Preliminary Suggestion about Staging of Anorectal Malignant Melanoma May Be Used to Predict Prognosis

Survival and Prognosis for Patients with Rectal Melanomas in the United States: A SEER-Based Study

PURPOSE

Limited attention was paid to focus on rectal melanomas (RM). This study aimed to evaluate the survival rate and prognostic factors of RM.

METHODS

The data for patients with RM from Surveillance, Epidemiology, and End Results (SEER) database were used to analyze tumor survival. Kaplan-Meier method and log-rank test were employed to estimate cancer-specific survival (CSS) and overall survival (OS). A nomogram was established based on the risk factors of survival by the forest plot for multivariate Cox regression analysis. Receiver operating characteristic (ROC) and calibration curve were conducted for validation.

RESULTS

A total of 187 patients with RM were selected to perform survival analyses. The median survival time of OS was 12 months (range: 0-146 months), and the median survival time of CSS was 12 months (range: 0-74 months). Patients' age, tumor size, stage, the number of nodes examined, surgery, and radiation were identified as prognostic indicators for CSS by the forest plot for multivariate Cox regression analysis. The nomogram was validated as a reliable model for CSS.

CONCLUSION

Clinicopathologic relevance with tumor prognosis was confirmed in this study. Our nomogram can provide a relatively accurate prediction of the survival rate of patients with RM.

Incidence and survival of patients with primary gastrointestinal melanoma: a population-based study

BACKGROUND

Primary gastrointestinal melanoma (PGIM) has received more attention because of its inferior prognosis. Less is known about the incidence and survival rate of PGIM.

METHODS

PGIM data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The incidence was estimated by age, sex, race, and primary site. Trends in incidence were described as annual percent change (APC). Cancer-specific survival (CSS) and overall survival (OS) rates were estimated and compared using log-rank tests. Cox regression analyses were performed to identify independent prognostic factors.

RESULTS

The overall incidence of PGIM was 0.360/1,000,000 with a significant upward trend (APC = 1.77%; 95% CI 0.89%-2.67%, p < 0.001) from 1975 to 2016. Most PGIM occurred in the large intestine (0.127/1,000,000) and anorectum (0.182/1,000,000), and both incidences were almost 10 times higher than those of other sites, including the esophagus, stomach, and small intestine. The median survival time was 16 months (IQR, 7-47 months) for CSS and 15 months (IQR, 6-37 months) for OS, and the 3-year CSS and OS rates were 29.5% and 25.4%, respectively. Older age, advanced stage, absence of surgery, and melanoma in the stomach were the independent risk indicators of survival and associated with worse CSS and OS.

CONCLUSION

The incidence of PGIM has been increasing over the past decades and the prognosis is poor. Thus, further studies are warranted to improve the survival, and more attention should be paid to the patients that are elderly, patients with advanced stage, and patients with melanoma in the stomach.

Difficulties in diagnosing anorectal melanoma: A case report and review of the literature

BACKGROUND

Anorectal melanoma is a tumour that is difficult to identify due to its rarity and variability of presentation. Insufficient data published in the literature do not allow for diagnostic and treatment guidelines to be established. Anorectal melanoma has the worst prognosis among mucosal melanomas and is frequently misdiagnosed by standard identification methods.

CASE SUMMARY

A 66-year-old woman presented with intermittent anal bleeding, pain, and tenesmus in the past month, with no associated weight loss. Colonoscopy revealed a cauliflower-like tumour with a diameter of 1.5 cm, with exulcerated areas and an adherent clot but without obstruction. Biopsy results identified an inflammatory rectal polyp with nonspecific chronic rectitis. Tumour markers CA 19-9 and CEA were within the normal range. After 6 mo, due to the persistence of symptoms, a pelvic magnetic resonance imaging scan was performed. A lesion measuring 2.8 cm × 2.7 cm × 2.1 cm was identified at the anorectal junction, along with two adjacent lymphadenopathies. No distant metastases were detected. Immunohistochemistry was performed on the second set of biopsies, and a diagnosis of anorectal melanoma was established. Surgical treatment by abdominoperineal resection was performed. Evolution was marked by the appearance of lung metastases at 1 mo postoperatively, detected on a positron emission tomography-computer tomography scan, and perineal recurrence after 5 mo. After molecular testing, the patient was included in an immunotherapy trial.

CONCLUSION

This case highlights the difficulty of establishing a definitive early diagnosis of anorectal melanoma, the importance of performing histological analysis on a well-represented biopsy specimen, and the poor prognosis, even with radical surgery.

