Less is more: A systematic review and meta-analysis of the outcomes of radical versus conservative primary resection in anorectal melanoma

Survival Outcomes in Patients Undergoing Pelvic Exenteration for Pelvic Mucosal Melanomas: Retrospective Single Institution Australian Study

BACKGROUND

Pelvic mucosal melanomas, including anorectal and urogenital melanomas, are rare and aggressive, with a median overall survival of up to 20 months. Pelvic mucosal melanomas behave differently from their cutaneous counterparts and present late with locoregional disease, making pelvic exenteration its only curative surgical option.

OBJECTIVE

This study aimed to evaluate the survival outcomes after pelvic exenteration in pelvic mucosal melanomas at Royal Prince Alfred Hospital.

DESIGN

Retrospective case series from a prospectively collected pelvic exenteration database from October 1994 to November 2023.

SETTING

Royal Prince Alfred Hospital (quaternary institution), Camperdown, New South Wales, Australia.

PATIENTS

Seven patients undergoing pelvic exenteration for pelvic mucosal melanoma.

MAIN OUTCOME MEASURES

Overall survival, disease-free survival, and complication rates.

RESULTS

Of the 7 patients, most were women (n = 5; 71.4%) and had a median age of 65 years (range, 36-79). Five patients (71.4%) underwent pelvic exenteration for primary pelvic mucosal melanoma, 3 of which were anorectal and 2 vaginal melanomas. Two patients (28.6%) had recurrent anorectal melanoma and received neoadjuvant radiotherapy after an initial wide local excision. Three patients (42.9%) required total pelvic exenteration, whereas 2 required a central pelvic exenteration (28.6%). The remaining procedures included central and lateral pelvic exenteration and anterior, central, and lateral pelvic exenteration. The median length of hospital stay was 19.7 days. Five patients had postoperative complications with 1 major complication (Clavien-Dindo grade IIIa). At the completion of the study, there were 4 mortalities. Mean survival was 23.6 months (range, 2-100) with a recurrence rate of 83%. The median time to recurrence was 3 months, despite 6 patients (85.7%) having R0 resections. Distant recurrence, specifically to bone, the lungs, and the liver, was most common.

LIMITATIONS

Small study cohort due to rarity of disease, limiting generalizability.

CONCLUSIONS

Pelvic exenteration for pelvic mucosal melanoma appears to help control local disease as recurrence is most commonly distant or regional. See Video Abstract .

RESULTADOS DE SUPERVIVENCIA EN PACIENTES SOMETIDOS A EXENTERACIN PLVICA POR MELANOMAS DE LA MUCOSA PLVICA ESTUDIO RETROSPECTIVO AUSTRALIANO DE UNA SOLA INSTITUCIN

