The LEGACy study: a European and Latin American consortium to identify risk factors and molecular phenotypes in gastric cancer to improve prevention strategies and personalized clinical decision making globally.

BACKGROUND: Gastric Cancer (GC) is the fourth most deadly cancer worldwide. Enhanced understanding of its key epidemiological and molecular drivers is urgently needed to lower the incidence and improve outcomes. Furthermore, tumor biology in European (EU) and Latin American (LATAM) countries is understudied. The LEGACy study is a Horizon 2020 funded multi-institutional research approach to 1) detail the epidemiological features including risk factors of GC in current time and 2) develop cost-effective methods to identify and integrate biological biomarkers needed to guide diagnostic and therapeutic approaches with the aim of filling the knowledge gap on GC in these areas. METHODS: This observational study has three parts that are conducted in parallel during 2019-2023 across recruiting centers from four EU and four LATAM countries: Part 1) A case-control study (800 cases and 800 controls) using questionnaires on candidate risk factors for GC, which will be correlated with clinical, demographic and epidemiological parameters. Part 2) A case-control tissue sampling study (400 cases and 400 controls) using proteome, genome, microbiome and immune analyses to characterize advanced (stage III and IV) GC. Patients in this part of the study will be followed over time to observe clinical outcomes. The first half of samples will be used as training cohort to identify the most relevant risk factors and biomarkers, which will be selected to propose cost-effective diagnostic and predictive methods that will be validated with the second half of samples. Part 3) An educational study, as part of our prevention strategy (subjects recruited from the general public) to test and disseminate knowledge on GC risk factors and symptoms by a questionnaire and informative video. Patients could be recruited for more than one of the three LEGACy studies. DISCUSSION: The LEGACy study aims to generate novel, in-depth knowledge on the tumor biological characteristics through integrating epidemiological, multi-omics and clinical data from GC patients at an EU-LATAM partnership. During the study, cost-effective panels with potential use in clinical decision making will be developed and validated. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: Part 1: NCT03957031 . Part 2: NCT04015466 . Part 3: NCT04019808 .

From colorectal cancer pattern to the characterization of individuals at risk: Picture for genetic research in Latin America.

Colorectal cancer (CRC) is one of the most common cancers in Latin America and the Caribbean, with the highest rates reported for Uruguay, Brazil and Argentina. We provide a global snapshot of the CRC patterns, how screening is performed, and compared/contrasted to the genetic profile of Lynch syndrome (LS) in the region. From the literature, we find that only nine (20%) of the Latin America and the Caribbean countries have developed guidelines for early detection of CRC, and also with a low adherence. We describe a genetic profile of LS, including a total of 2,685 suspected families, where confirmed LS ranged from 8% in Uruguay and Argentina to 60% in Peru. Among confirmed LS, path_MLH1 variants were most commonly identified in Peru (82%), Mexico (80%), Chile (60%), and path_MSH2/EPCAM variants were most frequently identified in Colombia (80%) and Argentina (47%). Path_MSH6 and path_PMS2 variants were less common, but they showed important presence in Brazil (15%) and Chile (10%), respectively. Important differences exist at identifying LS families in Latin American countries, where the spectrum of path_MLH1 and path_MSH2 variants are those most frequently identified. Our findings have an impact on the evaluation of the patients and their relatives at risk for LS, derived from the gene affected. Although the awareness of hereditary cancer and genetic testing has improved in the last decade, it is remains deficient, with 39%-80% of the families not being identified for LS among those who actually met both the clinical criteria for LS and showed MMR deficiency.

Differentiated precursor lesions and low-grade variants of squamous cell carcinomas are frequent findings in foreskins of patients from a region of high penile cancer incidence.

