Non-classic EGFR mutations in a cohort of Dutch EGFR-mutated NSCLC patients and outcomes following EGFR-TKI treatment

BACKGROUND

Data on non-small-cell lung cancer (NSCLC) patients with non-classic epidermal growth factor receptor (EGFR) mutations are scarce, especially in non-Asian populations. The purpose of this study was to evaluate prevalence, clinical characteristics and outcome on EGFR-TKI treatment according to type of EGFR mutation in a Dutch cohort of NSCLC patients.

METHODS

We retrospectively evaluated a cohort of 240 EGFR-mutated NSCLC patients. Data on demographics, clinical and tumour-related features, EGFR-TKI treatment and clinical outcome were collected and compared between patients with classic EGFR mutations, EGFR exon 20 insertions and other uncommon EGFR mutations.

RESULTS

Classic EGFR mutations were detected in 186 patients (77.5%) and non-classic EGFR mutations in 54 patients (22.5%); 23 patients with an exon 20 insertion (9.6%) and 31 patients with an uncommon EGFR mutation (12.9%). Median progression-free survival (PFS) and overall survival (OS) on EGFR-TKI treatment were 2.9 and 9.7 months, respectively, for patients with an EGFR exon 20 insertion, and 6.4 and 20.2 months, respectively, for patients with an uncommon EGFR mutation. Patients with a double uncommon EGFR mutation that included G719X/L861Q/S768I had longer PFS and OS on EGFR-TKI treatment compared with patients with a single G719X/L861Q/S768I EGFR mutation (both P=0.02).

CONCLUSIONS

In our Dutch cohort, prevalence and genotype distribution of non-classic EGFR mutations were in accordance with previously reported data. The PFS and OS on EGFR-TKI treatment in patients with an uncommon EGFR mutation were shorter compared with patients with classic EGFR mutations, but varied among different uncommon EGFR mutations.

Risk of spontaneous pneumothorax due to air travel and diving in patients with Birt-Hogg-Dubé syndrome

Background and objectives

Birt–Hogg–Dubé syndrome is an autosomal dominant disorder characterized by skin fibrofolliculomas, lung cysts, spontaneous pneumothorax and renal cell cancer due to germline folliculin (FLCN) mutations (Menko et al. in Lancet Oncol 10(12):1199–1206, 2009). The aim of this study was to evaluate the incidence of spontaneous pneumothorax in patients with BHD during or shortly after air travel and diving.

Methods

A questionnaire was sent to a cohort of 190 BHD patients and the medical files of these patients were evaluated. The diagnosis of BHD was confirmed by FLCN mutations analysis in all patients. We assessed how many spontaneous pneumothoraces (SP) occurred within 1 month after air travel or diving.

Results

In total 158 (83.2 %) patients returned the completed questionnaire. A total of 145 patients had a history of air travel. Sixty-one of them had a history of SP (42.1 %), with a mean of 2.48 episodes (range 1–10). Twenty-four (35.8 %) patients had a history of pneumothorax on both sides. Thirteen patients developed SP < 1 month after air travel (9.0 %) and two patients developed a SP < 1 month after diving (3.7 %). We found in this population of BHD patients a pneumothorax risk of 0.63 % per flight and a risk of 0.33 % per episode of diving. Symptoms possible related to SP were perceived in 30 patients (20.7 %) after air travel, respectively in ten patients (18.5 %) after diving.

Conclusion

Based on the results presented in this retrospective study, exposure of BHD patients to considerable changes in atmospheric pressure associated with flying and diving may be related to an increased risk for developing a symptomatic pneumothorax. Symptoms reported during or shortly after flying and diving might be related to the early phase of pneumothorax. An individualized advice should be given, taking also into account patients’ preferences and needs.

Is the current diagnostic algorithm reliable for selecting cases for EGFR- and KRAS-mutation analysis in lung cancer?

