PMS2 negative

When compared with the group of MMRp, MLH1/PMS2 had an increased rate of FIGO stage IIIC1 and IIIC2 (p=0.001), nodal involvement (p<0.001), lymphovascular space invasion (p=0.007), deeper myometrial invasion (p=0.002), and larger tumor dimensions (p=0.002). Comparison for the same pathological features between the MSH2/MSH6 and MMRp groups did not detect any difference.Conclusion The MMRd MLH1/PMS2 pattern is associated to higher risk clinicopathological features compared to the MHS2/MSH6 counterpart.

Results A total of 79 colorectal cancer patients were included in this study,with the male-to-female ratio of 1.26:1 and the mean age of(57.06±12.74)years(24-83 years).Among them,4 patients received preoperative neoadjuvant therapy.Colonic cancer and rectal cancer occurred in 57(57/79,72.15%,including 31 and 26 in the right colon and left colon,respectively)and 22(22/79,27.85%)patients,respectively.The maximum diameter of tumor varied within the range of 1-20 cm,with the mean of(6.61±3.33)cm.Among the 79 colorectal cancer patients,75(75/79,94.94%)patients showed adenocarcinoma.Lymph node metastasis occurred in 12(12/21,57.14%)out of the 21 patients with severe tumor budding,13(13/23,56.52%)out of the 23 patients with moderate tumor budding,and 2(2/31,6.45%)out of the 31 patients with mild tumor budding,respectively.The lymph node metastasis rate showed differences between the patients with severe/moderate tumor budding and the patients with mild tumor budding(all P<0.001).The IHC staining showed that mismatch repair protein was negative in 10(10/65,15.38%)patients,including 5 patients with both MSH2 and MSH6 negative,4 patients with both MLH1 and PMS2 negative,and 1 patient with MSH6 negative.Pan-TRK was negative in 65 patients.The IHC results of HER2 showed 0 or 1+ in 60 patients and 2+ in 5 patients.FISH showed no positive signal in the 5 patients with HER2 IHC results of 2+.The detection with EBV-encoded small RNA showed positive result in 1(1/65,1.54%)patient. Conclusions Non-specific adenocarcinoma of the right colon is the most common in the patients with colorectal cancer resected in Tibet,and 15% of the patients showed mismatch repair protein defects.EBV-associated colorectal carcer is rare,Pan-TRK expression and HER2 gene amplification are seldom.The colorectal cancer patients with moderate and severe tumor budding are more likely to have lymph node metastasis.

Reporting of MMR proteins by IHC is a fast, inexpensive and less labor-intensive method for detecting MMR-D in PBC with high sensitivity and specificity. Further molecular testing showed no added benefits in cases with preserved MMR protein expression by IHC. However, MSI PCR testing was useful in cases with aberrant MMR staining by IHC.

The association between breast and colon cancers should not be dismissed merely as metastasis and males should undergo a thorough physical exam during follow up. Figure: A - Sigmoid colon adenocarcinoma B - Apple core mass in the ascending colon C - Left breast mass without lymphadenopathy D - Ulcerated left breast mass involving areola

When compared to a universal methylation analysis, selective testing with a cut-off age of 65 years, would have reduced the testing effort by 70.7% with a false negative rate for LS detection of 0% and 3% in the clinic and registry-based cohorts, respectively. The use of age-selective methylation analysis is a feasible way of reducing the costs and laboratory burden in LS screening for EC patients.

Using IHC and NGS, MSI status, protein expression, tumor mutation burden (TMB) and genetic alterations were identified in patients with GC, which provides a theoretical basis for the future clinical treatment of GC.