A Case of Radiation Recall Pneumonitis Induced by Erlotinib, Which Can be Related to High Plasma Concentration

Radiation Recall Pneumonitis: Imaging Appearance and Differential Considerations

Radiation recall pneumonitis is an inflammatory reaction of previously radiated lung parenchyma triggered by systemic pharmacological agents (such as chemotherapy and immunotherapy) or vaccination. Patients present with non-specific symptoms such as cough, shortness of breath, or hypoxia soon after the initiation of medication or vaccination. Careful assessment of the patient's history, including the thoracic radiation treatment plan and timing of the initiation of the triggering agent, in conjunction with CT findings, contribute to the diagnosis. Once a diagnosis is established, treatment includes cessation of the causative medication and/or initiation of steroid therapy. Differentiating this relatively rare entity from other common post-therapeutic complications in oncology patients, such as recurrent malignancy, infection, or medication-induced pneumonitis, is essential for guiding downstream clinical management.

Radiation Recall Pneumonitis Induced by Sintilimab: A Case Report and Literature Review

Radiation recall pneumonitis (RRP) is described as an unpredictable acute inflammatory reaction within the previously irradiated lung site during the administration of systematic therapy after radiotherapy. Here, we reported a case of a 54-year-old woman with non-small lung cancer (NSCLC), who had pneumonitis at 3 and 10 months after radiotherapy regarded as radiation pneumonitis (RP) and RRP induced by anti-PD-1 sintilimab, respectively. This unique patient with double pneumonitis (RP and RRP) has drawn attention to the identification of immune or radiation pneumonitis, its potential mechanism, and further treatment strategy after the emergence of RRP.

The knowns & unknowns of pulmonary toxicity following immune checkpoint inhibitor therapies: a narrative review

Since their discovery immune checkpoint inhibitors (ICI) have dramatically changed the treatment landscape for many cancers. In addition to their efficacy they are generally well tolerated, however, they have led to a new range of immune-related adverse events (irAEs) including pneumonitis. While not the most frequently reported immune-related adverse event in the clinical trial setting, recent real-world data suggests a significantly higher rate of pneumonitis leading to treatment suspension or cessation. It also appears to disproportionately contribute to immune-related mortality, particularly with anti-PD-1/PD-L1 treatment. While indicators have emerged regarding risk factors, incomplete prospective recording of patient characteristics hampers strong conclusions. Presenting symptoms are non-specific and the differential diagnosis is broad, made more complex by concomitant treatment with traditional chemotherapy or radiotherapy. Radiological findings are diverse and inconsistent terminology makes comparison and more complete characterization difficult. Further, little is known about the role of baseline testing or surveillance for early detection of pneumonitis, or the real-world role of bronchoscopy or biopsy in assessment. Scant literature exists to direct these complex decisions, so treatment guidelines have been published based on expert consensus. Here we provide a narrative review of what is known about ICI pneumonitis and propose key questions to enhance our understanding into the future.

“Radiation Recall Phenomenon” with Novel Cytotoxic Agents: An Emerging Trend in the Last Decade

Radiation recall phenomenon (RRP) is an acute inflammatory reaction manifested in the previously irradiated tissues after the administration of various pharmacologic compounds. While skin manifestations are the most common clinical features, patients may also present with visceral recall events including pneumonitis, hematuria, myopathy, and mucositis if any particular organ was exposed to the prior radiation portals. This article has reviewed the published case reports, case series, abstracts, and poster presentations in the past 10 years in any language on RRP caused by various novel cytotoxic drugs including immunotherapies, molecularly targeted agents, and unconventional chemotherapies. We retrieved the data through the literature search of MEDLINE and PubMed using the keywords “radiation,” “recall,” “targeted therapy,” and “immunotherapy,” and references identified in retrieved articles were also used for further search of the literature. With the increasing use of unconventional, novel cytotoxic agents and targeted molecules, concurrent or sequentially with radiation, we expect more incidences of RRP in future that may present with either dermatological or visceral recall reactions.