OBJECTIVES

Adenocarcinoma (ADC) of the lung may harbor EGFR- or KRAS-mutations, which are relevant for treatment decisions. There is no consensus on the percentages of EGFR- and KRAS-mutations that are allowed to be missed by a diagnostic algorithm, although a percentage of less than 1% for EGFR-mutations has been suggested. The current guidelines do not advise to perform EGFR-mutation analysis in unequivocal squamous cell carcinoma (SqCC). For KRAS-mutations no threshold for missing cases is suggested yet. To improve segregation between ADC and SqCC in small samples, the classification of lung cancer was updated in 2011, adding immunohistochemistry (IHC) for p63 and TTF-1 to the diagnostic algorithm. In this study we examined how many cases with an EGFR- or KRAS-mutation in our database would have been missed, if the current guideline for selecting cases for mutation analysis would have been applied.

MATERIALS AND METHODS

From an institutional lung cancer database of specimens analyzed for EGFR- and KRAS-mutations (n=816), cases harboring a mutation without being treated prior with an EGFR-TKI were selected (n=336). Corresponding original histological diagnoses and IHC for TTF-1, p63 and PAS-D were collected. Cases with SqCC on HE or with an IHC pattern favoring SqCC were reassessed according to the criteria of the 2011-classification.

RESULTS

From the 336 cases 70% had a KRAS-mutation and 30% an EGFR-mutation. The number of cases with SqCC on HE and/or an IHC-profile favoring SqCC was 12. After the reassessment six specimens (1.8%) would not have been tested for EGFR-/KRAS-mutations, if the current diagnostic algorithm had been used: 2.0% of EGFR-mutations and 1.7% KRAS-mutations. All six cases were NSCLC with an IHC-profile favoring SqCC.

CONCLUSION

Most NSCLC-cases with EGFR- and KRAS-mutations are selected by the current diagnostic algorithm. As a small but relevant fraction is missed, there is room for improvement.

DNA hypermethylation analysis in sputum for the diagnosis of lung cancer: training validation set approach

Background:

Lung cancer has the highest mortality of all cancers. The aim of this study was to examine DNA hypermethylation in sputum and validate its diagnostic accuracy for lung cancer.

Methods:

DNA hypermethylation of RASSF1A, APC, cytoglobin, 3OST2, PRDM14, FAM19A4 and PHACTR3 was analysed in sputum samples from symptomatic lung cancer patients and controls (learning set: 73 cases, 86 controls; validation set: 159 cases, 154 controls) by quantitative methylation-specific PCR. Three statistical models were used: (i) cutoff based on Youden's J index, (ii) cutoff based on fixed specificity per marker of 96% and (iii) risk classification of post-test probabilities.

Results:

In the learning set, approach (i) showed that RASSF1A was best able to distinguish cases from controls (sensitivity 42.5%, specificity 96.5%). RASSF1A, 3OST2 and PRDM14 combined demonstrated a sensitivity of 82.2% with a specificity of 66.3%. Approach (ii) yielded a combination rule of RASSF1A, 3OST2 and PHACTR3 (sensitivity 67.1%, specificity 89.5%). The risk model (approach iii) distributed the cases over all risk categories. All methods displayed similar and consistent results in the validation set.

Conclusions:

Our findings underscore the impact of DNA methylation markers in symptomatic lung cancer diagnosis. RASSF1A is validated as diagnostic marker in lung cancer.

Long-term follow-up after first-line bronchoscopic therapy in patients with bronchial carcinoids

BACKGROUND

Carcinoid of the lung is considered to be a low-grade malignancy. A subgroup presents as an endobronchial tumour. Surgical resection is considered the standard approach because of its metastatic potential and the possibility of an iceberg phenomenon for the endobronchial subgroup. Advances in non-invasive and minimally invasive technologies seem to justify a more lung parenchyma-sparing approach.

METHODS

In patients presenting with bronchial carcinoids, initial bronchoscopic treatment (IBT) is first attempted for complete tumour eradication and sufficient tissue sampling for the proper differentiation of typical (TC) versus atypical (AC) histological type. Furthermore in cases with postobstruction problems the desobstruction is aimed at improving the patient's condition and by that alleviate surgery if that is needed. High resolution CT is performed 6 weeks post IBT to determine local tumour growth. Surgical resection follows in case of extraluminal disease, residual carcinoid inaccessible for IBT, or late recurrences not salvaged by repeat IBT.

RESULTS

Minimum follow-up was 5 years from start of treatment for 112 patients (65 women, 47 men), with a median age of 47 years (range 16-77 years). Eighty-three patients (74%) had TC, and 29 (26%) AC. IBT only was ultimately curative in 42% of the cases (47/112): 42 TC, 5 AC. Disease-specific mortality including surgical mortality has been 2.6% (3/112) in patients with extraluminal carcinoids (3 AC).

