High prevalence of DNA damage repair gene defects and TP53 alterations in men with treatment-naïve metastatic prostate cancer -Results from a prospective pilot study using a 37 gene panel

BACKGROUND

Defects in DNA damage repair genes characterize a subset of men with prostate cancer and provide an attractive opportunity for precision oncology approaches. The prevalence of such perturbations in newly diagnosed, treatment-naïve patients with a high risk for lethal disease outcome, however, has not been sufficiently explored.

PATIENTS AND METHODS

Prostate cancer specimens from 67 men with newly diagnosed early onset, localized high-risk/locally advanced or metastatic prostate cancer were included in this prospective pilot study. Tumor samples, including 30 prostate biopsies, were analyzed by targeted next generation sequencing using a formalin-fixed, paraffin-embedded tissue-optimized 37 DNA damage repair and checkpoint gene panel.

RESULTS

The drop-out rate due to an insufficient quantity of DNA was 4.5% (3 of 67 patients). In the remaining 64 patients, the rate of pathogenic DNA damage repair gene mutations was 26.6%. The highest rate of pathogenic DNA damage repair and checkpoint gene mutations was found in men with treatment-naïve metastatic prostate cancer (38.9%). In addition, a high number of likely pathogenic mutations and gene deletions were detected. Altogether, one or more pathogenic mutation, likely pathogenic mutation or gene deletion affected 43 of 64 patients (67.2%) including 29 of 36 patients (80.6%) with treatment-naïve metastatic prostate cancer. Men with metastatic prostate cancer showed a high prevalence of alterations in TP53 (36.1%).

CONCLUSIONS

This pilot study demonstrates the feasibility, performance and clinical relevance of somatic targeted next generation sequencing using a unique 37 DNA damage repair and checkpoint gene panel under routine conditions. Our results indicate that this approach can detect actionable DNA repair gene alterations, uncommon mutations as well as mutations associated with therapy resistance in a high number of patients, in particular patients with treatment-naïve metastatic prostate cancer.

Low frequency of mismatch repair deficiency in gallbladder cancer

Background

DNA mismatch repair (MMR) deficiency is a major pathway of genomic instability in cancer. It leads to the accumulation of numerous mutations predominantly at microsatellite sequences, a phenotype known as microsatellite instability (MSI). MSI tumors have a distinct clinical behavior and commonly respond well to immune checkpoint blockade, irrespective of their origin. Data about the prevalence of MSI among gallbladder cancer (GBC) have been conflicting. We here analyzed a well-characterized cohort of 69 Western-world GBCs.

Methods

We analyzed the mononucleotide MSI marker panel consisting of BAT25, BAT26, and CAT25 to determine the prevalence of MMR deficiency-induced MSI.

Results

MSI was detected in 1/69 (1.4%) of analyzed GBCs. The detected MSI GBC had a classical histomorphology, i.e. of acinar/tubular/glandular pancreatobiliary phenotype, and showed nuclear expression of all four MMR proteins MLH1, MSH2, MSH6, and PMS2. The MSI GBC patient showed a prolonged overall survival, despite having a high tumor stage at diagnosis. The patient had no known background or family history indicative of Lynch syndrome.

Conclusions

Even though the overall number of MSI tumors is low in GBC, the potentially therapeutic benefit of checkpoint blockade in the respective patients may justify MSI analysis of GBC.

Electronic supplementary material

The online version of this article (10.1186/s13000-019-0813-5) contains supplementary material, which is available to authorized users.

Mismatch repair deficiency is a rare but putative therapeutically relevant finding in non-liver fluke associated cholangiocarcinoma

Background

A major molecular pathway of genetic instability in cancer is DNA mismatch repair deficiency. High-level microsatellite instability (MSI-H) is currently the best predictor of responsiveness towards immune checkpoint blockade. Data about the prevalence of high-level microsatellite instability in cholangiocarcinoma (CCA) has been conflicting.

Methods

We employed a cohort comprising 308 Western-world, non-liver fluke-associated CCAs (159 intrahepatic, 106 perihilar, and 43 distal). We analysed the mononucleotide microsatellite instability marker panel consisting of BAT25, BAT26, and CAT25 and detected MSI-H in 4/308 CCAs (1.3%).

