Abstract
Context
Lynch syndrome (LS) is a cancer-predisposing syndrome caused by germline mutations in genes involved in DNA mismatch repair (MMR). Patients are at high risk for several types of ...cancer, but pituitary tumors have not previously been reported.
Case
A 51-year-old man with LS (MSH2 mutation) and a history of colon carcinoma presented with severe Cushing disease and a locally aggressive pituitary tumor. The tumor harbored a mutation consistent with the patient’s germline mutation and displayed defect MMR function. Sixteen months later, the tumor had developed into a carcinoma with widespread liver metastases. The patient prompted us to perform a nationwide study in LS.
Nationwide Study
A diagnosis consistent with a pituitary tumor was sought for in the Swedish National Patient Registry. In 910 patients with LS, representing all known cases in Sweden, another two clinically relevant pituitary tumors were found: an invasive nonsecreting macroadenoma and a microprolactinoma (i.e., in total three tumors vs. one expected).
Conclusion
Germline mutations in MMR genes may contribute to the development and/or the clinical course of pituitary tumors. Because tumors with MMR mutations are susceptible to treatment with immune checkpoint inhibitors, we suggest to actively ask for a family history of LS in the workup of patients with aggressive pituitary tumors.
To our knowledge, this is the first case of a pituitary carcinoma caused by a mutation in a DNA mismatch repair gene (Lynch syndrome). Among 910 patients with LS, 3 had pituitary tumors, a higher number than expected.
Background
To evaluate the psychosocial consequences of surveillance with whole‐body MRI (WB‐MRI) in individuals with the heritable TP53‐related cancer (hTP53rc) syndrome, also known as the ...Li‐Fraumeni syndrome, with regard to cancer worry, perceived benefits and risks to surveillance and overall health.
Patients and methods
Since 2016, the national Swedish TP53 Study (SWEP53) has offered surveillance with WB‐MRI to all individuals with hTP53rc syndrome. Seventy‐five individuals have been included in the study. Sixty consecutive participants fulfilled a base‐line evaluation as well as an evaluation after 1 year with structured questionnaires including the Cancer Worry Scale (CWS), perceived benefits and risks of surveillance, and the 36‐item Short Form Survey (SF‐36). Individuals with or without previous personal cancer diagnosis were enrolled and results at baseline and after 1 year of surveillance were compared. For SF‐36, a comparison with the normal population was also made.
Results
Participants with previous cancer tend to worry more about cancer, but both individuals with and without cancer had a positive attitude toward surveillance with no differences regarding perceived benefits and barriers to surveillance. Participants with a previous cancer scored significantly lower on some of the SF‐36 subscales, but between‐group differences were found only for social functioning after 1 year.
Conclusions
Surveillance with WB‐MRI is feasible from a psychosocial point of view both among TP53 carriers with as well as without a previous history of cancer and does not increase cancer worry in any of the groups.
Plain language summary
Individuals with heritable TP53‐related cancer syndrome (also known as the Li‐Fraumeni syndrome) have a high lifetime risk of developing cancer.
These TP53 carriers are offered surveillance with whole‐body MRI to detect cancer early. There are few reports of the psychosocial impact of surveillance.
In this study, we wanted to evaluate cancer worry, benefits and barriers to participation, and perceived overall health.
Our study shows no increase in cancer worry after 1 year of surveillance, regardless of previous cancer.
Individuals with heritable TP53‐related cancer, regardless of previous cancer, had a positive attitude toward surveillance and did not have increased cancer worry after the first year of whole‐body MRI surveillance.
