Melanoma in Mexico: Clinicopathologic Features in a Population with Predominance of Acral Lentiginous Subtype.

BACKGROUND: The aim of this study was to analyze the clinicopathologic features of melanoma in México as the demographics of melanoma are not well known in Mexican and Latin American people. MATERIALS AND METHODS: A total of 1219 patients with cutaneous melanoma were analyzed through a retrospective database collected from a cancer referral institute, and the results were compared with developed countries. RESULTS: Median age was 57 years, and 713 (58.5 %) were females. The most common melanoma subtype was acral lentiginous melanoma (ALM), which was observed in 538 (44.1 %) patients. Median Breslow thickness was 5.2 mm. Among 837 patients with complete data, the 5-year disease-specific survival (DSS) was 52.3 %. Factors associated with worse DSS on univariate analysis were Breslow thickness (p < 0.001), recurrence (p < 0.001), ulceration (p < 0.001), positive margin (p < 0.001), ALM (p = 0.001), and male sex (p = 0.001). Multivariate analysis demonstrated Breslow thickness [hazard ratio (HR) 1.45, 95 % confidence interval (CI) 1.27-1.65; p < 0.001], positive margin (HR 1.25, 95 % CI 1.03-1.57; p = 0.018), recurrence (HR 9.56, 95 % CI 6.89-9.87; p = 0.002), ALM (HR 8.07, 95 % CI 6.77-8.95; p = 0.004), and male sex (HR 1.33, 95 % CI 1.06-1.68; p = 0.013) as independent risk factors for DSS. CONCLUSION: Our patients had worse prognosis compared with data from the US Surveillance, Epidemiology, and End Results database. We found male sex and ALM as independent risk factors for worse survival, in addition to known risk factors.

Mesorectal pathologic assessment in two grades predicts accurately recurrence, positive circumferential margin, and correlates with survival.

BACKGROUND AND OBJECTIVES: We aimed to determine the prognostic value of the mesorectum quality assessed in a two-grade system compared with a classic system. METHODS: Consecutive patients undergoing surgery for rectal cancer were included (n = 103). Mesorectum was assessed into three grades (classic system: complete, nearly complete, incomplete) and compared with a two-grade system (adequate, inadequate). RESULTS: Mesorectum was complete in 62 (60.25%) patients, nearly complete in 21, and incomplete in 20. Reassessment showed adequate mesorectum in 83 (80.5%) patients and inadequate in 20. A R0 resection was achieved in 90.4% of adequate mesorectum and in 65% of inadequate mesorectum (P = 0.006). Recurrence was present in 18% of adequate mesorectum patients as compared with 50% of inadequate mesorectum (P = 0.003). The classic system failed to accurately predict the 5-year survival rate between complete (78.9%) and nearly complete (86.2%) categories (P = 0.235); whereas a two grading system showed a 5-year survival rate of 80.8% for adequate versus 39.3% for inadequate (P = 0.034). CONCLUSION: High recurrence occurred in inadecuate mesorectum patients and was correlated with R1/R2 resections, positive margins, and decreased survival. We propose a simplified classification of mesorectum that correlates with survival and overall recurrence.

Mesorectal Invasion Depth in Rectal Carcinoma Is Associated With Low Survival.

BACKGROUND: Most cases of rectal cancer (RC) in our institution are in pathologic stage T3. They are a heterogeneous group but have been classified in a single-stage category. We performed the present study to validate the prognostic significance of the mesorectal extension depth (MED) in T3 RC measured in millimeters beyond the muscularis propria plane. MATERIALS AND METHODS: We performed a retrospective analysis of 104 patients with T3 RC who had undergone curative surgery after a course of preoperative chemoradiotherapy at a tertiary referral cancer hospital. The patients were grouped by MED (T3a, < 1 mm; T3b, 1-5 mm; T3c > 5-10 mm; and T3d > 10 mm). The clinicopathologic data and disease-free survival were analyzed. RESULTS: The 5-year disease-free survival rate according to the T3 subclassification was 87.5% for those with T3a, 57.9% for T3b, 38.7% for T3c, and 40.3% for those with T3d tumors (P = .050). On univariate and multivariate analysis, the prognostic factors affecting survival were overall recurrence (hazard ratio [HR], 3.670; 95% confidence interval [CI], 1.710-7.837; P = .001), histologic grade (HR, 2.204; 95% CI, 1.156-4.199; P = .016), mesorectal invasion depth (HR, 1.885; 95% CI, 1.164-3.052; P = .010), and lymph node metastasis (HR, 1.211; 95% CI, 1.015-1.444; P = .033). CONCLUSION: MED is a significant prognostic factor in patients with T3 RC who have undergone neoadjuvant chemoradiotherapy, especially when the MED is > 5 mm. The MED could be as important as other clinicopathologic factors in predicting disease-specific survival.

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.

Medullary colonic carcinoma with microsatellite instability has lower survival compared with conventional colonic adenocarcinoma with microsatellite instability.

INTRODUCTION: Colorectal medullary carcinoma (MC) is a rare subtype of poorly differentiated adenocarcinoma (PDA) with unclear prognostic significance. Microsatellite instable (MSI) colorectal carcinomas have demonstrated better prognosis in clinical stage II. AIM: To analyze the survival and clinicopathological characteristics of MCs versus PDAs with MSI in clinical stage III. MATERIAL AND METHODS: We studied 22 cases of PDAs with MSI versus 10 MCs. RESULTS: Of the 10 MCs, 7 patients were men; the mean age was 57.8 ±5.6 years. The mean tumor size was 9.6 ±4.1 cm, and the primary site was the right colon in 9; 7 patients showed lymph node metastases (LNM) and lymphovascular invasion (LVI). Of the 22 PDA cases, 12 (54.5%) were women with a mean age of 75 ±16.1 years. The mean tumor size was 6.4 ±3.2 cm. Twelve (54.5%) presented in the right colon, 21 (95.5%) showed LNM and 7 (31.8%) LVI. Follow-up was 32 ±8 months, with a 5-year overall survival of 42.9% for MCs and 76.6% for PDAs (p = 0.048). Univariate analysis found local recurrence (p = 0.001) and medullary subtype (p = 0.043) associated with lower survival. CONCLUSIONS: Medullary carcinomas were of greater tumor size and associated with more LVI and worse survival versus PDAs with MSI in stage III.

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.