The impact of surgery on the multidisciplinary treatment of bronchogenic small cell carcinoma (updated review including ongoing studies)

[Surgery for small-cell lung cancer]

Small-cell lung cancer (SCLC) is a high-grade neuroendocrine carcinoma, metastatic at the time of initial diagnosis in 70% of cases. Within the 30% of localised tumours only 5% of patients are eligible for surgical treatment according to the recommendations of learned societies. These recommendations are mainly based on old phase II and III randomised prospective trials and more recent registry studies. Surgical care is only possible within a multimodal treatment and essentially concerns small-sized tumours without involvement of hilar or mediastinal lymph nodes. As with non-small cell lung cancer (NSCLC), lobectomy with radical lymph node removal is the recommended procedure to achieve complete tumour resection. Patient selection for surgery includes age, performance status and comorbidity factors. Adjuvant chemotherapy combining Platinum salts and Etoposide for resected stage I tumours is recommended by ASCO, ACCP and NCCN. The precise sequence of neo-adjuvant or adjuvant treatments remains controversial because of the large heterogeneity in clinical practice reported in the studies and the context at the time of SCLC discovery. The 5-year survival rate of patients with early stage disease (pT1-2N0M0) treated by lobectomy and adjuvant chemotherapy is between 30% and 58%, which validates the primary place that surgery must have in these early forms. There is certainly little or even no place for such a therapeutic sequence in locally advanced stages (T3-T4 or N2). However, the stage heterogeneity, as in NSCLC, makes final conclusions difficult. In fact, some registry studies with pairing scores reported a median survival of more than 20 months in N2 SCLC. So, all files of SCLC must be evaluated in a multidisciplinary meeting in order to find the optimal solution for patients with rare and heterogeneous tumours.

Surgery for limited-stage small-cell lung cancer

BACKGROUND

Current treatment guidelines for limited-stage small-cell lung cancer (SCLC) recommend concomitant platinum-based chemo-radiotherapy plus prophylactic cranial irradiation, based on the premise that SCLC disseminates early, and is chemosensitive. However, although there is usually a favourable initial response, relapse is common and the cure rate for limited-stage SCLC remains relatively poor. Some recent clinical practice guidelines have recommended surgery for stage 1 (limited) SCLC followed by adjuvant chemotherapy, but this recommendation is largely based on the findings of observational studies.

OBJECTIVES

To determine whether, in patients with limited-stage SCLC, surgical resection of cancer improves overall survival and treatment-related deaths compared with radiotherapy or chemotherapy, or a combination of radiotherapy and chemotherapy, or best supportive care.

SEARCH METHODS

We performed searches on CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science up to 11 January 2017. We handsearched review articles, clinical trial registries, and reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with adults diagnosed with limited-stage SCLC, confirmed by cytology or histology, and radiological assessment, considered medically suitable for resection and radical radiotherapy, which randomised participants to surgery versus any other intervention.

DATA COLLECTION AND ANALYSIS

We imported studies identified by the search into a reference manager database. We retrieved the full-text version of relevant studies, and two review authors independently extracted data. The primary outcome measures were overall survival and treatment-related deaths; and secondary outcome measures included loco-regional progression, quality of life, and adverse events.

MAIN RESULTS

We included three trials with 330 participants. We judged the quality of the evidence as very low for all the outcomes. The quality of the data was limited by the lack of complete outcome reporting, unclear risk of bias in the methods in which the studies were conducted, and the age of the studies (> 20 years). The methods of cancer staging and types of surgical procedures, which do not reflect current practice, reduced our confidence in the estimation of the effect.Two studies compared surgery to radiation therapy, and in one study chemotherapy was administered to both arms. One study administered initial chemotherapy, then responders were randomised to surgery versus control; following, both groups underwent chest and whole brain irradiation.Due to the clinical heterogeneity of the trials, we were unable to pool results for meta-analysis.All three studies reported overall survival. One study reported a mean overall survival of 199 days in the surgical arm, compared to 300 days in the radiotherapy arm (P = 0.04). One study reported overall survival as 4% in the surgical arm, compared to 10% in the radiotherapy arm at two years. Conversely, one study reported overall survival at two years as 52% in the surgical arm, compared to 18% in the radiotherapy arm. However this difference was not statistically significant (P = 0.12).One study reported early postoperative mortality as 7% for the surgical arm, compared to 0% mortality in the radiotherapy arm. One study reported the difference in mean degree of dyspnoea as -1.2 comparing surgical intervention to radiotherapy, indicating that participants undergoing radiotherapy are likely to experience more dyspnoea. This was measured using a non-validated scale.

AUTHORS' CONCLUSIONS

Evidence from currently available RCTs does not support a role for surgical resection in the management of limited-stage small-cell lung cancer; however our conclusions are limited by the quality of the available evidence and the lack of contemporary data. The results of the trials included in this review may not be generalisable to patients with clinical stage 1 small-cell lung cancer carefully staged using contemporary staging methods. Although some guidelines currently recommend surgical resection in clinical stage 1 small-cell lung cancer, prospective randomised controlled trials are needed to determine if there is any benefit in terms of short- and long-term mortality and quality of life compared with chemo-radiotherapy alone.