Differences in short-term outcomes among patients undergoing IPAA with or without preoperative radiation: a National Surgical Quality Improvement Program analysis

Rectal Cancer and Radiation in Colitis

Inflammatory bowel disease (IBD) is associated with an increased risk of colorectal cancer. When IBD patients develop a rectal cancer, this should be treated with the same oncological principles and guidelines as the general population. Rectal cancer treatment includes surgery, chemotherapy, and radiation therapy (RT). Many IBD patients will require a total proctocolectomy with an ileal-pouch anal anastomosis (IPAA) and others, restoration of intestinal continuity may not be feasible or advisable. The literature is scarce regarding outcomes of IPAA after RT. In the present review, we will summarize the evidence regarding RT toxicity in IBD patients and review surgical strategies and outcomes of IPAA after RT.

Delivery of Personalized Care for Locally Advanced Rectal Cancer: Incorporating Pathological, Molecular Genetic, and Immunological Biomarkers Into the Multimodal Paradigm

Approximately one-third of all newly diagnosed colorectal cancer (CRC) is composed of rectal cancer, with the incidence rising in younger patients. The principal neoadjuvant treatments consist of neoadjuvant short-course radiotherapy and long-course chemoradiation. Locally advanced rectal cancer (LARC) is particularly challenging to manage given the anatomical constrictions of the pelvis and the risk for local recurrence. In appropriately treated patients, 5- and 10-year overall survival is estimated at 60 and 50%, respectively. The prognosis for LARC has improved in recent years with more access to screening, advances in surgical techniques, and perioperative care. Furthermore, the refinement of the multidisciplinary team with combined-modality management strategies has improved outcomes. These advancements have been augmented by significant improvements in the understanding of the underlying tumor biology. However, there are many instances where patient outcomes do not match those for their tumor stage and accurate prognostic information for individual patients can be difficult to estimate owing to the heterogeneous nature of LARC. Many new combinations of chemotherapy with radiotherapy, including total neoadjuvant therapy with targeted therapies that aim to diminish toxicity and increase survival, are being evaluated in clinical trials. Despite these advances, local recurrence and distant metastasis remain an issue, with one-third of LARC patients dying within 5 years of initial treatment. Although much of the new pathological, molecular genetics, and immunological biomarkers allow refinement in the classification and prognostication of CRC, the relative importance of each of these factors with regards to the development and progression of LARC remains incompletely understood. These factors are often insufficiently validated and seldom consider the individual characteristics of the host, the tumor and its location, the local available expertise, or the probable location of recurrence. Appreciating the mechanisms behind these differences will allow for a more comprehensive, personalized approach and more informed treatment options, leading to ultimately superior outcomes. This review aims to first outline the current multidisciplinary context in which LARC care should be delivered and then discuss how some key prognosticators, including novel histopathological, molecular genetics, and immunological biomarkers, might fit into the wider context of personalized LARC management in the coming years.

Better characterization of operation for ulcerative colitis through the National surgical quality improvement program: A 2-year audit of NSQIP-IBD

INTRODUCTION

There is little consensus of quality measurements for restorative proctocolectomy with ileal pouch-anal anastomosis(RPC-IPAA) performed for ulcerative colitis(UC). The National Surgical Quality Improvement Program(NSQIP) cannot accurately classify RPC-IPAA staged approaches. We formed an IBD-surgery registry that added IBD-specific variables to NSQIP to study these staged approaches in greater detail.

METHODS

We queried our validated database of IBD surgeries across 11 sites in the US from March 2017 to March 2019, containing general NSQIP and IBD-specific perioperative variables. We classified cases into delayed versus immediate pouch construction and looked for independent predictors of pouch delay and postoperative Clavien-Dindo complication severity.

RESULTS

430 patients received index surgery or completed pouches. Among completed pouches, 46(28%) and 118(72%) were immediate and delayed pouches, respectively. Significant predictors for delayed pouch surgery included higher UC surgery volume(p = 0.01) and absence of colonic dysplasia(p = 0.04). Delayed pouch formation did not significantly predict complication severity.

CONCLUSIONS

Our data allows improved classification of complex operations. Curating disease-specific variables allows for better analysis of predictors of delayed versus immediate pouch construction and postoperative complication severity.

SHORT SUMMARY

We applied our previously validated novel NSIP-IBD database for classifying complex, multi-stage surgical approaches for UC to a degree that was not possible prior to our collaborative effort. From this, we describe predictive factors for delayed pouch formation in UC RPC-IPAA with the largest multicenter effort to date.

Management of genetically determined colorectal cancer

Surgeons are increasingly treating patients for colorectal cancer who are known to have a genetic predisposition to develop the disease; this may modify the surgical and oncological management of the patient. In this review the approach to the patient with colorectal cancer on a background of Lynch syndrome or familial adenomatous polyposis is explored.

Does external beam radiation therapy to the pelvis portend worse ileal pouch outcomes? An international multi-institution collaborative study

AIM

Short-term morbidity and long-term functional outcome of patients with an ileal pouch-anal anastomosis (IPAA) exposed to pelvic external beam radiation therapy (EBRT) remains unknown. We report the largest series to date regarding the effects of pelvic EBRT on: (i) 30-day postoperative outcomes; and (ii) long-term functional outcome following IPAA.

METHOD

A retrospective chart review was conducted of patients who received EBRT before or after IPAA between 1980 and 2017 across three international inflammatory bowel disease referral centres.

