Multivariate statistical approach and machine learning for the evaluation of biogeographical ancestry inference in the forensic field.

The biogeographical ancestry (BGA) of a trace or a person/skeleton refers to the component of ethnicity, constituted of biological and cultural elements, that is biologically determined. Nowadays, many individuals are interested in exploring their genealogy, and the capability to distinguish biogeographic information about population groups and subgroups via DNA analysis plays an essential role in several fields such as in forensics. In fact, for investigative and intelligence purposes, it is beneficial to inference the biogeographical origins of perpetrators of crimes or victims of unsolved cold cases when no reference profile from perpetrators or database hits for comparative purposes are available. Current approaches for biogeographical ancestry estimation using SNPs data are usually based on PCA and Structure software. The present study provides an alternative method that involves multivariate data analysis and machine learning strategies to evaluate BGA discriminating power of unknown samples using different commercial panels. Starting from 1000 Genomes project, Simons Genome Diversity Project and Human Genome Diversity Project datasets involving African, American, Asian, European and Oceania individuals, and moving towards further and more geographically restricted populations, powerful multivariate techniques such as Partial Least Squares-Discriminant Analysis (PLS-DA) and machine learning techniques such as XGBoost were employed, and their discriminating power was compared. PLS-DA method provided more robust classifications than XGBoost method, showing that the adopted approach might be an interesting tool for forensic experts to infer BGA information from the DNA profile of unknown individuals, but also highlighting that the commercial forensic panels could be inadequate to discriminate populations at intra-continental level.

The impact of log odds of positive lymph nodes (LODDS) in colon and rectal cancer patient stratification: a single-center analysis of 323 patients.

Log odds of positive nodes (LODDS), defined as the log of the ratio between the number of positive nodes and the number of negative nodes, has been recently introduced as a tool in predicting prognosis. This study aims to establish the effective and prognostic value of LODDS in predicting the survival outcome of CRC patients undergoing surgical resection. The study population is represented by 323 consecutive patients with primary colon or rectal adenocarcinoma thatunderwent curative resection. LODDS values were calculated by empirical logistic formula, log(pnod + 0.5)/(tnod - pnod + 0.5). It was defined as the log of the ratio between the number of positive nodes and the number of negative nodes. The patients were divided into three groups: LODDS0 (≤ - 1.36), LODDS1 (> - 1.36 ≤ - 0.53) and LODDS2 (> - 0.53). Kaplan-Meier curve analyses showed 3-year OS rates of the patients staged by LODDS classification. These values were 88.3, 74.8 and 61.8% for LODDS0, LODDS1 and LODDS2, respectively (P ≤ 0.001). In a multivariate analysis, LODDS is an independent prognostic factor of 3-year OS. This is in contrast to pN stage and lymph node ratio, which shows no statistical significance. ROC analyses showed that LODDS predicted OS better than lymph node ratio. LODDS classification has a better prognostic effect than pN stage and lymph node ratio. LODDS offers a finer stratification and accurately predicts survival of CRC patients.

Prognostic assessment of different lymph node staging methods for pancreatic cancer with R0 resection: pN staging, lymph node ratio, log odds of positive lymph nodes.

BACKGROUND AND AIMS: Survival after surgical resection of pancreatic adenocarcinoma is poor. Several prognostic factors such as the status of the resection margin, lymph node status, or tumour grading have been identified. The aims of the present study were to evaluate and compare the prognostic assessment of different lymph nodes staging methods: standard lymph node (pN) staging, metastatic lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS) in pancreatic cancer after pancreatic resection. MATERIALS AND METHODS: Data were retrospectively collected from 143 patients who had undergone R0 pancreatic resection for pancreatic ductal adenocarcinoma. Survival curves (Kaplan-Meier and Cox proportional hazard models), accuracy, and homogeneity of the 3 methods (LNR, LODDS, and pN) were compared to evaluate the prognostic effects. RESULTS: Multivariate analysis demonstrated that LODDS and LNR were an independent prognostic factors, but not pN classification. The scatter plots of the relationship between LODDS and the LNR suggested that the LODDS stage had power to divide patients with the same ratio of node metastasis into different groups. For patients in each of the pN or LNR classifications, significant differences in survival could be observed among patients in different LODDS stages. CONCLUSION: LODDS and LNR are more powerful predictors of survival than the lymph node status in patients undergoing pancreatic resection for ductal adenocarcinoma. LODDS allows better prognostic stratification comparing LNR in node negative patients.

Hospital volume, margin status, and long-term survival after pancreaticoduodenectomy for pancreatic adenocarcinoma.

