Ultrastructural differences between synovial sarcoma and solitary fibrous tumor: comparative study in adult patients from the National Cancer Institute of Mexico

Synovial sarcoma (SS) and solitary fibrous tumor (SFT) are entities with considerable morphological and immunohistochemical similarities that sometimes show a non-confirmatory profile (TLE1 negative, CD34 and focal or negative STAT6 and lack of specific fusion IHC markers), in which the utility ultrastructure is unknown. A cross-sectional, retrospective, analytical, nonexperimental study was carried out by the Department of Pathology of the National Cancer Institute of Mexico (INCan) e from January 1, 2009 to December 31, 2018. With 17 SFT cases with diffuse or focal CD34 and STAT6 positivity and 18 cases of SS with positive FISH molecular test t(X:18) breakapart were studied by electron microscopy of fresh glutaraldehyde fixed or paraffin-embedded tissue. The ultrastructural findings with a significant difference present in the SS were tandem tight junctions, desmosomes and abundance of dilated rough endoplasmic reticulum (RER) cisternae (p < 0.001, 0.003, and 0.001, respectively); while in the (SFT) the presence of abundant glycogen, basal lamina, long and slender cytoplasmic processes, pinocytic vesicles, hemidesmosomes, and/or dense plaques, collagen skein, and microvilli-like buds (p = 0.028, 0.005, and <0.001 for the last five). We then infer that the five distinctive markers of the SFT are the collagen skeins intermingled with cellular processes in a shape of "squid can," and the pinocytic vesicles as they were not observed in any case of SS. Conversely, tandem junctions were not found in any SFT case. Although the presence of multivesicular buds in the SFT was not significant, it had not been previously described.

Prognostic significance of tumour budding in Merkel cell carcinoma

Prognostic factors in Merkel cell carcinoma (MCC) are scarce. Tumour budding (TB) has been shown to have a prognostic role in different cancers but has not been explored in MCC. We aimed to determine if TB influences survival in MCC. We performed a retrospective evaluation of 45 cases of MCC in a cancer centre. This included a survival analysis involving TB in patients with MCC, and we searched for variables associated with TB. The mean age of the patients was 69 years. Histologically, the average Breslow was 11.36 mm, and the mean mitotic rate was 31.9 mitoses/mm2. The diagnosis was made in clinical stages I and II in 40% of cases, 22.2% in stage III, and 37.8% in stage IV. Tumour budding was low ( 10 buds/0.785 mm2) in 24.4%. There were no clinical or pathological features associated with high TB. Among the prognostic factors for 5-year survival, we found that tumour size and clinical stage were statistically associated with survival (p = 0.031 and 0.021), but TB was not. No clinical or pathological characteristics of MCC are associated with any degree of TB. Tumour budding does not influence overall survival.

Exhaustive pathologic work-up in sentinel lymph node biopsy for melanoma: is it necessary?

The objective of this study is to determine whether a less exhaustive pathologic work-up to detect melanoma metastasis is clinically useful and does not affect patient prognosis. The success and evolution of the sentinel lymph node (SLN) depends on histological techniques. Several exhaustive protocols of SLN analysis have been published, but are time and cost consuming, with slight increases in the rates of metastasis detection. From 281 patients with SLN biopsy, each SLN was sectioned every 2 mm and from each paraffin block, 2-3 histological sections were evaluated. The patients were divided as follows: the first group (n=185) was subjected to extensive SLN examination (eSLNe) and the second group (n=96) was not subjected to an extensive SLN examination (wSLNe). The average SLN resected was 2 (range: 1-7), evaluating one in 50.9%. The SLN metastasis detection rate was 28.5%, whereas eSLNe increased by 3.2%. During follow-up, 4/26 (17.4%) cases in the wSLNe group showed recurrence in the SLN basin. Factors associated with decreased survival in univariant analysis were recurrence, Breslow thickness, advanced clinical stage, ulceration, and SLN metastasis. eSLNe did not affect disease-specific survival. Multivariate analysis showed recurrence (hazard ratio 23.475, 95% confidence interval: 1903-4559, P<0.001) and Breslow thickness of more than 3.5 mm (hazard ratio 15.222, 95% confidence interval: 1448-3059, P<0.001) as independent risk factors for decreased survival. Our routine for SLN examination enabled an adequate rate of SLN metastasis detection and the eSLNe increased the rate of detection in 3.2%, but did not affect the survival. We did not find any benefit from performing the eSLNe in patients with Breslow thickness less than 3.5 mm.