ANTECEDENTES:Los melanomas de la mucosa pélvica (MM), incluidos los melanomas anorrectales y urogenitales, son raros y agresivos, con una supervivencia global media de hasta 20 meses. Los melanomas de la mucosa pélvica se comportan de manera diferente a sus contrapartes cutáneas y se presentan tardíamente con enfermedad locoregional, lo que hace que la exenteración pélvica (EP) sea su única opción quirúrgica curativa.OBJETIVO:Este estudio tuvo como objetivo evaluar los resultados de supervivencia tras la exenteración pélvica en melanomas de la mucosa pélvica en el Royal Prince Alfred Hospital.DISEÑO:Serie de casos retrospectivos de una base de datos de exenteración pélvica recopilada prospectivamente desde octubre de 1994 hasta noviembre de 2023.ESCENARIO:Royal Prince Alfred Hospital (institución cuaternaria), Camperdown, Nueva Gales del Sur, Australia.PACIENTES:Siete pacientes sometidos a exenteración pélvica por melanoma de la mucosa pélvica.PRINCIPALES MEDIDAS DE RESULTADOS:Supervivencia general, supervivencia libre de enfermedad y tasas de complicaciones.RESULTADOS:De los siete pacientes, la mayoría fueron mujeres (n = 5, 71,4%) y tenían una edad media de 65 años (rango 36-79). Cinco pacientes (71,4%) fueron sometidos a una exenteración pélvica por melanoma primario de la mucosa pélvica; tres de los cuales eran melanomas anorrectales y dos vaginales. Dos pacientes (28,6%) tuvieron melanoma anorrectal recurrente y recibieron radioterapia neoadyuvante después de una escisión local amplia inicial.Tres pacientes (42,9%) requirieron una exenteración pélvica total, mientras que dos requirieron una exenteración pélvica central (28,6%). Los procedimientos restantes fueron una exenteración pélvica central y lateral; junto con una exenteración pélvica anterior, central y lateral. La duración media de la estancia hospitalaria fue de 19,7 días. Cinco pacientes tuvieron complicaciones postoperatorias con una complicación mayor (Clavien-Dindo IIIa). Al finalizar el estudio, hubo cuatro muertes. La supervivencia media fue de 23,6 meses (rango 2-100) con una tasa de recurrencia del 83%. El tiempo medio hasta la recurrencia fue de tres meses, a pesar de que seis pacientes (85,7%) tuvieron resecciones R0. La recurrencia distante, es decir, en hueso, pulmón e hígado fueron la más comúnes.LIMITACIONES:Cohorte de estudio pequeña debido a la rareza de la enfermedad, lo que limita la generalización.CONCLUSIÓN:La exenteración pélvica para el melanoma de la mucosa pélvica parece ayudar a controlar la enfermedad local, ya que la recurrencia es más comúnmente distante o regional. (Traducción-Dr Osvaldo Gauto ).

Feasibility and impact of sentinel lymph node biopsy in patients affected by ano-rectal melanoma

INTRODUCTION

Anorectal melanoma (ARM) is rare and highly lethal neoplasm. It has a poorer prognosis compared with cutaneous ones. Sentinel lymph node biopsy (SLNB) has become the preferred method of nodal staging method for cutaneous melanoma. The role of SLNB for staging of anal melanoma remains unclear. This study investigates SLN identification and biopsy in patients with ARM.

METHODS AND PATIENTS

We present our experience of patients affected by ARM who underwent to SLNB. Clinical workup included digital rectal examination, anoscopy, rigid proctoscopy, total body (computed tomography) CT scan, pelvic magnetic resonance imaging (MRI), and fludeoxyglucose-18-positron emission tomography-CT (FDG-PET-CT) to obtain an adequate pretreatment staging of the patients. Wide local excision and contemporary SLNB were performed to remove primary neoplasm and detect inguinal lymph node metastases.

RESULTS

In total, five female patients, median age 68 years, were included. All were affected by anal melanoma. Detection rate of SLNB was 100% and scintigraphic migration was unilateral in three patients and bilateral in the other two. Definitive inguinal histological exam revealed unilateral metastases in three patients, bilateral metastases in one case, and the presence of isolated neoplastic cells in the remaining case. SLNB allowed a diagnostic upgrading of inguinal metastases in three of five patients (60%), permitting better staging and further appropriate treatment.

CONCLUSIONS

Our experience demonstrates SLN biopsy is a minimally invasive, cost-effective, and rapid procedure for accurately staging patients with clinically occult disease. In fact, SLNB emerges as an appropriate procedural tool to identify patients with occult lymph node metastases who could undergo immune or target therapy, as well as to avoid unnecessary inguinal lymph node dissection for patients who would not benefit.

Combined Neoadjuvant-Adjuvant Immunotherapy and Abdominoperineal Resection for a Primary Anorectal Melanoma: A Case Report

Anorectal melanoma (ARM) is a rare entity with aggressive biological behavior and poor prognosis. Clinically, ARM presents with atypical symptoms, such as anal pain and bleeding, thus often being misdiagnosed as a benign anorectal pathology and leading to delayed diagnosis. We present a case of a 73-year-old female patient with stage I ARM, treated successfully with a combination of neoadjuvant-adjuvant immunotherapy (nivolumab, an anti-PD-1 monoclonal antibody) and abdominoperineal resection. The patient is disease-free at a five-year follow-up after the operation, suggesting that long-term targeted immunotherapy offers a durable and promising response. This case highlights the critical role of a multidisciplinary approach, involving specialists in ARM surgery and systemic therapies, to improve prognosis and ensure an optimal quality of life for patients with ARM. Given the limited scientific evidence, further prospective and randomized trials are required to develop effective systemic therapies and improve the survival of patients with ARM.