Results

Patients affected by MSI-H CCA had mostly an atypical histomorphology (p = 0.004), showed a longer overall survival, although having a high tumour stage, and were of younger age. Correlation analysis of microsatellite instability status with tumour-infiltrating immune cells, MHC I, and PD-L1 expression in the same cholangiocarcinoma cohort showed higher numbers of CD8 + T cells, FOXP3 + regulatory T cells, CD20 + B cells and high or at least moderate MHC I expression levels in MSI-H CCAs.

Conclusions

Even though the overall number of MSI-H CCAs is low, the dismal prognosis of the disease and the therapeutic option of immune checkpoint blockade in the respective patients justify MSI testing of cholangiocarcinoma, particularly in younger patients showing an atypical histomorphology.

Successful immune checkpoint blockade in a patient with advanced stage microsatellite-unstable biliary tract cancer

Cancers acquire multiple somatic mutations that can lead to the generation of immunogenic mutation-induced neoantigens. These neoantigens can be recognized by the host's immune system. However, continuous stimulation of immune cells against tumor antigens can lead to immune cell exhaustion, which allows uncontrolled outgrowth of tumor cells. Recently, immune checkpoint inhibitors have emerged as a novel approach to overcome immune cell exhaustion and reactivate antitumor immune responses. In particular, antibodies blocking the exhaustion-mediating programmed death receptor (PD-1)/programmed death receptor ligand (PD-L1) pathway have shown clinical efficacy. The effects were particularly pronounced in tumors with DNA mismatch repair (MMR) deficiency and a high mutational load, which typically occur in the colon and endometrium. Here, we report on a 24-yr-old woman diagnosed with extrahepatic cholangiocarcinoma who showed strong and durable response to the immune checkpoint inhibitor pembrolizumab, although treatment was initiated at an advanced stage of disease. The patient's tumor displayed DNA MMR deficiency and microsatellite instability (MSI) but lacked other features commonly discussed as predictors of response toward checkpoint blockade, such as PD-L1 expression or dense infiltration with cytotoxic T cells. Notably, high levels of HLA class I and II antigen expression were detected in the tumor, suggesting a potential causal relation between functionality of the tumor's antigen presentation machinery and the success of immune checkpoint blockade. We suggest determining MSI status in combination with HLA class I and II antigen expression in tumors potentially eligible for immune checkpoint blockade even in the absence of conventional markers predictive for anti-PD-1/PD-L1 therapy and in entities not commonly linked to the MSI phenotype. Further studies are required to determine the value of these markers for predicting the success of immune checkpoint blockade.

[Durable remission under dual HER2 blockade with Trastuzumab and Pertuzumab in a patient with metastatic gallbladder cancer]

Gallbladder cancer represents a rare but dismal disease. The only curative option is complete surgical resection, though patients often develop recurrent disease. In patients with advanced biliary tract cancer, the combination of cisplatin and gemcitabine showed a benefit in overall survival compared to gemcitabine alone. However, there is no standardized second-line regimen after treatment failure. We report on a young patient with early recurrence of a gallbladder cancer with cutaneous and peritoneal metastases. Upon identification of an ERBB2 gene amplification within the NCT MASTER (Molecularly Aided Stratification for Tumor Eradication Research) exome sequencing program with resulting overexpression of HER2 in the tumors cells, the patient received a targeted therapy with the HER2 antibodies pertuzumab and trastuzumab in combination with nab-paclitaxel, which led to a durable remission for more than one year. This case report underlines the potential of molecularly aided personalized targeted therapy for patients with biliary tract cancer and the need for respective clinical trials.

