Table 5. Oligometastatic lung cancer.
| 1st Author, Year [Ref] | Strength of evidence-based on study design / endpoint | Prospective (P) or Retrospective (R) | Sample size | Definition-Oligometastases | Therapy | Endpoint | Conclusion |
|---|---|---|---|---|---|---|---|
| DeRuysscher, 2012 [81] | 2 /A | P | 39 | <5 synchronous mets | Local trt to mets | MOS-13.5 mths. 3yr OS- 17.5% | Subgroup with synchronous OM may benefit from radical trt |
| Collen, 2014 [80] | 2 /A | P | 26 | ≤5 met lesions | SBRT to primary and all mets | MOS-23 mths. 1yr OS- 67% | SBRT acceptable option and results in acceptable PFS |
| Khan, 2006 [83] | 3i /A | R | 23 | 1–2 sites | CT + local-regional therapy | MOS- 20 mths | Subset of pats may benefit from aggressive local, regional, and systemic treatment |
| Nieder, 2014 [82] | 3i /A | R | 23 | maximum of 3 metastases to 1 organ | ‘Active therapy’, irrespective of specific treatment received | MOS- 11.7 mths for OM and 5.6 mths for advanced mets | Prospective studies for this population are warranted |
| Guerra 2012 [85] | 3ii/A | R | 78 | <5 mets at diagnosis | Definitive CRT to primary + mets | 3yr OS-25% | Tumor volume, KPS, + at least 63Gy to primary tumor are associated with improved OS in OM NSCLC |
| Ashworth, 2014 [84] | 3ii /A | R | 757 | Hx of curative trt to primary and w 1–5 mets treated w surgery, RT or XRT | Controlled primary tumor and locally ablative treatments to all mets | MOS-26 mths, 5yr OS- 29.4%; | Significant OS differences in OM according to type of metastatic presentation and N status |
| Collaud, 2012 [86] | 3iii /A | R | 29 | Synchronous single organ met | Lung resection and local trt to mets | 1yr OS- 65%, 5yr OS- 36%; MOS- 20.5 mths | Multimodality trt including lung resection should be considered in select pats |
| Congedo, 2012 [87] | 3iii /A | R | 53 | Resected primary with 1–2 met lesions considered to be resectable | Trt with curative intent | 5yr OS- 24%, MOS- 19 mths | Surgical trt for selected patients is feasible and safe |
| Hasselle 2012 [88] | 3iii/A | R | 25 | ≤5 mets | Hypofractionated image-guided RT (HIGRT) | MOS- 22.7 mths; 18mth OS- 52.9% | HIGRT for OM NSCLC provides durable control in ≤2 lesions |
| Ashworth, 2013 [76] | 3iii /A | R | 2176 | 1–5 mets | Surgery, SART or SRS | 5yr OS-8.3–86%, MOS- range- 5.9–52 mths | Survival times for OM were highly variable, however long-term survivors do exist. |
| Griffioen, 2013 [89] | 3iii /A | R | 61 | 1–3 synchronous mets | Radical trt (Surgery or RT) to primary and mets | MOS- 13.5 mths; 2yr OS- 38% | Radical trt to selected pats can result in favorable 2yr survival |
| Yano 2013 [90] | 3iii/Diii | R | 13 | Completely resected NSCLC, with post-op recurrence, excluding secondary lung site. 1–3 distant mets, not brain only | Resection or RT of mets versus CT of mets | Median PFS resection/RT-20 mths; Median PFS for CT was 5 and 15 mths, respectively | Local therapy is a choice for 1st line treatment in post-op OM recurrence |
| Yu 2013 [91] | 3iii/A | R | 18 | EGFR-mutant lung cancer previously treated with erlotinib or gefitinib, then progression on EGFR TKI therapy, (<5 sites disease) | RT, RFA, or resection of a site of progressive disease | MOS from local therapy was 41 mths | EGFR-mutant lung cancers q acquired resistance to EGFR TKI therapy are amenable to local therapy to treat OM disease when used in conjunction with continued EGFR inhibition |
| Endo, 2014 [98] | 3iii/A | P | 20 | single-organ met, or single-organ metachronous met s/p resect path T1–2N0–1 lung cancer | Resection primary tumor and mets | 5yr OS-44.7% | Resection of primary tumor and mets had outcomes comparable to stage II patients |
| Gray, 2014 [92] | 3iii /A | R | 66 | 1–4 synchronous brain mets | Aggressive thoracic therapy (ATT) Surgery or CRT versus no-ATT | MOS-26.4 mths for ATT versus 10.5 mths no-ATT | Aggressive management of thoracic disease in OM NSCLC associated with improved survival |
| Cheufou, 2014 [93] | 3iii /A | R | 37 | Synchronous single brain met | Resection cerebral mets and primary tumor | 2yr OS- 24% | No increased risk of complication or mortality; median survival encouraging |
| Parikh, 2014 [94] | 3iii /A | R | 186 | ≤5 synchronous distant met lesions | Definitive primary therapy | MOS-17 mths for OM versus 14 mths for advanced disease; Among OM, MOS- 19 mths for definitive therapy versus 16 mths for no definitive therapy | Definitive therapy to primary tumor may provide survival benefit |
| Sheu, 2014 [95] | 3iii/A | R | 90 | ≤3 synchronous mets | CT, then Surgery or RT before disease progression. Then +/−comprehensive local therapy (CLT) | MOS- 22.3 mths; 1yr OS- 75% | CLT associated with improved OS and PFS with matched analysis using propensity score's |
| Tonnies, 2014 [96] | 3iii/A | R | 99 | Solitary hematogenous metastasis within 3 mths of primary resection | Primary NSCLC curatively resected; then metastasectomy | 5yr OS- 38% | Metastasectomy for synchronous OM NSCLC can be performed in selected patients |
| Ouyang, 2014 [97] | 3iii/A | R | 95 | Not defined | 3DRT + CT | 3yr OS-15.8% | Radiation dose ≥63Gy and having bone only mets associated with better OS; aggressive thoracic radiation may play a role in improving OS |
Abbreviations: Met(s) = metastasis(es); Trt = treatment; MOS = median overall survival; OM = oligometastases; SBRT = stereotactic body radiation therapy; mths = months; PFS = progression free survival; CT = chemotherapy; CRT = chemoradiation therapy; SART = Stereotactic ablative radiation therapy; KPS = Karnofsky performance status; OS = overall survival; NSCLC = non-small cell lung cancer; Hx = history; RT = radiation therapy; XRT = external radiation therapy; N = node; EGFR = epidermal growth factor receptor; TKI = tyrosine kinase inhibitor; RFA = radio-frequency ablation