Endoscopic ultrasound features of rectal melanoma: A case report and review of literature

BACKGROUND

Rectal mucosal melanoma is a rare and highly aggressive disease. Common symptoms include anal pain, an anal mass, or bleeding. As such, the disease is usually detected on rectal examination of patients with other suspected anorectal diseases. However, due to its rarity and nonspecific symptoms, melanoma of the rectal mucosa is easily misdiagnosed.

CASE SUMMARY

This report describes the case of a 58-year-old female patient who presented with a history of blood in her stool for the prior one or two months, without any identifiable cause. During colonoscopy, a bulge of approximately 2.2 cm × 2.0 cm was identified. Subsequently, the patient underwent endoscopic ultrasound (EUS) to characterize the depth of invasion of the lesions. EUS suggested a hypoechoic mucosal mass with involvement of the submucosal layer and heterogeneity of the internal echoes. Following surgical intervention, the excised tissue samples were examined and confirmed to be rectal malignant melanoma. The patient recovered well with no evidence of recurrence during follow-up.

CONCLUSION

This case shows that colonoscopy with EUS and pathological examination can accurately diagnose rare cases of rectal mucosal melanoma.

A national database analysis of the evolution of outcomes of surgery for anal melanoma

BACKGROUND

This study assessed trends in treatment and outcomes of anal melanomas over a 17-year period.

METHODS

NCDB was searched for patients with anal melanoma (2004-2020). Receiver-operating characteristic curve analysis was used to determine cutoff year marking increased overall survival (OS) of anal melanoma. Characteristics, treatments, and outcomes in consecutive time periods were compared.

RESULTS

A total of 815 patients (mean age: 67.2 years; 59.4% female) were included: 354 in Period 1 (2004-2012) and 461 in Period 2 (2013-2020). Period 2 included fewer abdominoperineal resections (18% vs. 28%, p = 0.002), more local tumor excisions (61.1% vs. 55%, p = 0.002), more often immunotherapy (odds ratio [OR]: 3.41, 95% confidence interval [CI]: 2.22-5.22, p < 0.001) and less often chemotherapy (OR: 0.516, 95% CI: 0.352-0.755, p < 0.001) administered and longer median OS (25.2 vs. 19.8 months, p = 0.006). Independent predictors of worse OS were older age (hazard ratio [HR]: 1.02, p = 0.012), higher Charlson score (HR: 2.32, p = 0.02), and greater number of positive lymph nodes (HR: 1.15, p < 0.001); conversely private insurance (HR: 0.385, p = 0.008) was predictive of increased OS.

CONCLUSIONS

Anal melanoma patients diagnosed between 2013 and 2020 underwent fewer abdominoperineal resections and more local excisions than patients diagnosed between 2004 and 2013. Increased immunotherapy and longer median OS were noted in period two. Age and private insurance were significant predictors of OS, remaining constant across time periods.

Surgical Management of Primary Anorectal Melanoma: Is Less More?

PURPOSE

Ano-uro-genital (AUG) Mucosal Melanoma UK guidelines recommended a less radical surgical strategy for anorectal melanoma (ARM) where possible. We report our experience of ARM consistent with that approach including clinical presentation, intervention undertaken and prognosis.

METHODS

We present a retrospective study of 15 consecutive patients with ARM surgically treated between November 2014 and April 2023. Patients were divided into the two surgery types: wide local excision (WLE, n = 9) and abdominoperineal resection (APR, n = 6). Data on demographics, diagnosis, treatment and oncological outcomes were assessed between the groups.

