Effect of build orientation on the fracture resistance and marginal quality of 3D-printed anatomic provisional crowns: An in-vitro study.

Introduction: Computer-aided design and computer-aided manufacturing (CAD/CAM) technologies have been increasingly used to fabricate provisional restorations in recent years. This study assessed how build orientation influences the fracture resistance and marginal quality of 3D-printed crowns compared with milled provisional crowns. Methods: The test group included 3D-printed crowns (Freeprint temp Shade A2, Detax, Ettlingen, Germany), which were further subdivided based on print orientation (0°, 45°, and 90°; n = 10 for each subgroup). The control group (n = 10) included milled crowns (Coratemp, White Peaks, Germany) with the same design as those of the test group. The margin quality of each crown was assessed at 60 × magnification using a digital stereomicroscope. A load-to-fracture test was performed by applying a force at a rate of 2 mm/min to assess fracture resistance. One sample from each subgroup was also subjected to scanning electron microscope (SEM) analysis. Results: The milled group exhibited the highest fracture resistance and marginal quality. Within the printed subgroups, the 0° group showed the best mean marginal quality, whereas the 90° group showed the lowest mean marginal quality (p < 0.05). Within the test groups, the 90° group had the highest mean fracture resistance (p < 0.05). In the SEM analysis, the milled group exhibited the most homogenous boundaries, whereas among the 3D-printed subgroups, the samples printed at 0° had the best margin quality. Conclusion: The manufacturing method significantly influences the marginal quality and fracture resistance. Milled crowns demonstrated superior marginal quality and fracture resistance compared to those of 3D printed crowns. Furthermore, the print orientation of 0° led to the best marginal quality, whereas printing at 90° led to the highest fracture resistance.

Efficacy and Feasibility of Complete Mesocolic Excision with Central Vascular Ligation in Complicated Colorectal Cancer.

Complete mesocolic excision (CME) with central vascular ligation (CVL) involves sharp dissection through the embryological planes. However, it may be associated with high mortalities and morbidities especially in colorectal emergencies. This study aimed to investigate the outcomes of CME with CVL in complicated colorectal cancers (CRCs). This was a retrospective study of emergency CRC resection in a tertiary center between March 2016 and November 2018. A total of 46 patients, with a mean age of 51 years, underwent an emergency colectomy for cancer (males, 26 [56.5%]; females, 20 [43.5%]). CME with CVL was performed for all patients. The mean operative time and blood loss were 188 min and 397 mL, respectively. Only five (10.8%) patients presented with burst abdomen, whereas only three (6.5%) presented with anastomotic leakage. The mean length of vascular tie was 8.7 cm, and the mean number of harvested lymph nodes (LNs) was 21.2. Emergency CME with CVL is a safe and feasible technique when performed by a colorectal surgeon and will result in obtaining a superior specimen with a large number of LNs.

CD133 is an independent predictive and prognostic marker in metastatic breast cancer.

BACKGROUND: CD133 is a transmembrane glycoprotein and is considered the most common cell surface marker to identify cancer stem cells in hematological and solid tumors, including breast cancer. OBJECTIVES: To evaluate the impact of immunohistochemical expression of CD133 on response rate and survival in metastatic breast cancer, as well as to correlate it with various demographics and clinicopathological characteristics. METHODS: One-hundred metastatic breast cancer patients were prospectively recruited at the Medical Oncology Department at South Egypt Cancer Institute during the period from January 2018 to January 2020. RESULTS: There was a statistically significant correlation between CD133 positive patients with various adverse clinicopathological parameters such as high grade (p= 0.013), higher tumor (p= 0.001), and nodal staging (p= 0.024) during a median follow-up time of 17 months. In addition, cases with CD133 positive expression had a significantly lower survival time than those with negative expression (3-years OS 37.4% versus 85.5%, p= 0.024). Regarding the response rate, CD133 positive patients had a lower response rate than negative patients (50% versus 54%, p= 0.012). CONCLUSIONS: Positive CD133 is correlated with poor prognosis in metastatic breast cancer patients.

Signet ring cell component predicts the response to neoadjuvant chemoradiotherapy in rectal cancer. Long interim results of a single institution experience.

