Regarding the Clinical Practice Guidelines for the Surgical Treatment of Patients With Lynch Syndrome

Current status on microsatellite instability, prognosis and adjuvant therapy in colon cancer: A nationwide survey of medical oncologists, colorectal surgeons and gastrointestinal pathologists

BACKGROUND

There is significant variation in attitude both towards the role of microsatellite instability (MSI) in predicting prognosis, and towards its role in guiding which Stage II colon cancer patients may benefit from adjuvant chemotherapy.

AIM

To examine the current status of specialist attitudes towards MSI in guiding prognosis and adjuvant therapy in stage II colon cancer.

METHODS

The Pathology in Colon Cancer, Prognosis and Uptake of Adjuvant Therapy (PiCC UP) Australia and New Zealand questionnaire was distributed to colorectal surgeons, medical oncologists and pathologists after institutional board approval. A 5-scale Likert score was used to assess attitudes towards 23 pathological features for prognosis and 18 features for adjuvant therapy. Data were analysed using a rating scale and graded response model in item response theory (IRT) on STATA (Stata MP, version 15; StataCorp LP).

RESULTS

164 specialists (45 oncologists, 86 surgeons and 33 pathologists) participated. 80.5% regularly attended colorectal multidisciplinary team (MDT) meetings. 89.63% and 59.26% of specialists reported that MSI status was likely or definitely to influence prognosis in colon cancer and recommendations for adjuvant therapy in Stage II colon cancer respectively. IRT modelling was achieved in 17 pathological features for prognosis. MSI IRT score was 4.47 (95% CI: 4.05-4.68). IRT modelling was achieved in 10 pathological features for adjuvant therapy. MSI IRT score was 3.62 (2.89-4.15). MSI ranked 10 (of 17) in order of importance in determining prognosis and ranked three (of 10) in guiding adjuvant therapy.

CONCLUSION

MSI status is considered an important biomarker when selecting patients for adjuvant therapy in Stage II colon cancer. MSI is also considered useful in prognostication of colon cancer. MSI status was ranked similar to the tumour grade of differentiation and the presence of perineural invasion.

Clostridioides difficile Enteritis in Patients Following Total Colectomy-a Rare but Genuine Clinical Entity

Objective

Clostridioides difficile infection (CDI) frequently causes colitis following antibiotic exposure and is a leading cause of gastrointestinal infectious mortality. Infection in the small bowel, C. difficile enteritis (CDE), was previously thought impossible, but case series have challenged this dogma. Clostridioides difficile enteritis prevalence, severity, and potential risk factors are unknown.

Methods

We retrospectively analyzed all total colectomy patients over a 20-year period at our institution. C. difficile enteritis was defined by clinical symptoms and positive C. difficile stool testing after colectomy. We compared CDE cases to controls using multivariable analysis to identify potential CDE risk factors.

Results

C. difficile enteritis occurred in 44 of 855 (5.1%) patients, a median of 130 days after colectomy. Compared to controls, CDE patients were similar in age, gender, and presence of immunosuppression. The majority (64%) had antibiotics <30 days prior to CDE. In multivariable analysis, CDE risk factors included perioperative acid suppression (hazard ratio [HR], 2.52; 95% confidence interval [CI], 1.26–5.04; P = .009), colectomy for inflammatory bowel disease (HR, 2.95; CI, 1.29–6.72; P = .010), colectomy for CDI (HR, 9.95; CI, 2.70–36.63; P ≤ .001), and β-lactam use in the setting of enteral feeds (HR, 17.83; CI, 2.75–115.68; P = .003). C. difficile enteritis presented with severe disease half of the time, with 81.8% requiring hospitalization.

Conclusions

C. difficile enteritis is a rare clinical entity that should be considered in postcolectomy patients presenting with CDI symptoms, even years after surgery. Like traditional CDI, likely CDE risk factors include acid suppression and inflammatory bowel disease. Prior antibiotic use in the setting of enteral feeds may amplify CDE risk. C. difficile enteritis often presents as severe disease and frequently requires hospitalization.