Germline Cancer Susceptibility Gene Testing in Unselected Patients With Colorectal Adenocarcinoma: A Multicenter Prospective Study

BACKGROUND & AIMS

Hereditary factors play a role in the development of colorectal cancer (CRC). Identification of germline predisposition can have implications on treatment and cancer prevention. This study aimed to determine the prevalence of pathogenic germline variants (PGVs) in CRC patients using a universal testing approach, association with clinical outcomes, and the uptake of family variant testing.

METHODS

We performed a prospective multisite study of germline sequencing using a more than 80-gene next-generation sequencing platform among CRC patients (not selected for age or family history) receiving care at Mayo Clinic Cancer Centers between April 1, 2018, and March 31, 2020.

RESULTS

Of 361 patients, the median age was 57 years (SD, 12.4 y), 43.5% were female, 82% were white, and 38.2% had stage IV disease. PGVs were found in 15.5% (n = 56) of patients, including 44 in moderate- and high-penetrance cancer susceptibility genes. Thirty-four (9.4%) patients had incremental clinically actionable findings that would not have been detected by practice guideline criteria or a CRC-specific gene panel. Only younger age at diagnosis was associated with the presence of PGVs (odds ratio, 1.99; 95% CI, 1.12-3.56). After a median follow-up period of 20.7 months, no differences in overall survival were seen between those with or without a PGV (P = .2). Eleven percent of patients had modifications in their treatment based on genetic findings. Family cascade testing was low (16%).

CONCLUSIONS

Universal multigene panel testing in CRC was associated with a modest, but significant, detection of heritable mutations over guideline-based testing. One in 10 patients had changes in their management based on test results. Uptake of cascade family testing was low, which is a concerning observation that warrants further study.

NCCN Guidelines Insights: Colorectal Cancer Screening, Version 2.2020

The NCCN Guidelines for Colorectal Cancer (CRC) Screening describe various colorectal screening modalities as well as recommended screening schedules for patients at average or increased risk of developing sporadic CRC. They are intended to aid physicians with clinical decision-making regarding CRC screening for patients without defined genetic syndromes. These NCCN Guidelines Insights focus on select recent updates to the NCCN Guidelines, including a section on primary and secondary CRC prevention, and provide context for the panel's recommendations regarding the age to initiate screening in average risk individuals and follow-up for low-risk adenomas.

Fine-tuning Convolutional Neural Networks for Biomedical Image Analysis: Actively and Incrementally

Intense interest in applying convolutional neural networks (CNNs) in biomedical image analysis is wide spread, but its success is impeded by the lack of large annotated datasets in biomedical imaging. Annotating biomedical images is not only tedious and time consuming, but also demanding of costly, specialty-oriented knowledge and skills, which are not easily accessible. To dramatically reduce annotation cost, this paper presents a novel method called AIFT (active, incremental fine-tuning) to naturally integrate active learning and transfer learning into a single framework. AIFT starts directly with a pre-trained CNN to seek "worthy" samples from the unannotated for annotation, and the (fine-tuned) CNN is further fine-tuned continuously by incorporating newly annotated samples in each iteration to enhance the CNN's performance incrementally. We have evaluated our method in three different biomedical imaging applications, demonstrating that the cost of annotation can be cut by at least half. This performance is attributed to the several advantages derived from the advanced active and incremental capability of our AIFT method.

A retrograde-viewing device improves detection of adenomas in the colon: a prospective efficacy evaluation (with videos)

BACKGROUND

Colonoscopy may fail to detect neoplasia located on the proximal sides of haustral folds and flexures. The Third Eye Retroscope (TER) provides a simultaneous retrograde view that complements the forward view of a standard colonoscope.

OBJECTIVE

To evaluate the added benefit for polyp detection during colonoscopy of a retrograde-viewing device.

DESIGN

Open-label, prospective, multicenter study evaluating colonoscopy by using a TER in combination with a standard colonoscope.

SETTING

Eight U.S. sites, including university medical centers, ambulatory surgery centers, a community hospital, and a physician's office.

PATIENTS

A total of 249 patients (age range 55-80 years) presenting for screening or surveillance colonoscopy.