There are limited studies evaluating the correlation between the presence of signet ring carcinoma and tumor response to neoadjuvant therapy in the rectum. Hereby, we aimed to report for the first time our experience from Upper Egypt through assessing the predictive role of signet ring cell component (SRCC) in the response to preoperative chemoradiotherapy (PCRT) and the impact of histological types (SRCC versus other types) on survival. This retrospective study analysed the medical records of 195 patients with locally advanced rectal cancer treated from 2011, to 2018. Patients were divided into two groups according to histological types: SRCC group and non SRCC group. All patients received PCRT followed by surgery. SRCC group was associated with significant higher rate of complete clinical response (cCR) and pathologic complete response (pCR) (83.3% and 88.9% respectively) as compared to non SRCC group (9.0% and 10.2% respectively); P<0.0001. Fifteen cases (93.8%) who were diagnosed by magnetic resonance tumor regression grade (mrTRG) and diffusion weighted imaging (DWI) as cCR after PCRT, also achieved pCR, in contrast to 88.9% of cases without SRCC. Signet ring histology was the only predictor of pCR in multivariate analysis (P=0.027). There was no statistically significant difference between both histological groups as regard to survival. SRCC is an important predictor of pCR and assessing their response to PCRT using mrTRG and DWI showed high sensitivity for the detection of cCR, making them good candidates for watch-and-wait approach. Histological types did not significantly affect the survival outcome.

The efficacy and safety of extended adjuvant temozolomide following concurrent radio-chemotherapy among Egyptian patients with newly diagnosed glioblastoma multiforme.

Although concurrent radio-chemotherapy and adjuvant temozolomide (TMZ) treatment for 6 cycles has been established as a standard of care for newly diagnosed glioblastoma multiforme (GBM) patients, the recommended duration of adjuvant TMZ remains a matter of debate. Hereby, we aimed to report for the first time our experience from Upper Egypt through comparing survival and toxicity profile between two treatment modalities of adjuvant TMZ (> six cycles versus six cycles) and delineating factors of prognostic significance in Egyptian patients with newly diagnosed GBM treated by radiation therapy with concomitant and adjuvant TMZ. Between June 2016 and February 2018, the medical records of 121 patients were eligible to be retrospectively reviewed to extract the study relevant data. All patients received concurrent radio-chemotherapy, followed by TMZ for 6 cycles in 29 patients (Group 1) and for >6 cycles in 26 patients (Group 2). Patients in Group 1 had a median PFS of 15 months (95% CI: 10.215-19.785), while those in Group 2 had a median PFS of 18 months (95% CI: 16.611-19.389). After a median follow up duration of 20 months (range: 12-41), the median OS was 18 months (95% CI: 13.420-22.580) in Group 1 and 22 months (95% CI: 18.777-25.223) in Group 2. There was no statistically significant correlation between the number of chemotherapy cycles and PFS (P=0.513) or OS (P=0.867). The extent of surgical resection was the only independent prognostic factor for both PFS (P=0.015) and OS (P=0.028) by multivariate analysis. Three grade ≥3 hematologic toxicity were encountered in 3 patients. One in the six-cycle group (neutropenia), and two in the extended cycles group (one had neutropenia and the other one developed thrombocytopenia). No statistically significant difference in the toxicity profile between both groups. The results of our study suggest that extended TMZ therapy is safe and tolerable, however it did not significantly improve PFS or OS as compared to the standard six-cycle course. Larger randomized studies are required to shed more light on this issue.

Ewing sarcoma outcomes in a country with limited resources: Egypt as an example.

As the scarcity of published research that comprehensively and meticulously analyzed the patient, disease, and treatment factors of prognostic significance in Ewing sarcoma (EWS) in Egypt; This study aimed at assessing survival outcomes of EWS in Upper Egypt, delineating factors of prognostic significance in comparison to other leading oncology centers in Egypt and internationally. By retrospectively reviewing medical records of 85 patients with a verified diagnosis of EWS in the period from 2001 to 2015 at Pediatric and Medical Oncology Departments at South Egypt Cancer Institute; We gathered data relevant to the patient, disease, and treatment variables of the study. Survival was estimated using the Kaplan Meier method and differences between various groups were determined by log rank test. Univariable and multivariable analyses were performed using Cox regression. With a median follow-up period of 62.7 months (95% CI 52.2-73.2, SE=5.4) for the study patients, the estimates of event-free survival (EFS) and overall survival (OS) at 3 and 5 years were 42.1% and 50.6%, and 40.8% and 48.5%, respectively. Metastatic disease at initial presentation (HR=8.91, 95% CI, 4.00-19.9; P<0.0001) stood as the most powerful predictor of OS in the multivariable analysis, followed by surgery used as a local modality (HR=0.16, 95% CI, 0.06-0.44; P=0.0004). Response to neoadjuvant chemotherapy (HR=2.61, 95% CI, 1.11-6.13; P=0.028), primary tumor size (HR=2.49, 95% CI, 1.03-6.03; P=0.044) were also shown to be significantly associated with OS. Radiotherapy as a local modality, whose effect, apparently shown to increase the hazard of events occurrence in the univariable analysis, an effect that was reversed to reveal EFS advantage (HR=0.41, 95% CI, 0.18-0.95; P=0.036) after control of other variables. With 5-year OS of 48.5%, our survival results were comparable to those previously published from Egypt; however, differences still exist between centers due to varied representative study samples. However, outcomes in Egypt in general are still inferior to internationally published studies.