RESULTS

The mean age was 65.3 ± 17.4 years and 6 (40.0%) were female patients. Nine patients (60.0%) were diagnosed with stage I and six patients (40.0%) with stage II disease. R0 margins were achieved in all cases. The overall mean length of stay was lower following WLE compared to APR (2.6 ± 2.4 days versus 14.0 ± 9.8 days, p = 0.032). Two complications were observed in the WLE group compared to four complications after APR (p = 0.605). Five patients (55.5%) developed local/distant recurrence in the WLE group compared to three patients (50.0%) in the APR group (p = 0.707), with a median overall survival of 38.5 (12-83) months versus 26.5 (14-48) months, respectively.

CONCLUSIONS

Achieving clear margins by the least radical fashion may have equivalent oncological outcomes to radical surgery, potentially reducing patient morbidity and preserving function. In our experience, the surgical management of ARM consistent with the 'less is more' approach adhering to AUG guidelines has acceptable outcomes.

Successful Multidisciplinary Treatment with Laparoscopic Hepatectomy and Adjuvant Therapy for Metachronous Solitary Hepatic Metastasis after Excision of a Primary Anorectal Malignant Melanoma: A Case Report

Anorectal malignant melanoma (ARMM) is extremely rare and generally lethal, irrespective of the treatment administered. The disease is often diagnosed late, metastases being present in approximately two-thirds of patients at the time of initial diagnosis. Solitary metastasis of ARMM to a distant organ is exceedingly rare. A 76-year-old woman with a history of laparoscopic abdominoperineal resection of an ARMM 13 months previously, was found to have a solitary liver metastasis in the follow-up computed tomography. A preoperative work-up showed no other distant metastases nor contraindication to surgery. It was therefore considered that resection was indicated. The metachronous solitary liver metastasis from an ARMM was treated by laparoscopic wedge hepatectomy of the eighth segment 18 months after excision of her primary ARMM. Adjuvant therapy with pembrolizumab was initiated and continued at 6-week intervals. The patient has not exhibited any immune related Adverse Effects (irAE) during or subsequent to treatment with pembrolizmab and has now completed 12 months of adjuvant pembrolizumab therapy, having survived 33 months from the initial operation for primary ARMM, and remaining recurrence-free 14 months after hepatectomy. ARMM is extremely rare and resection of a metachronous solitary metastasis followed by adjuvant therapy has not previously been reported. We hope this case will be useful for clinicians who might treat similar patients.

Organ preservation in anorectal melanoma: A tempting challenge-a case report

Melanoma arising from melanocytes is an uncommon neoplastic lesion, with rare occurrences in anorectal mucosa. While mucosal melanomas constitute a small portion of all melanomas, anorectal cases are even rarer and present with aggressive behavior and poor prognosis. Surgical management is central, with evolving debates regarding optimal approaches. We present a case of a 60-year-old woman with anorectal melanoma. She complained of rectal bleeding and weight loss. Clinical examination and pelvic magnetic resonance imaging revealed a 3-cm budding lesion on the anterior rectal wall. Colonoscopy identified a pedunculated anorectal tumor of 3 cm, situated 4 cm from the anal margin. A biopsy led us to a malignant lesion: anorectal melanoma. Pelvic imaging displayed a localized tumor, prompting wide local excision with millimetric negative margins. These resection margins were estimated insufficient, even in front of R0 resection. Thus, and after multidisciplinary discussion, we opted for abdominoperineal resection after wide local excision. Lymph nodes were biopsied, confirming no residual tumor. Follow-up exhibited no recurrence at 1 year. Our case emphasizes the pivotal role of surgical strategy in managing anorectal melanoma, challenging the paradigm of organ preservation. Despite therapeutic progress, surgery remains integral, contributing to improved outcomes and addressing the metastatic potential inherent to this disease.

Management of primary anorectal mucosal melanoma during the COVID-19 pandemic

Anorectal melanoma is a rare and difficult-to-diagnose highly malignant cancer with a poor prognosis. The treatment usually involves surgery and often includes adjuvants such as radiation therapy and immunotherapy. We present a case of a 77-year-old Peruvian who was eventually diagnosed with this cancer during the COVID-19 pandemic, which complicated her treatment and allowed the cancer to spread. Her treatment included abdominoperineal resection, bilateral pelvic lymphadenectomy, left internal iliac vein raffia and end colostomy, followed by 3D radiation therapy (50 Gy, 25 sessions) and systemic treatment with nivolumab, all of which were well tolerated. The patient was alive as of 20 August 2023, having survived for more than 3 years since the onset of symptoms.

