements.

Development of nomograms to predict recurrence after conversion hepatectomy for hepatocellular carcinoma previously treated with transarterial interventional therapy

BackgroundLack of opportunity for radical surgery and postoperative tumor recurrence are challenges for surgeons and hepatocellular carcinoma (HCC) patients. This study aimed to develop nomograms to predict recurrence risk and recurrence-free survival (RFS) probability after conversion hepatectomy for patients previously receiving transarterial interventional therapy.MethodsIn total, 261 HCC patients who underwent conversion liver resection and previously received transarterial interventional therapy were retrospectively enrolled. Nomograms to predict recurrence risk and RFS were developed, with discriminative ability and calibration evaluated by C-statistics, calibration plots, and the Area under the Receiver Operator Characteristic (AUROC) curves.ResultsUnivariate/multivariable logistic regression and Cox regression analyses were used to identify predictive factors for recurrence risk and RFS, respectively. The following factors were selected as predictive of recurrence: age, tumor number, microvascular invasion (MVI) grade, preoperative alpha‐fetoprotein (AFP), preoperative carbohydrate antigen 19-9 (CA19-9), and Eastern Cooperative Oncology Group performance score (ECOG PS). Similarly, age, tumor number, postoperative AFP, postoperative protein induced by vitamin K absence or antagonist-II (PIVKA-II), and ECOG PS were incorporated for the prediction of RFS. The discriminative ability and calibration of the nomograms revealed good predictive ability. Calibration plots showed good agreement between the nomogram predictions of recurrence and RFS and the actual observations.ConclusionsA pair of reliable nomograms was developed to predict recurrence and RFS in HCC patients after conversion resection who previously received transarterial interventional therapy. These predictive models can be used as guidance for clinicians to help with treatment strategies.

P21.01.A EPIDEMIOLOGY OF ISCHEMIC LESIONS AFTER RESECTION OF LOW-GRADE GLIOMAS

Abstract BACKGROUND Diffuse low-grade gliomas are slow-growing malignant brain tumors that mainly affect people in their 30s and 40s, usually resulting in death within a decade. The standard treatment is surgery, which has a moderate risk of neurological sequelae. Clinical experience indicates that not all sequels are directly related to the resected area but rather caused by collateral damage, such as tissue- and vascular damages at the surgical site, causing ischemic lesions in the surrounding tissue. In this study, the epidemiology of these lesions is investigated, in terms of how common they are and how they are related to the size, type and location of the tumor. MATERIAL AND METHODS One hundred and sixty-six patients who underwent resection for grade II glioma (WHO 2007 or 2016) between 2012 and 2017 at any of nine hospitals in Sweden and Norway and had a postoperative MRI scan including diffusion-weighted imaging within three days after surgery, were included in this study. Lesions were segmented on the b1000 image, using the ADC and T1 image to exclude hyperintense areas caused by other factors than ischemia. Statistical analyses were performed using IBM SPSS Statistics version 27.0 (IBM Corp., Armonk, NY, USA). Analyses were carried out with ischemic lesion size as a continuous variable, and since the volumes were not normally distributed, non-parametric tests were used. RESULTS Ischemic lesions were found in 146 out of 166 (88%) cases, the median volume of the segmented lesions was 1.9 ml, with an interquartile range (IQR) of 0.95-4.5 ml. Patients with new or worsened deficits did have significantly larger ischemic volumes than does who did not (1.7 vs 2.8 ml, p=0.03). Ischemic volume was significantly correlated to both pre- and post-operative tumor volume (Spearmans rho = 0.370 and 0.304, p<0.001). No difference in ischemic volume was found between astrocytoma and oligodendroglioma, based on reported histopathologic diagnosis (p=0.43) or molecular status (p=0.44), neither between main tumor local (frontal (60%) vs temporal (19%), parietal (8%) or insular (12%), p>0.37). CONCLUSION Ischemic lesions after glioma resection are very common, but mostly small and restricted to a region close to the resection cavity. Large ischemic regions were associated with new or worsened neurological deficits and were mostly found in association with large tumors. More fine-tuned measures might be needed to find potential associations between tumor local and ischemic lesions.

Non-coding RNAs: The potential biomarker or therapeutic target in hepatic ischemia-reperfusion injury.

