Metachronous ipsilateral lung cancer: reoperate if you can!

The standard of care in operable patients with early-stage lung cancer is surgery, consisting of anatomical parenchymal resection with systematic lymph node dissection. However, there is no firm recommendation regarding the strategy to adopt in patients with a second primary (or multiple primary) lung cancer. This clinical scenario of metachronous lung cancer is not uncommon, with a reported incidence from 0.2% to 20% (1–2% per patient per year) at follow-up after a first lung cancer surgery [1, 2], and is more complex to treat because of the association of several parameters: (i) compromised pulmonary function as the result of the first surgery, (ii) technical surgical difficulties of ipsilateral redo surgeries due to pleural adhesions and/or hilar and mediastinal fibrosis, and intraoperative issues of one-lung ventilation in contralateral surgeries, (iii) higher rate of postoperative complications and (iv) equipoise of alternative ablative options (i.e. SBRT: stereotactic radiotherapy, RFA: radiofrequency ablation). In addition, uncertainty about the possible metastatic nature of a lung nodule thought to be a new primary cancer typifies the complexity to determine the best treatment strategy and results in variable modalities proposed to patients depending on consultant specialty [3].

Among all possible clinical scenario, ipsilateral disease following a first anatomical lung resection appeared to be the most challenging one, as it may add moderate to extreme intraoperative difficulties of dissection in theoretically more compromised patient. In the current issue of the EJCTS, Okazaki et al. focused on these singular cases of early-stage ipsilateral metachronous lung cancer following lobectomy and requiring a local treatment [4]. They conducted a multicentre retrospective study of a cohort of 6293 patients from 23 institutes over a 7-year period (2012–2018), identifying 51 patients who underwent ipsilateral redo lung resections for a new primary lung cancer. The study of this cohort (n = 51), as well as the comparison of a subgroup of these patients with clinical stage I lung cancer (n = 34) with those of 66 patients treated with non-anatomical sublobar resections, and of 4049 patients who underwent pulmonary resection without prior ipsilateral pulmonary resection, resulted in the main following findings:

1. Patients undergoing anatomical resection after ipsilateral lobectomy for lung cancer had a similar age (mean age around 70–71 years old), similar pulmonary function (mean FEV1 around 90–91%, vital capacity around 101%) and similar performance status than those patients without prior ipsilateral resection. This suggests a stringent selection of candidates for redo surgery, which is also observable in the comparison with patients treated with non-anatomical resection, who were older, and with a lower vital capacity.

2. Ipsilateral redo surgeries appeared extremely challenging technically and medically, with higher occurrence of intraoperative complications and bleeding, longer operative time, a trend towards higher rate of postoperative complications (especially when only the middle lobe was preserved on the right side), and decreased feasibility of minimally invasive surgery.

3. Remarkable outcomes without postoperative mortality, and with similar and eventually a noticeable trend towards a better overall survival in these patients (overall survival of 96.7% at 5 years vs 83.1% at 5 years in patients without prior ipsilateral resection) which is possibly explained by a better fitness and a close medical follow-up with early detection of metachronous lung lesion. In contrast, patients treated with non-anatomical resection (wedge) had worse long-term outcomes (overall survival of 73.1% vs 96.7% at 5 years).

Based on those results, authors discussed treatment options, including second surgery and alternative ablative options and proposed that patients who are ineligible for lung resection should be treated with SBRT/RFA, patients with impaired lung function and peripheral lesion should be treated with non-anatomical resection (wedge) and patients with adequate lung function without major comorbidities should be treated with anatomical resection.

The main axis of discussion in this article is the thorough selection of surgical candidates for anatomical resection for a second primary lung cancer. To better appreciate this improved selection of winners, it would have been of interest to know the proportion of those patients who were denied for surgery and redirected to alternative treatments, as the selection process seems quite harsh (51 patients selected among 6297, 0.8%). Outcomes in those patients redirected towards alternative treatments would have been a meaningful contribution to this paper, too.

Furthermore, as this surgery is known for its high degree of technical difficulty due to a modified anatomy and tight local adhesions, it would have been valuable to have data regarding surgical parameters such as extent of lymphadenectomy, tumour/nodal upstaging, intraoperative conversion rate and intraoperative change of extent of resection (from segmental to lobar and from lobar to completion pneumonectomy).

In summary, despite being a challenging procedure, Okazaki et al. reported remarkable short- and long-term outcomes in patients treated surgically with anatomical lung resection of ipsilateral metachronous lung cancer following a first anatomical resection for lung cancer. These results should stimulate an accurate follow-up of patients following a first resection for lung cancer and a systematic meticulous assessment for operability in case of ipsilateral metachronous lung cancer.

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