Adverse Events of Concurrent Radiotherapy and ALK Inhibitors for Brain Metastases of ALK-Rearranged Lung Adenocarcinoma

Recent advances progress of targeted drugs combined with radiotherapy for advanced non-small cell lung cancer: a review

Targeted drug therapy plays an important role in the clinical application of non-small cell lung cancer, especially adenocarcinoma. However, for patients with advanced disease, drug resistance after targeted therapy, unclear target, and other reasons that cannot or do not want surgery, the combination of chemotherapy, radiotherapy, immunity, etc. is often used. The synergistic effect of targeted drugs and radiotherapy in non-small cell lung cancer has shown good clinical efficacy. This article reviews the clinical progress of targeted drug therapy combined with radiotherapy in advanced non-small cell lung cancer in recent years, in order to provide new ideas for further clinical research of this treatment mode.

Brain metastases: increasingly precision medicine-a narrative review

Objective

To broadly review the modern management of brain metastases.

Background

Brain metastases are the commonest neurological manifestation of cancer and a major cause of morbidity in cancer patients. Brain metastases are increasing in frequency, as a result of longer life expectancy of cancer patients, more sensitive methods for brain metastasis detection and an ageing population. The proportional incidence of brain metastases according to cancer of origin, from greatest to least, is lung cancer, melanoma, renal, breast and colorectal cancers. Patients with lung cancer and melanoma are most likely to have brain metastases at diagnosis. Brain metastases cause a variety of symptoms, depending on their size and location, whether they cause mass effect and oedema, compression of the brain parenchyma, or focal neurological deficits. The major differential diagnoses of brain metastases include primary tumours and vascular/inflammatory lesions. Prognosis is dependent on the site, number and volume of lesions, the patients’ performance status, age and the activity and extent of extracranial disease.

Methods

English literature articles in PubMed from 1950 to June 2021 were reviewed. Article bibliographies provided further references.

Conclusions

Treatment of brain metastasis patients has moved from considering them as a homogenous population of patients, to individualised treatment. In those brain metastases patients of satisfactory performance status with a solitary lesion, especially one in a non-eloquent/accessible area causing significant mass effect and/or raised intracranial pressure or for whom the diagnosis is in doubt (histology needed), surgical resection is usually the treatment of choice. For multiple brain metastases, radiotherapy with or without systemic therapies are usually employed. For relatively fit patients with limited numbers of brain metastases (e.g., 4 or less), stereotactic radiosurgery is standard of care. Current clinical trials are testing the efficacy of stereotactic treatment alone for >4 brain metastases (although it is increasingly used for such patients in many centres) as well as integration of local therapies with targeted and immunological therapies in appropriately selected cases. In certain circumstances, cranial irradiation can be omitted.

ALK-positive non-small cell lung cancer; potential combination drug treatments

Advances in chromosomally rearranged ALK positive non-small cell lung cancer have been dramatic in only the last few years. Survival times have improved dramatically due to the introduction of ever more efficacious ALK inhibitors. These improvements have been due largely to improvements in blood-brain barrier penetration and the breadth of ligand binding pocket mutations against which the drugs are effective. However, the advances maybe slow as compared to the frequency of cancers with compound resistance mutations are appearing, suggesting the need to develop multiple ALK inhibitors to target different compound mutations.Another research area that promises to provide further gains is the use of drug combinations, with an ALK inhibitor combined with a drug targeting a "second driver" to overcome resistance. In this review, the range of secondary targets for ALK+ lung cancer and the potential for their clinical success are reviewed.

Case Report: Treatment of Alectinib in NSCLC With Brain Metastasis Patient Refractory to Radiotherapy After Resistance to Crizotinib

Background

Brain metastasis is the most common form of tumor recurrence after resistance to crizotinib in patients with anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC). The treatment of brain metastasis in patients with ALK-positive NSCLC requires a multidisciplinary approach, including targeted therapy, chemotherapy, and radiotherapy. At present, no optimal treatment for these patients has been identified, although radiotherapy has remained a vital treatment.

Case Presentation

We experienced a patient with ALK-positive NSCLC who developed brain metastasis after crizotinib therapy. ALK rearrangement was not detected in a blood sample using next-generation sequencing. In accordance with National Comprehensive Cancer Network guidance, the patient underwent whole-brain radiotherapy. However, the number of metastatic sites unexpectedly increased. In desperation, the patient was empirically given alectinib after radiotherapy failure, and unanticipated success was achieved.

Conclusions

This case revealed some new insights. First, liquid biopsy is complementary to tissue biopsy in patients with NSCLC, mainly in those with EGFR mutation. However, ALK rearrangement should be assessed using tissue biopsy as much as possible. Second, brain metastasis of NSCLC might respond to second-generation tyrosine kinase inhibitors (TKIs), such as alectinib and ceritinib, after resistance to crizotinib regardless of the presence or absence of ALK rearrangement in liquid biopsy. Finally, combined radiotherapy and TKI therapy appears optimal in patients with brain metastasis of NSCLC after resistance to crizotinib in the absence of a definitive driver gene.

Treatment of brain metastases in ALK-positive non-small cell lung cancer

Brain metastases are quite frequent in patients with ALK-translocated non-small cell lung cancer (NSCLC): they are often not amenable to surgical resection and are generally treated with radiotherapy (RT). This however causes severe late toxic side effects that may become invalidating considering the relatively long survival provided by recent medical treatment with target therapies. Several clinical trials have demonstrated that ALK-inhibitors (crizotinib, alectinib, brigatinib) show excellent activity also against brain metastases. It is therefore reasonable, in asymptomatic patients, to start treatment with specific inhibitors: RT will be used at the time of tumor progression or when symptoms appear. This sequence provides the best quality of life for patients.