Utility of CD99 Paranuclear Expression in the Differential Diagnosis of Merkel Cell Carcinoma

BACKGROUND

Recent reviews have referred to the paranuclear dot-like staining pattern of CD99 in several neoplasms, including solid pseudopapillary tumors in the pancreas, colonic adenocarcinomas, and colonic adenomas as well as in Merkel cell carcinoma (MCC). The aim of this work was to explore the utility of CD99 paranuclear staining in the differential diagnosis of MCC.

MATERIAL AND METHODS

We explore paranuclear dot-like CD99 expression in several small, round blue cell neoplasms, including neuroendocrine neoplasms, Ewing sarcomas/primitive neuroectodermal tumors (EWS/PNET), melanomas, small cell lung carcinomas (SCC), lymphoblastic lymphoma/leukemia, and rhabdomyosarcomas, in comparison with 33 cases of MCC, to determine the specificity of the paranuclear dot-like CD99 expression in MCC.

RESULTS

Twenty MCC (60%) demonstrated focal expression of CD99 and of those, 14 (42.4%) showed the characteristic paranuclear dot-like expression. CD99 was also paranuclear positive in 4 of 11 (36%) SCC, in 3 of 7 (43%) EWS/PNET, in 1 of 6 (16%) lymphoblastic lymphoma/leukemia cases, in 3 of 3 (100%) rhabdomyosarcomas and all melanomas were negative for the CD99 reaction.

CONCLUSION

CD99 paranuclear dot-like expression was not exclusive of the MCC compared with several neoplasms included in its differential diagnosis. This expression is not a great diagnostic aid.

Prognostic importance of lymph node ratio after resection of ampullary carcinomas

BACKGROUND

The prognosis of the lymph node ratio (LNR) in Vater's ampulla carcinomas (VACs) is recently studied. However, there are not enough data in several populations like Latin American people. Our aim is to demonstrate the prognosis significance of the LNR in this setting.

METHODS

Pancreaticoduodenectomies for VACs were identified (n=128) from 1980 through 2015. Based on a ROC curve, a cut-off point of 0.1 was assigned for the LNR and the population was divided into two groups for comparison.

RESULTS

The LNR ≥0.1 group was statistically significant associated with recurrence (38.5% vs. 19.5%), pT3-T4 tumors (69.2% vs. 29.3%), poorly differentiated tumors (46.2% vs. 17.5%), lymphovascular invasion (61.5 vs. 17.1%), perineural invasion (38.5% vs. 19.5%), and positive margins (15.4% vs. 2.4%). In the multivariate analysis, LNR (HR 2.891; CI: 1.987-3.458, P=0.02), LNM (HR 2.945; CI: 2.478-3.245, P=0.002), perineural invasion (HR 3.327; CI: 3.172-4.156, P=0.003), and recurrence (HR 3.490; CI: 2.896-4.122, P=0.001) were associated with lower survival.

CONCLUSIONS

The LNR is a good predictor of survival and worse oncological outcomes for VACs after resection.

BRAF V600E Expression by Immunohistochemistry in Colon Cancer and Clinico-pathologic Features Associated with BRAF-Mutated Colonic Cancers in Mexican Patients

BACKGROUND

BRAF evaluation is currently limited to molecular techniques, which are expensive and not widely available to practicing pathologists. Our objective was to determine the diagnostic performance of immunohistochemistry (IHC) against BRAF V600E for BRAF mutation and the secondary objective was determining histopathological characteristics of colon carcinomas with BRAF mutated.

METHODS

Cases of adenocarcinoma of the colon with a known BRAF mutation status were identified from the pathological files of our institution.