AIMS: About 10-20% of all penile squamous cell carcinomas (SCCs) originate in the foreskin, but knowledge about preputial precursor and associated lesions is scant. The aims of the present study were to determine the prevalence of various precancerous and cancerous lesions exclusively affecting the foreskin, and to describe their pathological features. METHODS AND RESULTS: One hundred consecutive circumcision specimens from symptomatic patients living in a region of high penile cancer incidence were analysed. Clinical diagnoses included mostly phimosis and chronic balanoposthitis (40 and 35 cases, respectively), but also a tumour mass (11 cases). Histopathological lesions found included: squamous hyperplasia in 61 cases; lichen sclerosus in 53 cases; penile intraepithelial neoplasia (PeIN) in 30 cases (all differentiated PeIN, with two cases showing multicentric foci of basaloid and warty-basaloid PeIN); and invasive SCC in 11 cases (three usual, three pseudohyperplastic, two verrucous-pseudohyperplastic, and one case each of basaloid, papillary and mixed usual-basaloid carcinomas). Lichen sclerosus was present in all low-grade SCC cases. Patients with no lesions were younger (mean age 44 years) than those with precursor lesions (mean age 54 years) or with invasive SCC (mean age 68 years). Immunohistochemistry for p16(INK4a) was performed in 19 precancerous lesions. All differentiated PeINs (18 lesions) were negative, and one basaloid PeIN was positive. CONCLUSIONS: The frequent coexistence of lichen sclerosus, squamous hyperplasia, differentiated PeIN and low-grade SCC suggests a common non-human papillomavirus related pathogenic pathway for preputial lesions, and highlights the importance of circumcision in symptomatic patients for the prevention of penile cancer.

The prognostic index: a useful pathologic guide for prediction of nodal metastases and survival in penile squamous cell carcinoma.

A concern of surgical oncologists has been to find a method to select patients for groin dissection in penile carcinomas considering the high morbidity of this procedure. A promising methodology, in the identification of early metastatic foci by the sentinel lymph node technique (initiated in Paraguay in the 1970s), was found, using a static anatomic approach, to be associated with a recurrence rate of 30%. Later, a dynamic method using radioactive tracers and peritumoral dye injection was introduced with an improvement in patients' outcome. Recurrences, however, remained high in most studies at a rate of about 15% to 20% except in few highly specialized centers with failure rates of 5%. The technical sophistication, lack of multicenter reproduction, and cost of dynamic sentinel node biopsies preclude their routine implementation in developing countries and other approaches are necessary. Because histologic grade, depth of tumor infiltration, and perineural invasion (PNI) are considered among the most important pathologic prognostic parameters in penile cancer, we devised a Prognostic Index combining these 3 factors. In this study, we are evaluating the incidence of nodal metastasis according to the Prognostic Index score. Pathologic materials from 193 patients with penectomy/circumcision and bilateral groin dissections for invasive squamous cell carcinoma were analyzed. The Prognostic Index (ranging from 2 to 7) consisted in the addition of numerical values given to histologic grade (1 to 3), deepest anatomic level involved by cancer (1 to 3), and presence of PNI (0 or 1). Histologic grades were defined as follows: grade 1, carcinomas with minimal to no atypias; grade 3, tumors showing any proportion of anaplastic cells; and grade 2, the remainder tumors. The anatomic levels and their numerical values were: in glans, lamina propria, 1; corpus spongiosum, 2; and corpus cavernosum, 3. In foreskin they were: lamina propria, 1; dartos, 2; and skin, 3. PNI was evaluated as follows: absence of PNI, 0; presence of PNI, 1. Penile intraepithelial neoplasia (carcinoma in situ), or index 1, was excluded from the study. Mean follow-up obtained in all patients was of 81 months. The distribution of cases and rate of metastasis according to index scores were: 2 (1 case), no metastasis; 3 (17 cases), no metastasis; 4 (35 cases), 20% of metastasis; 5 50 cases), 50% of metastasis; 6 (47 cases), 66% of metastasis; and 7 (43 cases), 79% of metastasis. On logistic regression analysis evaluating various pathologic factors, Prognostic Index scores were found as the best predictors of inguinal node metastasis and patients' survival. Inguinal node dissections might not be necessary for patients with low indices (2 and 3). Nodal dissections might be formally indicated for high-grade indexes (5 to 7). Patients with index 4 should be individually assessed for nodal dissection. If sentinel node biopsy cannot be performed for various reasons the Prognostic Index might represent a useful pathologic guide to the clinicians in the often difficult decision to perform an inguinal dissection or not.