Outcomes of exenteration in cT4 and fixed cT3 stage primary rectal adenocarcinoma: a subgroup analysis of consolidation chemotherapy following neoadjuvant concurrent chemoradiotherapy

Real-World Data on the Practice of Chemoradiation with Select Cohort Consolidation Chemotherapy in High-Risk Locally Advanced Rectal Cancers (SOLAR study)

Chemoradiation with capecitabine radiotherapy (Cape–RT) has been the standard of care as neoadjuvant treatment in locally advanced rectal cancer (LARC) for more than a decade. However, total neoadjuvant therapy has recently emerged as an alternative with the potential to impact survival outcomes; baseline outcomes with Cape–RT in real-world practice in the Indian context are not well known.

Treatment-naive patients with adenocarcinoma on histology and clinical-radiologically diagnosed LARC who received Cape–RT from June 2014 to December 2021 after multidisciplinary discussion were included. Patients received a long course of conventionally fractionated external beam RT (45–50 Gy in 25#) with concurrent oral capecitabine at a dose of 1650 mg/m2/day. Post approximately 6 to 8 weeks of completion of Cape–RT, patients were evaluated clinically and by magnetic resonance imaging pelvis for total mesorectal excision (TME) in the multidisciplinary team meetings. The primary endpoint of the study was event-free survival (EFS), and the secondary endpoint was overall survival (OS) and pathological complete response (PCR) rates. EFS and OS were calculated using the Kaplan–Meier method.

A total of 1,189 patients with a median age of 49 years (range: 15–95) were identified and included. A significant proportion of patients had high-risk characteristics, such as T3/T4 disease (94%) and node positivity (90%), and they involved circumferential resection margin (CRM) (51%) at baseline. Signet ring and mucinous histology were seen in 13 and 11% of patients. Two hundred and seventy-six patients (23%) required further consolidation chemotherapy (commonly CAPOX [capecitabine-oxaliplatin] or modified FOLFIRINOX [5-fluorouracil-leucovorin-irinotecan-oxaliplatin]) post-Cape–RT prior to attempting surgery due to either persistent CRM positivity, clinical T4 disease, prostate abutment, sphincter involvement (248 patients, 21%), or extensive bulky disease with poor response (12 patients, 1%). Overall, 14 patients (6%) had an interruption in RT and 22 (8%) in chemotherapy. Post-Cape–RT, with or without chemotherapy, 945 patients (79%) underwent TME. Chemotherapy post-TME was administered in 808 patients (78%). With a median follow-up of 54 months (range: 51.2–57.2), the 3- and 5-year EFS for the entire cohort was 73.2% (95% confidence interval [CI]: 70.6–75.8) and 64.3% (95% CI: 61.1–67.5), respectively, while the estimated 3- and 5-year OS was 81.3% (95% CI: 78.9–83.7) and 73% (95% CI: 70–76), respectively. On multivariate analysis, the presence of higher T stage (p < 0.001) and signet ring histology (p = 0.004) predicted inferior OS.

Real-world data in a less-resourced setting concurs with published prospective and Western real-world data. This provides confidence in implementing consolidation chemotherapy in total neoadjuvant settings in countries with fewer resources.

A systematic review of the pathological determinants of outcome following resection by pelvic exenteration of locally advanced and locally recurrent rectal cancer

BACKGROUND

Despite multimodal therapy 5-15% of patients who undergo resection for advanced rectal cancer (LARC) will develop local recurrence. Management of locally recurrent rectal cancer (LRRC) presents a significant therapeutic challenge and even with modern exenterative surgery, 5-year survival rates are poor at 25-50%. High rates of local and systemic recurrence in this cohort are reflective of the likely biological aggressiveness of these tumour types. This review aims to appraise the current literature identifying pathological factors associated with survival and tumour recurrence in patients undergoing exenterative surgery.

METHODS

A systematic review was carried out searching MEDLINE, EMBASE and COCHRANE Trials database for all studies assessing pathological factors influencing survival following pelvic exenteration for LARC or LRRC from 2010 to July 2021 following PRISMA guidelines. Risk of bias was assessed using QUIPS tool.