RESULTS

Nineteen patients were included. Indications for EBRT were rectal adenocarcinoma (n = 13), prostate adenocarcinoma (n = 4) or anal squamous cell carcinoma (ASCC) (n = 2). EBRT was given prior to IPAA in 12 (63%) patients and after IPAA in seven (37%). In EBRT before IPAA, patients had a median of 5 (range: 4-8) daytime bowel movements, 1 (range: 0-5) night-time bowel movement, no daytime incontinence, and only one patient used pads at a median follow up of 25 (range: 11-163) months; one patient underwent pouch excision 15 months after IPAA. In EBRT after IPAA, patients reported a median of 8 (range: 5-10) daytime and 2 (range: 0-5) night-time bowel movements, 80% had either daytime or night-time incontinence and 80% used pads at a median follow up of 90 (range: 25-315) months.

CONCLUSION

Pelvic EBRT administered prior to IPAA is associated with acceptable long-term function outcome. However, when pelvic EBRT is given to an IPAA in situ, most patients experience poor long-term pouch function without pouch failure.

Using the National Surgical Quality Improvement Project (NSQIP) to Perform Clinical Research in Colon and Rectal Surgery

The American College of Surgeons' National Surgical Quality Improvement Project (ACS-NSQIP) is probably the most well-known surgical database in North American and worldwide. This clinical database was first proposed by Dr. Clifford Ko, a colorectal surgeon, to the ACS, and NSQIP first started collecting data ca. 2005 with the intent of comparing hospitals (benchmarking) and for hospital-level quality improvement projects. Since then, its popularity has grown from just a few participating hospitals in the United States to more than 708 participating hospitals worldwide, and collaboration allows regional or disease-specific data sharing. Importantly, from a methodological perspective, as the number of hospitals has grown so has the hospital heterogeneity and thus generalizability of the results and conclusions of the individual studies. In this article, we will first briefly present the structure of the database (aka the Participant User File) and other important methodological considerations specific to performing clinical research. We will then briefly review and summarize the approximately 60 published colectomy articles and 30 published articles on proctectomy. We will conclude with future directions relevant to colorectal clinical research.

The current value of determining the mismatch repair status of colorectal cancer: A rationale for routine testing

Colorectal Cancer (CRC) is the third most prevalent cancer in men and women. Up to 15% of CRCs display microsatellite instability (MSI). MSI is reflective of a deficient mismatch repair (MMR) system and is most commonly caused by hypermethylation of the MLH1 promoter. However, it may also be due to autosomal dominant constitutional mutations in DNA MMR, termed Lynch Syndrome. MSI may be diagnosed via polymerase chain reaction (PCR) or alternatively, immunohistochemistry (IHC) can identify MMR deficiency (dMMR). Many institutions now advocate universal tumor screening of CRC via either PCR for MSI or IHC for dMMR to guide Lynch Syndrome testing. The association of sporadic MSI with methylation of the MLH1 promoter and an activating BRAF mutation may offer further exclusion criteria for genetic testing. Aside from screening for Lynch syndrome, MMR testing is important because of its prognostic and therapeutic implications. Several studies have shown MSI CRCs exhibit different clinicopathological features and prognosis compared to microsatellite-stable (MSS) CRCs. For example, response to conventional chemotherapy has been reported to be less in MSI tumours. More recently, MSI tumours have been shown to be responsive to immune-checkpoint inhibition providing a novel therapeutic strategy. This provides a rationale for routine testing for MSI or dMMR in CRC.

DNA Mismatch Repair Deficiency in Rectal Cancer: Benchmarking Its Impact on Prognosis, Neoadjuvant Response Prediction, and Clinical Cancer Genetics

PURPOSE

DNA mismatch repair deficiency (dMMR) hallmarks consensus molecular subtype 1 of colorectal cancer. It is being routinely tested, but little is known about dMMR rectal cancers. The efficacy of novel treatment strategies cannot be established without benchmarking the outcomes of dMMR rectal cancer with current therapy. We aimed to delineate the impact of dMMR on prognosis, the predicted response to fluoropyrimidine-based neoadjuvant therapy, and implications of germline alterations in the MMR genes in rectal cancer.

METHODS

Between 1992 and 2012, 62 patients with dMMR rectal cancers underwent multimodality therapy. Oncologic treatment and outcomes as well as clinical genetics work-up were examined. Overall and rectal cancer-specific survival were calculated by the Kaplan-Meier method.

RESULTS

The median age at diagnosis was 41 years. MMR deficiency was most commonly due to alterations in MSH2 (53%) or MSH6 (23%). After a median follow-up of 6.8 years, the 5-year rectal cancer-specific survival was 100% for stage I and II, 85.1% for stage III, and 60.0% for stage IV disease. Fluoropyrimidine-based neoadjuvant chemoradiation was associated with a complete pathologic response rate of 27.6%. The extent of surgical resection was influenced by synchronous colonic disease at presentation, tumor height, clinical stage, and pelvic radiation. An informed decision for a limited resection focusing on proctectomy did not compromise overall survival. Five of the 11 (45.5%) deaths during follow-up were due to extracolorectal malignancies.

CONCLUSION

dMMR rectal cancer had excellent prognosis and pathologic response with current multimodality therapy including an individualized surgical treatment plan. Identification of a dMMR rectal cancer should trigger germline testing, followed by lifelong surveillance for both colorectal and extracolorectal malignancies. We herein provide genotype-specific outcome benchmarks for comparison with novel interventions.