Can we rely on contrast-enhanced CT to identify pancreatic ductal adenocarcinoma? A population-based study in sensitivity and factors associated with false negatives.

OBJECTIVES: To determine the sensitivity of contrast-enhanced computed tomography (CECT) in detecting pancreatic ductal adenocarcinoma (PDAC) and identify factors associated with false negatives (FNs). METHODS: Patients diagnosed with PDAC in 2014-2015 were retrospectively identified by a cancer registry. CECTs performed during the diagnostic interval were retrospectively classified as true positive (TP), indeterminate, or FN. Sensitivity TP/(TP+FN) was calculated for all CECTs and the following subgroups: protocol (uniphasic vs. biphasic); tumor size (≤ 2 cm vs. > 2 cm); and resectability (potentially resectable vs. unresectable). Multivariate logistic regression was performed to assess which of the following factors were associated with FN: clinical suspicion of PDAC; size >2 cm; presence of metastases; protocol; isoattenuating tumor; and potentially resectable disease on imaging. RESULTS: In total, 176 CECTs (127 uniphasic; 49 biphasic) in 154 patients (90 men, mean age 72 ± 11 years) were included. Sensitivity was 125/149 (83.9%) overall and 87/106 (82.1%) and 38/43 (88.4%) for uniphasic and biphasic protocols, respectively. Sensitivity was decreased for tumors ≤ 2 cm (45.4% vs. 90.6%), no liver metastases (78.0% vs. 95.9%), and potentially resectable disease (65.3% vs. 93.0%). Factors significantly associated with FN were clinical suspicion (OR, 0.24, 95% CI: 0.07-0.75), size>2 cm (OR, 0.10, 95% CI: 0.02-0.44), absence of liver metastases (OR, 4.94, 95% CI: 1.29-22.99), and potentially resectable disease (OR, 4.13, 95% CI: 1.07-16.65). CONCLUSIONS: In our population, the overall sensitivity of CECT to detect PDAC is 83.9%; however, this is substantially lower in several scenarios, including patients with potentially resectable disease. This finding has important implications for patient outcomes and efforts to maximize CECT sensitivity should be sought. CLINICAL RELEVANCE STATEMENT: The sensitivity of CECT to detect PDAC is significantly decreased in the setting of sub-2 cm tumors and potentially resectable disease. A dedicated biphasic pancreatic CECT protocol has higher sensitivity and should be applied in patients with suspected pancreatic disease. KEY POINTS: • The sensitivities of contrast-enhanced CT for the detection of PDAC were 87/106 (82.1%) and 38/43 (88.4%) for uniphasic and biphasic protocols, respectively. • The sensitivity of contrast-enhanced CT was decreased for small tumors ≤ 2 cm (45.4% vs. 90.6%), if there were no liver metastases (78.0% vs. 95.9%), and with potentially resectable disease (65.3% vs. 93.0%). • Absence of liver metastases (OR, 4.94, 95% CI: 1.29-22.99) and potentially resectable disease (OR, 4.13, 95% CI: 1.07-16.65) were associated with a false--negative (FN) CT result; suspicion of malignancy on the imaging requisition (OR, 0.24, 95% CI: 0.07-0.75) and size > 2 cm (OR, 0.10, 95% CI: 0.02-0.44) were negatively associated with FN.

Increasing Undergraduate Exposure to Oncology: the Role of Oncology Interest Groups.

This study describes a medical school oncology interest group (OIG) and assesses its influence on student perceptions of oncology, interest in pursuing oncology as a career, and comfort levels with oncology topics such as breaking bad news. From 2015 to 2017, the OIG annual event took place at a satellite campus of a larger Canadian undergraduate medical school. The event provided a question and answer period with a panel of physicians from multiple oncology specialties-discussions focused around lifestyle, training, clinical work, lifestyle, and career focus. Small physician-led groups taught breaking bad news using the SPIKES framework. The interest group also provided a mentoring and networking opportunity to interested students. Pre- and post-event surveys were distributed to students and physicians. For three consecutive years, the student-run, and physician-mentored OIG successfully recruited student and physician participants, providing a clinical skill teaching session as well as mentorship opportunities to students. Pre-event surveys found that only 20% of students believed their current curriculum was adequate as it relates to oncology education. In pre-session, 13% (6/45) of students indicated comfort with the skill of breaking bad news, compared with that in post-session with 81% (34/42) of students feeling comfortable. When asked "How likely are you to pursue a future elective opportunity in oncology?" 49% (20/41) of students indicated "likely" as their response in the pre-session. This response increased post-session to 70% (28/40). The event highlighted the potential for OIGs to increase student interest in pursuing oncology electives and student-perceived comfort with breaking bad news. OIGs are important in promoting interest in the field of oncology and in improving confidence in breaking bad news. This medical student-created, run and maintained oncology interest group supplemented standard curriculum by providing relevant educational and mentorship opportunities to students. This study highlights the feasibility of implementing a self-sustaining medical school oncology interest group and its potential to positively impact student learning and interest in oncology.