Hepatic ischemia-reperfusion injury (HIRI) is the major complication of liver surgery and liver transplantation, that may increase the postoperative morbidity, mortality, tumor progression, and metastasis. The underlying mechanisms have been extensively investigated in recent years. Among these, oxidative stress, inflammatory responses, immunoreactions, and cell death are the most studied. Non-coding RNAs (ncRNAs) are defined as the RNAs that do not encode proteins, but can regulate gene expressions. In recent years, ncRNAs have emerged as research hotspots for various diseases. During the progression of HIRI, ncRNAs are differentially expressed, while these dysregulations of ncRNAs, in turn, have been verified to be related to the above pathological processes involved in HIRI. ncRNAs mainly contain microRNAs, long ncRNAs, and circular RNAs, some of which have been reported as biomarkers for early diagnosis or assessment of liver damage severity, and as therapeutic targets to attenuate HIRI. Here, we briefly summarize the common pathophysiology of HIRI, describe the current knowledge of ncRNAs involved in HIRI in animal and human studies, and discuss the potential of ncRNA-targeted therapeutic strategies. Given the scarcity of clinical trials, there is still a long way to go from pre-clinical to clinical application, and further studies are needed to uncover their potential as therapeutic targets.

Surgical management and outcome of newly diagnosed glioblastoma without contrast enhancement (low-grade appearance): a report of the RANO resect group.

Resection of the contrast-enhancing (CE) tumor represents the standard of care in newly diagnosed glioblastoma. However, some tumors ultimately diagnosed as glioblastoma lack contrast enhancement and have a 'low-grade appearance' on imaging (non-CE glioblastoma). We aimed to (a) volumetrically define the value of non-CE tumor resection in the absence of contrast enhancement, and to (b) delineate outcome differences between glioblastoma patients with and without contrast enhancement. The RANO resect group retrospectively compiled a global, eight-center cohort of patients with newly diagnosed glioblastoma per WHO 2021 classification. The associations between postoperative tumor volumes and outcome were analyzed. Propensity score-matched analyses were constructed to compare glioblastomas with and without contrast enhancement. Among 1323 newly diagnosed IDH-wildtype glioblastomas, we identified 98 patients (7.4%) without contrast enhancement. In such patients, smaller postoperative tumor volumes were associated with more favorable outcome. There was an exponential increase in risk for death with larger residual non-CE tumor. Accordingly, extensive resection was associated with improved survival compared to lesion biopsy. These findings were retained on a multivariable analysis adjusting for demographic and clinical markers. Compared to CE glioblastoma, patients with non-CE glioblastoma had a more favorable clinical profile and superior outcome as confirmed in propensity score analyses by matching the patients with non-CE glioblastoma to patients with CE glioblastoma using a large set of clinical variables. The absence of contrast enhancement characterizes a less aggressive clinical phenotype of IDH-wildtype glioblastomas. Maximal resection of non-CE tumors has prognostic implications and translates into favorable outcome.

Combination of biodegradable hydrogel and antioxidant bioadhesive for treatment of breast cancer recurrence and radiation skin injury

Postoperative radiotherapy is the standard method for inhibition of breast cancer recurrence and metastasis, whereas radiation resistant and ineluctable skin radiation injury are still key problems encountered in the prognosis of breast cancer. Herein, we design an internally implantable biodegradable hydrogel and extracutaneously applicable antioxidant bioadhesive to concurrently prevent postoperative tumor recurrence and radioactive skin injury after adjuvant radiotherapy. The biodegradable silk fibroin/perfluorocarbon hydrogel loading doxorubicin (DOX) formed by consecutive ultrasonication-induced β-sheets-crosslinked amphiphilic silk fibroin/perfluorocarbon/DOX nanoemulsion, exhibits continuous release of oxygen in physiological environment to improve hypoxia and sensitivity of radiotherapy, as well as simultaneous release of DOX to finally achieve effective anti-cancer effect. A stretchable bioadhesive is fabricated by copolymerization of α-thioctic acid and N, N-diacryloyl-l-lysine, and gold nanorods and gallic acid are loaded into the bioadhesive to afford gentle photothermal therapy and antioxidant functions. The near-infrared light-induced controlled release of gallic acid and mild photothermal therapy can efficiently eliminate excess free radicals generated by radiotherapy and promote radioactive wound healing. Ultimately, in vivo animal studies substantiate the efficacy of our methodology, wherein the post-tumor resection administration of hydrogel and concomitant application of an antioxidant bioadhesive patch effectively inhibit tumor recurrence and attenuate the progression of skin radiation damage.

