A Case of Primary Pulmonary Combined Small Cell Carcinoma With Adenocarcinoma Harboring the Same KLC1-ALK Fusion in Both Histologic Components

Are anaplastic lymphoma kinase (ALK) and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation driver biomarkers of pulmonary neuroendocrine tumors (NETs) and carcinomas (NECs)?

Background: Novel targets in neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs) are needed to improve outcome. The presence of O6-Methylguanine-DNA methyltransferase (MGMT) promoter methylation in NETs and NECs may act as a predictive marker for response on treatment with temozolomide. As anaplastic lymphoma kinase (ALK) plays an important role in the nervous system we hypothesized that ALK rearrangement can act as a biomarker in patients with NETs and NECs.

Materials and Methods: We performed a retrospective analysis to establish the frequency of MGMT promoter methylation and ALK expression in tissue samples of patients with NETs and NECs.

Results: 21% (14/67) of patients tested positive for MGMT promoter methylation. MGMT promoter methylation was present in 33% (3/9) patients with typical carcinoid, in 22% (2/9) patients with atypical carcinoid, in 22% (8/37) patients with small cell lung cancer and in 8% (1/12) patient with large cell neuroendocrine carcinoma. ALK- expression was present in 14% (10 of 70 patients). In all of these patients, no ALK-rearrangement nor ALK-mutation was revealed.

Conclusions: Routine testing of NET and NEC samples for an ALK rearrangement is not recommended as ALK-expression is not associated with an ALK-rearrangement. Routine testing of NET and NEC samples for MGMT will detect a promoter hypermethylation in a sizable minority of patients who are eligible for a targeted treatment with temozolomide.

Case Report: Combined Small Cell Lung Carcinoma With Pulmonary Adenocarcinoma

Background

Combined small cell lung carcinoma is defined as cancer tissues that mainly contain small cell lung cancer (SCLC) components with non-SCLC (NSCLC) histopathological types. The most common part of NSCLC is squamous cell carcinoma or large cell carcinoma. Combined SCLC (CSCLC) contains adenocarcinoma is extremely rare.

Case Presentation

We reported a case with surgically treated diagnosed as CSCLC with adenocarcinoma in an elderly and we summarized the clinical features of this disease. The patient has remained well for over 2 weeks after the treatment.

Conclusion

There are still few research reports on CSCLC. Since the survival time of patients with advanced CSCLC is shorter than that of simple SCLC, the recommended treatment for CSCLC is early detection and early surgery. In order to facilitate preoperative diagnosis and avoid misdiagnosis of such rare diseases, more cases need to be reported.

Combined small cell lung carcinoma harboring ALK rearrangement: A case report and literature review

Combined small cell lung cancer (c‐SCLC) is a relatively rare subtype of SCLC and is defined by the combination of SCLC and any elements of non‐small cell carcinoma (NSCLC). Standard chemotherapy for patients with c‐SCLC has not yet been established. Gene mutations such as epidermal growth factor receptor (EGFR) mutations may be detected in patients with c‐SCLC. However, little is known about anaplastic lymphoma kinase (ALK) rearrangement in c‐SCLC patients. Here, we report a young female patient who was successfully treated with alectinib for ALK‐positive c‐SCLC after failure of immunochemotherapy for SCLC and cytotoxic chemotherapy for adenocarcinoma. Moreover, we performed a literature review of EGFR‐ or ALK‐positive c‐SCLC patients. Our report suggests that ALK testing may be justified in patients with SCLC that contain an adenocarcinoma component.

Key points

Significant findings of the study

• This is the first report describing the treatment course comprising immunochemotherapy and ALK‐TKI in a patient with c‐SCLC harboring ALK rearrangement.

What this study adds

• Our case and literature review suggest that although ALK mutation is rare in patients with c‐SCLC, its identification and treatment with ALK‐TKIs may contribute to clinical benefits.

Transformational Changes Between Non-Small Cell and Small Cell Lung Cancer-Biological and Clinical Relevance-A Review

During the course of therapy, patients with small cell lung cancer have been noted to develop transformation to non-small cell lung cancer and conversely, patients with non-small cell lung cancer have had transformation to small cell lung cancer or other non-small cell histologies. Transformation may occur after prior tyrosine kinase inhibitors, chemotherapy, immunotherapy or radiation therapy. These changes reflect on the overlapping biology of these cell types and the clinical need for re-biopsy at times of disease progression. The optimum therapy after transformation will depend upon prior therapies received, the functional capacity of the patient, and further research to define the best therapy options.