Melatonin as a radioprotective agent against flattening filter and flattening filter-free beam in radiotherapy-induced lung tissue damage.

BACKGROUND: Radiotherapy is a widely used treatment method in oncology, applied by delivering high-energy particles or waves to the tumor tissue. Although tumor cells are targeted with radiotherapy, it can cause acute or long-term damage to healthy tissues. Therefore, the preservation of healthy tissues has been an important subject of various scientific researches. Melatonin has been shown to have a radioprotective effect on many tissues and organs such as liver, parotid gland, brain, and testicles. This study aimed to evaluate the protective effect of melatonin against the radiation at various doses and rates administered to the lung tissue of healthy mice. METHODS: This study was a randomized case-control study conducted with 80 rats comprising 10 groups with eight animals per group. Of the 10 groups, first is the control group, which is not given any melatonin, and second is the group that does not receive RT, which is given only melatonin, and the other eight groups are RT groups, four with melatonin and four without melatonin. RESULTS: There was no statistical difference in terms of histopathological findings in the lung tissue between the second group, which did not receive radiotherapy and received only melatonin, and the control group. Lung damage due to radiotherapy was statistically significantly higher in the groups that did not receive melatonin compared to the groups that received melatonin. CONCLUSIONS: This study revealed that melatonin has a protective effect against the cytotoxic damage of RT in rats receiving RT.

EBUS ROSE-guided cytological evaluations of intrathoracic lesions. Assessments of the pathological material adequacy and the diagnostic efficacy.

BACKGROUND: Several clinical groups consider cytological assessment under EBUS (Endobronchial Ultrasonography)-ROSE (Rapid Onsite Evaluation) as the golden standard for diagnosis and staging of intrathoracic lesions. On the other hand, some investigators proposed that EBUS-TBNA (Transbronchial Needle Aspiration) has considerably high false-negative rates for diagnosis. In this study, we analyzed our patient cohort (n = 152) with intrathoracic lesions and suspected malignancies evaluated by EBUS-ROSE. Our specific aims were: (i) to determine whether EBUS-ROSE could provide sufficient pathologic material for diagnosis and staging; (ii) to determine the fidelity of EBUS-ROSE-guided initial diagnoses in comparison to paraffin block diagnoses; (iii) to evaluate whether anatomical localization of sampled lymph nodes associate with material adequacy and final diagnoses. METHODS: NCSS (Number Cruncher Statistical System) 2020 Statistical Software (Utah, USA) was used for statistical analysis. RESULTS: In EBUS-ROSE cytological assessment, material adequacy was determined in 50,7% (n = 77) of the cases. Considering the paraffin block pathology as the golden standart, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy rates of EBUS-ROSE were 90,2%, 93,1%, 94,8%, 87,1%, and 91,4%, respectively. There was no statistically significant difference between the final pathology and EBUS cytology results (p > .05) with a non-random Kappa agreement rate as 82.9%. There were differences in material adequacy and diagnoses according to the localization of sampled lymph node stations. CONCLUSIONS: EBUS-ROSE is efficient to decide for the adequacy of the pathological specimen and provides diagnoses with reliable fidelity.

Deficient Mismatch Repair and Lymphocytic Response to Tumor as Prognostic Markers in Stage II Colon Cancer Patients.

OBJECTIVE: To investigate the relationship between colon cancer (CC) subtypes defined by the status of tumor-infiltrating lymphocytes (TIL) and mismatch repair (MMR) combination with clinicopathological features and survival. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Department of Medical Oncology, Haydarpasa Numune Research and Training Hospital, Istanbul, Turkey, from July 2010 to March 2020. METHODOLOGY: Eighty-three patients with operated stage II colon cancer were included in the study. Pathology, surgery and oncological treatment and follow-up information were obtained from patient files; and statistical analyses were performed on overall survival (OS). Tumor-infiltrating lymphocytes and mismatch repair status was determined with the help of immunohistochemistry. RESULTS: TIL-high and deficient MMR (dMMR) status were detected in 26 patients (31.3%) and 21 patients (25.3%), respectively. Tumors were divided into four subgroups according to TIL and MMR status. TIL-high/dMMR tumors had the most favourable prognosis, while TIL-low/proficient MMR tumors exhibited poor OS. CONCLUSION: The combination of TIL and MMR could enable us to differentiate patients' survival outcomes in more details. Therefore, considering that the TIL and MMR status, evaluated by IHC, may be a cost-effective and effective option for risk classification in patients with stage II colon cancer. Key Word: Lymphocytic response, Mismatch repair, Prognosis, Tumor-infiltrating lymphocytes, Stage II cancer, Colon cancer.