Long-term treatment outcomes of temozolomide-based chemoradiation in patients with adult-type diffuse IDH-mutant grade 2 astrocytoma

PurposeTo report the long-term outcomes in adult patients with grade 2 IDH-mutant astrocytoma treated with temozolomide (TMZ)-based chemoradiation. Methods: One hundred and three patients with histologically proven grade 2 astrocytoma received radiation therapy (RT), 50.4–54 Gy in 1.8 Gy fractions, and adjuvant TMZ up to 12 cycles. Fifty-two patients received RT at the time of tumor progression and 51 in the early postoperative period for the presence of at least one high-risk feature (age > 40 years, preoperative tumor size > 5 cm, large postoperative residual tumor, tumor crossing the midline, or presence of neurological symptoms). Overall survival (OS) and progression-free survival (PFS) were calculated from the time of diagnosis.ResultsWith a median follow-up time of 9.0 years (range, 1.3–15 years), median PFS and OS times were 9 years (95%CI, 6.6–10.3) and 11.8 years (95%CI, 9.3–13.4), respectively. Median PFS was 10.6 years in the early treatment group and 6 years in delayed treatment group (hazard ratio (HR) 0.30; 95%CI 0.16–0.59; p = 0.0005); however, OS was not significantly different between groups (12.8 vs. 10.4 years; HR 0.64; 95%CI 0.33–1.25; p = 0.23). Extent of resection, KPS, and small residual disease were associated with OS, with postoperative tumor ≤ 1 cc that emerged as the strongest independent predictor (HR: 0.27; 95%CI 0.08–0.87; p = 0.01).ConclusionsTMZ-based chemoradiation is associated with survival benefit in patients with grade 2 IDH-mutant astrocytoma. For this group of patients, chemoradiation can be deferred until time of progression in younger patients receiving extensive resection, while early treatment should be recommended in high-risk patients.

A multicenter retrospective analysis of patients with salivary gland carcinoma treated with postoperative radiotherapy alone or chemoradiotherapy

BackgroundThe aim of this study was to interrogate if the use of postoperative chemoradiotherapy (POCRT) correlated with superior oncological outcomes for certain subgroups of patients with high-risk salivary gland carcinoma (SGC), compared with postoperative radiotherapy (PORT) alone. MethodsThis multicenter retrospective study included 411 patients with surgically resected SGC who underwent PORT (n = 263) or POCRT (n = 148) between 2000 and 2015. Possible correlations of clinical parameters with outcomes were examined using the Kaplan-Meier analysis and Cox proportional-hazards regression model. ResultsThe median follow-up of survivors is 10.9 years. For the entire cohort, adding concurrent chemotherapy to PORT was not associated with OS, PFS, or LRC improvement. However, patients with nodal metastasis who underwent POCRT had significantly higher 10-year OS (46.2% vs. 18.2%, P = 0.009) and PFS (38.7% vs. 10.0%, P = 0.009) rates than those treated with PORT alone. The presence of postoperative macroscopic residual tumor (R2 resection) was identified as an independent prognosticator for inferior OS (P = 0.032), PFS (P = 0.001), and LRC (P = 0.007). Importantly, POCRT significantly correlated with higher 10-year LRC rates in patients with R2 resection (74.2% vs. 40.7%, P = 0.034) or adenoid cystic carcinoma (AdCC, 97.6% vs. 83.6%, P = 0.039). On multivariate analyses, the use of POCRT significantly predicted superior OS (P = 0.037) and PFS (P = 0.013) for node-positive patients and LRC for patients with R2 resection (P = 0.041) or AdCC (P = 0.005). ConclusionsFor surgically resected SGC, POCRT was associated with improved long-term OS and PFS for patients with nodal metastasis and superior LRC for patients with R2 resection or AdCC.