The mechanism and risk factors for immune checkpoint inhibitor pneumonitis in non-small cell lung cancer patients

Immune checkpoint inhibitors (ICIs) are new and promising therapeutic agents for non-small cell lung cancer (NSCLC). However, along with demonstrating remarkable efficacy, ICIs can also trigger immune-related adverse events. Checkpoint inhibitor pneumonitis (CIP) has been reported to have a morbidity rate of 3% to 5% and a mortality rate of 10% to 17%. Moreover, the incidence of CIP in NSCLC is higher than that in other tumor types, reaching 7% to 13%. With the increased use of ICIs in NSCLC, CIP has drawn extensive attention from oncologists and cancer researchers. Identifying high risk factors for CIP and the potential mechanism of CIP are key points in preventing and monitoring serious adverse events. In this review, the results of our analysis and summary of previous studies suggested that the risk factors for CIP may include previous lung disease, prior thoracic irradiation, and combinations with other drugs. Our review also explored potential mechanisms closely related to CIP, including increased T cell activity against associated antigens in tumor and normal tissues, preexisting autoantibodies, and inflammatory cytokines.

Radiation Recall Pneumonitis Induced by Anti-PD-1 Blockade: A Case Report and Review of the Literature

Background: Radiation recall pneumonitis (RRP) is an unpredictable but relatively severe subclinical radiation damage which occurs in the previously irradiated fields of pulmonary tissue after administration of a systemic agent. Previous reports of RRP were mainly attributed to chemotherapy and molecular-target agents. RRP induced by immunotherapy has been rarely reported. Here we describe a case of a novel pattern of RRP induced by anti-PD-1 blockade Camrelizumab 2 years after radiotherapy, with some focus on further understanding of this phenomenon.

Case Report: A 64-year-old man with non-small cell lung cancer (NSCLC) received two cycles of chemotherapy with cisplatin and pemetrexed first. Subsequently, he underwent concomitant chemoradiotherapy with cisplatin and pemetrexed to simultaneous integrated boost (SIB) radiotherapy. After 15 months, due to tumor progression and brain metastasis, he started with administration of anti-PD-1 blockade Camrelizumab (200 mg q2w) and stereotactic radiosurgery (SRS). The patient developed fever, dyspnea and cough after the eighth administration of Camrelizumab. Meanwhile, his chest CT revealed patchy consolidation and ground-glass opacities localized within the previously irradiated area. Subsequent treatment regimen was adjusted to 80 mg q12h prednisolone with discontinuation of Camrelizumab. Then the symptoms gradually eased and reexamination of CT showed significant improvement in RRP after 2 weeks.

Conclusion: Our case report presents a novel pattern of RRP induced by anti-PD-1 blockade Camrelizumab 2 years after radiotherapy. This indicates that previous radiotherapy combined with subsequent anti-PD-1 blockade has a potential to cause overlapping damage to lung, suggesting that intensive attention might be needed for patients who are treated with anti-PD-1 blockade in conjunction with a prior history of thoracic radiation.

Radiation-Induced Lung Injury: Assessment and Management

Radiation-induced lung injury (RILI) encompasses any lung toxicity induced by radiation therapy (RT) and manifests acutely as radiation pneumonitis and chronically as radiation pulmonary fibrosis. Because most patients with thoracic and breast malignancies are expected to undergo RT in their lifetime, many with curative intent, the population at risk is significant. Furthermore, indications for thoracic RT are expanding given the advent of stereotactic body radiation therapy (SBRT) or stereotactic ablative radiotherapy (SABR) for early-stage lung cancer in nonsurgical candidates as well as oligometastatic pulmonary disease from any solid tumor. Fortunately, the incidence of serious pulmonary complications from RT has decreased secondary to advances in radiation delivery techniques. Understanding the temporal relationship between RT and injury as well as the patient, disease, and radiation factors that help distinguish RILI from other etiologies is necessary to prevent misdiagnosis. Although treatment of acute pneumonitis is dependent on clinical severity and typically responds completely to corticosteroids, accurately diagnosing and identifying patients who may progress to fibrosis is challenging. Current research advances include high-precision radiation techniques, an improved understanding of the molecular basis of RILI, the development of small and large animal models, and the identification of candidate drugs for prevention and treatment.

