Tumour touching fat at the invasion front flags worse colorectal cancer survival

The edition in brief

A meta-analysis published in July pooled eight retrospective colorectal cancer cohorts and found that direct tumour-adipocyte contact at the invasion front without intervening stroma (TAC, previously called SARIFA) was independently associated with worse cancer-specific survival (HR 1.77, 95% CI 1.55–2.01; 5,932 patients) and overall survival (HR 1.53), with little heterogeneity; it needs prospective validation but costs only a careful look at the H&E. A single-institution review of 626 thyroidectomies with follicular-cell carcinoma found 63 glands with coexisting RAS-like and BRAF V600E-like tumours; nodal metastases came mostly from the BRAF-like papillary carcinoma, often the smaller focus. In 79 pigmented spindle cell naevi of Reed, an optimised pan-TRK immunostain had high specificity and positive predictive value for NTRK3 rearrangement but sensitivity of only about 35%, so a negative stain does not exclude a fusion. A Chinese cohort of 666 resected gastric cancers found those with a neuroendocrine carcinoma component (27 cases) had worse survival and higher recurrence, with nodal metastases composed mainly of the neuroendocrine component. The pearl is about sampling every focus in a multifocal thyroid.