Correction: Gill et al. Report from the 24th Annual Western Canadian Gastrointestinal Cancer Consensus Conference on Colorectal Cancer, Richmond, British Columbia, 28-29, October 2022. Curr. Oncol. 2023, 30, 7964-7983.

Karen Mulder was not included as an author in the original publication [...].

Transverse Colon Primary Tumor Location as a Biomarker in Metastatic Colorectal Cancer: A Pooled Analysis of CCTG/AGITG CO.17 and CO.20 Randomized Clinical Trials.

PURPOSE: Sidedness is prognostic and predictive of anti-EGFR efficacy in metastatic colorectal cancer (mCRC). Transverse colon has been historically excluded from several analyses of sidedness and the optimal division between left- and right-sided colorectal cancer is unclear. We investigated transverse colon primary tumor location as a biomarker in mCRC. EXPERIMENTAL DESIGN: Pooled analysis of CCTG/AGITG CO.17 and CO.20 trials of cetuximab in chemotherapy-refractory mCRC. Outcomes of patients with RAS/BRAF wild-type (WT) mCRC from CO.17 and KRAS WT mCRC from CO.20 were analyzed according to location. RESULTS: A total of 553 patients were analyzed, 32 (5.8%) with cancers from the transverse, 101 (18.3%) from right, and 420 from (75.9%) left colon. Transverse mCRC failed to reach significant benefit from cetuximab versus best supportive care (BSC) for overall survival [OS; median, 5.9 vs. 2.1 months; HR, 0.63; 95% confidence interval (CI), 0.28-1.42; P=0.26] and progression-free survival (PFS; median, 1.8 vs. 1.3 months; HR, 0.57; 95% CI, 0.26-1.28; P=0.16). Analyzing exclusively patients randomized to cetuximab, right-sided and transverse had comparable outcomes for OS (median, 5.6 vs. 5.9 months; HR, 0.82; 95% CI, 0.50-1.34; P=0.43) and PFS (median, 1.9 vs. 1.8 months; HR, 0.78; 95% CI, 0.49-1.26; P=0.31). Patients with left-sided mCRC had superior outcomes with cetuximab compared with transverse for OS (median, 9.7 vs. 5.9 months; HR, 0.42; 95% CI, 0.27-0.67; P=0.0002) and PFS (median, 3.8 vs. 1.8 months; HR, 0,49; 95% CI, 0.31-0.76; P=0.001). Location was not prognostic in patients treated with BSC alone. CONCLUSIONS: Transverse mCRC has comparable prognostic and predictive features with right-sided mCRC.

Clinical impact of unsuccessful subcutaneous administration of octreotide LAR instead of intramuscular administration in patients with metastatic gastroenteropancreatic neuroendocrine tumors.

Octreotide LAR is a long-acting somatostatin analogue (SSA) used in the management of metastatic gastroenteropancreatic neuroendocrine tumors (GEP NETs). It requires intramuscular (IM) injection. Missed IM injections cause subcutaneous nodules (SCNs) on radiologic images. We reviewed the rates of SCNs in a real-world cohort of GEP NETs receiving octreotide LAR and explored treatment outcomes. Patients commencing octreotide LAR between August 5, 2010 and March 8, 2018 at a single cancer center in Canada were identified from pharmacy records. Patients were included if they had a computed tomography (CT) scan performed at the time of progression and a preceding CT with pelvis included to enable assessment for the presence of nodules. Fisher's exact test was used to examine predictors of SCNs, and Kaplan-Meier curves summarized differences in progression free (PFS) and overall survival (OS) that were compared with log-rank tests. Of 243 patients receiving octreotide LAR, 45 had all required CT images available for central review. SCNs were found in 20/45 (44%) of patients on the last scan showing stable disease before progression and were numerically but not statistically more likely in females (OR: 2.36, 95% CI: 0.66-8.29, p = .23). There was an increased risk of SCNs in patients with a skin-to-muscle distance >38 mm (the length of an octreotide LAR needle) on CT (OR: 5.09, 95% CI: 1.39-16.6, p = .018) and a trend toward increased risk in obese patients (OR: 5.71, 95% CI: 1.26-23.4, p = .061). PFS (HR: 1.01, 95% CI: 0.56-1.78, p = .98) and OS (HR: 0.86, 95% CI: 0.41-1.8, p = .70) was similar between those with/without SCNs. In conclusion, almost half of patients receiving octreotide LAR had SCNs; however, missed administration of SSA did not appear to result in worse survival in this small study. Factors such as sex, younger age skin-to-muscle distance, and obesity may affect SCN development and should be considered when choosing an SSA.

Report from the 24th Annual Western Canadian Gastrointestinal Cancer Consensus Conference on Colorectal Cancer, Richmond, British Columbia, 28-29, October 2022.

The 24th annual Western Canadian Gastrointestinal Cancer Consensus Conference (WCGCCC) was held in Richmond, British Columbia, on 28-29 October 2022. The WCGCCC is an interactive multidisciplinary conference attended by healthcare professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals such as dieticians, nurses and a genetic counsellor participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

Circulating tumor DNA in early-stage colon cancer: ready for prime time or needing refinement?

Liquid biopsies are the detection of molecular information in fluids from patients with cancer. In colorectal cancer (CRC), the most promising liquid biopsy strategy is the use of circulating tumor DNA (ctDNA) from plasma. In early-stage CRC, the potential for ctDNA to impact care stems from the detection of minimal residual disease (MRD) to guide adjuvant therapy after curative intent treatment and in identifying recurrences during surveillance. As for any new diagnostic test, ctDNA assays must overcome pre-analytical and analytical challenges before clinical implementation. We will discuss important logistical and assay considerations that clinicians and patients should understand when assessing ctDNA assays. We will also delve into important concepts to aid in interpreting ctDNA results and potential incidental findings that may arise. Sequencing errors, germline variants, and clonal hematopoiesis of indeterminate potential (CHIP) must be addressed to properly interpret results. CHIP is also an important consideration that impacts patient prognosis through association with cardiovascular and hematologic diseases. With this background in place, we next review the best available evidence for the use of ctDNA in early-stage colon cancer. Observational cohorts have established MRD after surgery as a significant prognostic factor for recurrence in stage II and III colon cancer. It also has the ability to anticipate clinical recurrence before standard investigations when used in surveillance. The first and only interventional randomized trial to date evaluating ctDNA is DYNAMIC. The study demonstrated the noninferiority of a MRD detection-guided approach in selecting patients with stage II colon cancer for adjuvant treatment. Notwithstanding the important results, there are still important questions to be answered before ctDNA enters prime time in the clinic. However, future appears bright and ongoing trials will help clarify how to best use this technology in early-stage colon cancer.