Detected, yet not Diagnosed - Breast Cancer Screening with MRI Mammography in High-Risk Women

BACKGROUND: MRI has been demonstrated to be the most sensitive imaging method for detecting breast cancer in women at high risk, allowing depiction of cancers that are occult on mammography, ultrasound and clinical breast examination. This high sensitivity is tempered by imperfect specificity due to overlap in the features of benign and malignant lesions. CASE: We present the case of a young BRCA2 mutation carrier whose breast cancer could have been diagnosed 2 years earlier; this is a rare case of a false-negative finding in MRI. DISCUSSION: We discuss morphological, physiological and psychological reasons for underestimation of MRI sets, especially in young women. CONCLUSION: We conclude that double reading in MR screening for breast cancer in high-risk women, as conducted for mammography screening, could be considered.

Do reexcisions impair aesthetic outcome in breast conservation surgery? Exploratory analysis of a prospective cohort study

PURPOSE

Reexcision is a clinically relevant aspect of oncological breast conservation surgery. The influence of reexcision on aesthetic outcome is described differently in the literature. Our aim was to analyze this question in a well-defined cohort with standardized study instruments.

METHODS

A total of 439 patients from a prospectively followed cohort were included in this analysis. Aesthetic results were assessed by the Breast Cancer Treatment Outcome Scale (BCTOS) aesthetic status. Dates of assessments were shortly after surgical interventions and before surgery. Group comparison was performed between patients with reexcisions (80 cases; 18%) and patients without reexcision (359 cases; 82%). We considered variables of differing distribution between the two groups that could hypothetically influence BCTOS aesthetic status in a nonparametric analysis of covariance (ANCOVA).

RESULTS

The aesthetic status of patients with reexcisions was found to be significantly worse than for patients with a single breast conservation surgery (P < 0.0001) when tested by a nonparametric ANCOVA model. Because patients with reexcisions had more noninvasive tumors (25% vs. 8%, P = 0.0001) and tumors were larger in patients with reexcision (P = 0.01), we included these variables as possible covariates in the multivariate model. The model was adjusted for the BCTOS aesthetic status before and shortly after the first surgery.

CONCLUSIONS

Our findings suggest that reexcision in breast conservation surgery impairs aesthetic outcome, at least when assessed shortly after surgery.

Low activity of the classical complement pathway predicts short survival of patients with chronic lymphocytic leukaemia

The activities of the classical (CP) and alternative (AP) complement pathways as well as the levels of some complement components and circulating immune complexes were measured in 43 patients with chronic lymphocytic leukaemia (CLL) between 1980 and 1984. Depressed CP activities were frequently found in these patients. Clinical course of the disease in the patients was followed until 1992, and compared with the initial complement values. During the follow-up period 36 patients died, death of 33 patients being related to the underlying disease. A strong positive correlation (P < 0.01) was found between the length of survival of the patients and the initial CP values. Patients were divided into two groups: group A, short-term survivors, i.e patients who died in CLL-related complications within 3 years after the complement measurements; and group B, long-term survivors who died > or = 4 years after the complement measurements due to any cause, or were alive at the end of the follow-up period. Average CP values in Group B were almost twice those in group A (P = 0.002), and a similar but less pronounced difference was found in C3 levels (P = 0.055). These differences were even more marked (P = 0.0006 and P = 0.0015, respectively) when only patients in Rai stage 2 and 3 were considered. Low classical pathway activities predicted short survival time: according to the logrank test, patients in Rai stage 2-3 with low (< mean - 2s.d. of the normal values), and normal CP levels survived for 2.0 +/- 1.1, and 4.6 +/- 3.0 years, respectively. All the nine and 11/13 patients with low CP and C4 levels, respectively, died within 3 years after the complement measurements were made. These findings indicate that complement measurements performed in CLL patients have a clinical value.

[Calcipenic osteopathy in transfusion hemosiderosis and idiopathic hemochromatosis]

Bone metabolism studies were performed on 5 patients with transfusion haemosiderosis (2 male, 3 female; mean age: 30.8 years) and 5 patients with idiopathic haemochromatosis (2 male, 3 female; mean age: 48.8 years). In the majority of the patients, the modern osteodensitometric method showed a significant decrease of the mineral content of the trabecular and cortical bones. Low calcitonin and dehydroepiandrosterone-sulphate concentrations were measured in the majority of the patients with calcipenic osteopathy. Besides marked bone loss, hypogonadotropic hypogonadism was found in 3 male patients, while normal LH, FSH concentration values were measured in 3 female patients. The prolactin concentration was normal in all 6 patients. The authors suppose that besides the already known pathogenetic factors, insufficient calcitonin effect and especially the partial lack of dehydroepiandrosterone-sulphate can play a role in the development of bone loss connected with iron overload. Further study with a greater number of patients in required to support the above findings.