Tyrosine Kinase Inhibitor-Induced Interstitial Lung Disease: Clinical Features, Diagnostic Challenges, and Therapeutic Dilemmas

Since the approval of the first molecularly targeted tyrosine kinase inhibitor (TKI), imatinib, in 2001, TKIs have heralded a new era in the treatment of many cancers. Among their innumerable adverse effects, interstitial lung disease (ILD) is one of the most serious, presenting most frequently with dyspnea, cough, fever, and hypoxemia, and often treated with steroids. Of the 28 currently approved TKIs, 16 (57 %) are reported to induce ILD with varying frequency and/or severity. The interval from drug administration to onset of ILD varies between patients and between TKIs, with no predictable time course. Its incidence is variously reported to be approximately 1.6-4.3 % in Japanese populations and 0.3-1.0 % in non-Japanese populations. The mortality rate is in the range of 20-50 %. Available evidence (primarily following the use of erlotinib and gefitinib in Japan because of the unique susceptibility of that population) has identified a number of susceptibility and prognostic risk factors (male sex, a history of smoking, and pre-existing pulmonary fibrosis being the main ones). Although the precise mechanism is not understood, collective evidence suggests that immune factors may be involved. If TKI-induced ILD is confirmed by thorough evaluation of the patient and exclusion of other causes, management is supportive, and includes discontinuation of the culprit TKI and administration of steroids. Discontinuing the culprit TKI presents a clinical dilemma because the diagnosis of TKI-induced ILD in a patient with pre-existing pulmonary fibrosis can be challenging, the patient may have TKI-responsive cancer with no suitable alternative, and switching to an alternative agent, even if available, carries the risk of the patient experiencing other toxic effects. Preliminary evidence suggests that therapy with the culprit TKI may be continued under steroid cover and/or at a reduced dose. However, this approach requires careful individualized risk-benefit analysis and further clinical experience.

Oral Targeted Therapies and Central Nervous System (CNS) Metastases

The purpose of our review is to summarize the clinical activity of oral targeted agents against brain metastases. This includes BRAF inhibitors (dabrafenib and vemurafenib), human epidermal growth factor receptor inhibitors (lapatinib, gefitinib, erlotinib, and afatinib), multi-kinase angiogenesis inhibitors (sorafenib, sunitinib, pazopanib, and vandetanib), and ALK/c-MET (crizotinib) and ALK/IGF-1 (ceritinib) inhibitors. Effective systemic therapies are needed for long-term benefit in brain metastases and documentation of intracranial activity for many therapies is poor. Our review provides a summary of the literature with pertinent data for clinicians. This is needed as subjects with brain metastases are often prevented from enrolling in clinical trials and investigations focused on systemic therapies for brain metastases are rare.

Radiation recall dermatitis and radiation pneumonitis during treatment with vemurafenib

The basis of radiation recall reactions (RRR) is a subclinical radiation damage that is uncovered later by treatment with anticancer agents. Several drugs have been associated with RRR, in particular taxanes and anthracyclines. Recently, a few cases were reported concerning radiation recall dermatitis caused by vemurafenib. Up to now, there have been no reports of RRR in the lung induced by vemurafenib. We describe the occurrence of RRR in three melanoma patients who had undergone radiotherapy for metastases followed by systemic treatment with the BRAF inhibitor vemurafenib. Two patients developed radiation recall pneumonitis (RRP) and one patient developed radiation recall dermatitis (RRD) 5-7 weeks after the radiation treatment was finished and 2-4 weeks after vemurafenib was started. The early application of systemic (RRP) and topical corticosteroids (RRD) enabled us to continue the treatment with vemurafenib without dose reduction. Caution is needed when vemurafenib is planned for patients who have undergone previous radiotherapy, and RRR of the skin and the lung have to be taken into account.

Preliminary analysis of the risk factors for radiation pneumonitis in patients with non-small-cell lung cancer treated with concurrent erlotinib and thoracic radiotherapy

Purpose

The aim of this study was to investigate radiation pneumonitis and its associated risk factors in patients with non-small-cell lung cancer treated with concurrent erlotinib and thoracic radiotherapy.