Anorectal melanoma

Anorectal melanoma is an aggressive mucosal melanoma subtype with a poor prognosis. Although recent advancements have been seen for cutaneous melanoma, the optimal treatment paradigm for management of anorectal melanoma is evolving. In this review, we highlight differences in the pathogenesis of mucosal versus cutaneous melanoma, new concepts of staging for mucosal melanoma, updates to surgical management of anorectal melanoma, and current data for adjuvant radiation and systemic therapy in this unique patient population.

Extensive resection improves overall and disease-specific survival in localized anorectal melanoma: A SEER-based study

Background

Anorectal melanoma is a rare tumor with a dismal prognosis. The only promising treatment for anorectal melanoma is surgery, either extensive resection (ER) or local excision (LE). However, the optimal extent of resection is still controversial. The purpose of this study was to investigate whether the survival outcomes of anorectal melanoma at different stages are influenced by the surgical approaches (LE or ER) using the National Institute of Health's Surveillance, Epidemiology, and End Results Program (SEER) database.

Methods

The Surveillance, Epidemiology and End Results (SEER) database was queried to identify patients treated for anorectal melanoma (2000–2018). Overall survival (OS) and disease-specific survival (DSS) outcomes were compared for the two surgical approaches (ER or LE) stratified by stage (localized, regional and distant).

Results

A total of 736 patients were included in the study. Details of previous surgical procedures were available for 548 of the study patients: 360 (65.7%) underwent LE, and 188 (34.3%) underwent ER. In localized cases, 199 underwent LE, and 48 underwent ER. The OS (median 45 vs. 29 months, 5-year rate 41.7% vs. 23.4%) and DSS (median 66 vs. 34 months, 5-year rate 51% vs. 30.7%) of patients undergoing ER were significantly better (p = 0.009 and 0.041, respectively) than those who received LE. Multivariate analysis showed that the type of surgery was an independent prognostic factor for both OS and DSS. Among the regional cases, 89 cases had LE, and 96 cases had ER. Patients with regional disease who underwent ER had no significant differences in OS (23 vs. 21 months; p = 0.866) or DSS (24 vs. 24 months; p = 0. 907) compared to patients who underwent LE. In distant cases, 72 cases had LE, and 44 cases had ER. Patients with metastatic disease who had ER also had similar OS (median 11 vs. 8 months; p = 0.36) and DSS (median 11 vs. 8 months; p = 0.593) to those who underwent LE.

Conclusion

Extensive resection can improve the long-term prognosis of localized anorectal melanoma compared to local excision, but the prognosis of the two surgical techniques is comparable in both regional patients and distant patients.

Surgical treatment of anorectal melanoma: a systematic review and meta-analysis

Background

Anorectal melanoma is a rare neoplasm with a poor prognosis. The surgical approaches for anorectal melanoma can be categorized into local excision (procedures without lymph node removal and preservation of the rectum) and extensive resection (procedures with rectum and pararectal lymph node removal). The aim of this systematic review and meta-analysis was to compare the survival of patients who underwent extensive resection with that of patients who underwent local excision, stratifying patients according to tumour stage.

Methods

A literature review was performed according to PRISMA guidelines by searching MEDLINE/PubMed for manuscripts published until March 2021. Studies comparing survival outcomes in patients with anorectal melanoma who underwent local excision versus extensive resection were screened for eligibility. Meta-analysis was performed for overall survival after the different surgical approaches, stratified by tumour stage.