RESULTS

We analyzed 135 cases, 13 cases had the BRAF mutation (9.6%) and 122 were non-mutated. The mutated cases expressed intense and diffusely the anti-antibody against BRAF V600E, and 119 (97.5%) of the 122 cases without mutation were negative and the remaining 3 were focal and weakly positive. The IHC demonstrated a sensitivity of 100%, specificity of 97.5%, positive predictive value of 81.3% (95% CI = 56.9 to 93.4%), negative predictive value of 100% (95% CI = 89 to 100%), and an overall accuracy of 97.8%. The only significant clinicopathological differences between cancers with BRAF mutated compared with BRAF non-mutated were that mutated had less lymph node metastases (23% vs. 68.1%) and the tumor size was greater (median 90 mm vs. 60 mm). The survival between groups was not statistically significant.

CONCLUSION

IHC against BRAF V600E showed an excellent performance, making it feasible as an alternative for molecular examination. Tumors with BRAF mutated did not show distinctive clinico-pathological characteristics, except for a larger tumor size.

Giant-cell ependymoma: Presentation of a case of the sacral region and literature review

Ependymoma is a rare central nervous system neoplasm with an even rarer morphologic variant called giant-cell ependymoma (GCE). GCE has a characteristic discrepant, malignant-like morphology but indolent behavior. We present the case of a 21-year-old female with an extra-axial GCE located in the sacral region. To date, 16 cases of sacral GCE have been reported in the literature, with 4 cases in the sacral region; however, all those cases were intra-axial. We present the first case of an extra-axial sacral GCE.

Mantle cell lymphoma with involvement of the digestive tract

INTRODUCTION AND AIM

Mantle cell lymphoma is an aggressive subtype of B-cell non-Hodgkin lymphoma and its incidence is 0.5/100,000 inhabitants. Gastrointestinal involvement at diagnosis is 15-30%. The aim of our study was to analyze the clinical and endoscopic characteristics of mantle cell lymphoma affecting the digestive tract.

MATERIAL AND METHODS

A retrospective study was conducted, based on a case series of patients with mantle cell lymphoma affecting the gastrointestinal tract that were diagnosed over a 10-year period.

RESULTS

Ten patients (11.7%) had gastrointestinal tract involvement. The upper endoscopic findings were polypoid lesions (66%), thickened folds (44%), and nonspecific changes in the mucosa (33%). At colonoscopy, polypoid lesions were viewed in 100% of the patients and ulcerated lesions in 40%.

CONCLUSION

Polypoid lesions are the most common endoscopic characteristics in patients with mantle cell lymphoma of the gastrointestinal tract. Upper endoscopy and colonoscopy should be carried out on patients with mantle cell lymphoma, even those with nonspecific symptoms, to check their gastrointestinal status. Gastrointestinal involvement has an impact on disease staging.

Two cases of sternectomy for bone metastasis due to aggressive variants of thyroid papillary carcinoma

INTRODUCTION

There are only few cases reported about the role of surgery in the presence of single or multiple bulky bone metastases. The literature about treatment for bulky sternal metastases is scarce.

PRESENTATION OF CASE

We present two patients treated surgically for metastatic thyroid lesions. Case 1 is a female with tumor of the thyroid right lobe, mediastinal extension and multiple pulmonary metastases. Bony infiltration was observed in the sternum and ribs. Case 2 is a female with a lesion in the cervical region of the thyroid left lobe and increase in volume on the upper sternal manubrium.

DISCUSSION

Patients with well-differentiated thyroid cancer may present with extracervical metastasis in 5-10% of cases at diagnosis. Bone metastases occur in 0.4% of cases of papillary carcinoma. Management remains controversial. There are only isolated cases reported in the literature of the role surgery plays in the presence of single or multiple bulky bone metastases. The basis for initial surgical approach is keeping in mind that the surgical procedure is palliative in order to achieve optimal hypothetical ablation as a result of reduced tumor volume.

CONCLUSION

Surgery is the elective treatment and can be performed safely and with adequate results, allowing proper optimization of the dose of (131)I for ablative therapy.