Materials and methods

We conducted an analysis of patients with nonoperable stage IIIA–IV non-small-cell lung cancer who were treated with concurrent thoracic radiotherapy and erlotinib (ClinicalTrials.gov identifier: NCT00973310). The Common Terminology Criteria for Adverse Events version 3.0 grading system was applied to evaluate the incidence of radiation pneumonitis. The lung dosimetric parameters were recorded in accordance with the treatment plan, and the study endpoint was radiation pneumonitis at grade 2 or more.

Results

Among the 24 selected clinical cases, nine were identified with radiation pneumonitis of grade 2 or above (37.5%). This included four cases with grade 2 (16.7%), two cases with grade 3 (8.3%), and three cases with grade 5 (12.5%). The results showed that the planning target volume was a significant factor affecting the incidence of radiation pneumonitis. All lung dosimetric parameters exhibited statistically significant differences between patients with pneumonitis and patients without pneumonitis. The receiver operating characteristic (ROC) curve analysis showed that all lung dosimetric parameters were useful in predicting the incidence of radiation pneumonitis. In addition, the threshold values of V5, V10, V15, V20, V30, and mean lung dose were >44%, >29%, >27%, >22%, >17% and >1,027 cGy, respectively.

Conclusion

Special attention should be paid to the adverse effects of radiation pneumonitis in concurrent thoracic radiotherapy and erlotinib treatment. Lung dosimetric parameters are important predictive factors in radiation pneumonitis.

Population pharmacokinetics/pharmacodynamics of erlotinib and pharmacogenomic analysis of plasma and cerebrospinal fluid drug concentrations in Japanese patients with non-small cell lung cancer

BACKGROUND

Erlotinib shows large inter-patient pharmacokinetic variability, but the impact of early drug exposure and genetic variations on the clinical outcomes of erlotinib remains fully investigated. The primary objective of this study was to clarify the population pharmacokinetics/pharmacodynamics of erlotinib in Japanese patients with non-small cell lung cancer (NSCLC). The secondary objective was to identify genetic determinant(s) for the cerebrospinal fluid (CSF) permeability of erlotinib and its active metabolite OSI-420.

METHODS

A total of 88 patients treated with erlotinib (150 mg/day) were enrolled, and CSF samples were available from 23 of these patients with leptomeningeal metastases. Plasma and CSF concentrations of erlotinib and OSI-420 were measured by high-performance liquid chromatography with UV detection. Population pharmacokinetic analysis was performed with the nonlinear mixed-effects modelling program NONMEM. Germline mutations including ABCB1 (1236C>T, 2677G>T/A, 3435C>T), ABCG2 (421C>A), and CYP3A5 (6986A>G) polymorphisms, as well as somatic EGFR activating mutations if available, were examined. Early exposure to erlotinib and its safety/efficacy relationship were evaluated.

RESULTS

The apparent clearance of erlotinib and OSI-420 were significantly decreased by 24 and 35 % in patients with the ABCG2 421A allele, respectively (p < 0.001), while ABCB1 and CYP3A5 polymorphisms did not affect their apparent clearance. The ABCG2 421A allele was significantly associated with increased CSF penetration for both erlotinib and OSI-420 (p < 0.05). Furthermore, the incidence of grade ≥2 diarrhea was significantly higher in patients harboring this mutant allele (p = 0.035). A multivariate logistic regression model showed that erlotinib trough (C0) levels on day 8 were an independent risk factor for the development of grade ≥2 diarrhea (p = 0.037) and skin rash (p = 0.031). Interstitial lung disease (ILD)-like events occurred in 3 patients (3.4 %), and the median value of erlotinib C0 levels adjacent to these events was approximately 3 times higher than that in patients who did not develop ILD (3253 versus 1107 ng/mL; p = 0.014). The objective response rate in the EGFR wild-type group was marginally higher in patients achieving higher erlotinib C0 levels (≥1711 ng/mL) than that in patients having lower erlotinib C0 levels (38 versus 5 %; p = 0.058), whereas no greater response was observed in the higher group (67 %) versus the lower group (77 %) within EGFR mutation-positive patients (p = 0.62).

