First case report of Muir–Torre syndrome associated with non-small cell lung cancer

Microsatellite Instability and Mismatch Repair Deficiency Define a Distinct Subset of Lung Cancers Characterized by Smoking Exposure, High Tumor Mutational Burden, and Recurrent Somatic MLH1 Inactivation

INTRODUCTION

Microsatellite instability (MSI) and mismatch repair (MMR) deficiency represent a distinct oncogenic process and predict response to immune checkpoint inhibitors (ICIs). The clinicopathologic features of MSI-high (MSI-H) and MMR deficiency (MMR-D) in lung cancers remain poorly characterized.

METHODS

MSI status from 5171 patients with NSCLC and 315 patients with SCLC was analyzed from targeted next-generation sequencing data using two validated bioinformatic pipelines.

RESULTS

MSI-H and MMR-D were identified in 21 patients with NSCLC (0.41%) and six patients with SCLC (1.9%). Notably, all patients with NSCLC had a positive smoking history, including 11 adenocarcinomas. Compared with microsatellite stable cases, MSI-H was associated with exceptionally high tumor mutational burden (37.4 versus 8.5 muts/Mb, p < 0.0001), MMR mutational signatures (43% versus 0%, p < 0.0001), and somatic biallelic alterations in MLH1 (52% versus 0%, p < 0.0001). Loss of MLH1 and PMS2 expression by immunohistochemistry was found in MLH1 altered and wild-type cases. Similarly, the majority of patients with MSI-H SCLC had evidence of MLH1 inactivation, including two with MLH1 promoter hypermethylation. A single patient with NSCLC with a somatic MSH2 mutation had Lynch syndrome as confirmed by the presence of a germline MSH2 mutation. Among patients with advanced MSI-H lung cancers treated with ICIs, durable clinical benefit was observed in three of eight patients with NSCLC and two of two patients with SCLC. In NSCLC, STK11, KEAP1, and JAK1 were mutated in nonresponders but wild type in responders.

CONCLUSIONS

We present a comprehensive clinicogenomic landscape of MSI-H lung cancers and reveal that MSI-H defines a rare subset of lung cancers associated with smoking, high tumor mutational burden, and MLH1 inactivation. Although durable clinical benefit to ICI was observed in some patients, the broad range of responses suggests that clinical activity may be modulated by co-mutational landscapes.

Squamous Cell Carcinoma of the Lung With Microsatellite Instability in a Patient With Lynch Syndrome: A Case Report

Lynch syndrome is the most common autosomal dominant inherited cancer predisposing syndrome, due to mutations in DNA mismatch repair genes. The key feature of cancers in Lynch syndrome is microsatellite instability and a high risk of developing mainly colorectal and uterine cancers. However, cancers with microsatellite instability outside this spectrum, for example, lung cancer, are extremely rare. Here, we report a case of squamous cell carcinoma of the lung with microsatellite instability in a patient with Lynch syndrome.

Lung Cancer in Patients With Lynch Syndrome: Association or Coincidence?

Lynch syndrome (LS), also known as hereditary nonpolyposis colorectal cancer (HNPCC) occurs due to microsatellite instability (MSI) caused by mutations in one of the mismatch repair genes leading to deficient mismatch repair proteins (dMMR). Although lung cancer is very common there is no established association between LS and lung cancer. In this manuscript we describe a case of lung cancer in a LS patient and then summarize available literature on this topic. Sixty seven y/o female patient with history of stage I colon and urothelial cancer, meeting the Amsterdam criteria, was diagnosed with LS on genetic testing. Sixteen years after the diagnosis of colon cancer, she was found to have adenocarcinoma of the lung with Next-generation sequencing (NGS) testing revealing the presence of germline mutation in MSH2 in the tumor cells indicating the possibility of LS driven lung cancer. However, subsequent immunohistochemistry (IHC) on tumor cells indicated proficient mismatch repair genes confirming the sporadic nature of lung cancer. On review of literature, we found that the coincidental presence of lung cancer in patients with LS can sometimes be mistaken for causation and may lead to confusion. Lynch syndrome associated tumors which are microsatellite instable (MSI) can be treated effectively with immunotherapy with durable responses, however, not all tumors in patient with LS are MSI impacting the choice of therapy.

