MLH1 and MSH2 mutation screening in HNPCC families of Hungary - Two new MMR gene mutations

Identification of Novel Pathogenic Sequence Variants of the Mismatch Repair Genes During Screening for Lynch Syndrome in a Single Centre of Eastern Hungary

Introduction

Lynch syndrome is an autosomal dominant disorder, most frequent leading to colon cancer. Identification of patients with Lynch syndrome and screening of their family members are available prevention approach that can significantly decrease mortality. Unfortunately, routine screening still does not belong to standard of care in Hungary. In this study, we performed a comprehensive screening in order to identify patients with mismatch repair (MMR) mutation between the years of 2011 and 2014. Identified mutations were compared with those already published in the international databases.

Patients and Methods

Patients who underwent treatment for colorectal cancer at the Surgical Institute of the University of Debrecen were screened using the modified Amsterdam and Bethesda Criteria. Immunohistochemistry and microsatellite analyses were performed in order to identify possible mutation carrier cases. Suspicious cases underwent DNA sequencing to detect mutations in the mismatch repair genes (hMLH1, hMSH2).

Results

All together 760 colorectal cancer patients were screened. A total of 28 patients were identified as possible MMR mutation carrier and underwent further genetic evaluation. Pathogenic sequence variants of the MMR gene were found in 5 patients. Hypermethylation of the promoter region of the hMLH1 gene was identified in 2 patients. Two out of the 5 pathogenic sequence variants of the MMR gene were first identified by our group while other 2 mutations were previously published as possible founder mutations.

Conclusion

Identification of families with Lynch syndrome, while challenging because of variable phenotypes at diagnosis, is feasible with available molecular biological technologies and crucial to reduce mortality caused by this syndrome.

Role of Kalpa Chikitsa in the management of Lynch syndrome- A case report

Lynch syndrome (hereditary non-polyposis colorectal cancer) is an autosomal dominant condition and it is caused by germline mutations in the DNA mismatch repair genes. The present case report was conducted to evaluate the efficacy of Madhuyasti (Glycyrrhiza glabra) Ksheerpaka kalpa in Lynch syndrome. A 28-year-old male was diagnosed with Lynch syndrome in 2016. The patient was operated three times followed by chemotherapy. In 2019, he was diagnosed with adenocarcinoma and advised for surgery. But despite getting surgery patient prefer to take Ayurvedic consultation considering his miserable condition after previous surgeries. It is decided to give the kalpa method of therapy prescribed in Ayurveda for rejuvenation and overall improvement of health. After the 15 days of treatment with Madhuyasti (Glycyrrhiza glabra) Ksheerpaka Kalpa chikitsa, the patient showed significant improvement in quality of life (P < 0.001 for SPF) and CT abdomen showed a reduction in circumferential thickening from 2.8 to 1.5 cm (~50% improvement) with no worsening complications. Although the pathogenesis cannot be revert back to the normalcy as the patient already had resection of the total colon, it can be concluded that with the help of Ayurveda, the appearance of complications can be delayed and the quality of life can be improved in such patients. It is further suggested that better result may obtained if the Ayurvedic therapy starts at earlier stage.

Familial/inherited cancer syndrome: a focus on the highly consanguineous Arab population

The study of hereditary cancer, which accounts for ~10% of cancer cases worldwide is an important subfield of oncology. Our understanding of hereditary cancers has greatly advanced with recent advances in sequencing technology, but as with any genetic trait, gene frequencies of cancer-associated mutations vary across populations, and most studies that have located hereditary cancer genes have been conducted on European or Asian populations. There is an urgent need to trace hereditary cancer genes across the Arab world. Hereditary disease is particularly prevalent among members of consanguineous populations, and consanguineous marriages are particularly common in the Arab world. There are also cultural and educational idiosyncrasies that differentiate Arab populations from other more thoroughly studied groups with respect to cancer awareness and treatment. Therefore, a review of the literature on hereditary cancers in this understudied population was undertaken. We report that BRCA mutations are not as prevalent among Arab breast cancer patients as they are among other ethnic groups, and therefore, other genes may play a more important role. A wide variety of germline inherited mutations that are associated with cancer are discussed, with particular attention to breast, ovarian, colorectal, prostate, and brain cancers. Finally, we describe the state of the profession of familial cancer genetic counselling in the Arab world, and the clinics and societies dedicated to its advances. We describe the complexities of genetic counselling that are specific to the Arab world. Understanding hereditary cancer is heavily dependent on understanding population-specific variations in cancer-associated gene frequencies.

Small bowel adenocarcinoma in Lynch syndrome: A case report

Small bowel adenocarcinoma is part of the tumor spectrum of Lynch syndrome, which is caused by germline mutations in the mismatch repair genes. The present study describes the case of a 51-year-old man fulfilling the Amsterdam II criteria for Lynch syndrome, who had a 15-mm early-stage colorectal cancer resected endoscopically from the ascending colon. Due to upper abdominal discomfort after eating and consequent anorexia, a computed tomography scan performed 1 month later showed a tumoral mass of the upper jejunum with local lymphadenopathy. The laparotomy revealed a completely obstructing mass. Intraoperative frozen section showed a small bowel adenocarcinoma. Subsequent genetic testing confirmed the germline mutation of mutL homolog 1. The patient received 6 cycles of an adjuvant folinic acid, fluorouracil and ocaliplatin chemotherapy regimen. The latest CT scan, 16 months after the chemotherapy, did not show any recurrence. This case highlights the importance of considering the possibility of small bowel adenocarcinoma in patients with upper bowel obstruction, particularly for patients with Lynch syndrome.