CONCLUSIONS

ABCG2 can influence the apparent clearance of erlotinib and OSI-420, and their CSF permeabilities in patients with NSCLC. Our preliminary findings indicate that early exposure to erlotinib may be associated with the development of adverse events and that increased erlotinib exposure may be relevant to the antitumor effects in EGFR wild-type patients while having less of an impact on the tumor response in EGFR mutation-positive patients.

Targeted therapy for non-small cell lung cancer

The treatment of advanced non-small cell lung cancer has been with systemic chemotherapy and usually consists of a platinum doublet chemotherapy. The identification of somatic driver mutations has resulted in new drugs that target these mutations. This report discusses the two most important new targeted therapy drugs for the treatment of advanced non-small cell lung cancer that have these driver mutations.

Targeted therapy-induced radiation recall

INTRODUCTION

Radiation recall (RR) is an acute inflammatory reaction confined to previously irradiated areas after the administration of various pharmacological agents. A diverse range of chemotherapies has been associated with RR but no case series with targeted therapies (TT) has been reported.

PATIENTS AND METHODS

From a database of 346,933 cancer patients ≥18 years treated at Institut Gustave Roussy between June 1986 and August 2012, clinical data and the pattern of treatment of TT-induced RR were collected. Results were compared with those of prior TT-induced RR publications.

RESULTS

Sixteen patients with different tumour types were diagnosed with RR observed in the heart, bladder, salivary glands, skin and gastrointestinal tract. The median duration of RR was 1.7 weeks (range: 0.1-13.7) and median time to onset from TT to RR was 16.9 weeks (range: 1-86.9). TT consisted of inhibitors of the mammalian target of rapamycin (mTOR) (n=5), endothelial growth factor receptor (EGFR) (n=2), integrin (n=2), histone deacetylase (HDAC) (n=2), cell division cycle 7 (CDC7) (n=1), insulin-like growth factor 1 receptor (IGFR1) (n=1), cyclin-dependent kinase (CDK) (n=1), BRAF (n=1) and a vascular disrupting agent (VDA) (n=1). Thirteen incriminated TT (81%) were evaluated during early clinical trials and RR led to discontinuation of TT in six patients. All patients had previously received radiotherapy at a median biologically effective dose (BED) of 47 Gy (range: 20-70). The median interval from radiation to TT was 30 months (range: 0.3-363). Immunohistochemical analysis of skin biopsy specimens did not show any transforming growth factor-beta (TGF-β) activation. TT-induced RR characteristics in our population were comparable to those of the nine other cases previously reported in the literature.

CONCLUSION

This is the largest case series ever reported on TT-induced RR. RR could be a potential dose-limiting toxicity in early clinical trials. Research is warranted to further understand the exact pathophysiology of this rare but clinically relevant phenomenon.

Development and validation of a spectrofluorimetric method for the determination of erlotinib in spiked human plasma

A rapid and sensitive spectrofluorimetric method was developed and validated for the determination of erlotinib (ETB), a potent anticancer drug, in spiked human plasma without any derivatization. The described method was validated and the analytical parameters of linearity, accuracy, precision (intra- and inter-day), limit of detection (LOD), and limit of quantification (LOQ) were evaluated. The relation between the fluorescence intensity and concentration was found to be linear (r(2) 0.9998) over the range 125 to 1000 ng/mL with the detection limit of 15 ng/mL. A simple liquid-liquid extraction method was followed in order to extract the drug from spiked plasma. The mean absolute recoveries of ETB were 85.59 % (±0.57), 86.91 % (±1.77) and 89.31 % (±3.01) at spiked plasma ETB concentration of 5000, 3750 and 2500 ng/mL, respectively. The spectrofluorimetric method presented here is a rapid, simple, specific, and reproducible method and can be used to characterize the plasma pharmacokinetics of ETB.

