Lynch Syndrome Testing on Preoperative Biopsy Specimens Is Accurate
Douglas K. Rex, MD, FASGE, reviewing Harrigan J, et al. Clin Gastroenterol Hepatol 2020 May 16.
In this study, there were 96 patients with matched preoperative and postoperative immunohistochemistry (IHC) and microsatellite instability testing results for Lynch syndrome. The concordance of IHC testing between preoperative and postoperative specimens was 100% for MLH1, 100% for MSH2, 97.1% for MSH6, and 98.8% for PMS2.
In the total group of persons tested preoperatively, 2 of the 8 patients underwent subtotal colectomy compared to none of the 10 patients who were tested postoperatively. One of the 5 women in the preoperative group underwent hysterectomy and oophorectomy compared to none of the 6 women in the postoperative group.
COMMENTTwenty years ago, I would very commonly diagnose a colon cancer by colonoscopy, get same-day chest, abdominal, and pelvic CT scans with intravenous contrast, and have the patient operated on the same or the next day. Now that universal Lynch syndrome screening is recommended for all colorectal cancers, that rapid treatment may be efficient but is not always smart. All biopsies from cancers should be tested by IHC, as those that are positive may benefit from a more extensive colectomy, or prophylactic hysterectomy and oophorectomy in females. This study shows that preoperative Lynch syndrome screening on biopsy samples is highly accurate, and in many cases, we should wait the few days it sometimes takes to receive the IHC report before proceeding with surgery.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
CITATION(S)
Harrigan J, Davis C, Chauhan M, et al. Preoperative screening of colorectal cancers is as accurate as postoperative screening for detection of Lynch syndrome. Clin Gastroenterol Hepatol 2020 May 16. (Epub ahead of print) (https://doi.org/10.1016/j.cgh.2020.05.016)