[Trends of thyroid pathology in a referral center: steady prevalence of papillary thyroid carcinoma but goiter increase in thyroidectomies]

INTRODUCTION

Changes in the prevalence of papillary thyroid carcinoma (PTC) have been reported in institutions and national cancer registries.

OBJECTIVE

To describe time trends in benign and malignant thyroid diseases in a national endocrine referral center.

MATERIALS AND METHODS

Systematic review and classification of consecutive specimens with slides/paraffin blocks in surgical pathology archives (January 1990 to December 2009). Institutional registries, size, type of surgery and number of inclusion blocks were recorded. Patients whose registries were granted before January 1990 without nodules, but treated after twelve months for a suspicious thyroid lesion, were included. These patients in a passive follow-up permitted incidence density calculations. Cases were grouped by quinquennium.

RESULTS

Institutional registers were conceded to 103,961 persons worthy of attention, and 1,269 were submitted to thyroidectomies (1.2%). One hundred twenty four patients none treated for thyroid diseases before 1990, developed thyroid nodules after 1991. The incidence density for goiter was 0.05 person/year and for PTC 0.04 person/year in that group. In all series woman to man relation was 9:1 with a mean age of 45 years. Total or near total thyroidectomies were performed in 60% patients and benign diseases were diagnosed in 732 (52%) cases. Thyroid surgeries increased since 2005 (p=0.03) with a rise in goiter prevalence (0.25, 0.31, 0.35, 0.38, p for trend 0.0005), without significant increase in PTC prevalence (0.41, 0.43, 0.35, 0.40, p for trend 0.71) in thyroidectomies.

CONCLUSIONS

Goiter as the only finding in thyroid specimens increased 52% in the last 20 years. PTC prevalence is steady with a higher number of tumors<3 cm.

A fucoidan plant drink reduces Helicobacter pylori load in the stomach: a real-world study

BACKGROUND

Helicobacter pylori (Hp) infection is highly prevalent globally and is predominantly managed by antibiotics. Recently, the anti-adhesive, antioxidant, antitoxin, immunomodulatory, anti-coagulant, and anti-infective activities of fucoidan, a polysaccharide extracted from brown seaweeds, have been widely studied, and the results showed promise. Fucoidan has the potential to be utilized in Hp eradication therapy. Our present clinical study was designed to evaluate the efficiency of Lewuyou®, a fucoidan plant drink (FPD) in eradicating Hp in humans.

METHODS

This multi-center, clinical study was conducted between October 2020 and July 2021. Hp infection was confirmed by urea breath test (UBT). A total of 122 patients with confirmed Hp infection were enrolled; after exclusion of incomplete data, 85 eligible patients (37 males and 48 females aged 20-81 years) were included in the final analysis. FPD (50 mL per vial) was orally administered twice daily for a 4-week cycle, and 41 patients completed an 8-week cycle.

RESULTS

No adverse event (AE) was reported in all 122 participants who had consumed FPD. The Hp eradication rate and clearance rate were 77.6% (66/85) and 20.0% (17/85), respectively, after 4 weeks of FPD consumption and 80.5% (33/41) and 26.8 (11/41) , respectively, after 8 weeks of consumption.

CONCLUSIONS

The 4- and 8-week protocols of FPD consumption were safe and effective at reducing Hp load on the gastric mucosa, with Hp eradicated in the majority of participants.

Integrated clinico-molecular analysis of gastric cancer in European and Latin American populations: LEGACY project

BACKGROUND

Gastric cancer (GC) is recognized for intrinsic heterogeneity, although it is similarly approached in Europe and Latin America (LATAM). The LEGACY project aimed to deepen GC molecular understanding through multi-omics analysis in Europe and LATAM GC samples.

PATIENTS AND METHODS

Tumor samples were centrally reviewed for histology, human epidermal growth factor receptor 2 (HER2) expression, and mismatch repair-deficient (dMMR)/microsatellite instability (MSI) status. In addition, we assessed Epstein-Barr virus (EBV) status, programmed death-ligand 1 (PD-L1) combined positive score (CPS), and carried out tissue genomic profiling including tumor mutation burden (TMB) quantification plus targeted transcriptomics for immune microenvironment and cancer cell signaling scores.

