RT Journal Article
SR Electronic
T1 Effect of surgical treatment for anorectal melanoma: a propensity score-matched analysis of the Surveillance, Epidemiology, and End Results programme data
JF BMJ Open
JO BMJ Open
FD British Medical Journal Publishing Group
SP e053339
DO 10.1136/bmjopen-2021-053339
VO 12
IS 4
A1 Lei, Xiao
A1 Qingqing, Luo
A1 Weijie, Yuan
A1 Li, Peng
A1 Huang, Changhao
A1 Kexun, Yu
A1 Zihua, Chen
YR 2022
UL http://bmjopen.bmj.com/content/12/4/e053339.abstract
AB Objective Anorectal melanoma (AM) is a rare but aggressive tumour with limited information in the existing literature. This study aimed to assess the effect of surgical treatment for AM and predict the prognosis of affected patients.Design A retrospective cohort study.Setting Data of patients diagnosed with AM between 1975 and 2016 in the USA were collected from the Surveillance, Epidemiology, and End Results (SEER) database.Participants This study enrolled a total of 795 patients with AM from the SEER database and the validation cohort comprised 40 patients with AM enrolled from Chinese institutes.Primary and secondary outcome measures Overall survival (OS) and AM-specific survival (AM-SS).Results A total of 795 patients with AM diagnosed between 1975 and 2016 were enrolled in this study. Data over the past four decades showed a trend of increase in incidence rate. A nomogram based on a multivariate Cox regression model was generated to predict AM-SS. The C-index of the nomogram was 0.74 (95% CI 0.71 to 0.77) on internal verification. In the validation cohort, the C-index of the nomogram was 0.72 (95% CI 0.68 to 0.76). The results of propensity score matching (PSM) analysis showed that patients who underwent surgical treatment achieved significant survival (OS: log-rank=17.41, p<0.001; AM-SS: log-rank=14.55, p<0.001). Patients who underwent surgery were stratified into local and extended surgery subgroups. AM-SS and OS were also compared after PSM, but the results were not significantly different between the two surgery subgroups (all p>0.05).Conclusions The nomogram based on the analysis of SEER data showed good performance in predicting OS and AM-SS. Patients with AM can benefit from surgery; however, extensive surgery and appendectomy may not improve AM-SS or OS.Public data of this study are available from the SEER database (https://seer.cancer.gov). The validation data are from our hospital and available from the corresponding author upon reasonable request.