CHEK2 Alleles Predispose to Renal Cancer in Poland

Characteristics, aetiology and implications for management of multiple primary renal tumours: a systematic review

In a subset of patients with renal tumours, multiple primary lesions may occur. Predisposition to multiple primary renal tumours (MPRT) is a well-recognised feature of some inherited renal cancer syndromes. The diagnosis of MPRT should therefore provoke a thorough assessment for clinical and genetic evidence of disorders associated with predisposition to renal tumourigenesis. To better define the clinical and genetic characteristics of MPRT, a systematic literature review was performed for publications up to 3 April 2024. A total of 7689 patients from 467 articles were identified with MPRT. Compared to all patients with renal cell carcinoma (RCC), patients with MPRT were more likely to be male (71.8% versus 63%) and have an earlier age at diagnosis (<46 years, 32.4% versus 19%). In 61.1% of cases MPRT were synchronous. The proportion of cases with similar histology and the proportion of cases with multiple papillary renal cell carcinoma (RCC) (16.1%) were higher than expected. In total, 14.9% of patients with MPRT had a family history of cancer or were diagnosed with a hereditary RCC associated syndrome with von Hippel-Lindau (VHL) disease being the most common one (69.7%), followed by Birt-Hogg-Dubé (BHD) syndrome (14.2%). Individuals with a known or likely genetic cause were, on average, younger (43.9 years versus 57.1 years). In rare cases intrarenal metastatic RCC can phenocopy MPRT. We review potential genetic causes of MPRT and their implications for management, suggest an approach to genetic testing for individuals presenting with MPRT and considerations in cases in which routine germline genetic testing does not provide a diagnosis.

A deep intronic recurrent CHEK2 variant c.1009-118_1009-87delinsC affects pre-mRNA splicing and contributes to hereditary breast cancer predisposition

Germline CHEK2 pathogenic variants confer an increased risk of female breast cancer (FBC). Here we describe a recurrent germline intronic variant c.1009-118_1009-87delinsC, which showed a splice acceptor shift in RNA analysis, introducing a premature stop codon (p.Tyr337PhefsTer37). The variant was found in 21/10,204 (0.21%) Czech FBC patients compared to 1/3250 (0.03%) controls (p = 0.04) and in 4/3639 (0.11%) FBC patients from an independent German dataset. In addition, we found this variant in 5/2966 (0.17%) Czech (but none of the 443 German) ovarian cancer patients, three of whom developed early-onset tumors. Based on these observations, we classified this variant as likely pathogenic.

CHEK2 C1100del mutation associated with papillary renal cell carcinoma type II

CHEK2 mutations have been noted in bone, brain, breast, colon, lung, thyroid, and prostate cancer. Although now reported in both clear cell and non-clear cell renal cancer, we have not found CHEK2 2 mutations reported in the papillary type II subtype (PRCC). Here, we report a 63-year-old female with a PRCC type II with a concomitant CHEK2 C1100del mutation, who is currently in complete remission three years post tumor resection.

A case report of biallelic CHEK2 heterozygous variant presenting with breast cancer

Pathogenic germline variants in the CHEK2 gene have been shown to cause a moderate increased risk of breast cancer. Here, we present a striking CHEK2 family with a biallelic carrier of two frameshift pathogenic variants, to draw attention and to encourage a comprehensive genetic and cancer risk education for biallelic carriers of CHEK2 pathogenic variants.

Frequency of pathogenic germline variants in cancer susceptibility genes in 1336 renal cell carcinoma cases

Renal cell carcinoma (RCC) occurs in a number of cancer predisposition syndromes, but the genetic architecture of susceptibility to RCC is not well defined. We investigated the frequency of pathogenic and likely pathogenic (P/LP) germline variants in cancer susceptibility genes (CSGs) within a large series of unselected RCC participants. Whole-genome sequencing data on 1336 RCC participants and 5834 controls recruited to the UK 100 000 Genomes Project, a nationwide multicentre study, was analyzed to identify rare P/LP short variants (single nucleotide variants and insertions/deletions ranging from 1 to 50 base pairs) and structural variants in 121 CSGs. Among 1336 RCC participants [mean: 61.3 years (±12 SD), range: 13-88 years; 64% male], 85 participants [6.4%; 95% CI (5.1, 7.8)] had one or more P/LP germline variant in a wider range of CSGs than previously recognized. A further 64 intragenic variants in CSGs previously associated with RCC were classified as a variant of uncertain significance (VUS) (24 'hot VUSs') and were considered to be of potential clinical relevance as further evaluation might results in their reclassification. Most patients with P variants in well-established CSGs known to predispose to renal cell carcinoma (RCC-CSGs) were aged <50 years. Burden test analysis for filtered variants in CSGs demonstrated a significant excess of CHEK2 variants in European RCC participants compared with the healthy European controls (P = 0.0019). Approximately, 6% of the patients with RCC unselected for family history have a germline variant requiring additional follow-up analysis. To improve diagnostic yield, we suggest expanding the panel of RCC-CSGs tested to include CHEK2 and all SDHx subunits and raising the eligibility criteria for age-based testing.