An association between hospital surgical volume and short- and long-term outcomes after pancreatic surgery has been demonstrated. Identification of specific factors contributing to this relationship is difficult. In this study, the authors evaluated if margin status can be identified as a measure of surgical quality, affecting overall survival, as a function of hospital pancreaticoduodenectomy volume. A systematic review of the literature was performed. Two models for analysis were created, dividing the 18 studies identified into quartiles and two quantiles based on the average annual hospital pancreatectomy volume. Regression modeling and analysis of variance were used to find an association between hospital volume, margin status, and survival. Increasing hospital volume was associated with a significantly increased negative margin status rate: 55 per cent for low-volume, 72 per cent for medium-volume, 74.3 per cent for high-volume, and 75.7 per cent for very high-volume centers (P = 0.008). The negative margin status rates were 64 per cent and 75.1 per cent for volume centers with less and more than 12 pancreaticoduodenectomies/year, respectively (P = 0.04). Low-volume centers negatively affected both margin positive resection and 5-year survival rates, compared with high-volume centers. Margin status rate after pancreaticoduodenectomy could, therefore, be considered a measure of quality for selection of hospitals dedicated to pancreatic surgery.

Role of the lymph node ratio in pancreatic ductal adenocarcinoma. Impact on patient stratification and prognosis.

BACKGROUND: Survival after resection of pancreatic adenocarcinoma is poor. Several prognostic factors such as the status of the resection margin, lymph node status, or tumor grading have been identified. Aim of the study was to evaluate the prognostic significance of the lymph node ratio (LNR) for resected pancreatic ductal adenocarcinoma. MATERIALS AND METHODS: Data were collected from 101 patients who had undergone pancreatoduodenectomy for pancreatic ductal adenocarcinoma. Patients were divided into four groups according to the absolute LNR (0, 0-0.199, 0.2-0.399, >0.4). Kaplan-Meier and Cox proportional hazard models were used to evaluate the prognostic effect. RESULTS: The actuarial 3- and 5-year survival rates were 32 and 17%, respectively. The median survival was 19 months. Patients with LNR 0/0-0.199/0.2-0.399/>0.4 survived 40.2/30.5/18.1, and 13.6 months, respectively (P = 0.001). At the multivariate analysis, lymph node status was not found to be a significant prognostic factor; on the contrary LNR >0.2 (P = 0.007), positive resection margin (P = 0.001), and grading (P = 0.05) were significantly related to survival. CONCLUSION: LNR is a more powerful predictor of survival than the lymph node status in patients undergoing pancreaticoduodenectomy for ductal adenocarcinoma.

Multiple giant diverticula of the foregut causing upper gastrointestinal obstruction.

Small bowel diverticulosis represents an uncommon disorder (except for Meckel diverticulum) often misdiagnosed since it causes non-specific gastrointestinal symptoms. Most of times the diagnosis is carried out in case of related complications, such as diverticulitis, hemorrhage, perforation or obstruction. Intestinal obstruction can be caused by inflammatory stenosis due to repeated episodes of diverticulitis, volvulus, intussusception or jejunal stones. Herein we report a case of multiple jejunal diverticula causing chronic gastrointestinal obstruction.

Gastric metastasis 14 years after mastectomy for breast lobular carcinoma: case report and literature review.

In planning treatment of a gastric neoplasm in a patient previously treated for lobular breast carcinoma, it is important to differentiate a primary gastrointestinal tract tumor from a metastatic form. We report a case of a breast lobular carcinoma metastatic to the stomach. The patient underwent a subtotal gastrectomy for symptomatic disease. Although gastric symptoms appeared 14 years after the breast carcinoma, immunohistochemical analysis of the surgical specimen helped to establish that the gastric lesion, thought to be primary, was effectively a metastatic repetition of the breast neoplasm. To better define treatment in a gastric neoplasm patient previously treated for breast carcinoma, the preoperative diagnosis should rule out a metastatic disease. The patient described received an adjuvant chemotherapy according to breast cancer protocol after gastric resection for symptomatic disease. The patient is still alive and undergoing chemotherapy for peritoneal carcinosis.

Male breast cancer: a case report and review of the literature.

Breast cancer in men is an uncommon disease. Because of its rarity little is known about its aetiology, clinical behaviour and treatment. Retrospective studies show that when age- and stage-matched breast cancer in men and women are compared, there is no difference in survival between the two groups. Nevertheless, because of the absence of screening protocols and the limited amount of mammary tissue in men, allowing rapid local infiltration, a late diagnosis is often made, with a poor survival rate. Most of our current knowledge about the biology, natural history, surgical therapeutic strategies, adjuvant radiotherapy and chemotherapy protocols of male breast carcinoma has been extrapolated from its female counterpart. The Authors report the case of a male patient with breast cancer and pagetoid diffusion in the nipple region, and, on the basis of a review of the literature, summarise what is currently known about this rare neoplasm in terms of prognostic factors, therapy and survival.