CONCLUSIONS

IBT, if with unsuccessful rescue surgery, is justifiable with excellent long-term outcome. IBT made surgery unnecessary in 42% of the cases. Iceberg phenomenon and metastatic potential in this group of patients with bronchial carcinoids are clinically insignificant.

Detecting resistance in EGFR-mutated non-small-cell lung cancer after clonal selection through targeted therapy

Tumor heterogeneity plays an important role in the development of treatment-resistance, especially in the current era of targeted therapies. Although tumor heterogeneity is a widely recognized phenomenon, it is at present unclear how this knowledge should be incorporated into daily clinical practice. In this report, we describe an innovative nuclear imaging method that may play a role in detecting tumor heterogeneity in the future.

Retrospective evaluation of thromboembolic events in patients with non-small cell lung cancer treated with platinum-based chemotherapy

OBJECTIVES

Thromboembolic events (TE) are common in patients with cancer and are potentially life-threatening. In lung cancer, little is known about thrombosis during chemotherapy treatment. The aim of this study was to describe the incidence of TE in patients with non-small cell lung cancer (NSCLC), occurring during treatment with platinum-based chemotherapy.

METHODS

We retrospectively selected patients with NSCLC treated with platinum-based chemotherapy at the VU University Medical Center Amsterdam between 2000 and 2012. Patients who underwent recent surgery were excluded. All TE were included that occurred from start of chemotherapy treatment until 30 days after last administration.

RESULTS

Among 784 included patients, 63 (8.0%) patients had 69 TE during treatment. Forty-five venous TE (VTE) and 24 arterial TE (ATE). Six patients had multiple events within treatment period, 3 of which had simultaneous ATE and VTE. In total, 613 patients were treated with cisplatin, 119 patients received carboplatin and 52 patients received both in first- or second-line treatment. In 8% (55/665) of the patients exposed to cisplatin a TE had occurred vs. 5% (8/171) in patients exposed to carboplatin (p=0.42). The majority of TE occurred in the first 2 cycles (70%). History of TE was related to occurrence of TE during chemotherapy (p<0.01). Median PFS was similar in patients with and without TE (6.2 vs. 7.2 months, respectively; p=0.10). Median OS was significantly shorter in patients with TE (9.5 vs. 12.9 months, respectively; p=0.03).

CONCLUSION

In our series, both ATE and VTE were a common finding during chemotherapy. TE was a poor prognostic factor. No difference in TE incidence was found between patients treated with cisplatin or carboplatin.

Spontaneous pneumothorax as indicator for Birt-Hogg-Dubé syndrome in paediatric patients

Background

Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominantly inherited disorder caused by germline mutations in the folliculin (FLCN) gene. Clinical manifestations of BHD include skin fibrofolliculomas, renal cell cancer, lung cysts and (recurrent) spontaneous pneumothorax (SP). All clinical manifestations usually present in adults > 20 years of age.

Case presentations

Two non-related patients with (recurrent) pneumothorax starting at age 14 accompanied by multiple basal lung cysts on thoracic CT underwent FLCN germline mutation analysis. A pathogenic FLCN mutation was found in both patients confirming suspected BHD. The family history was negative for spontaneous pneumothorax in both families.

Conclusion

Although childhood occurrence of SP in BHD is rare, these two cases illustrate that BHD should be considered as cause of SP in children.

Benefit of a second opinion for lung cancer: no metastasis to the kidney but a synchronous primary renal neoplasm

Background

The finding of a renal mass on imaging is suggestive of metastatic non-small cell lung cancer in the presence of a lung tumor but can also have another origin.

Case Report

We describe the case of a patient diagnosed with stage IV lung cancer based on a renal metastasis. A second opinion including review of histopathological data and additional imaging followed by lung surgery and cryoablation of the kidney lesion revealed two tumors of different origins, non-small cell lung cancer and a renal cell carcinoma.

Discussion

The presence of a renal mass diagnosed on a CT scan in a patient with lung cancer is not always synonymous with metastatic disease. Confirmation of diagnosis by tissue sampling is mandatory, especially if a synchronous primary tumor is possible.