RESULTS

In total, 328 GC patients were enrolled. HER2-positive GC and high PD-L1 CPS were more frequent in Europe than in LATAM (9% versus 3% and 15% versus 3%, respectively), whereas EBV was mainly found in LATAM (7%, versus 3% in Europe), and dMMR/MSI tumors were equally distributed (16%). High TMB was enriched in dMMR/MSI and EBV tumors. Mutations in homologous recombination repair (HRR) genes were frequent in both cohorts (24.8% and 14.7% in Europe and LATAM, respectively), and mostly found in dMMR/MSI (63.6%) and intestinal HER2-negative (18.7%) tumors. The prognosis was poor in diffuse HER2-negative GC patients, whose tumors presented an immunosuppressive microenvironment and other distinct pathway activation signatures.

CONCLUSIONS

Our findings relate specific molecular alterations of GC tumors from Europe and LATAM to actionable biomarkers for precision cancer therapies. The proposed GC stratification can be implemented in routine care and guide drug development strategies.

Report of three cases of gastric choriocarcinomas-an emphasis on morphologic changes in the non-affected gastric mucosa

Primary gastric choriocarcinomas (PGC) are very rare and aggressive neoplasms with a worrisome prognosis. Most cases are reported in Asia and presented in middle-aged adults with male predominance. Most cases are associated with an intestinal adenocarcinoma; however, the pathogenesis of this tumor is uncertain. No previous reports exist of the characteristics of the non-tumoral stomach in these patients, and this data that could help to clarify their pathogenesis. We presented a series of three cases of PGC in Latin American patients, emphasizing the characteristics of non-neoplastic mucosa.

Prognostic variables in patients with thick melanomas. Analysis of 362 cases

BACKGROUND

Melanoma epidemiological and prognostic studies are based on Caucasian populations, in whom the predominant subtype is superficially-spreading melanoma and in whom thin melanomas (Breslow < 3 mm) predominate. Mexican patients show a predominance of thick melanomas (Breslow ≥ 3 mm), and the acral subtype is the most common. There are no publications on prognostic factors in thick melanomas. We hypothesize that we will identify factors that determine the prognosis in this group of patients.

OBJECTIVE

To identify clinical-pathological factors associated with the prognosis of patients with thick melanomas in the Mexican population.

MATERIAL AND METHODS

Data on melanomas with Breslow > 3 mm were collected from 2010 to 2015. The prognostic influence of various clinical-pathological factors was analyzed.

RESULTS

The most common subtypes were acral melanoma in 271 patients (74.9 %) and nodular melanoma in 49 (13.5 %). Median Breslow thickness was 7 mm. 56.6 % of the patients had lymph node metastases (clinical stage [CS] III), 269 (74.3 %) had ulceration, and surgical margins were positive in 15 (4.1 %). Elevated neutrophil: lymphocyte ratio (≥ 2) was found in 188 (51.9 %). The variables associated with lower overall survival were CS (p < 0.001), Breslow thickness (p = 0.044), ulceration (p = 0.004), mitotic activity (p < 0.001), < 2-cm margin (p < 0.001) and an increased neutrophil: lymphocyte ratio (p = 0.037). In the multivariate analysis, the factors associated with overall survival were CS, mitotic activity, and surgical margin.

CONCLUSIONS

In patients with thick melanomas, overall survival is influenced by mitotic activity, a positive margin, and clinical stage.

Aflatoxin levels and prevalence of TP53 aflatoxin-mutations in hepatocellular carcinomas in Mexico

OBJECTIVE

To determine the exposure to aflatoxin B1 (AFB1) in southern Mexico and the presence of the aflatoxin signature mutation in hepatocellular carcinoma (HCC) tissue from patients from a cancer referral center.

MATERIALS AND METHODS

We estimated the prevalence and distribution of AFB1 in a representative sample of 100 women and men from Chiapas using the National Health and Nutrition Survey 2018-19. We also examined the presence of the aflatoxin signature mutation in codon 249 (R249S), and other relevant mutations of the TP53 gene in HCC tissue blocks from 24 women and 26 men treated in a national cancer referral center.

RESULTS

The prevalence of AFB1 in serum samples was 85.5% (95%CI 72.1-93.1) and the median AFB1 was 0.117 pg/μL (IQR, 0.050-0.350). We detected TP53 R249S in three of the 50 HCCs (6.0%) and observed four other G>T transversions potentially induced by AFB1.

CONCLUSION

Our analysis provides evidence that AFB1 may have a relevant role on HCC etiology in Mexico.