Use of Diffusion-Weighted Magnetic Resonance Imaging and Apparent Diffusion Coefficient in Gastric Cancer Staging.

BACKGROUND: The apparent diffusion coefficient (ADC), the quantitative parameter of diffusion-weighted magnetic resonance imaging (DW-MRI), is a measure for this restricted diffusion, and its role in gastric cancer (GC) including distinguishing malignant segments from healthy gastric wall, metastatic perigastric lymph nodes from benign nodes and evaluating response of GC to neoadjuvant chemotherapy has been investigated in previous studies. Evidence suggests that ADC may also be of help in assessment of aggressiveness and preoperative staging of gastric cancer, which needs to be explored in further studies. OBJECTIVE: To investigate the role of DW-MRI and its quantitative parameter, ADC in staging of gastric cancer. METHODS: Forty-six patients (28 male, 18 female, mean age 62 years) with non-metastatic biopsy- proven GC who underwent abdominal DW-MRI before surgery were included in this retrospective study. Tumor invasion depth (T-stage) and nodal involvement (N-stage) were evaluated using signal increase on DW-MRI, and tumor ADC was measured. Diagnostic performance of these results was assessed by comparing them with postsurgical histopathology based on 8th TNM classification. RESULTS: Sensitivity, specificity, and accuracy of DW-MRI in T-staging were 92.1%, 75%, 89.1% for ≤T2 vs. ≥T3; and 75%, 88.5%, 82.6% for ≤T3 vs. T4. However, sensitivity, specificity, and accuracy of DW-MRI in N-staging were 89.3%, 88.9%, 89.1% for ≤N1 vs. ≥N2; and 73.7%, 96.3%, 86.9% for ≤N2 vs. N3, respectively. Relative preoperative ADC values correlated with pT staging (r=-0.397, p=0.006). There was also a statistically significant difference of relative ADC values between ≤T3 and T4 stages, and a cut-off of 0.64 s/mm2 could differentiate these stages with an odds ratio of 7.714 (95% confidence interval, 1.479-40.243). The area under the receiver operating characteristic curve for differentiating ≤T3 and T4 stages was 0.725. CONCLUSION: DW-MRI may contribute to the clinical staging of non-metastatic GC. In particular, relative ADC of DW-MRI can distinguish T4 gastric cancer from less advanced T-stages.

Effect of high-risk human papillomavirus in esophageal squamous cell carcinoma in Somalian and Turkish cases.

This study aimed to investigate the role of high-risk human papillomavirus (Hr-HPV) in Somalian and Turkish patients with esophageal squamous cell carcinoma (ESCC). In the sections obtained from paraffin-embedded blocks, the results of invasive tumor, peripheral tumor dysplasia and normal mucosa were examined. Samples containing 45 and 47 ESCC, 46 and 42 dysplasia in Somalian (n = 52) and Turkish (n = 53) cases, respectively, were included in the study. We examined the presence of 14 types of Hr-HPV in ESCC collected from Somalia and Turkey by Aptima® Panther System. Hr-HPV types were not detected in Somalian cases. p16INK4a is positive in 5 (11.4%) tumors and 6 (13%) dysplasia. p53 is positive in 28 (62.2%) tumors and 35 (76.1%) dysplasia. HPV16-18/45 are positive only in one of the Turkish cases. p16INK4a is positive in 5 (10.6%) tumors and 4 (9.5%) dysplasia. p53 is positive in 31 (63.3%) tumors and 24 (57.1%) dysplasia. No reaction was detected in normal mucosa samples in both countries. This study is regional. Although the findings did not reflect the general population, the present study shows that the effect of HPV on carcinogenesis in Somalian and Turkish ESCC patients was not significant.