The role of surgery in high grade neuroendocrine tumours of the lung

Abstract

High grade lung neuroendocrine tumours are a heterogeneous subtype of pulmonary cancers including small cell lung cancer (SCLC) and large-cell neuroendocrine carcinoma (LCNEC). LCNEC represents approximately 2-3% of lung cancers, whereas SCLC represents 15-20% of lung cancers. Patients with SCLC and LCNEC have a poor prognosis compared with patients with non-small cell lung cancer (NSCLC). LCNEC is treated with primary surgical resection in stages I-II, which is similar to other NSCLCs. Neo-adjuvant treatment in stage III is similar to NSCLC but has not been well studied. LCNEC tumours have an unfavourable prognosis in higher stages but a more favourable prognosis in earlier stages. Surgery plays a minor role in treatment of SCLC because tumours are often locally advanced or have metastasized at the time of presentation and treatment relies on chemo- or chemoradiotherapy. However, patients with limited cancer may demonstrate better disease control upon surgical treatment. The resection rate of limited disease (LD) SCLC is low (1-6%), but 5-year survival rates of 31-42% after surgical resection are encouraging and are significantly higher than the survival rates of comparable patients that did not have surgery. Curing SCLC in stage I is reported in up to 66% of cases. Local treatment with either resection or radiotherapy alone is followed by high rates of locoregional and distant recurrences, so preoperative or adjuvant treatment is recommended. Here, we summarise the similarities and differences of SCLC and LCNEC and highlight the role of surgery in the treatment of SCLC and LCNEC and its effect on local recurrence prevention.

Keywords: Lung cancer; locoregional recurrence; neuroendocrine tumors of the lung; operation of small cell lung cancer (operation of SCLC).

Figure 1

Centrally located small cell lung cancer (SCLC). Inoperable 68-year-old female, complaining about chest pain and shortness of breath. Heavy smoker for over 45 years. T4 tumour invading the pulmonary artery, left main bronchus, left atrium and subcarinal as well as contralateral hilar lymph nodes.

Figure 2

Distant recurrence of a stage IIa LCNEC after complete resection. 71-year-old male with distant recurrence 12 months after resection of a 5.2-cm LCNEC of the left upper lobe [pT2, pN1 (1/15), M0, R0, G3] followed by four cycles of adjuvant chemotherapy. Multiple liver metastases and one osteolytic lesion in the 10th thoracic vertebra were detected during regular follow-up.

Figure 3

Potential algorithm for the use of surgery in small cell lung cancer (SCLC) compared to non-small cell lung cancer (NSCLC). “Limited disease” (LD) means potentially operable from a surgeon’s point of view and does not mean the old classification of SCLC restricted to one hemithorax accessible within one radiation field. The exclusion of viable N2-disease from surgery leaves the option to indicate resection for N− patients after induction chemoradiotherapy.