Medulloblastoma

In the 5th edition of the WHO classification, medulloblastomas, which are representative pediatric brain tumors, are categorized into four groups: WNT, SHH-TP53 wild, SHH-TP53 mutant, and non-WNT/non-SHH, based on their molecular background. While the histopathological findings still hold importance in predicting prognosis, the histopathological classification is no longer utilized in this edition. SHH medulloblastomas are further subdivided into two groups based on the presence or absence of TP53 mutation, as their clinical characteristics and prognosis differ. Group 3 and Group 4 medulloblastomas, recognized as distinct molecular groups in clinical practice, are combined into a single group called "non-WNT/non-SHH", because they lack specific molecular pathway activation. Furthermore, based on methylation profiling, dividing SHH medulloblastoma into four subgroups and non-WNT/non-SHH medulloblastoma into eight subgroups was proposed. Understanding the unique clinical characteristics and prognosis associated with each group is crucial. However, it is important to acknowledge that our current understanding of prognosis is based on treatment approaches guided by clinical risk factors such as postoperative residual tumor volume and the presence of metastatic disease. This molecular-based classification holds promise in guiding the development of optimal treatment strategies for patients with medulloblastoma.

Role of Cavernous Sinus Extension and MRI T2 Hypointensity in the Extent of Resection following Trans-Sphenoidal Surgery for Giant Pituitary Adenomas.

Giant pituitary adenomas (GPA) pose a significant neurosurgical challenge. In this study, we present an experience of 60 consecutive patients with GPA operated by trans-sphenoidal surgery (microscopic/endoscopic). The aim of this study was to elucidate preoperative factors predicting extent of resection (EOR) following transsphenoidal surgery for GPA. The study was a retrospective evaluation of 60 adult patients (>18 years) with GPA operated over a decade. The patients were analyzed for their clinical presentation, EOR, radiology, visual outcome, endocrinological outcome, and complications. The mean age of the cohort was 41.5 ± 13.3 years, mean tumor volume was 38.2 ± 19.1 cm3, and mean follow-up was 30.6 ± 21.7 months. Improvement in vision was seen in forty patients (66.7%), while another 16 (26.7%) had stable vision as prior to surgery. Duration of visual symptoms was found to be statistically significantly associated with postoperative improvement of vision (P = 0.001). Twenty-four patients (40.0%) underwent subtotal resection (STR), while the remaining 36 patients (60.0%) underwent either gross total or near-total resection. Factors associated with STR were retrosellar (P = 0.04), subfrontal (P = 0.02), Knosp 3,4 cavernous sinus extension (P = 0.03), and MRI T2 hypointensity (P = 0.02). During follow-up, eight patients (13.3%) had radiological evidence of growth of residual tumor. Most cases of GPA can be adequately handled by trans-sphenoidal surgery. The presence of retrosellar, subfrontal, cavernous sinus extensions, and T2 hypointensity should alert the surgeon for likelihood of STR, postoperative residual tumor hemorrhage and need for second-stage endonasal or transcranial surgery. However, utilization of extended endoscopic route has allowed good debulking of tumors having subfrontal and parasellar extensions, which was not possible previously using traditional microscopic transsphenoidal surgery.

491. VITAMIN B12 DEFICIENCY AFTER ONCOLOGICAL ESOPHAGECTOMY AND GASTRECTOMY

Abstract Vitamin B12 deficiency is common in patients with resections of the upper digestive tract and must be expected during follow-up examinations. While esophagectomy with gastric pull-ups preserve the duodenal passage and a large part of the stomach, (sub)total gastrectomies result in significant losses of gastric tissue and the common Y-Roux reconstruction bypasses the duodenal passage. This is a monocentric, retrospective, descriptive analysis of prospectively collected follow-up data. Between January 2015 and December 2019, 232 patients underwent an oncological (sub)total gastrectomy or esophagectomy. After applying the exclusion criteria (patient below 18, primary bone marrow disease, hereditary forms of anemia, postoperative tumor recurrence, R1/R2 situation), 157 patients remained for analysis: 103 patients (=66%) with esophagectomy (ER) and 54 (=34%) with (sub)total gastrectomy (SGE). Vitamin B12 levels were analyzed three, six, twelve, 18, and 24 months after the surgery. Prophylactic intramuscular vitamin B12 substitution (Erycytol 1 mg depot) was routinely prescribed quarterly only in patients with a total gastrectomy. After 3 postoperative months the incidence of vitamin B12 deficiency were 24% in the ER group vs. 5% (p = 0,064) in the SGE group; 17% vs. 10% (p = 0.4) after 6 months; 8% vs. 5% (p = 0.65) after 1 year; 10% vs. 10% (p = 0.83) after 18 months, and 12.5% vs. 39% (p = 0.022) after 2 years. The resulted incidence of hyperchromic macrocytic anemia is furtherly discussed in the abstract entitled ‘Types and incidence of postoperative anemia after oncological esophageal and gastric resections’. Comparing the total gastrectomy versus subtotal gastrectomy subgroups, patients with a subtotal gastrectomy have higher vitamin B12 deficiency incidences throughout the 24-month follow-up period. The human body physiologically provide a sufficient vitamin B12 storage for minimum 6–9 months. The high incidence of vitamin B12 deficiency in the ER group in the first 6 postoperative months might be due to a pre-existing vitamin B12 deficiency. After the 6th postoperative month there is an approximation between the Vitamin B12 deficiency incidences of ER and (S)GE patients. In the final 2-year follow-up, the incidence of vitamin B12 deficiency was significantly higher in the (S)GE group.

