Cancer risk and genotype-phenotype correlation in Japanese patients with Cowden syndrome

Cancer and Overgrowth Manifestations of PTEN Hamartoma Tumor Syndrome: Management Recommendations from the International PHTS Consensus Guidelines Working Group

PURPOSE

PTEN hamartoma tumor syndrome (PHTS) is an autosomal dominant cancer predisposition and overgrowth syndrome caused by pathogenic germline variants in the PTEN gene, with an increased risk of both benign and malignant tumors involving the breast, colon, endometrium, thyroid, skin, and kidney. The objective of these clinical guidelines was to use the latest knowledge to generate an international consensus resource for providers, researchers, and individuals with PHTS on the best practices in the surveillance and management of cancer and overgrowth in PHTS.

EXPERIMENTAL DESIGN

The International PHTS Cancer and Overgrowth Guidelines Working Group was established, comprising a core group of six international experts in the diagnosis and management of PHTS. The working group held joint meetings with individuals with PHTS and their advocates. Informed by the literature, the working group met regularly between 2022 and 2024 to produce guideline statements, refined through iterative feedback. A modified Delphi approach was used with an independent external panel of PHTS, genetics, and cancer experts to establish final consensus guidelines.

RESULTS

Clinical consensus recommendations for the surveillance and management of cancer and overgrowth in individuals with PHTS were formed. The guidelines encompass the recommended practices in cases of breast, colon, endometrial, thyroid, and kidney cancers, as well as overgrowths.

CONCLUSIONS

The clinical management of individuals with PHTS is complex and necessitates a multidisciplinary approach. We generated international consensus guidelines for the surveillance and management of cancer and overgrowth in PHTS, aiming at improving care for affected individuals and families.

Prevalence and Incidence of Peutz-Jeghers Syndrome and Juvenile Polyposis Syndrome in Japan: A Nationwide Epidemiological Survey in 2022

BACKGROUND AND AIM

Peutz-Jeghers syndrome (PJS) and juvenile polyposis syndrome (JPS) are autosomal dominant diseases associated with high cancer risk. In Japan, knowledge about the prevalence and incidence of PJS and JPS is lacking despite being crucial for providing appropriate medical support. We aimed to determine the prevalence and incidence of these diseases.

METHODS

In 2022, a nationwide questionnaire survey was conducted to determine the number of patients with PJS or JPS by sex and the number of newly confirmed cases from 2019 to 2021. The target facilities included gastroenterology, pediatrics, and pediatric surgery departments, which were stratified into seven classes on the basis of the total number of beds. We randomly selected target facilities using different extraction rates in each class, resulting in 1748/2912 facilities (extraction rate: 60%) as the final sample. We calculated the estimated number of patients using the response and extraction rates.

RESULTS

A total of 1077 facilities responded to the survey. The estimated numbers of patients with PJS and JPS were 701 (95% confidence interval [CI]: 581-820) and 188 (95% CI: 147-230), respectively. The 3-year period prevalences of PJS and JPS were 0.6/100000 and 0.15/100000, whereas the incidences in 2021 were 0.07/100000 and 0.02/100000, respectively. Male patients constituted 53.5% and 59.6% in the PJS and JPS groups, respectively.

CONCLUSIONS

We determined the prevalence and incidence of PJS and JPS in Japan for the first time. Further research is needed to obtain more detailed information, including the clinical differences and outcomes in Japan.

Breast Cancer with a Newly Diagnosed Variant in the PTEN Gene: A Case Report

INTRODUCTION

The phosphatase and tensin homolog hamartoma tumor syndrome (PHTS) refers to a spectrum of disorders caused by variants of the phosphatase and tensin homolog (PTEN) gene, including Cowden syndrome (CS), Bannayan-Riley-Ruvalcaba syndrome, adult Lhermitte-Duclos disease, and autism spectrum disorders associated with macrocephaly. PHTS is characterized by hamartomas in multiple organs and is associated with an increased risk of developing malignant tumors including, breast, thyroid, endometrial, colorectal, and kidney tumors. Breast cancer is the most common malignancy associated with PHTS.

CASE PRESENTATION

We describe the case of a 44-year-old female patient with invasive ductal carcinoma of the right breast. Cobblestone papillomatosis was present in the gingiva. She had a medical history of bilateral adenomatous goiters for 10 years. Her mother had been diagnosed with breast cancer, thyroid and tongue tumors, gastric polyps, hepatic hemangioma, and collagen disease. Additionally, the patient's maternal grandmother had a history of colon cancer. Based on the patient's family history and physical findings, CS was suspected, and direct DNA sequencing analysis revealed a haplotype c.634del mutation in exon 7 of the PTEN gene. Although there is no clear evidence supporting risk-reducing surgery for PHTS, a right nipple-sparing mastectomy, sentinel lymph node biopsy, and tissue expander reconstruction were performed.

CONCLUSIONS

We report a case of breast cancer with a newly diagnosed c.634del mutation in the PTEN gene. We also reviewed the current literature on PTEN genetic variants and breast cancer subtypes.

Case Report: Duodenal Carcinoma in a 40-Year-Old Asian Man With Cowden Syndrome

INTRODUCTION

Cowden syndrome is a rare autosomal dominant genetic disease associated with PTEN mutation and is mainly shown as systemic multisystem lesions. The incidence of adenocarcinoma of the duodenum with Cowden syndrome in Asian males is rare. We hereby describe the diagnosis, treatment, and prognosis of a patient with duodenal carcinoma and Cowden syndrome.

CASE DESCRIPTION

A 40-year-old Chinese man was hospitalized because of gastrointestinal hemorrhage and anemia due to infiltrating adenocarcinoma of the descending part of the duodenum. He also had typical signs of Cowden syndrome, such as multiple polyps of the gastrointestinal tract, macrocephaly, papilloma of the tongue, soles hyperkeratosis, and melanosis spots. After the pancreaticoduodenectomy (classic Whipple), the lesions revealed the presence of hamartomatoid polyps, and some of them mutated into non-mucinous adenocarcinoma (80%) and mucinous adenocarcinoma (20%). Further investigation showed a lack of PTEN protein expression in the duodenal neoplasm, and genetic analysis showed the mutation of p.E242fs in PTEN. The patient was followed up for 1 year. There was no appearance of recurrence or distant metastasis.

CONCLUSION

It is suggested that we should pay more attention to the differential diagnosis of duodenal carcinoma combined with gastrointestinal polyps. If multiple gastrointestinal polyps with gastrointestinal bleeding are encountered, Cowden syndrome should be considered, and timely diagnosis and treatment should be implemented.