PMS2 (PMS1 protein homolog 2)

The findings favored metastatic colorectal carcinoma involving the pancreas in the setting of clinically suspected Lynch syndrome. This case emphasizes the importance of clinicopathologic correlation, cautious interpretation of MMR deficiency, and long-term multidisciplinary surveillance.

Postoperative circulating tumor DNA was negative, and the patient was placed on active surveillance; however, neurological symptoms persisted, and immunomodulatory therapy access was initially limited. This case highlights a rare association between anti-Hu-associated myeloneuropathy and early-onset colon cancer and underscores the importance of malignancy evaluation in unexplained sensory neuronopathy.

Perceived risk was intertwined with cancer worry, and individuals made decisions regarding RRSO based on factors such as perceived risk, control, family planning, hormonal impacts, and recovery. Importantly, healthcare providers exerted both direct and indirect influences on the decision-making process.

It underscores the importance of maintaining diagnostic vigilance in patients with hereditary cancer syndromes and supports an aggressive, multidisciplinary approach, including neoadjuvant therapy, even in cases initially presumed to represent locally advanced PDAC. Recognition of such atypical presentations is essential not only for optimising management but also for reinforcing the central role of tumour biology in guiding diagnosis, therapeutic decision-making, and future research in hereditary malignancies.

In this retrospective cross-sectional study, cascade testing was underused, especially among specific demographic groups, with clinical and cultural factors appearing to play a larger role than financial barriers. These findings may guide efforts to address barriers preventing wider uptake of cascade testing and improve cancer prevention efforts, particularly among racial and ethnic minority groups.

Understanding its histological features and immunohistochemical profile facilitates its diagnosis and differential diagnosis, including CK20 positivity and Ki-67 negativity in the superficial layer, and high Ki-67 expression with negative CK20 staining in the deep layer. KRAS gene mutation is also an important diagnostic feature.

These findings support the value of routine IHC-based MMR testing in CRC patients. However, confirmatory molecular testing (e.g., MSI analysis, BRAF V600E mutation, MLH1 promoter methylation, or germline sequencing) is necessary to differentiate sporadic from Lynch syndrome-associated dMMR cases and to fully guide Lynch syndrome screening and immunotherapy decisions.

MSI testing by MSI PCR, however, showed a microsatellite stable result. This highlights how MSI PCR may not be sufficiently sensitive in detecting MSI-H status in tumour types outside of colorectal carcinomas.

The worse outcomes of rectal MAC appear to be driven largely by late-stage presentation, possibly owing to later diagnosis. MAC nonetheless carries a distinct immune phenotype, detectable even in histologically normal surrounding mucosa, that likely contributes to its treatment resistance. These observations provide a basis for developing histotype-specific approaches to both early detection and treatment in this uncommon but clinically challenging tumour subtype.

Our ML approach accurately predicted MSI status in colorectal and uterine cancers using multiomics data derived from NGS, without relying on direct microsatellite sequencing. The ability to identify MSI-high tumors among indeterminate cases demonstrates potential to improve diagnostic precision and ensures timely access to immunotherapy for patients with MSI-high disease.

We report an extremely rare case of SR of poorly differentiated CRC with dMMR and marked TILs. Enhanced tumor immunogenicity associated with dMMR and immune activation may contribute to CRC regression.

Median overall survival was 23 months, reflecting the high mortality burden of mCRC after hepatectomy. Among all molecular markers evaluated, pS6 was the only one independently associated with worse disease-free survival and higher mortality risk, consistent with its role as a surrogate marker of PI3K/AKT/mTORC1 pathway activation, though a direct causal relationship cannot be established from the present data. A significant association between pS6 and FUS positivity suggests a possible convergence of oncogenic pathways warranting further investigation. Postoperative complications were independent predictors of recurrence, and adjuvant chemotherapy was the strongest independent predictor of improved overall survival. Given the retrospective single-center design and limited sample size, these findings are hypothesis-generating and require prospective multicenter validation before clinical application.