Prognostic impact of microsatellite instability in gastric cancer

Gastric cancer is a common and deadly cancer. Several factors are associated with its prognosis; however, controversy exists about the role of microsatellite instability (MSI). We aimed to determine the 5-year overall survival (OS) of MSI in gastric adenocarcinoma. A cross-sectional study was carried out on gastric adenocarcinoma in clinical stages I to III treated with D2 gastrectomy between 2010-2013. MSI was demonstrated by immunohistochemistry. We performed a survival analysis comparing cases with and without MSI. From 102 cases, 9.8% showed MSI. The median age was 63 years (range 33-91 years), and 57.8% were men. The more prevalent site of occurrence was the antrum (46.1%), 78.5% of the cases presented in stage III, 47.1% were of the diffuse type, 45.1% were of an intestinal type, and 7.8% were mixed. MSI cases were associated with lower clinical stages (stages I-II) and with better 5-year OS (100 vs. 47 months, p = 0.017). In a multivariate analysis, MSI was independently associated with better survival (HR = 0.209, 95% CI: 0.046-0.945, p = 0.042). MSI gastric cancers presented in early clinical stages and had favourable prognosis compared with non-MSI cancers.

Overweight but not obesity is associated with decreased survival in rectal cancer

AIM OF THE STUDY

To analyse the influence of overweight and obesity in disease-specific survival (DSS) in rectal cancers at stages I-III in a population with high prevalence of overweight/obesity.

MATERIAL AND METHODS

The population (N = 304) consisted of Mexican patients with stage I-III rectal cancer during the period between 2009 and 2015. Patients were divided based on their body mass index (BMI) into normal weight 18-25 kg/m2, overweight 25-29 kg/m2, and obesity BMI > 30 kg/m2 groups. Comparison of clinicopathologic features and survival analysis were performed.

RESULTS

The median age was 58 years (interquartile range [IQR] 50-65) and the mean BMI was 26.03 ±4.06 kg/m2. Patients in the obesity and overweight groups received a lower proportion of preoperative treatment and had a higher proportion of patients in stage II. Overweight patients had a lower baseline neutrophil/lymphocyte ratio and lower survival rate than patients with normal weight and with obesity (mean survival of 69.5 months vs. 81.15 months and 86.4 months, respectively). The estimated five-year DSS was 51% for the overweight group, 81% for the normal group, and 82% for the obesity group (p = 0.026).

CONCLUSIONS

Patients with stage I-III rectal cancer in the overweight group showed a lower DSS compared to groups with normal weight and with obesity, with the last two being similar.

Extracapsular Extension Does Not Decrease Overall Survival in Rectal Cancer Patients with Lymph Node Metastasis Following Neoadjuvant Chemoradiotherapy

Background. The Tumor-Node-Metastasis system does not include additional prognostic factors present in the Lymph Node Metastasis (LNM) such as extra-capsular extension (ECE), which is associated with decreased survival. There are not studies addressing this topic in rectal cancer patients with preoperative chemoradiotherapy (nCRT) and total mesorectal excision (TME). Aim. We aimed to examine the survival influence of ECE in patients with stage III rectal cancer who received nCRT followed by surgery. Methods. A retrospective study of 126 patients prospectively collected with rectal cancer in clinical stage III rated with nCRT and TME from 2010 to 2015 was performed. Results. In total, 71.6% of cases had 1 to 3 lymph node metastases, most tumors were grade 2 (52.4%), 25.4% had good pathologic response, 77.8% had a good quality TME, and the median tumor budding count was 4/0.785 mm2. Forty-four (34.9%) patients had ECE+, which was associated with a higher nodal stage (pN2), perineural invasion and a higher lymph node retrieval. The factors associated with the survival were a higher pathologic T stage, higher pathological N stage, high-grade tumors, and perineural invasion. The ECE did not decrease the 5–year survival with a similar median survival (86.5 months for the ECE+ group vs. 84.1 for the ECE–). Conclusion. Our results demonstrate that ECE has no impact on overall survival in rectal cancer patients who received nCRT and this was independent of nodal stage or number of lymph nodes examined.