Results

There were 347 studiesidentified of which 34 were included for meta-analysis with a total of 1858 patients. There was no significant difference in overall survival between the surgical approaches in patients per stage (stage I odds ratio 1.30 (95 per cent c.i. 0.62 to 2.72, P = 0.49); stage II odds ratio 1.61 (95 per cent c.i. 0.62 to 4.18, P = 0.33); stage I–III odds ratio 1.19 (95 per cent c.i. 0.83 to 1.70, P = 0.35). Subgroup analyses were conducted for the time intervals (<2000, 2001–2010 and 2011–2021) and for continent of study origin. Subgroup analysis for time interval and continent of origin also showed no statistically significant differences in overall survival.

Conclusion

No significant survival benefit exists for patients with anorectal melanoma treated with local excision or extensive resection, independent of tumour stage.

Multimodality Imaging and Genetics of Primary Mucosal Melanomas and Response to Treatment

Mucosal melanomas (MMs) are rare and aggressive tumors that arise from melanocytes in the mucosal tissues that line the respiratory, gastrointestinal, and urogenital tracts. Most MMs occur during the 6th and 7th decades of life. MMs may be asymptomatic but may also cause bleeding, pain, and itching, depending on the site of origin. Because of their asymptomatic or oligosymptomatic nature and the difficulty of visualizing them in some cases, they are often advanced tumors at patient presentation. MM staging varies depending on the site of the primary tumor. A simplified staging system allows classification of clinically localized disease as stage I, regional nodal involvement as stage II, and distant metastasis as stage III. MM differs genetically from its cutaneous counterparts. Common drivers in cutaneous melanoma such as B-raf proto-oncogene serine/threonine kinase (BRAF) have a lower mutation rate in MM, whereas mutations of other genes including the KIT proto-oncogene, receptor tyrosine kinase (KIT) and splicing factor 3b subunit 1 gene (SF3B1) are more common in MM. Complete resection is the best curative option. However, surgical intervention with wide local excision and negative margins may be difficult to attain because of the local anatomy and the extent of disease. In addition, despite aggressive surgical resection, most patients develop local recurrence and metastatic disease. Recent advances in the treatment of melanoma include immunotherapy and targeted therapy. Unfortunately, MMs have a relatively poor prognosis, with an overall 5-year survival rate of 25%. Online supplemental material is available for this article. ^©RSNA, 2021.

Trends in the management of anorectal melanoma: A multi-institutional retrospective study and review of the world literature

BACKGROUND

Anorectal melanoma (ARM) is a rare disease with a poor prognosis. Evidence on optimal treatment is limited and surgical management varies widely. We hypothesized that the frequency of abdominoperineal resection used as primary treatment of ARM has decreased over the past several decades.

AIM

To update our understanding of outcomes for patients with ARM and analyze management trends around the world.

METHODS

This is a multi-institutional, retrospective study of patients treated for ARM at 7 hospitals. Hospitals included both large, academic, tertiary care centers and smaller, general community hospitals. Using prospectively maintained institutional tumor registries, we identified 24 patients diagnosed with ARM between January 2000 and May 2019. We analyzed factors prognostic for recurrence and survival. We then used Cox regression to measure overall survival (OS) and melanoma-specific survival. We also performed a literature review to assess trends in surgical management and outcomes.

RESULTS

Of the 24 patients diagnosed with ARM, 12 (50.0%) had local, 8 (33.3%) regional, and 4 (16.7%) distant disease at diagnosis. Median time to recurrence was 10.4 mo [interquartile range (IQR) 7.5-17.2] with only 2 patients (9.3%) not developing recurrence following surgical resection. Median OS was 18.8 mo (IQR 13.5-33.9). One patient is still alive without recurrence at 21.4 mo from diagnosis; no other patient survived 5 years. Primary surgical management with abdominoperineal resection (APR) vs wide excision (WE) did not lead to differences in OS [hazard ratio = 1.4 (95%CI: 0.3-6.8)]. Review of the literature revealed geographic differences in surgical management of ARM, with increased use of WE in the United States and Europe over time and more frequent use of APR in Asia and India. There was no significant improvement in survival over time.

CONCLUSION

There is wide variation in the management of ARM and survival outcomes remain poor regardless of approach. Surgical management should aim to minimize morbidity.