Lynch syndrome caused by constitutional mismatch‑repair defects is one of the most common hereditary cancer syndromes with a high risk for colorectal, endometrial, ovarian and urothelial cancer. ...Lynch syndrome is caused by mutations in the mismatch repair (MMR) genes i.e., MLH1, MSH2, MSH6 and PMS2. After 20 years of genetic counseling and genetic testing for Lynch syndrome, we have compiled the mutation spectrum in Sweden with the aim to provide a population-based perspective on the contribution from the different MMR genes, the various types of mutations and the influence from founder mutations. Mutation data were collected on a national basis from all laboratories involved in genetic testing. Mutation analyses were performed using mainly Sanger sequencing and multiplex ligation-dependent probe amplification. A total of 201 unique disease-predisposing MMR gene mutations were identified in 369 Lynch syndrome families. These mutations affected MLH1 in 40%, MSH2 in 36%, MSH6 in 18% and PMS2 in 6% of the families. A large variety of mutations were identified with splice site mutations being the most common mutation type in MLH1 and frameshift mutations predominating in MSH2 and MSH6. Large deletions of one or several exons accounted for 21% of the mutations in MLH1 and MSH2 and 22% in PMS2, but were rare (4%) in MSH6. In 66% of the Lynch syndrome families the variants identified were private and the effect from founder mutations was limited and predominantly related to a Finnish founder mutation that accounted for 15% of the families with mutations in MLH1. In conclusion, the Swedish Lynch syndrome mutation spectrum is diverse with private MMR gene mutations in two-thirds of the families, has a significant contribution from internationally recognized mutations and a limited effect from founder mutations.
Telomerase reverse transcriptase (TERT) activity is up-regulated in several types of tumors including glioblastoma (GBM). In the present study, 128 primary glioblastoma patients were examined for ...single nucleotide polymorphisms of TERT in blood and in 92 cases for TERT promoter mutations in tumors. TERT promoter mutations were observed in 86% of the tumors and of these, C228T (-124 bp upstream start codon) was detected in 75% and C250T (-146 bp) in 25% of cases. TERT promoter mutations were associated with shorter overall survival (11 vs. 20 months p = 0.002 and 12 vs. 20, p = 0.04 for C228T and C250T, respectively). The minor alleles of rs2736100 and rs10069690 SNP's, located in intron 2 and the promotor regions, respectively, were associated with an increased risk of developing GBM (p = 0.004 and 0.001). GBM patients having both TERT promoter mutations and being homozygous carriers of the rs2853669 C-allele displayed significantly shorter overall survival than those with the wild type allele. The rs2853669 SNP is located in a putative Ets2 binding site in the promoter (-246 bp upstream start codon) close to the C228T and C250T mutation hot spots. Interleukin-6 (IL-6) expression regulated by TERT promoter status and polymorphism, what leads us to think that TERT and IL-6 plays a significant role in GBM, where specific SNPs increase the risk of developing GBM while the rs2853669 SNP and specific mutations in the TERT promoter of the tumor lead to shorter survival.
Temozolomide (TMZ) increases the overall survival of patients with glioblastoma (GBM), but its role in the clinical management of diffuse low-grade gliomas (LGG) is still being defined. DNA ...hypermethylation of the
O
6
-
methylguanine
-
DNA methyltransferase
(
MGMT)
promoter is associated with an improved response to TMZ treatment, while inactivation of the DNA mismatch repair (MMR) pathway is associated with therapeutic resistance and TMZ-induced mutagenesis. We previously demonstrated that TMZ treatment of LGG induces driver mutations in the RB and AKT–mTOR pathways, which may drive malignant progression to secondary GBM. To better understand the mechanisms underlying TMZ-induced mutagenesis and malignant progression, we explored the evolution of
MGMT
methylation and genetic alterations affecting MMR genes in a cohort of 34 treatment-naïve LGGs and their recurrences. Recurrences with TMZ-associated hypermutation had increased
MGMT
methylation compared to their untreated initial tumors and higher overall
MGMT
methylation compared to TMZ-treated non-hypermutated recurrences. A TMZ-associated mutation in one or more MMR genes was observed in five out of six TMZ-treated hypermutated recurrences. In two cases, pre-existing heterozygous deletions encompassing
MGMT
, or an MMR gene, were followed by TMZ-associated mutations in one of the genes of interest. These results suggest that tumor cells with methylated
MGMT
may undergo positive selection during TMZ treatment in the context of MMR deficiency.