Perineurioma versus meningioma. A multi-institutional immunohistochemical and ultrastructural studY

The differential diagnosis between perineurioma (PN) and meningioma (MEN) can be difficult by histology and immunohistochemistry (IHC) because the perineurium and arachnoid have the same embryological origin. However, there are no comparative studies determining conclusive parameters for the differential diagnosis. The aim of this study is to compare IHC of PN and MEN and their ultra-structural characteristics to elucidate which are the useful data that allow differentiate both entities. Thirty-five MEN were analyzed, and 15 PN, (11 skin and soft tissues and four oral cavity). IHC for epithelial membrane antigen (EMA), Claudin-1, GLUT-1, somatostatin-2 receptor (SSTR-2), and progesterone receptor (RP) was performed. Ultrastructural studies were performed on 8 MEN and 15 PN. Only in PN Claudin-1 was positive in 9/11 (90%) cases and GLUT-1 in 7/11 (63%) cases. In MEN, the progesterone receptor was expressed in 21/35 (60%) cases and no case expressed Claudin-1 and GLUT-1; EMA was expressed in all MEN cases and 93% of PN. SSTR-2 was expressed weakly in six cases of MEN (17%), and it was not considered useful for differential diagnosis. On ultrastructure, PN showed thin and parallel processes, some caveolae, and lacked cell junctions. The cellular processes were surrounded by a collagenous stroma in 94% of the cases. MEN were characterized by curved cytoplasmic cell processes showing desmosomes in 75% of cases. Ultrastructural findings aid in the differential diagnosis between PN and MEN, especially if molecular studies are not available.

Primary retroperitoneal Merkel cell carcinoma: Case report and literature review

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma that affects elderly patients and typically arises in sun-exposed skin. The disease is very rare and only few cases present with no apparent skin lesion. In the retroperitoneum there are only two cases reported in the literature.

CASE PRESENTATION

We report a case of a 54-year-old Mexican male with MCC, which presented as a large retroperitoneal mass. Pathological and immunohistochemical analysis of the transabdominal CT-guided biopsy specimen revealed a MCC. The patient underwent preoperative chemotherapy followed by a laparotomy and the mass was successfully excised.

DISCUSSION

There are two possible explanations for what occurred in our patient. The most plausible theory is the retroperitoneal mass could be a massively enlarged lymph node where precursor cells became neoplastic. This would be consistent with a presumptive diagnosis of primary nodal disease. Moreover, metastasis to the retroperitoneal lymph nodes has been reported as relatively common when compared to other sites such as liver, bone, brain and skin. The less probable theory is the non-described "regression" phenomena of a cutaneous MCC, but we are not found a primary skin lesion.

CONCLUSION

Preoperative chemotherapy and excision of the primary tumor is the surgical treatment of choice for retroperitoneal MCC. We propose that further studies are needed to elucidate the true efficacy of chemotherapy in conventional and unconventional patients with MCC.

IMMUNOTHERAPY TREATMENT AGAINST CERVICAL CANCER

Cervical cancer (CC) is one of the most common gynecological tumors and an important health problem, especially in developing countries. The vast majority of patients in early stages are cured of the disease with surgical treatment and with concomitant chemoradiotherapy in locally advanced stages. However, in patients with recurrent, persistent, or metastatic cervical CC, the effectiveness of treatment is limited, except for the combination of chemotherapy based on platinum doublets plus bevacizumab, the treatment that has achieved the best results to date. Programmed cell death-1/PD ligand-1 (PD-1/PD-L1) inhibitors could be a novel and cutting-edge therapeutic option to improve clinical outcomes in this group of patients. Thus far, there are a few Phase I/II clinical trials that have assessed the usefulness of pembrolizumab and nivolumab in this group of patients; these include the KEYNOTE 028, KEYNOTE 158, and CHECKMATE 358 trials, in which clinical benefit has been proven with PD-1/PD-L1 inhibitors in recurrent, persistent, or metastatic CC, as second-line treatment. There are also some ongoing trials that could provide further evidence on the PD-1/PD-L1 pathway as a therapeutic target in CC. In this review, we will focus on the usefulness of these PD-1/PDL1 inhibitors in CC, as well as on trials that are still in the recruitment phase, to confirm their effectiveness in this clinical setting.