Cerebrospinal fluid concentration of gefitinib and erlotinib in patients with non-small cell lung cancer

PURPOSE

Several cases have been reported in which central nervous system (CNS) metastases of non-small cell lung cancer (NSCLC) resistant to gefitinib were improved by erlotinib. However, there has been no study in which cerebrospinal fluid (CSF) concentrations of gefitinib and erlotinib are directly compared. Thus, we aimed to compare them.

METHODS

We examined 15 Japanese patients with NSCLC and CNS metastases with epidermal growth factor receptor gene mutations who received CSF examinations during epidermal growth factor receptor-tyrosine kinase inhibitors treatment (250 mg daily gefitinib or 150 mg daily erlotinib). Plasma and CSF concentrations were determined using high-performance liquid chromatography with tandem mass spectrometry.

RESULTS

The concentration and penetration rate of gefitinib (mean ± standard deviation) in the CSF were 3.7 ± 1.9 ng/mL (8.2 ± 4.3 nM) and 1.13 ± 0.36 %, respectively. The concentration and penetration rate of erlotinib in the CSF were 28.7 ± 16.8 ng/mL (66.9 ± 39.0 nM) and 2.77 ± 0.45 %, respectively. The CSF concentration and penetration rate of erlotinib were significantly higher than those of gefitinib (P = 0.0008 and <0.0001, respectively). The CNS response rates of patients with erlotinib treatment were preferentially (but not significantly) higher than those with gefitinib treatment. (1/3 vs. 4/7, respectively). Leptomeningeal metastases in one patient, which were refractory to gefitinib, dramatically responded to erlotinib.

CONCLUSIONS

This study suggested that higher CSF concentration could be achieved with erlotinib and that erlotinib could be more effective for the treatment for CNS metastases, especially leptomeningeal metastases, than gefitinib.

Fatal interstitial lung disease associated with high erlotinib and metabolite levels. A case report and a review of the literature

INTRODUCTION

Erlotinib is an agent in the class of oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors. Although this class of agents is considered to be relatively safe, the most serious, but rare, adverse reaction is drug-associated interstitial lung disease (ILD). This potentially fatal adverse reaction has been often described with gefitinib, but has been less well described for erlotinib. We here describe a case report of fatal interstitial lung disease in a Caucasian man associated with erlotinib and high erlotinib and metabolite plasma levels and discuss it in the context of all documented cases of erlotinib associated ILD.

METHODS

Our case was described and for the literature review a Pubmed and Google Scholar search was conducted for cases of erlotinib associated ILD. The retrieved publications were screened for relevant literature.

RESULTS

Besides our case, a total of 19 cases of erlotinib-associated ILD were found. Eleven out 19 cases had a fatal outcome and in only one case erlotinib plasma concentrations were measured and found to be high.

CONCLUSION

Erlotinib-associated ILD is a rare, serious and often fatal adverse reaction. Most likely, the cause for erlotinib-associated ILD is multifactorial and high drug levels may be present in patients without serious adverse reactions. However, considering the pharmacology of EGFR inhibitors, high drug and metabolite levels may play a role and future studies are warranted to identify risk factors and to investigate the role of elevated levels of erlotinib and its metabolites in the development of pulmonary toxicity.

Efficacy of increased-dose erlotinib for central nervous system metastases in non-small cell lung cancer patients with epidermal growth factor receptor mutation

PURPOSE

Recent reports indicate that refractory central nervous system (CNS) metastases of non-small cell lung cancer (NSCLC) are improved by high-dose gefitinib or erlotinib administration. We describe a Japanese woman with NSCLC and CNS metastases who was resistant to 75 mg daily erlotinib, but the metastases were improved by 150 mg daily erlotinib. We investigated the plasma and CSF concentrations of erlotinib at each dose as well as the correlation between the plasma and CSF concentrations of erlotinib.

METHODS

Including this patient, we administered 150 mg erlotinib daily to nine NSCLC patients with CNS metastases and measured the plasma and CSF concentrations just before administration on day 8. The concentrations were determined using high-performance liquid chromatography with ultraviolet detection.

