Published online Aug 27, 2019. doi: 10.4240/wjgs.v11.i8.334
Peer-review started: June 4, 2019
First decision: August 2, 2019
Revised: August 10, 2019
Accepted: August 13, 2019
Article in press: August 2, 2019
Published online: August 27, 2019
The anorectal leiomyosarcoma (LMS) is an aggressive malignant neoplasm. Owing to the rarity of LMSs, an optimal treatment modality has yet to be determined.
To collect all published data on anorectal LMS characteristics, explore current treatment options, and review recent cases of postradiation LMS.
A literature search of the PubMed electronic database was conducted using the MeSH terms “rectal neoplasms”, “anus neoplasms” and “gastrointestinal neoplasms” combined with “leiomyosarcoma”. The search was limited to English language and human studies. All available case reports and case series of anal or rectal LMSs that were published from the beginning of January 1996 to May 2017 were included if the diagnosis of LMS had been confirmed by histopathologic examination. Data were analyzed using simple statistics (mean, median, and standard deviation). Independent sample t-test was used to compare means for continuous variables.
A total of 27 articles reporting on 51 cases of anorectal LMS were identified. Among these cases, 11.7% had undergone previous pelvic radiotherapy (developing LMS at 13-35 years afterwards). Anorectal LMS affected the rectum in 92.2% of the cases, and no sex-based predominance was observed. Surgical resection with negative margins remains the mainstay of treatment, which can be accomplished with wide local excision or radical resection. The local recurrence rate was higher among cases who received wide local excision (30%), as compared to radical resection (20%); however, the overall rate of metastasis was 51.61% regardless of the treatment approach. The use of neoadjuvant radiation lowers the risk of local recurrence compared to adjuvant radiotherapy, and facilitates R0 resection of the tumor. Cases treated with adjuvant chemotherapy showed better rates of distant recurrence and overall survival. Nonetheless, multidisciplinary team discussion is necessary to determine the optimal management plan whilst considering patient- and disease-related factors.
A multidisciplinary team approach, considering the underlying patient- and disease- related factors, is necessary for optimal management of these complex tumors.
Core tip: The current mainstay treatment of anorectal leiomyosarcoma is surgical resection with negative margins. Based on the published case series and reports, sphincter-preserving surgery followed by radiotherapy yields local recurrence rates that are comparable to radical resection. Moreover, neoadjuvant radiation improves local recurrence rates, as compared to adjuvant radiation. Adjuvant chemotherapy significantly improves rates of distant recurrence and overall survival; however, the choice to use chemotherapy in this setting should be determined according to a multidisciplinary team consideration of patient-related factors and treatment toxicity. Since local and distant tumor recurrences are common, even years after resection, post-surgery long-term follow-up is needed.