Satellitosis and CD117 immunohistochemical expression correlates with poor outcome in thick vulvar melanoma

BACKGROUND

Melanoma of the vulva is the second most common vulvar cancer after epidermoid carcinoma. Patients suffering from this disease usually present with a late-stage disease with a poor prognosis. The prognostic factors reported in previous studies are not homogeneous and the clinical/pathogenic role of c-KIT expression is not clear. Breslow staging currently is the most accurate predictor factor.

METHODS

A clinicopathological study with literature review was performed to identify predictors of prognosis and survival in melanoma of the vulva and investigated the expression of c-KIT (by immunohistochemistry) in 10 patients from the National Institute for Cancer Research (Mexico City).

RESULTS

The 10 patients enrolled were all older women with delayed presentation, high-stage disease and limited response to treatment. Five patients (50%) were found to have c-KIT expression; 4 of them recurred (P=0.01), and ultimately 3 died (P=0.038). We identified satellitosis and c-KIT expression as prognostic predictors for death.

CONCLUSIONS

We conclude that c-KIT expression is a valuable predictor of prognosis and survival, especially in thick (>4 mm) melanomas.

Ovarian undifferentiated carcinoma with voluminous mesenteric presentation

INTRODUCTION

About 5% of ovarian cancers are so poorly differentiated and difficult to classify that they are called undifferentiated carcinomas and usually have disseminated disease at presentation. Extra pelvic debulking it is difficult to complete.

PRESENTATION OF CASE

We report a case of a rare ovarian tumor presented as a large mesenteric tumor of 14cm diameter in a 73 years old woman.

DISCUSSION

Undifferentiated carcinomas are usually large, solid with hemorrhage and necrosis, bilateral and most are difficult to classify histologically. Rarely are pure, generally identified through the extensive sampling of lesions, some other components of surface epithelial carcinoma and usually the predominant element is the latter. Cases with predominantly undifferentiated component are rare.

CONCLUSION

The treatment and diagnostic approach is the same as for other high-grade epithelial tumors of the ovary, but in this particular case the differential diagnosis and diagnostic approach is that of a mesenteric tumor.

The influence of body mass index on the survival of patients with melanoma. A cross-sectional study of 707 patients

INTRODUCTION

Obesity has been linked with an increased incidence of melanoma; however, there are few data about its impact on melanoma prognosis. We aimed to determine if there is an association between body mass index (BMI) and overall survival (OS) in 707 patients with melanoma.

MATERIAL AND METHODS

A retrospective study of 707 patients with melanoma collected consecutively from 2005 to 2015 with a diagnosis of melanoma, who were been diagnosed and treated in our institution and who had clinical follow-up was carried out. Survival analysis was performed comparing patients according to their BMI.

RESULTS

In a multivariate analysis, factors influencing the 5-year OS were a positive margin (HR = 3.475, 95% CI: 1.829-6.600), the clinical-stage (HR = 2.565, 95% CI: 2.020-3.257, per switch to the upper stage), ulceration (HR = 3.475, 95% CI: 1.829-6.600), and BMI (HR .905, p = 0.018 for the overweight group; HR = 0.663, p = 0.021 for obesity grade I).

CONCLUSIONS

Patients who had a BMI between 25 and 34.9 kg/m2 had better survival.

Outcome of young patients with rectal adenocarcinoma

BACKGROUND

There is an increase in the incidence of rectal carcinoma (RC) in young patients.

METHODS

We analyzed 175 patients with sporadic RC which were divided in two groups according their age: 24 patients ≤40 years and 151 patients >40 years and the two groups were compared in order to determine if the outcomes (especially overall 5-year survival) were different.

