Clinical characteristics of rectal cancer involving the anal canal

Necessity of external iliac lymph nodes and inguinal nodes radiation in rectal cancer with anal canal involvement

Background and purpose

We aimed to explore the necessity of the external iliac lymph nodes (EIN) along with inguinal nodes (IN) region in clinical target volume (CTV) for rectal carcinomas covering the anal canal region.

Materials and methods

This research premise enrolled 399 patients who had primary low rectal cancer detected below the peritoneal reflection via magnetic resonance imaging (MRI) and were treated with neoadjuvant radiotherapy (NRT), without elective EIN along with IN irradiation. We stratified the patients into two groups based on whether the lower edge of the rectal tumor extended to the anal canal (P group, n = 109) or not (Rb group, n = 290). Comparison of overall survival (OS), locoregional recurrence-free survival (LRFS), disease-free survival (DFS), as well as distant metastasis-free survival (DMFS) were performed via inverse probability of treatment weighting (IPTW) along with multivariable analyses. We compared the EIN and IN failure rates between the two groups via the Fisher and Gray’s test.

Results

P group showed a similar adjusted proportion along with five-year cumulative rate of EIN failure compared with the Rb group. The adjusted proportion and five-year cumulative rate of IN failure in the P group was higher in comparison to the Rb group. There were no remarkable differences in the adjusted five-year OS, DFS, DMFS or LRFS between the two groups. Anal canal involvement (ACI) exhibited no effect on OS, LRFS, DFS, or DMFS.

Conclusions

During NRT for rectal cancer with ACI, it may be possible to exclude the EIN and IN from the CTV.

Anal Neoplasia in Inflammatory Bowel Disease: Classification Proposal, Epidemiology, Carcinogenesis, and Risk Management Perspectives

Patients with inflammatory bowel disease [IBD] may develop, similarly to individuals from general population, rare cases of human papilloma virus [HPV]-related anal canal squamous cell carcinoma [SCC] and intra-epithelial precursor lesions, as well as very rare cases of anal canal adenocarcinoma. Patients with chronic perianal Crohn's disease [CD] are at substantial risk of developing SCC or adenocarcinoma from the fistula-lining epithelium, as well as SCC or adenocarcinoma arising from chronic anorectal ulcerations or strictures. Based on this lesion stratification, we provide in this review tailored incidence estimates and we propose an IBD-specific classification of all types of anal neoplasia that may occur in patients with IBD. After reviewing putative carcinogenesis of all types of neoplasia, we conclude that HPV vaccination could reduce the incidence of HPV-related lesions, although an anal screening programme related to these lesions is not mandatory on the sole basis of IBD. By contrast, we point out that all patients with chronic perianal CD should be explored in depth, including biopsies under anaesthesia and fistula curettage when necessary, in case of any change in anal symptoms ─in particular new, increasing, unexplained pain. Finally, we conclude that there is an urgent need for elaborating and evaluating surveillance algorithms in patients with chronic perianal CD, in order to avoid cancers with late diagnosis and poor prognosis.