Lung adenocarcinoma in a patient with Lynch syndrome: a case report and literature review

This article presents a case of a 62-year-old Vietnamese woman with a history of Lynch syndrome (LS), who developed lung adenocarcinoma with EGFR L858R mutation. LS is an autosomal dominant cancer predisposition syndrome caused by a pathogenic germline variant in DNA mismatch repair genes, often leading to microsatellite instability. While LS is primarily associated with gastrointestinal, endometrial, ovarian, and urologic tract cancers, lung cancer accounts for less than 1% of LS-related cancers, with only six cases of LS-related lung cancer previously reported in the literature. The patient underwent multiple lines of treatment for her lung adenocarcinoma, including tyrosine kinase inhibitors, stereotactic body radiation therapy, pemetrexed and pembrolizumab, amivantamab, and fam-trastuzumab deruxtecan, but all resulted in only a partial response followed by a progressive disease. This case highlights the complex interplay of genetic cancer predisposition syndromes and the development of spontaneous driver mutations in the disease course and the subsequent management of tumors arising in these patients.

Genomic characteristics and prognosis of lung cancer patients with MSI-H: A cohort study

BACKGROUND

Microsatellite instability (MSI) is the first pan-cancer biomarker approved to guide immune checkpoint inhibitor therapy for MSI-high (MSI-H) solid tumors. In lung cancer, the MSI-H frequency is very low, and the genetic characteristics and prognosis of lung cancer with MSI-H were rarely reported.

METHODS

Next-generation sequencing and immunohistochemistry were used detect MSI status, tumor mutation burden (TMB) and PD-L1 expression.

RESULTS

Among 12,484 lung cancer patients screened, 66 were found with MSI-H, the proportion was as low as 0.5%. Compared with Microsatellite stability (MSS), TMB was higher in MSI-H lung cancer patients, while PD-L1 expression showed no considerable difference between MSI-H and MSS. After propensity score matching, compared with MSS, the most common companion mutations in MSI-H were TP53, BRCA2, TGFBR2, PTEN and KMT2C. In MSI-H lung adenocarcinoma with EGFR mutation, TGFBR2 and ERBB2 had higher mutation frequency than in MSS.

CONCLUSION

The current study reveals the genetic characteristics of MSI-H lung cancer, which advanced our understanding of MSI-H lung cancer.

Second Primary Neoplasms in Patients With Sebaceous Carcinoma of the Eyelid: A Population-based Study, 2000 to 2016

PURPOSE

To investigate the risk of second primary neoplasms (SPNs) after primary sebaceous carcinoma of the eyelid (SCE).

METHODS

Data on patients diagnosed with primary SCE as their first malignancy were extracted from the Surveillance, Epidemiology, and End Results database from 2000 to 2016. Observed-to-expected ratios of SPNs were calculated to estimate standardized incidence ratios (SIRs). Patients were compared with a reference population (RP) matched for age, gender, and race.

RESULTS

Five hundred fifty-nine patients with primary SCE were identified, 16% of whom developed SPNs. SCE patients displayed a 61% increased risk of developing SPNs compared with the RP (p < 0.001). Overall, the risk of SPNs of the lungs (SIR = 1.82; p < 0.05), pancreas (SIR = 2.94; p < 0.05), salivary glands (SIR = 41.65; p < 0.001), and skin (SIR = 8.33; p < 0.05) was elevated. Only non-Hispanic Whites were at an increased risk (SIR = 1.51; p < 0.05). Patients 40-54 years old at the time of diagnosis were at the highest risk of developing SPNs compared with the RP (SIR = 3.15; p < 0.05). Women with SCE experienced an increased risk of breast cancer (SIR = 3.6; p < 0.05) and chronic lymphocytic leukemia (SIR = 8.8; p < 0.01).

CONCLUSION

SCE patients are more likely to develop SPNs of the lungs, pancreas, salivary gland, and skin than the RP. Forty to fifty-four years old Caucasian patients are at the highest risk. Women are at an increased risk of developing breast malignancies and chronic lymphocytic leukemia. Clinicians should be cognizant of these risks when managing SCE patients.