RESULTS

The plasma and CSF concentrations of erlotinib at a dose of 75 mg were 433 and 14 nM, respectively. The plasma and CSF concentrations of erlotinib at a dose of 150 mg were increased to 1,117 and 44 nM, respectively. The mean ± standard deviation of CSF concentrations and penetration rates were 106 ± 59 nM and 4.5 ± 1.5%, respectively. There was a good correlation (R(2) = 0.84) between plasma and CSF concentrations (P = 0.0005).

CONCLUSIONS

This study indicates that CSF concentrations of erlotinib depend on its plasma concentration. As seen in this patient, high CSF concentrations of erlotinib can be achieved by high-dose administration, and this finding suggests the efficacy of high-dose administration, especially to refractory CNS metastases of NSCLC patients.

Radiation recall pneumonitis induced by chemotherapy after thoracic radiotherapy for lung cancer

Background

Radiation recall pneumonitis (RRP) describes a rare reaction in previously irradiated area of pulmonary tissue after application of triggering agents. RRP remains loosely characterized and poorly understood since it has so far only been depicted in 8 cases in the literature. The objective of the study is to disclose the general characteristics of RRP induced by chemotherapy after thoracic irradiation for lung cancer, and to draw attention to the potential toxicity even after a long time interval from the previous irradiation.

Methods

Medical records were reviewed. RRP induced by chemotherapy was diagnosed by the history of chemotherapy after radiotherapy, clinical presentation and radiographic abnormalities including ground-glass opacity, attenuation, or consolidation changes within the radiation field, plus that radiographic examination of the thorax before showed no radiation pneumonitis. RRP was graded according to Common Terminology Criteria for Adverse Events version 3.0. The characteristics of the 12 RRP cases were analyzed.

Results

Twelve patients were diagnosed of RRP, of who 8 received taxanes. The median time interval between end of radiotherapy and RRP, between end of radiotherapy and beginning of chemotherapy, and between beginning of chemotherapy and RRP was 95 days, 42 days and 47 days, respectively. Marked symptomatic and radiographic improvement was observed in the 12 patients after withdrawal of chemotherapy and application of systemic corticosteroids. Seven patients were rechallenged with chemotherapy, of whom four with the same kind of agents, and showed no recurrence with steroid cover.

Conclusions

Doctors should pay attention to RRP even after a long time from the previous radiotherapy or after several cycles of consolidation chemotherapy. Taxanes are likely to be associated with radiation recall more frequently. Withdrawal of causative agent and application of steroids are the treatment of choice. Patients may be rechallenged safely with steroid cover and careful observation, which needs to be validated.

Erlotinib efficacy and cerebrospinal fluid concentration in patients with lung adenocarcinoma developing leptomeningeal metastases during gefitinib therapy

PURPOSE

We have treated patients with non-small-cell lung cancer (NSCLC) who developed leptomeningeal metastases (LM) during gefitinib therapy, and then found symptomatic improvement following treatment change to erlotinib. Based on this experience, we wondered whether erlotinib could be detected in cerebrospinal fluid (CSF) when it was used for NSCLC patients with LM. This study was conducted to determine erlotinib concentrations in CSF and assess responses to erlotinib in patients with NSCLC developing LM during gefitinib therapy.

METHODS

Three advanced NSCLC patients with LM that developed during gefitinib therapy were treated with erlotinib. On day 28 after the initiation of erlotinib treatment, plasma and CSF were obtained and the concentrations of erlotinib in these samples were measured. Eastern Cooperative Oncology Group (ECOG) performance status (PS) and neurologic symptoms were determined.

RESULTS

Erlotinib CSF penetration was 6.3% ± 6.1% (mean ± SD). In cases 1 and 2, we observed improvements in ECOG PS and neurologic symptoms. In case 3, cytological improvement was seen in the CSF. In each patient, deletion of exon 19 or exon 21 L858R mutation of the epidermal growth factor receptor (EGFR) gene was detected in carcinoma cells from the CSF.

CONCLUSIONS

We report on 3 patients with NSCLC who had developed LM during gefitinib treatment and showed clinical improvements following change to erlotinib therapy. In all cases, small but measurable penetration of erlotinib into CSF was observed. Because EGFR mutations were detected in all cases, we suggest that erlotinib is a therapeutic option for LM carcinoma cells with EGFR mutations.