Risk of Second Primary Thyroid Cancer in Women with Breast Cancer

Simple Summary

The goal of this study was to estimate the risk of thyroid cancer following a diagnosis of breast cancer and to identify (therapeutic and genetic) risk factors for the development of thyroid cancer after breast cancer. We followed 10,832 breast cancer patients for a mean of 14 years for new cases of thyroid cancer. Of the 10,832 women with breast cancer, 53 (0.49%) developed a second case of primary thyroid cancer. The ten-year risk of thyroid cancer was higher in women who carried a CHEK2 mutation (1.5%) than in women who carried no mutation (0.9%). In Poland, following a diagnosis of breast cancer, the risk of thyroid cancer is increased four times, but is increased nine times in women who carry a CHEK2 mutation.

Abstract

The goal of this study was to estimate the risk of thyroid cancer following breast cancer and to identify therapeutic and genetic risk factors for the development of thyroid cancer after breast cancer. We followed 10,832 breast cancer patients for a mean of 14 years for new cases of thyroid cancer. All women were genotyped for three Polish founder mutations in BRCA1 (C61G, 4153delA, 5382insC) and four mutations in CHEK2 (1100delC, IVS2 + 1G/A, del5395, I157T). Information was collected on chemotherapy, radiotherapy, hormonal therapies, and oophorectomy. Of the 10,832 women, 53 (0.49%) developed a second primary thyroid cancer. Based on Polish population statistics, the expected number was 12.4 (SIR = 4.3). The ten-year risk of developing thyroid cancer was higher in women who carried a CHEK2 mutation (1.5%) than in women who carried no mutation (0.9%). The age-adjusted hazard ratio for developing thyroid cancer was 1.89 (0.46–7.79; p = 0.38) for those with a CHEK2 protein-truncating mutation and 2.75 (1.29–5.85; p = 0.009) for those with a CHEK2 missense mutation.

Survival of bladder or renal cancer in patients with CHEK2 mutations

Purpose

The purpose of this study was to compare the clinical characteristics and the survival of CHEK2 mutation positive and CHEK2 mutation negative patients diagnosed with bladder or kidney cancer.

Materials and methods

1016 patients with bladder and 402 cases with kidney cancer and 8302 controls were genotyped for four CHEK2 variants: 1100delC, del5395, IVS2+1G>A and I157T. Predictors of survival were determined among CHEK2 pathogenic variant carriers using the Cox proportional hazards model. The median follow-up was 17.5 years. Covariates included age (≤60; >61 years), sex (female; male), clinical characteristics (stage: TNM, grade, histopathological type), smoking status (non-smoking; smoking) and cancer family history (negative; positive).

Results

We found no impact of CHEK2 mutations on bladder or kidney cancer survival. However, we observed a possible increased survival in the subgroup of patients with stage T1 bladder cancer with CHEK2 mutations but this did not meet statistical significance (HR = 0.14; 95% CI 0.02–1.04; p = 0.055). Moreover, we observed that the missense mutations were more frequent in the low grade invasive bladder cancer patient group (OR = 7.9; 95% CI 1.50–42.1; p = 0.04) and in patients with bladder cancer with stage Ta (OR = 2.4; 95% CI 1.30–4.55; p = 0.006). The different results where missense mutations occurs less often we observed among patients with high grade invasive bladder cancer (OR = 0.12; 95% CI 0.02–0.66; p = 0.04) and those with stage T1 disease (OR = 0.2; 95% CI 0.07–0.76; p = 0.01). Our investigations revealed that any mutation in CHEK2 occurs more often among patients with stage Ta bladder cancer (OR = 2.0; 95% CI 1.19–3.47; p = 0.01) and less often in patients with stage T1 disease (OR = 0.31; 95% CI 0.12–0.78; p = 0.01). In the kidney cancer patients, truncating mutations were present more often in the group with clear cell carcinoma GII (OR = 8.0; 95% CI 0.95–67.7; p = 0.05). The 10-year survival for all CHEK2 mutation carriers with bladder cancer was 33% and for non-carriers 11% (p = 0.15). The 10-year survival for CHEK2 mutation carriers with kidney cancer 34% and for non-carriers 20% (p = 0.5).