Case Report and Literature Review: Diagnosis, Tailored Genetic Counseling and Cancer Prevention for a Locally Advanced dMMR/MSI-H/TMB-H Lung Cancer Patient With Concurrent Lynch Syndrome Mediated by a Rare PMS2 Splicing Variant (c.1144+1G>A)

Lynch syndrome (LS) is a cancer-predisposing genetic disease mediated by pathogenic mutations in DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, and PMS2. Accumulating evidence demonstrates that there is significant biological heterogeneity across MMR genes. Compared to MLH1 and MSH2, PMS2 variant carriers have a much lower risk for LS-related cancers. Tumors in MLH1 and MSH2 variant carriers often display MMR deficiency (dMMR) and/or high microsatellite instability (MSI-H), two predictive biomarkers for immunotherapy efficacy. However, tumors in PMS2 variant carriers are largely microsatellite stable (MSS) instead of MSI. Therefore, the optimal management of cancer patients with LS requires the integration of disease stage, MMR gene penetrance, dMMR/MSI status, and tumor mutational burden (TMB). In this work, we presented a locally advanced lung cancer patient with dMMR/MSI-H/TMB-H tumor and selective loss of PMS2 by immunohistochemistry. Germline testing revealed a rare PMS2 splicing variant (c.1144+1G>A) in the proband and his healthy daughter. The diagnosis of LS was made based on genetic analysis of this variant and literature review. Given the incomplete penetrance of PMS2, the proband and the carrier received tailored genetic counseling. To reduce cancer risk, the proband received four cycles of nivolumab plus chemotherapy and achieved a disease-free survival of sixteen months.

Germline mutations in lung cancer

Genetic testing for alterations in oncogenic driver genes has become essential and standard in the clinical practice of the treatment of lung cancer. Germline mutations potentially predisposing patients to lung cancer are rare; however, with the introduction of next-generation sequencing in the clinical practice of lung cancer, the identification of potentially predisposing germline abnormalities is becoming more common. In addition, liquid biopsy, which analyzes cell-free DNA in blood, increases the possibility of detecting these germline mutations. In this review, we summarize the germline mutations detected in lung cancer patients and briefly describe the future perspectives.

Towards gene- and gender-based risk estimates in Lynch syndrome; age-specific incidences for 13 extra-colorectal cancer types

Background:

In Lynch syndrome, inherited mismatch repair (MMR) defects predispose to colorectal cancer and to a wide spectrum of extra-colorectal tumours. Utilising a cohort study design, we aimed to determine the risk of extra-colorectal cancer and to identify yet unrecognised tumour types.

Methods:

Data from 1624 Lynch syndrome mutation carriers in the Danish hereditary non-polyposis colorectal cancer register were used to estimate the sex- and age-specific incidence rate ratios (IRRs) for 30 extra-colorectal malignancies with comparison to the general population.

Results:

Significantly increased IRRs were identified for 13 cancer types with differences related to gender, age and disease-predisposing gene. The different cancer types showed variable peak age incidence rates (IRs) with the highest IRs for ovarian cancer at age 30–49 years, for endometrial cancer, breast cancer, renal cell cancer and brain tumours at age 50–69 years, and for urothelial cancer, small bowel cancer, gastric cancer, pancreatic cancer and skin tumours after age 70.

Conclusions:

The broad spectrum of tumour types that develop at an increased incidence defines Lynch syndrome as a multi-tumour syndrome. The variable incidences in relation to age, gender and gene suggest a need for individualised surveillance.

Muir-Torre syndrome (MTS): An update and approach to diagnosis and management

Muir-Torre syndrome (MTS) is a rare genetic condition that predisposes individuals to skin tumors and visceral malignancies. Because of the potentially aggressive nature of internal malignancies and sebaceous carcinoma, and the tendency to have multiple low-grade visceral cancers, close cancer surveillance is required in individuals and their families with this usually autosomal dominant disorder. Although the majority of MTS is caused by mutations in DNA mismatch repair genes resulting in microsatellite instability, a newly described subtype of MTS does not demonstrate microsatellite instability and may be inherited in an autosomal recessive pattern. In addition, MTS may be unmasked in transplant recipients taking specific immunosuppressant drugs or other immunosuppressed patients. Neoplasms may be subject to immunohistochemistry or both immunohistochemistry and genetic testing to confirm the diagnosis of MTS. Here, we offer an update and an approach to the diagnosis and management of MTS with a particular emphasis on the role of immunohistochemistry and genetic testing.

Germline mutations predisposing to non-small cell lung cancer

Lung cancer in multiple first degree relatives had previously been attributed to smoking and to inherited enzymes associated with increased activation of carcinogens in smoke. There was not clear agreement on the significance of the testing methods for lung cancer susceptibility. More recent studies have identified germline mutations associated with lung cancer even in the absence of smoking and other mutations with plausible explanations for their association with lung cancer caused by smoking. At this time, the clinical significance of the various germline mutations for screening and the implications for therapy are not certain. This review summarizes the currently identified germline mutations associated with lung cancer, but this growing area of research will very likely identify further significant mutations as well.

