Mary Kinloch

Variability in endometrial carcinoma pathology practice: opportunities for improvement with molecular classification

We assessed the landscape of diagnostic pathology practice and how molecular classification could potentially impact management of patients with endometrial cancer by collecting patient samples, clinicopathologic data, and patient outcomes from EC patients diagnosed in 2016 at 10 Canadian tertiary cancer centers and 19 community hospitals. ProMisE molecular subtype (POLEmut, MMRd, p53abn, No Specific Molecular Profile (NSMP)) was assigned retrospectively. 1357 patients were fully evaluable including 85 POLEmut (6.3%), 380 MMRd (28.0%), 643 NSMP (47.4%), and 249 p53abn ECs (18.3%). Immunohistochemistry (IHC) for MMR proteins was undertaken at the time of primary diagnosis in 2016 in only 42% of the cohort (570/1357; range 3.5-95.4%/center). p53 IHC had only been performed in 21.1% of the cohort (286/1357; range 10.1-41.9%/center). Thus, based on the retrospective molecular subtype assignment, 54.7% (208/380) of MMRd EC had not been tested with MMR IHC (or MSI) and 48.2% (120/249) of p53abn ECs were not tested with p53 IHC in 2016. Molecular subtype diversity within histotypes was profound; most serous carcinomas were p53abn (91.4%), but only 129/249 (51.8%) p53abn EC were serous. Low-grade (Gr1-2) endometrioid carcinomas were mostly NSMP (589/954, 61.7%) but included all molecular subtypes, including p53abn (19/954, 2.0%). Molecular subtype was significantly associated with clinical outcomes (p < 0.001) even in patients with stage I disease (OS p = 0.006, DSS p < 0.001, PFS p < 0.001). Assessment of national pathologic practice in 2016 shows highly variable use of MMR and p53 IHC and demonstrates significant opportunities to improve and standardize biomarker reporting. Inconsistent, non-reflexive IHC resulted in missed opportunities for Hereditary Cancer Program referral and Lynch Syndrome diagnosis, and missed potential therapeutic implications (e.g., chemotherapy in p53abn EC, immune blockade for MMRd EC). Routine integration of molecular subtyping into practice can improve the consistency of EC pathology assessment and classification.

HPV Self-Sampling for Cervical Cancer Screening in Under-Screened Saskatchewan Populations: A Pilot Study

Of all cancers in female Canadians, the most rapidly increasing incidence is that of cervical cancer. The objective of this pilot study was to assess how HPV self-sampling might improve cervical cancer screening participation in both urban and rural settings in Saskatchewan, one of the most sparsely populated provinces in Canada. Study groups consisted of n = 250 participants to whom self-swabbing kits were mailed with instructions and n = 250 participants to whom kits were handed out in 6 urban and rural clinics. The inclusion criteria selected subjects aged 30–69 years who were Saskatchewan residents for at least 5 years with valid health coverage, had a cervix, and had no record of cervical cancer screening in 4 years. The returned samples were analyzed for specific HPV strains using the Roche Molecular Diagnostics Cobas 4800® System. The overall response rate was ~16%, with the response to the handout distribution being roughly double that of the mailout. While HPV positivity did not differ across the distribution groups, participants at a specific inner-city clinic reported significantly higher positivity to at least one HPV strain as compared to any other clinic and all mailouts combined. For this high-risk population, in-person handout of self-sampling kits may be the most effective means of improving screening.