RESULTS

Overall 5-year survival was similar between groups (67.1% for patients over 40 years and 70.4% for those under 40 years, P=0.803). The only differences found were in some clinicopathologic features: patients <40 years showed more dissected lymph nodes (LNs) (21 vs. 15, P=0.035) and more LN metastasis (54.2% vs. 39.1%, P=0.048). In multivariate analysis factors associated with worse survival were incomplete resection and no use of neoadjuvant therapy. Age did not demonstrate prognostic value (P=0.077).

CONCLUSIONS

RC in people ≤40 years demonstrated greater number of LN harvested and LN metastases but oncologic outcomes, especially 5-year overall survival, were similar between groups.

Search of the p.M918T Mutation in the RET Oncogene in Mexican Adult Patients with Medullary Thyroid Carcinoma

Inherited mutations in the RET proto-oncogene, which encodes a receptor tyrosine kinase, predispose individuals to the multiple endocrine neoplasia type 2 (MEN 2) cancer syndromes. The major component tumor of these syndromes is medullary thyroid carcinoma (MTC). To date, somatic mutations in RET have been identified in tumors from individuals with MEN 2 finding. RET M918T mutation is present in 95% of the MEN2B cases, and approximately 50% of sporadic MTCs harbor this mutation. We performed a mutational analysis in 17 cases of Medullary thyroid carcinoma, the somatic missense mutation at codon 918 of RET was found in 2 of the 17 MTCs, and one case presented MEN2 phenotype including MTC. The percentage of RET M918T mutation is similar in Mexican MTC patients to other series, although other mutations could be implicated in our population.

Addition of analysis of KRAS mutation or immunohistochemistry with MUC1 and carcinoembryonic antigen improves the diagnostic performance of fine needle aspiration cytology for the diagnosis of pancreatic carcinoma

BACKGROUND

Pancreatic adenocarcinoma (PAC) is a health problem because of high lethality, increasing incidence and the absence of an early diagnosis. Biopsy by fine needle aspiration guided by endoscopic ultrasound has allowed obtaining tissue for cytopathological analysis, but there are several problems with their interpretation. We aimed to compare the diagnostic performance of the cytopathological analysis with the addition of either an immunohistochemical (IHC) panel or the KRAS mutation for the diagnosis of PAC.

METHODS

We evaluated 62 pancreatic lesions by fine needle aspiration guided by endoscopic ultrasound, applying an IHC panel with mucin (MUC)-1, MUC4, carcinoembryonic antigen (CEA) and p53. All cases also had a KRAS mutation determination. Three cytopathologists blinded to clinical data and the KRAS status reviewed the cytology independently. We calculated diagnostic performances for the cytology alone, cytology+IHC and cytology+KRAS to show the best method to diagnose PAC.

RESULTS

From 62 samples, 50 (80.6%) were PAC and 12 benign lesions. The cytopathological analysis correctly interpreted 26 malignant and 12 non-neoplastic cases (sensitivity 52%, specificity 100% and diagnostic accuracy 61.3%). The KRAS mutation was present in 88% of PAC. The cytology+ KRAS mutation increased the sensitivity by 10% and the diagnostic accuracy by 8%. The sensitivity increased by 2% adding either MUC1 or CEA to the cytology, and the diagnostic accuracy by 10 or 18%, respectively.

CONCLUSION

The addition of IHC either with CEA or MUC1 improved the diagnostic performance of the cytology alone to diagnose PAC. The cytology + IHC evaluation was superior to the cytology + KRAS mutation to diagnose PAC.

Thyroid Transcription Factor-1 Expression in Adenocarcinomas of the Bile Duct

BACKGROUND

The immunoreactivity of thyroid transcription factor-1 (TTF-1) is a very specific marker for lung and thyroid neoplasms; the expression of TTF-1 has also been demonstrated in extrapulmonary carcinomas. We examined the expression of TTF-1 in 15 intestinal-type adenocarcinomas of the extrahepatic bile duct. We then compared the expression to TTF-1 staining with other immunohistochemical markers including cytokeratin (CK) 7, CK20, caudal-type homeobox transcription factor 2 (CDX2), Napsin A, and MUC2. We additionally compared the clinicopathological prognostic factors with the TTF-1 expression status.