492. TYPES AND INCIDENCE OF POSTOPERATIVE ANEMIA AFTER ONCOLOGICAL ESOPHAGECTOMY AND GASTRECTOMY

Abstract According to current literature, anemias that develop after oncological esophageal and gastric resections are classified as deficiency anemias. Due to the surgery-related changes in the mechanical and biochemical conditions of the upper gastrointestinal tract, there is an alteration in the processing and absorption of hematopoietic-relevant vitamins and trace elements like iron, vitamin B6, vitamin B12, folic acid, copper and essential amino acids in the postoperative phase. Between January 2015 and December 2019, 232 patients underwent a (sub)total gastrectomy or esophagectomy at our center. In this monocentric retrospective analysis of prospectively collected follow-up data, 157 patients were included after applying the exclusion criteria: Age below 18, primary bone marrow disease, hereditary forms of anemia, postoperative tumor recurrence and R1/R2 situation. 103 patients (=66%) belonged to the esophagectomy group and 54 patients (=34%) to the (sub)total gastrectomy group. Preoperatively and three, six, twelve, 18, and 24 months postoperatively the following laboratory parameters were collected and descriptively analyzed: Hemoglobin, MCV, MCH, serum iron, ferritin, transferrin, and vitamin B12. Two years after the oncological resection 28% of patients with esophagectomy, EE, and 48% of patients with (sub)total gastric resection, (S)GE, show anemia. Normocytic anemia was the dominant type. The MCV distribution of anemic patients in the EE group was as follows: 3% microcytic, 77% normocytic, and 20% macrocytic. The anemic patients in the (S)GE group show the following MCV distribution: 16% microcytic, 81% normocytic, and 3% macrocytic. The (S)GE collective has more anemic patients in percentage terms than the EE collective throughout the whole follow-up period. This difference is significant at the 12th (p = 0.032) and 18th-month (p = 0.023) postoperative follow-up. A high percentage of patients with oncological resection of the upper gastrointestinal tract have a relevant postoperative anemia. The known postoperative iron and vitamin deficiencies, that would be associated with microcytic hypochromic and macrocytic hyperchromic anemia, are not the relevant causes for this anemia as it is predominantly a normocytic form. Normocytic anemia is an indication for an anemia of chronic disease. The reason for the predominance of normocytic anemia is not specifically known.

