Immunogenetic markers in IL17F predict the risk of metastases spread and overall survival in rectal cancer patients treated with neoadjuvant chemoradiotherapy

BACKGROUND AND PURPOSE

The role of the immune system in tumor response to chemo-radiotherapy (CRT) is an emerging issue. This work aimed at identifying predictive and prognostic immunogenetic variants in LARC patients after preoperative (po)-CRT and surgery.

MATERIALS AND METHODS

A set of 192 polymorphisms in 34 candidate genes involved in the regulation of the immune response signalling network, was selected and analyzed in 370 LARC patients treated with po-CRT and surgery, split into a Test Set (n = 233) and a Validation Set (n = 137). Immunogenetic markers were selected based on a concordant significant effect on 2-year relapse-free survival (2-yrRFS) (bootstrapped P < 0.05) in both patients Sets. The effect of the selected immunogenetic variants on 5-year metastases-free (5yrMFS), 5-year disease-free (5yrDFS), and 10-year overall (10yrOS) survival was tested in the entire Set of 370 patients.

RESULTS

Two immunogenetic IL17F (IL17F-rs641701 and IL17F-rs9463772) markers predictive of 2yrRFS, 5yrDFS, 5yrMFS, and 10yrOS were identified. The combination of tumor regression grade (TRG) and patients genotype for IL17F-rs641701 and IL17F-rs9463772 allowed the identification of subgroups of patients with differential prognosis in term of both 5yrDFS (HR 11.29, P-value <0.001, and HR 5.86, P-value = 0.001, respectively) and 10yrOS (HR 7.07, P-value = 0.005, and HR 6.05, P-value = 0.002, respectively).

CONCLUSION

IL17F-rs641701 and IL17F-rs9463772 were highlighted as promising immunogenetic markers significantly associated with the prognosis of LARC patients. After a prospective validation of the herein reported findings, the combination of TRG and patients genotype should be considered to provide additional stratification criteria for the selection of a personalized multimodality treatment.

Feasibility and oncological outcomes of laparoscopic rectal resection following neo-adjuvant chemo-radiotherapy: A systematic review

AIM: To study the feasibility and oncological outcomes following laparoscopic total mesorectal excision (LTME) in patients who have received Neo-adjuvant long course chemo-radiotherapy (LCRT).

METHODS: A protocol driven systematic review of published literature was undertaken to assess the feasibility and oncological outcomes following LTME in patients receiving LCRT. The feasibility was assessed using peri-operative outcomes and short term results. The oncological outcomes were assessed using local recurrence, disease free survival and overall survival.

RESULTS: Only 8 studies-1 randomized controlled trial, 4 Case Matched/Controlled Studies and 3 Case Series were identified matching the search criteria. The conversion rate was low (1.2% to 28.1%), anastomotic leak rates were similar to open total mesorectal excision (0%-4.1% vs 0%-8.3%). Only 3 studies reported on local recurrence rates (5.2%-7.6%) at median 34 mo follow-up. A single study described disease free survival and overall survival at 3 years as 78.8% and 92.1% respectively.

CONCLUSION: LTME following LCRT is feasible in experienced hands, with acceptable short term surgical outcomes and with the usual benefits associated with minimally invasive procedures. The long term oncological outcomes of LTME after LCRT appear to be comparable to open procedures but need further investigation.