Conclusion

CHEK2 mutations were not associated with any change in bladder or kidney cancer survival regardless of their age, sex, smoking status and family history. We observed a potentially protective effect of CHEK2 mutations on survival for patients with stage T1 bladder cancer. CHEK2 missense mutations were more common among patients with low grade invasive bladder cancer and in patients with stage Ta diease. The frequencies of the I157T CHEK2 pathogenic variant were less in patients with high grade invasive bladder cancer and those with stage T1 disease. Among patients with bladder cancer with stage Ta disease, the OR for any mutation in CHEK2 was 2.0 but for those with stage T1 disease, the OR was 0.3. We observed truncating CHEK2 mutations were associated with kidney cancer patients with GII clear cell carcinoma.

CHEK2 Germline Variants in Cancer Predisposition: Stalemate Rather than Checkmate

Germline alterations in many genes coding for proteins regulating DNA repair and DNA damage response (DDR) to DNA double-strand breaks (DDSB) have been recognized as pathogenic factors in hereditary cancer predisposition. The ATM-CHEK2-p53 axis has been documented as a backbone for DDR and hypothesized as a barrier against cancer initiation. However, although CHK2 kinase coded by the CHEK2 gene expedites the DDR signal, its function in activation of p53-dependent cell cycle arrest is dispensable. CHEK2 mutations rank among the most frequent germline alterations revealed by germline genetic testing for various hereditary cancer predispositions, but their interpretation is not trivial. From the perspective of interpretation of germline CHEK2 variants, we review the current knowledge related to the structure of the CHEK2 gene, the function of CHK2 kinase, and the clinical significance of CHEK2 germline mutations in patients with hereditary breast, prostate, kidney, thyroid, and colon cancers.

High risk of breast cancer in women with biallelic pathogenic variants in CHEK2

PURPOSE

Compared to breast cancer risk genes such as BRCA2, ATM, PALB2, and NBN, no defined phenotype is currently associated with biallelic pathogenic variants (PVs) in CHEK2. This study compared the prevalence of breast and other cancers in women with monoallelic and biallelic CHEK2 PVs.

METHODS

CHEK2 PV carriers were identified through commercial hereditary cancer panel testing (09/2013-07/2019). We compared cancer histories of 6473 monoallelic carriers to 31 biallelic carriers. Breast cancer risks were estimated using multivariate logistic regression and are reported as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Breast cancer frequency was higher among biallelic CHEK2 PV carriers (80.6%, 25/31) than monoallelic carriers (41.2%, 2668/6473; p < 0.0001). Biallelic carriers were more likely to be diagnosed at or before age 50 (61.3%, 19/31) and to have a second breast cancer diagnosis (22.6%, 7/31) compared to monoallelic carriers (23.9%, 1548/6473; p < 0.0001 and 8.1%, 523/6473; p = 0.0107, respectively). Proportionally more biallelic carriers also had any cancer diagnosis and > 1 primary diagnosis. Compared to women with no PVs, biallelic PV carriers had a higher risk of developing ductal invasive breast cancer (OR 8.69, 95% CI 3.69-20.47) and ductal carcinoma in situ (OR 4.98, 95% CI 2.00-12.35) than monoallelic carriers (OR 2.02, 95% CI 1.90-2.15 and OR 1.82, 95% CI 1.66-2.00, respectively).

CONCLUSIONS

These data suggest that biallelic CHEK2 PV carriers have a higher risk for breast cancer, are more likely to be diagnosed younger, and to have multiple primary breast cancers compared to monoallelic carriers. Biallelic carriers also appear to have a higher risk of cancer overall. Therefore, more aggressive management may be appropriate for women with biallelic PVs in CHEK2 compared with current recommendations for monoallelic carriers.

Hereditary prostate cancer - Primetime for genetic testing?

Prostate cancer (PCa) remains the most common cancer in men. The proportion of all PCa attributable to high-risk hereditary factors has been estimated to 5-15%. Recent landmark discoveries in PCa genetics led to the identification of germline mutations/alterations (eg. BRCA1, BRCA2, ATM or HOXB13), single nucleotide polymorphisms or copy number variations associated with PCa incidence and progression. However, offering germline testing to men with an assumed hereditary component is currently controversial. In the present review article, we provide an overview about the epidemiology and the genetic basis of PCa predisposition and critically discuss the significance and consequence in the clinical routine. In addition, we give an overview about genetic tests and report latest findings from ongoing clinical studies. Lastly, we discuss the impact of genetic testing in personalized therapy in advanced stages of the disease.