[Correlation of HLA antigens and idiopathic hemochromatosis in Hungary]

The aim of our present work was to collect data on HLA distribution in patients with idiopathic haemochromatosis in Hungary. Ten unrelated patients with idiopathic haemochromatosis (6 men, 4 women) were studied. Idiopathic haemochromatosis was diagnosed on clinical, biochemical and histological grounds. HLA typing was performed in 10 probands and in all of their first degree relatives available (24) through 7 pedigree studies. HLA A3 was present in 6 of 10 probands [6/10 vs. 18.8% in the group of healthy blood donors (No 53) and 22.4% in Hungarian population (No 1910]. HLA B7 was present in 4 of 10 probands (40% vs. 11.3% and 14.6%). A3B7 antigen association has been found in 4 of 10 patients. A3B7 and A2B38 haplotypes were present twice in 4 of 7 genotyped probands. Pedigree studies revealed one nonaffected homozygote, 17 heterozygotes and 6 non carriers. Extended family and population studies are necessary to establish the gene frequency in Hungary and the probability of the involved haplotypes other than A3B7.

C1 and C4 abnormalities in chronic lymphocytic leukaemia and their significance

Clinical and laboratory correlations of low C1 and C4 levels previously found to be a characteristic feature of chronic lymphocytic leukaemia (CLL) were analysed. Abnormalities of C4 were restricted to stage 1, 2 and 3 of CLL, whereas in the more advanced disease (stage 4) only low C1 levels were found. It was demonstrated that the observed disorders were associated with an increased susceptibility of the patients for infections and impair the immune complex precipitation inhibiting capacity of the patients' sera as well.

Depressed classical complement pathway activities in chronic lymphocytic leukaemia

Haemolytic activities of the classical and alternative complement pathways, and levels of C1, C4, C3, factor B and C1 inhibitor (C1-INH) were measured in 85 serum samples from 46 patients with chronic lymphocytic leukaemia (CLL). Significantly decreased mean C1 and C4 levels were found, and the haemolytic activities of these components were low or low normal in more than 50% of the sera tested. In 15 sera from 5 patients a complement profile characteristic of acquired C1-IHN deficiency was observed. These results indicate that the depression of the activity of the classical complement pathway is a frequently occurring feature in CLL.

Serial complement measurements in patients with leukaemia

Haemolytic activity of the classical and alternative pathways and the levels of C4, C3 and factor B were serially measured in 153 serum samples of 41 patients with different types of leukaemia (9 AML, 14 ALL, 10 CML and 8 CLL). In parallel, the concentration of circulating immune complexes (CIC) was estimated using two methods, the complement consumption assay and the Clq-solubility test. Different complement profiles were found in different types of leukaemia. In AML, each complement parameter tested was elevated as compared to the control values (sera of healthy blood donors). Similar results were observed in ALL, although the differences were less marked. In CML, dissociation of the classical and alternative pathway activities was found: activities of the classical pathway and C4 were significantly elevated, whereas activity of the alternative pathway as well as C3 and factor B concentration did not differ significantly from the control values. In CLL, normal or slightly depressed complement levels were found. The concentration of circulating immune complexes measured by both methods was significantly increased as compared to control values. No significant positive or negative correlations were found between the complement levels and the immune complex concentrations determined in the same sera. An association between the clinical course of acute leukaemia and the complement levels was observed: significantly elevated complement titres were found in the blastic stage of the disease, whereas in remission normal values were recorded. The results of complement measurements performed in serum samples obtained before and after combination chemotherapy were compared on 32 occasions. In parallel to a significant decrease in the absolute number of blast cells in the peripheral blood, a normalization of the increased complement levels was observed after treatment.