493. IRON DEFICIENCY AFTER ONCOLOGICAL ESOPHAGECTOMY AND GASTRECTOMY

Abstract Removal of the entire stomach or parts of it may affect iron absorption and storage. These conditions mainly caused by altering the acid environment, bypassing the duodenal passage during reconstruction or by chronic inflammatory processes. In addition, patients with esophageal or gastric cancer often have an iron deficiency preoperatively due to malnutrition, gastrointestinal hemorrhage, or inflammatory processes. Sometimes these iron deficiencies lead to microcytic hypochromic deficiency anemia. Between January 2015 and December 2019, 103 (=66%) esophagectomy patients and 54 (=34%) (sub)total gastrectomy patients were included. Fe, transferrin and ferritin were collected prospectively to be used for retrospective descriptive analysis: preoperatively and three, six, twelve, 18 and 24 months after the operations. The exclusion criteria were: Age below 18, primary bone marrow disease, hereditary forms of anemia, postoperative tumor recurrence, R1/R2 situation. Iron supplementation was not used in the first postoperative year, and thereafter only in cases of a severe iron deficiency. The severity of iron deficiency was classified by ferritin, according to iron deficiency stages I—III. 18% of patients with oncological esophagectomy and 45% of patients with oncological (sub)total gastrectomy have an iron deficiency two years after the operations. This is manifested mainly by pathologically decreased ferritin levels. There is only a significant difference between the groups, with respect to ferritin (p = 0.021) and transferrin levels (p = 0.028), after 2 postoperative years. 75% of esophagectomy patients with iron deficiency were in stage I, 12.5% in stage II and 12.5% in stage III of iron deficiency. 56% of iron deficiency patients with (sub)total gastrectomy were in stage I, 22% in stage II and 22% in stage III. Patients with (sub)total gastrectomy are more likely to have iron deficiency than patients with esophagectomy during the 24-month postoperative follow-up period. Due to the duodenal bypassing in the (sub)total gastrectomy group a higher prevalence of iron deficiency could have been expected. Most patients have storage iron deficiency (= stage I). Only few patients with iron deficiency have the more severe and decompensated form of iron deficiency, iron deficiency anemia (= stage III).

Identifying Tumor Deposits in Patients with Locally Advanced Rectal Cancer: Using Multiplanar High-Resolution T2WI.

The prognosis of postoperative tumor deposits (TDs) is worse than positive lymph node metastases alone. To detect TDs by using multiplanar high-resolution T2-weighted imaging (HRT2WI). This retrospective study enrolled 130 patients with locally advanced rectal cancer (LARC). Using pathology-proven tumor deposits (pTDs) as the gold standard, all patients were divided into the pTDs-negative and pTDs-positive groups, the correlation of clinicopathological factors and image features [such as MRI-detected tumor deposits (mTDs), MRI-detected metastatic lymph node (mLN), MRI-detected extramural vascular invasion (mEMVI), maximal extramural depth (EMD), etc.] with pTDs were analyzed by univariate analysis and multivariate binary logistic regression analysis, and the nomogram was established based on the latter. The diagnostic efficiency was evaluated by the receiver operating characteristic curve (ROC) analysis and area under curve (AUC). mTDs, mLN, mEMVI, and EMD were significantly different between the pTDs-positive and pTDs-negative groups (P < 0.05), with the AUC of 0.767, 0.746, 0.664 and 0.644, respectively. mTDs and mLN were independent risk factors for pTDs (odds ratio: 5.74 and 3.90, P < 0.05). The AUC, sensitivity, specificity, negative predictive value, and accuracy of the nomogram were 0.814 (95% CI: 0.720 ~ 0.908), 73.9%, 79.4%, 93.4%, and 78.5%, respectively. Seventeen of 23 patients with pTDs were identified as mTDs, with a moderate agreement between pTDs and mTDs (Kappa=0.419). Multiplanar HRT2WI can be used as a preoperative diagnostic tool to identify TDs in LARC. The combined model constructed by mTDs and mLN shows a good diagnostic performance for TDs.

A Novel Magnetic Resonance Imaging-Based Radiomics and Clinical Predictive Model for the Regrowth of Postoperative Residual Tumor in Non-Functioning Pituitary Neuroendocrine Tumor.

Background and Objectives: To develop a novel magnetic resonance imaging (MRI)-based radiomics-clinical risk stratification model to predict the regrowth of postoperative residual tumors in patients with non-functioning pituitary neuroendocrine tumors (NF-PitNETs). Materials and Methods: We retrospectively enrolled 114 patients diagnosed as NF-PitNET with postoperative residual tumors after the first operation, and the diameter of the tumors was greater than 10 mm. Univariate and multivariate analyses were conducted to identify independent clinical risk factors. We identified the optimal sequence to generate an appropriate radiomic score (Rscore) that combined pre- and postoperative radiomic features. Three models were established by logistic regression analysis that combined clinical risk factors and radiomic features (Model 1), single clinical risk factors (Model 2) and single radiomic features (Model 3). The models' predictive performances were evaluated using receiver operator characteristic (ROC) curve analysis and area under curve (AUC) values. A nomogram was developed and evaluated using decision curve analysis. Results: Knosp classification and preoperative tumor volume doubling time (TVDT) were high-risk factors (p < 0.05) with odds ratios (ORs) of 2.255 and 0.173. T1WI&T1CE had a higher AUC value (0.954) and generated an Rscore. Ultimately, the AUC of Model 1 {0.929 [95% Confidence interval (CI), 0.865-0.993]} was superior to Model 2 [0.811 (95% CI, 0.704-0.918)] and Model 3 [0.844 (95% CI, 0.748-0.941)] in the training set, which were 0.882 (95% CI, 0.735-1.000), 0.834 (95% CI, 0.676-0.992) and 0.763 (95% CI, 0.569-0.958) in the test set, respectively. Conclusions: We trained a novel radiomics-clinical predictive model for identifying patients with NF-PitNETs at increased risk of postoperative residual tumor regrowth. This model may help optimize individualized and stratified clinical treatment decisions.