RESULTS

Nuclear TTF-1 staining was detected in 2 cases (13.3%), and Napsin A was positive in the same 2 cases (13.3%). All cases were positive for CK20, CDX2, and MUC2; 5 cases were positive for CK7. There was no correlation between TTF-1 expression and the clinicopathological characteristics.

CONCLUSIONS

To avoid potential pitfalls, TTF-1 should be interpreted in conjunction with the clinical setting, histology, and the results of markers such as CK7, CK20, Napsin A, and CDX2. This report is the first of TTF-1 positivity in adenocarcinomas from the extrahepatic biliary tract.

Prognosis of polypoid melanoma: a comparative study with non-polypoid melanomas

Polypoid melanoma is considered an exophytic and frequently non-pigmented variant of nodular melanoma with an adverse prognosis; however, very few studies have been published about it with contradictory results. Therefore, our objective was to determine the prognostic value of this configuration in melanomas. A transversal retrospective study of 724 cases was analyzed according to the main configuration (polypoid vs. non-polypoid) regarding their clinicopathologic characteristics and survival analysis. Of the 724 cases, 35 (4.8%) met the definition of polypoid melanoma; such cases, compared with non-polypoid melanomas, were associated with a high Breslow thickness (7 mm vs. 3 mm), 68.6% had a Breslow >4 mm; showed different clinical stages of presentation, and presented more ulceration (77.1 vs. 51.4%). In the 5-year overall survival (OS) analysis, polypoid melanoma is associated with a lower 5-year OS, together with lymph node metastasis, Breslow thickness, clinical stage, mitoses per mm 2 , vertical growth phase, ulceration, and state of the surgical margins; however, in the multivariate analysis, the factors that remained independent predictors of death were the Breslow thickness groups, the clinical stage, the presence of ulceration, and the state of the surgical margins. Polypoid melanoma was not an independent predictor of OS. We found a prevalence of 4.8% of polypoid melanomas, which showed a worse prognosis than non-polypoid melanomas, explained by a higher proportion of ulcerated cases, greater Breslow thickness, and ulceration. However, polypoid melanoma was not an independent predictor of death.

SOX9 is associated with advanced T-stages of clinical stage II colon cancer in young Mexican patients

Colorectal cancer (CRC) is one of the most common malignancies worldwide and includes colon cancer (CC) and rectal cancer (RC). Regarding CC, the development of novel molecular biomarkers for the accurate diagnosis and prognosis, as well as the identification of novel targets for therapeutic intervention, are urgently needed. SRY-related high-mobility group box 9 (SOX9), a transcription factor, is involved in development, and has been associated with the progression of human cancer. However, its underlying clinical and functional effects in CRC have not been fully understood. Therefore, the present study aimed to evaluate the clinical and functional relevance of SOX9 expression in CC. The expression of SOX9 in tumor tissues was evaluated in 97 biopsies from Mexican patients with CC with early-stage I and II disease by immunohistochemistry (IHC). In addition, SOX9 silencing in the HCT116 cell line was performed using specific small interfering RNAs, while downregulation efficiency was verified by reverse transcription-quantitative PCR and immunofluorescence. Spheroid-formation assay was carried out using ultra-low attachment plates. The IHC results showed that SOX9 was upregulated in patients with stage II (91%) and advanced T3 stage (67%) CC. Interestingly, higher SOX9 expression was associated with clinical stage, tumor size and tumor location. Furthermore, increased SOX9 expression was found in relapsed cases with local tumors; however, it was not associated with increased survival probability. Additionally, functional analysis indicated that SOX9 silencing significantly attenuated the sphere-formation capability of HCT116 cells. The present study was the first to evaluate the expression levels of SOX9 in Mexican patients diagnosed with early-stage CC. The aforementioned findings indicated that high SOX9 expression could play an important role in tumorigenesis and be associated with advanced T-stages of clinical-stage II patients, but not with relapse-free survival.