The correct answer is the 4th option, based on the NCCN adaptation of a multidisciplinary expert panel (Dixon et al., Ann Surg Oncol 2013) of 16 physicians from 6 countries that scored 47 scenarios for the appropriateness of genetic counseling. The 1st option should read “DGC is diagnosed before age 40 without a family history”, the 2nd option should read “Personal or family history of diffuse DGC and lobular breast cancer, at least one diagnosed before age 50”, and the 3rd option should read “2 or more cases of gastric cancer in first or second degree relative with at least one confirmed DGC”. Of note, the panel felt that prophylactic total gastrectomy should be offered to CDH1 mutation carriers 20 years or older, and this is echoed by the NCCN recommendation (version 1.2019) to have this performed between ages 18 & 40. Prophylactic total gastrectomy could be considered before age 18 if a family member was diagnosed before age 25. For those mutation carriers that decline prophylactic total gastrectomy, surveillance should be offered every 6-12 months by upper endoscopy and random biopsies.
In our case, tumor perforated the visceral peritoneum. Intramurally, tumor also extended into the duodenum. Metastatic tumor with treatment effect was identified in one of 22 regional lymph nodes.
The correct answer is the 1st option. Per protocol for examination of stomach carcinoma CAP version 184.108.40.206/ AJCC 8th, extension of tumor through the serosa/ visceral peritoneum qualifies as pT4a. The prefix y indicates that the classification is done after or during neoadjuvant treatment (chemotherapy, radiation therapy or combined), as holds true for our case. The 3rd option is incorrect as the intramural extension of gastric cancer to the duodenum or esophagus is not considered invasion of an adjacent structure and is classified using the depth of the greatest luminal invasion in any of these sites. The 2nd and 4th options are incorrect as “r” denotes a recurrent tumor that is documented after a disease-free interval.