Lynch syndrome-associated neoplasms: a discussion on histopathology and immunohistochemistry

It was a century ago that Warthin, a pathologist, first described the clinical condition now known as Lynch syndrome. One hundred years later, our understanding of this syndrome has advanced significantly. Much of the progress took place over the last 25 years and was marked by a series of interacting developments from the disciplines of clinical oncology, pathology, and molecular genetics, with each development serving to guide or enhance the next. The advancement of our understanding about the pathology of Lynch syndrome associated tumors exemplifies such intimate interplay among disciplines. Today, accumulative knowledge has enabled surgical pathologists to detect tumors that are likely to be associated with Lynch syndrome, and the pathologist is playing an increasingly more important role in the care of these patients. The pathologist's ability is afforded primarily by information gained from tumor histopathology and by DNA mismatch repair protein immunohistochemistry. It is therefore pertinent both for the pathologists to accurately ascertain this morphologic information, and for all that are involved in the care of these patients to thoroughly understand the implications of such information. This article provides an overview of the development of histopathology and immunohistochemistry in Lynch syndrome-associated tumors, particularly in colorectal and endometrial cancers, and outlines the issues and current status of these specific pathologic aspects in not only the major tumors but also those less commonly seen or only newly reported in Lynch syndrome patients.

Unusual DNA mismatch repair-deficient tumors in Lynch syndrome: a report of new cases and review of the literature

Immunohistochemical detection of DNA mismatch repair proteins and polymerase chain reaction detection of microsatellite instability have enhanced the recognition of mismatch repair-deficient neoplasms in patients with Lynch syndrome and, consequently, led to the identification of tumors that have not been included in the currently known Lynch syndrome tumor spectrum. Here, we report 4 such unusual tumors. Three of the 4, a peritoneal mesothelioma, a pancreatic acinar cell carcinoma, and a pancreatic well-differentiated neuroendocrine tumor, represented tumor types that, to the best of our knowledge, have not been previously reported in Lynch syndrome. The fourth tumor was an adrenocortical carcinoma, which has rarely been reported previously in Lynch syndrome. Three of our 4 patients carried a pathogenic germ-line mutation in a mismatch repair gene. The unusual tumor in each of the 3 patients showed loss of the mismatch repair protein corresponding to the mutation. The fourth patient did not have mutation information but had a history of colonic and endometrial carcinomas; both lacked MSH2 and MSH6 proteins. Interestingly, none of the 4 unusual tumors revealed microsatellite instability on polymerase chain reaction testing, whereas an appendiceal carcinoma from 1 of the study patients who was tested simultaneously did. The recognition of such tumors expands the repertoire of usable test samples for the workup of high-risk families. As yet, however, there are no data to support the inclusion of these tumors into general screening guidelines for detecting Lynch syndrome, nor are there data to warrant surveillance for these tumors in patients with Lynch syndrome.

Pulmonary sclerosing hemangioma in a 21-year-old male with metastatic hereditary non-polyposis colorectal cancer: report of a case

Background

Pulmonary sclerosing hemangioma (SH) is a rare tumor of the lung predominantly affecting Asian women in their fifth decade of life. SH is thought to evolve from primitive respiratory epithelium and mostly shows benign biological behavior; however, cases of lymph node metastases, local recurrence and multiple lesions have been described.

Case Presentation

We report the case of a 21-year-old Caucasian male with a history of locally advanced and metastatic rectal carcinoma (UICC IV; pT4, pN1, M1(hep)) that was eventually identified as having hereditary non-polyposis colorectal cancer (HNPCC, Lynch syndrome). After neoadjuvant chemotherapy followed by low anterior resection, adjuvant chemotherapy and metachronous partial hepatectomy, he was admitted for treatment of newly diagnosed bilateral pulmonary metastases. Thoracic computed tomography showed a homogenous, sharply marked nodule in the left lower lobe. We decided in favor of atypical resection followed by systematic lymphadenectomy. Histopathological analysis revealed the diagnosis of SH.

Conclusions

Cases have been published with familial adenomatous polyposis (FAP) and simultaneous SH. FAP, Gardner syndrome and Li-Fraumeni syndrome, however, had been ruled out in the present case. To the best of our knowledge, this is the first report describing SH associated with Lynch syndrome.