Genetic screening for pathogenic variants (PVs) in cancer predisposition genes can affect treatment strategies, risk prediction and preventive measures for patients and families. For decades, ...hereditary breast and ovarian cancer (HBOC) has been attributed to PVs in the genes BRCA1 and BRCA2, and more recently other rare alleles have been firmly established as associated with a high or moderate increased risk of developing breast and/or ovarian cancer. Here, we assess the genetic variation and tumor characteristics in a large cohort of women with suspected HBOC in a clinical oncogenetic setting.
Women with suspected HBOC referred from all oncogenetic clinics in Sweden over a six-year inclusion period were screened for PVs in 13 clinically relevant genes. The genetic outcome was compared with tumor characteristics and other clinical data collected from national cancer registries and hospital records.
In 4622 women with breast and/or ovarian cancer the overall diagnostic yield (the proportion of women carrying at least one PV) was 16.6%. BRCA1/2 PVs were found in 8.9% of women (BRCA1 5.95% and BRCA2 2.94%) and PVs in the other breast and ovarian cancer predisposition genes in 8.2%: ATM (1.58%), BARD1 (0.45%), BRIP1 (0.43%), CDH1 (0.11%), CHEK2 (3.46%), PALB2 (0.84%), PTEN (0.02%), RAD51C (0.54%), RAD51D (0.15%), STK11 (0) and TP53 (0.56%). Thus, inclusion of the 11 genes in addition to BRCA1/2 increased diagnostic yield by 7.7%. The yield was, as expected, significantly higher in certain subgroups such as younger patients, medullary breast cancer, higher Nottingham Histologic Grade, ER-negative breast cancer, triple-negative breast cancer and high grade serous ovarian cancer. Age and tumor subtype distributions differed substantially depending on genetic finding.
This study contributes to understanding the clinical and genetic landscape of breast and ovarian cancer susceptibility. Extending clinical genetic screening from BRCA1 and BRCA2 to 13 established cancer predisposition genes almost doubles the diagnostic yield, which has implications for genetic counseling and clinical guidelines. The very low yield in the syndrome genes CDH1, PTEN and STK11 questions the usefulness of including these genes on routine gene panels.
Up to 10% of pediatric cancer patients harbor pathogenic germline variants in one or more cancer susceptibility genes. A recent study from the US reported pathogenic variants in 22 out of 60 analyzed ...autosomal dominant cancer susceptibility genes, implicating 8.5% of pediatric cancer patients. Here we aimed to assess the prevalence of germline pathogenic variants in these 22 genes in a population-based Swedish cohort and to compare the results to those described in other populations. We found pathogenic variants in 10 of the 22 genes covering 3.8% of these patients. The prevalence of TP53 mutations was significantly lower than described in previous studies, which can largely be attributed to differences in tumor diagnosis distributions across the three cohorts. Matched family history for relatives allowed assessment of familial cancer incidence, however, no significant difference in cancer incidence was found in families of children carrying pathogenic variants compared to those who did not.
Abstract
The risk of breast cancer associated with
CHEK2:
c.1100delC is 2–threefold but higher in carriers with a family history of breast cancer than without, suggesting that other genetic loci in ...combination with
CHEK2
:c.1100delC confer an increased risk in a polygenic model. Part of the excess familial risk has been associated with common low-penetrance variants. This study aimed to identify genetic loci that modify
CHEK2
:c.1100delC-associated breast cancer risk by searching for candidate risk alleles that are overrepresented in
CHEK2
:c.1100delC carriers with breast cancer compared with controls. We performed whole-exome sequencing in 28 breast cancer cases with germline
CHEK2
:c.1100delC, 28 familial breast cancer cases and 70 controls. Candidate alleles were selected for validation in larger cohorts. One recessive synonymous variant, rs16897117, was suggested, but no overrepresentation of homozygous
CHEK2
:c.1100delC carriers was found in the following validation. Furthermore, 11 non-synonymous candidate alleles were suggested for further testing, but no significant difference in allele frequency could be detected in the validation in
CHEK2
:c.1100delC cases compared with familial breast cancer, sporadic breast cancer and controls. With this method, we found no support for a
CHEK2
:c.1100delC-specific genetic modifier. Further studies of
CHEK2
:c.1100delC genetic modifiers are warranted to improve risk assessment in clinical practice.