Baseline labs predict adverse postoperative outcomes following metastatic brain tumor resection: Analysis of 5943 patients from a prospective surgical registry (2015–2019)

IntroductionThe present study sought to evaluate the predictive accuracy of preoperative lab values (PLV) on postoperative metastatic brain tumor resection (MBTR) outcomes using data queried from a large prospective international surgical registry, representing over 700 hospitals in 11 countries. MethodsAdult metastatic brain tumor patients (N = 5943) were queried from the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database, from 2015 to 2019, using diagnostic and procedural coding. The relationship between preoperative lab values and key indicators of adverse postoperative outcomes following metastatic brain tumor resection were assessed with univariate and multivariate analyses. Adverse postoperative outcomes of interest included: 30-day mortality, Clavien-Dindo Grade IV (CDIV) complications, extended length of stay (eLOS), and discharge to non-home destination (NHD), as well as secondary outcomes: non-Clavien-Dindo Grade IV complications, unplanned reoperation, and unplanned readmission. ResultsIndependent PLV most strongly associated with 30-day mortality were hypernatremia, increased serum creatinine, and thrombocytopenia. Significant predictors of CDIV complications were hypoalbuminemia and thrombocytopenia. eLOS was associated with hypoalbuminemia, anemia, and hyponatremia. The strongest independent predictors of NHD were anemia, hyperbilirubinemia, and hypoalbuminemia. ConclusionSeveral pre-operative lab values independently predicted worse outcomes for metastatic brain tumor resection patients. Hypoalbuminemia, thrombocytopenia, and anemia had the strongest association with the study's adverse postoperative outcomes. These baseline lab values may be considered for preoperative risk stratification of metastatic brain tumor patients.

Effects of propofol-based total intravenous anesthesia versus desflurane anesthesia on natural killer cell cytotoxicity after hepatocellular carcinoma resection.

Inhalation anesthesia suppresses the immune system and stimulates the growth of tumor cells, contrary to intravenous anesthesia. However, no consensus exists on which anesthetic technique is better for preventing cancer recurrence. Therefore, this study compared the effects of two different anesthetic techniques on natural killer cell cytotoxicity (NKCC) in hepatocellular carcinoma (HCC) patients undergoing open hepatic resection. Patients diagnosed with nonmetastatic HCC were scheduled for hepatic resection and randomly assigned to receive either propofol- or desflurane-based anesthesia. The primary outcome was pre- and postoperative NKCC assay. Cytokine levels were assessed by measuring interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) levels, and the secondary outcome was postoperative cancer recurrence evaluated using diagnostic imaging scans for 2 years. Twenty-eight patients were analyzed, including 15 and 13 in the total intravenous anesthesia (TIVA) and inhalation (INH) groups, respectively. Two patients in the INH group were excluded due to non-HCC postoperative pathologic results. At 24 h, the postoperative change in NKCC between both groups showed no significant differences at a ratio of effector cell: target cell = 1:1, 5:1, and 10:1 (P = 0.345, 0.345, and 0.565, respectively). Also, there were no significant differences in IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ levels (P = 0.588, 0.182, 0.730, 0.076, 0.518, 0.533, respectively). Postoperative tumor recurrence occurred in five and six patients in the TIVA and INH groups, respectively. NKCC did not differ significantly among HCC patients undergoing open hepatic resection under either propofol or desflurane anesthesia 24 h postoperatively.