I have dozens of so-called oligo-recurrence successfully treated with complete regression. Notable cases like, an elderly man with SCLC, limited stage having brain oligo-recurrence years later, proven after resection and became disease-free again for another several years. A woman with breast cancer with hepatic oligo-recurrence. Resected followed by chemotherapy and then enters into complete remission for more than a decade now. Lots of these cases. The point is don't easily give up when a patient got distant relapse even in brain.

Oligometastases is a disease with a biology different from other cases of metastatic disease as evidence in osteosarcoma or liver mets of colo-rectal cancer.

We must work in the search for predictive factors that may help improve the selection of patients and reduce morbidity and sometimes unnecessary costs.

What dou you think about miRNA?

The oligometastatic state is becoming an increasingly recognized entity. Most studies showing long term survival are retrospective, and the absence of randomized data created a big debate as whether the observed long term survival is a result of improved patients' selection or a reflection of effective therapeutic strategy (surgical resection of metastasis). This uncertainty was the rationale for conducting a randomized trial of pulmonary metastasectomy versus chemotherapy for colorectal cancer (CRC) pulmonary metastasis (Treasure T, et al. Pulmonary metastasectomy in colorectal cancer: the PulMiCC trial). Given that uncertainty, studies focused on identifying groups of patients that are expected to derive the best survival advantage following resection of oligometastatic sites through analysis of prognostic factors in an attempt to identify a tool for selecting patients. Certain groups of CRC patients and lung metastasis are expected to have a 5-year OS that approaches 70% following resection of pulmonary metastasis (Salah S, Watanabe K, Welter S, et al. Colorectal cancer pulmonary oligometastases: pooled analysis and construction of a clinical lung metastasectomy prognostic model. Ann Oncol. 2012 Oct;23(10):2649-55). Similarly, selected patients with oligometastatic NSCLC, even those with extra-adrenal or extra cranial metastasis, can have a chance of long term survival (5-year OS approaching 50%) with the surgical approach if the mediastinal LN are free of metastasis (Salah S, Tanvetyanon T, Abbasi S. Metastatectomy for extra-cranial extra-adrenal non-small cell lung cancer solitary metastases: systematic review and analysis of reported cases. Lung Cancer. 2012 Jan;75(1):9-14).

Encouraging survival data are also reported following resection of oligometastasis for renal cell carcinoma, melanoma, urothelial carcinomas...etc.

In my opinion, resection of the oligometastasis , although no randomized data are yet available, should be considered in every patient who is fit for surgery if the primary is controlled, the metastasis is limited to one organ, the disease is stable for at least 3-6 months and in the absence of LN involvement. This is the only approach that showed a chance for long term survival and the possibility of cure and as such, patients should not be denied a potentially curative surgery.

Data of the randomized PulMiCC trial is awaited and will better define the role of pulmonary metastasectomy in CRC pulmonary oligometastasis.

Finally, I encourage research projects that intend to identify bio-markers that may be linked to the oligometastatic state and may assist in selection of the "real" oligometastatic cases.