Among hereditary colorectal cancer predisposing syndromes, Lynch syndrome (LS) caused by mutations in DNA mismatch repair genes MLH1, MSH2, MSH6 or PMS2 is the most common. Patients with LS have an ...increased risk of early onset colon and endometrial cancer, but also other tumors that generally have an earlier onset compared to the general population. However, age at first primary cancer varies within families and genetic anticipation, i.e. decreasing age at onset in successive generations, has been suggested in LS. Anticipation is a well-known phenomenon in e.g neurodegenerative diseases and several reports have studied anticipation in heritable cancer. The purpose of this study is to determine whether anticipation can be shown in a nationwide cohort of Swedish LS families referred to the regional departments of clinical genetics in Lund, Stockholm, Linköping, Uppsala and Umeå between the years 1990-2013. We analyzed a homogenous group of mutation carriers, utilizing information from both affected and non-affected family members. In total, 239 families with a mismatch repair gene mutation (96 MLH1 families, 90 MSH2 families including one family with an EPCAM-MSH2 deletion, 39 MSH6 families, 12 PMS2 families, and 2 MLH1+PMS2 families) comprising 1028 at-risk carriers were identified among the Swedish LS families, of which 1003 mutation carriers had available follow-up information and could be included in the study. Using a normal random effects model (NREM) we estimate a 2.1 year decrease in age of diagnosis per generation. An alternative analysis using a mixed-effects Cox proportional hazards model (COX-R) estimates a hazard ratio of exp(0.171), or about 1.19, for age of diagnosis between consecutive generations. LS-associated gene-specific anticipation effects are evident for MSH2 (2.6 years/generation for NREM and hazard ratio of 1.33 for COX-R) and PMS2 (7.3 years/generation and hazard ratio of 1.86). The estimated anticipation effects for MLH1 and MSH6 are smaller.
Abstract Objective Women with Lynch syndrome (LS) have up to a 60% lifetime risk of endometrial cancer (EC) and up to a 24% risk of ovarian cancer (OC). Gynecological surveillance is recommended, but ...the benefit and how it should be performed remain unclear. The purpose of this study was to assess diagnostic modalities for gynecological screening of LS patients in Sweden and clinical outcome. Methods A retrospective nationwide study of 170 women with molecularly confirmed LS. Data including gynecological LS screening history, biopsy results (if any), genetic records, number of screening visits, results from screening including transvaginal ultrasound (TVUS), endometrial biopsy (EB), blood test for tumor marker cancer antigen (CA) 125, prophylactic surgery including age at procedure, and setting from which screening data were obtained from medical records. Results A total of 117 women were eligible for gynecological screening and of these, 86 patients attended screening visits. Of these, 41 underwent prophylactic hysterectomy and/or bilateral salpingo-oophorectomy. Two patients (4.9%) were diagnosed with EC and two (4.9%) with precancerous lesions in conjunction with prophylactic surgery. Total incidence of gynecological cancer in the surveillance group (45 women) was 20% EC, 4% OC. Five patients had endometrial cancer or complex hyperplasia with atypia (n = 2) detected by endometrial biopsy. Four additional cases were detected due to interval bleeding. Both cases of ovarian cancer were detected by transvaginal ultrasound in patients with ovarian cysts under surveillance. The youngest woman with endometrial cancer was diagnosed at 35 years of age, before she was aware of her diagnosis of Lynch syndrome. Conclusions Gynecological surveillance of women with Lynch syndrome may lead to earlier detection of precancerous lesions, which might have some impact on the morbidity from endometrial cancer although further studies are needed to prove this. Prophylactic hysterectomy with or without bilateral salpingo-oophorectomy reduces the cancer incidence. A practical approach to surveillance in Lynch syndrome women would be to offer annual surveillance beginning at age 30 years including probably both TVUS and EB in order to increase diagnostic yield with prospective data registry for follow-up studies. Prophylactic surgery could be performed at a suitable age after childbearing to obtain a balance between reducing the risk of cancer and minimizing long-term complications from premature menopause.
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