Why do patients and caregivers seek answers from the Internet and online lung specialists? A qualitative study

Background

Since its launch in 2003, the Dutch Lung Cancer Information Center’s (DLIC) website has become increasingly popular. The most popular page of the website is the section “Ask the Physician”, where visitors can ask an online lung specialist questions anonymously and receive an answer quickly. Most questions were not only asked by lung cancer patients but also by their informal caregivers. Most questions concerned specific information about lung cancer.

Objective

Our goal was to explore the reasons why lung cancer patients and caregivers search the Internet for information and ask online lung specialists questions on the DLIC’s interactive page, “Ask the Physician”, rather than consulting with their own specialist.

Methods

This research consisted of a qualitative study with semistructured telephone interviews about medical information-seeking behavior (eg, information needs, reasons for querying online specialists). The sample comprised 5 lung cancer patients and 20 caregivers who posed a question on the interactive page of the DLIC website.

Results

Respondents used the Internet and the DLIC website to look for lung cancer–related information (general/specific to their personal situation) and to cope with cancer. They tried to achieve a better understanding of the information given by their own specialist and wanted to be prepared for the treatment trajectory and disease course. This mode of information supply helped them cope and gave them emotional support. The interactive webpage was also used as a second opinion. The absence of face-to-face contact made respondents feel freer to ask for any kind of information. By being able to pose a question instantly and receiving a relatively quick reply from the online specialist to urgent questions, respondents felt an easing of their anxiety as they did not have to wait until the next consultation with their own specialist.

Conclusions

The DLIC website with its interactive page is a valuable complementary mode of information supply and supportive care for lung cancer patients and caregivers.

Benefit of a second opinion: From metastatic disease to resectable lung cancer with sarcoid-like reaction

Background

Mediastinal lymphadenopathy in combination with lung cancer is suggestive for lymph node metastases but can also have other origins.

Case report

We describe a patient diagnosed with stage IV lung cancer presenting with parenchymal lesions and enlarged mediastinal lymph nodes. A second opinion including FDG-PET scan review and a mediastinoscopy followed by surgery revealed tumor specimens originating from a single primary tumor with a sarcoid-like reaction in the mediastinal lymph nodes, changing the diagnosis from metastasized to resectable lung cancer.

Discussion

PET positive lesions are not always synonymous with metastatic disease in the presence of a malignant tumor. Conscientious review of FDG-PET scans and tissue sampling are therefore mandatory to determine definitive staging and subsequent interventions.

DNA copy number aberrations in endobronchial lesions: a validated predictor for cancer

We recently identified a DNA copy number aberration (CNA)-based classifier, including changes at 3p26.3-p11.1, 3q26.2-29, and 6p25.3-24.3, as a risk predictor for cancer in individuals presenting with endobronchial squamous metaplasia. The current study was set out to validate the prediction accuracy of this classifier in an independent series of endobronchial squamous metaplastic and dysplastic lesions. The study included 36 high-risk subjects who had endobronchial lesions of various histological grades that were identified and biopsied by autofluorescence bronchoscopy and were subjected to arrayCGH in a nested case-control design. Of the 36 patients, 12 had a carcinoma in situ or invasive carcinoma at the same site at follow-up (median 11 months, range 4-24), while 24 controls remained cancer free (78 months, range 21-142). The previously defined CNA-based classifier demonstrated 92% (95% CI 77% to 98%) accuracy for cancer (in situ) prediction. All nine subjects with CNA-based classifier-positive endobronchial lesions at baseline experienced cancer outcome, whereas all 24 controls and 3 cases were classified as being low risk. In conclusion, CNAs prove to be a highly accurate biomarker for assessing the progression risk of endobronchial squamous metaplastic and dysplastic lesions. This classifier could assist in selecting subjects with endobronchial lesions who might benefit from more aggressive therapeutic intervention or surveillance.

Lung cysts as indicator for Birt-Hogg-Dubé syndrome

In this case, we describe a patient with a history of recurrent pneumothorax. Based on CT-thorax and histopathology of the lung tissue, the Birt-Hogg-Dubé syndrome was suspected and confirmed after genetic testing. Recognizing this syndrome by pulmonologists and radiologists is very important, because the risk on developing of renal cell cancer is high.