INTERVENTIONS

After cecal intubation, the disposable TER was inserted through the instrument channel of the colonoscope. During withdrawal, the forward and retrograde video images were observed simultaneously on a wide-screen monitor.

MAIN OUTCOME MEASUREMENTS

The number and sizes of lesions (adenomas and all polyps) detected with the standard colonoscope and the number and sizes of lesions found only because they were first detected with the TER.

RESULTS

In the 249 subjects, 257 polyps (including 136 adenomas) were identified with the colonoscope alone. The TER allowed detection of 34 additional polyps (a 13.2% increase; P < .0001) including 15 additional adenomas (an 11.0% increase; P < .0001). For lesions 6 mm or larger, the additional detection rates with the TER for all polyps and for adenomas were 18.2% and 25.0%, respectively. For lesions 10 mm or larger, the additional detection rates with the TER for all polyps and for adenomas were 30.8% and 33.3%, respectively. In 28 (11.2%) individuals, at least 1 additional polyp was found with the TER. In 8 (3.2%) patients, the polyp detected with the TER was the only one found. Every polyp that was detected with the TER was subsequently located with the colonoscope and removed. For all polyps and for adenomas, the additional detection rates for the TER were 9.7%/4.1% in the left colon (the splenic flexure to the rectum) and 16.5%/14.9% in the right colon (the cecum to the transverse colon), respectively.

LIMITATIONS

There was no randomization or comparison with a separate control group.

CONCLUSIONS

A retrograde-viewing device revealed areas that were hidden from the forward-viewing colonoscope and allowed detection of 13.2% additional polyps, including 11.0% additional adenomas. Additional detection rates with the TER for adenomas 6 mm or larger and 10 mm or larger were 25.0% and 33.3%, respectively. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT00657371.).

Coexisting Crohn's Disease and Takayasu's Arteritis in Two Patients Treated with Anti-TNF-α Therapies

Crohn's disease (CD) and Takayasu's arteritis (TA) are inflammatory granulomatous autoimmune disorders. Simultaneous occurrence of CD and TA in the same individual is rare. We report two cases treated with biologic agents. Case 1: A 16-year-old male presented with abdominal pain, nausea, vomiting. CT angiogram showed thickening of the terminal ileum, wall thickening and narrowing of multiple large and medium arteries including aorta and left common carotid. Colonoscopy with biopsy of the stenotic ileocecal valve confirmed CD. Resected carotid artery pathology was consistent with TA. Treatment was initially begun with prednisone, then methotrexate was started followed by infliximab. Due to side effects, methotrexate was switched to azathioprine. He remained asymptomatic. Case 2: A 38-year-old male with well-characterized Crohn's ileocolitis for 15 years, who had been treated with prednisone, mesalamine, sulfasalazine, and azathioprine presented with chest, upper back and abdominal pain. CT angiogram showed vasculitis of large and medium arteries, with stenosis of the right renal artery, and wall thickening of the sigmoid colon. He was diagnosed with TA. He underwent treatment with infliximab and adalumimab on different occasions, which were later discontinued due to fever, bacteremia and complications from sepsis. He remained on prednisone and azathioprine. In these two patients with both CD and TA the diagnoses were confirmed by imaging and pathologic findings. Both patients developed vascular complications. Tumor necrosis factor inhibitor therapy was effective in one patient but discontinued in the other due to infection. Further research into the association of CD and TA may provide clues to their etiologies and guide effective interventions.

Inflammatory bowel disease

Although inflammatory bowel disease (IBD) usually presents in adolescents and young adults, both ulcerative colitis and Crohn's disease can also present in older adults. The diagnosis of IBD in the elderly is often difficult and can easily be confused with diverticulitis or ischaemic colitis. The symptoms and complications of IBD in the elderly are similar to those found in younger patients. However, when IBD presents later in life the disease is often less extensive and milder. Older IBD patients are treated with the same medications as younger patients, although the risk for drug toxicity is greater, especially with corticosteroid therapy. Comorbid illness in older patients often has a significant impact on the outcome of medical and surgical therapy for IBD but, in the absence of significant co-morbid disease, most elderly IBD patients can expect a good response to therapy.