Outcomes of Surgical Treatment for Patients with Anorectal Malignant Melanoma; Results of Nine Cases in a Single Institution

Anorectal melanoma (AM) is a rare and aggressive malignancy. Two main types of surgical approach for AM are abdominoperineal resection (APR) and wide local excision (WLE). Nine patients with AM underwent surgical treatment between July 2005 and October 2017 at our institution. Two of the patients were diagnosed with localized stage, four with regional stage, and three with distant stage. Laparoscopic APR was performed in six patients with localized and regional stages, whereas palliative APR and/or WLE were performed in those with distant metastasis. Both patients with localized stage lived without relapse for 6.8 years after surgery. One of the patients with regional stage had no relapse during 3.6 years of follow-up. The other three patients had recurrence and died between 6 and 32 months after surgery. The median overall survival (OS) of the cohort was 14.8 months, and the 5- and 10-year OS were 33.3% and 16.7%, respectively. The tumor at the regional stage could be removed through WLE, but preoperative diagnosis of lymph node metastasis is difficult in patients with AM. Further development of the diagnostic method is expected, and future tasks will be to establish the selection criteria to determine which surgical approach is optimal for this devastating disease.

Management and outcomes of primary anorectal melanoma in the United States

Aims: To analyze outcomes in primary anorectal melanoma, a rare disease with limited data and treatment guidelines. Materials & methods: We analyzed 305 subjects in the National Cancer Database from 2004 to 2015. The primary end point was overall survival (OS). Results: Surgery was predictive of OS (median 2.24 vs 1.18 years; p = 0.009) with no survival difference between local and transabdominal approaches (p = 0.77). No OS benefit was seen with chemotherapy (p = 0.16), radiotherapy (p = 0.31) or adjuvant therapy post surgery (p > 0.05 for all groups). Targeted therapy trended toward higher survival in metastatic patients (1.33 vs 0.55 years; p = 0.06). Conclusion: In nonmetastatic patients, surgery of any method is associated with a survival benefit. The trend for improved survival following targeted therapy in metastatic patients merits further exploration.

Beyond adenocarcinoma: MRI of uncommon rectal neoplasms and mimickers

OBJECTIVE

To provide a review of rare rectal tumors beyond adenocarcinoma.

RESULTS

Rectal cancer is a common malignancy, both in the United States and abroad. In addition to adenocarcinoma, abdominal radiologists will encounter a variety of other less common rectal masses, both benign and malignant neoplasms as well as non-neoplastic mimickers. Familiarity with these conditions and their characteristic features on MRI is useful in clinical practice. In this article, a number of such conditions are discussed, with an emphasis on distinguishing features on MRI of the rectum.

CONCLUSION

Familiarity with the MRI features of rare rectal tumors beyond adenocarcinoma, as well as a small number of non-neoplastic mimics, is important for abdominal imagers to make diagnostic differentials and to assist in treatment planning.

Prognostic factors in primary anorectal melanoma: a clinicopathological study of 60 cases in China

To investigate the clinicopathological features and prognostic factors of primary anorectal melanoma, we described the clinical presentations, histopathology, and prognosis of 60 cases in China. Patients' age ranged from 17 to 86 years, with a female-to-male ratio of 2.33:1. The prevalent anatomic site of tumor was the anorectum. The mean tumor thickness was 11.5 mm, and mean tumor size was 2.9 cm. Abdominoperineal resection was performed on 38 (63.3%) patients, whereas wide local excision was performed on 22 (36.7%) patients. Thirty-three (55.0%) patients were pathologically confirmed to have lymph node metastasis, and 9 (15%) patients had clinically distant metastasis at diagnosis. Histologically, epithelioid cell (91.7%) was the predominant cell type, followed by spindle (31.7%), pleomorphic (25.0%), and small round cell (5.0%). Solid sheet, nest, pseudopapillary, and pseudoalveolar growth patterns were noted in 45 (75.0%), 22 (36.7%), 13 (21.7%), and 6 (10.0%) cases, respectively. After a median follow-up of 44 months, the 5-year disease-specific survival rate was 33.3%. Age, tumor size, depth of invasion, tumor thickness, lymphatic metastasis, and lymphovascular and perineural invasion were significantly correlated with survival in univariate analysis. Multivariate analysis revealed that age greater than 70 years and tumor invasion beyond deep muscular layer/sphincter ani externus were independent poor prognostic factors. As the largest single-institution study of anorectal melanoma in an Asian population, we concluded that anorectal melanoma is a rare and lethal malignant neoplasm with morphologic diversity. Large population-based studies are still needed to establish an efficient staging system in evaluation of prognosis and facilitation of treatment for anorectal melanoma patients.

Surgical Approach to Anorectal Melanoma with PET-CT Staging: A Case Report

Rectal hemorrhage should be evaluated within a wide spectrum ranging from benign diseases to a malignant process. Especially, the melanomas of rectum are detected at an advanced stage when diagnosed since the present symptoms of rectal melanomas are similar. The question of what will be the surgical approach with MR, CT, and PET-CT imaging methods performed after histopathological diagnosis still conserves its topicality. PET-CT is a good imaging method for determination of distant metastasis and lymphatic involvement. In the present case, a patient with early-stage rectal melanoma was treated with APR. No relapse/metastasis was detected during the 18-month follow-up. The aggressive course of the disease and its low response rates to medical treatments may cause the surgical approaches to be more extensive.