RESULTS

Nine cohort studies met inclusion criteria, reporting outcomes for 2864 patients. Meta-analysis was not possible due to significant heterogeneity of reported outcomes. Resection margin status and nodal disease were the most commonly reported factors. A positive resection margin was demonstrated to be a negative prognostic marker in six studies. Involved lymph nodes and lymphovascular invasion also appear to be negative prognostic markers with tumour stage to be of lesser importance. No studies assessed other adverse tumour features that would not otherwise be included in a standard histopathology report.

CONCLUSION

Pathological resection margin status is widely demonstrated to influence disease free and overall survival following pelvic exenteration for rectal cancer. With increasing R0 rates, other adverse tumour features must be explored to help elucidate differences in survival and potentially guide tailored oncological treatment.

Learning curve analysis for lateral pelvic lymph node dissection in rectal cancers - Outcomes improve with experience

INTRODUCTION

Lateral pelvic lymph node dissection (LPLND) is a technically challenging procedure and its learning curve has not been analysed against an oncologically relevant outcome. The purpose of the study was to determine the learning curve for LPLND in rectal cancers using nodal retrieval as performance measure.

METHODS

Consecutive LPLND for rectal adenocarcinomas from a single institution were retrospectively analysed. Cumulative sum (CUSUM) control charts were used to detect difference in performance with respect to lymph node yield. Negative binomial regression was used to determine factors influencing nodal harvest using Incidence Risk Ratios (IRR). Separate CUSUM curves were generated for open and minimally invasive surgeries (MIS).

RESULTS

One-hundred and twenty patients were included and all received preoperative radiation. MIS was used in 53.3%. Median lymph node yield was 6 with 20% nodal positivity. Increasing experience (IRR - 1.196) and MIS (IRR - 1.586) were the only factors that influenced nodal harvest. CUSUM charts revealed that learning curve was achieved after the 83rd case overall and after the 19 operations in MIS. There was a 20% increase in nodal yield after every 30 MIS LPLND performed.

CONCLUSIONS

Learning curve for LPLND is relatively long and only increasing experience and minimally invasive operations increased nodal yield.

Optimal neoadjuvant strategy for signet ring cell carcinoma of the rectum-Is TNT the solution?

INTRODUCTION

The results of total neoadjuvant therapy (TNT) for locally advanced rectal cancers (LARC) cannot be extrapolated to signet-ring cell cancers (SRCC) that have an extremely aggressive biology.

METHODS

A retrospective study comparing long course chemoradiation (CTRT) against short course radiation (SCRT) and 12 weeks of chemotherapy for high-risk LARC. Primary endpoints were treatment failure and disease-free survival (DFS) RESULTS: CTRT was given to 74 (59.7%) and SCRT/Chemotherapy to 50 patients (40.3%). Additional chemotherapy was required in 54.1% and 28%, respectively. Except for nodal staging, no other MRI parameter down-staged. Treatment failures were seen in 33.9% and 25.8% had progression. The peritoneum was the commonest site of progression (59.4%). Of the patients that were surgically explored, 63.7% had R0 resections and pathological complete response was seen in 9.7%. At a median follow-up of 35 months, 56.5% had DFS events with a 3-year DFS of 39.5%. Recurrences were noted in 45.1% after curative resections and the 3-year OS/DFS of these patients were 67.2%/56.4%. On multivariate regression, the type of preoperative therapy did not influence treatment failures or DFS.

CONCLUSIONS

SRCC is a very aggressive disease and none of the treatment strategies could show superiority over the other with very high peritoneal progression rates and relapses.

State-of-the-art surgery for recurrent and locally advanced rectal cancers

Extended and beyond total mesorectal excisions (TME) for advanced and recurrent rectal cancers are increasingly performed with acceptable oncological and functional outcomes. These are undoubtedly due to better understanding of tumor biology and improved patient selection rather than surgical valor and technical refinements alone. In the present review, we attempt to present the current surgical standards for advanced and recurrent cancers requiring surgery outside the TME planes based on involved pelvic compartments. The available procedures, their indications, and extent of resection and reconstruction are highlighted. Emphasis is on formation of dedicated exenteration teams, structured training, and referral systems that increase hospital and surgeon volume to improve patient outcomes and reduce morbidity. Areas of deficiencies in literature were recognized with regards to factors influencing recurrences, patient selection, and quality of life. Finally, the most appropriate preoperative therapy for these tumors is unclear in both the primary and recurrent settings.