Exploring the microRNA profiles as potential diagnostic probes for oligo- and polymetastatic prognosis of lung metastasis(es) patients

Narrative review: molecular and genetic profiling of oligometastatic non-small cell lung cancer

Objective

The objectives of this review are to discuss: the definition, clinical and biologic features of oligometastatic non-small cell lung cancer (NSCLC), as well as the concept of treating oligoprogression in oligometastatic NSCLC.

Background

A substantial proportion of patients diagnosed with lung cancer present with metastatic disease, and a large portion of patients who present with localized disease later develop metastases. Oligometastatic NSCLC is defined as an intermediate state between localized and widespread metastatic disease, where there may be a role for curative localized therapy approach by treating the primary tumor and all metastases with radiotherapy or surgery. Despite the increasing application of this approach in patients with lung cancer, the identification of patients who might benefit from this approach is yet to be well characterized.

Methods

After a systematic review of the literature, a PubMed search was performed using the English language and the key terms: oligometastatic, non-small cell lung cancer (NSCLC), localized consolidative treatment (LCT), biomarkers, biologic features, clinical features. Over 500 articles were retrieved between 1889–2021. A total of 178 papers discussing the definition, clinical and biologic factors leading to oligometastatic NSCLC were reviewed and included in the discussion of this paper.

Conclusions

Oligometastatic NSCLC is a unique entity. Identifying patients who have oligometastatic NSCLC accurately using a combination of clinical and biologic features and treating them with localized consolidative approach appropriately results in improvement of outcome. Further understanding of the molecular mechanisms driving the formation of oligometastatic NSCLC is an important area of focus for future studies.

Does surgery benefit patients with oligometastatic or metastatic prostate cancer? - A retrospective cohort study and meta-analysis

BACKGROUND

To evaluate long-term oncological outcomes of radical prostatectomy (RP) plus androgen deprivation therapy (ADT) in oligometastatic prostate cancer (PCa) patients.

METHODS

Our study included oligometastatic PCa patients hospitalized between January 1, 2010 and December 31, 2015, who received ADT with or without RP. We evaluated survival by employing Kaplan-Meier methods, with log-rank tests and univariate and multivariate Cox regression analyses. A meta-analysis of previously published studies was additionally performed.

RESULTS

The median follow-up times of both groups were 68.4 months (interquartile range = 56.5-85.0). In this cohort study, significant statistical difference in preoperative total prostate-specific antigen (tPSA; p = .121), clinical T stage (p = .115), and N stage (p = .394) were not found between the two groups. Meanwhile, the difference in overall survival (OS) between the two groups did not reach statistical significance (p = .649). A significant difference was not observed in castration-resistant prostate cancer (CRPC)-free survival between two groups as well (p = .183). Numbers of metastases might be an independent prognosis factor (p = .05) for OS, and postoperative tPSA is a risk predictor for CRPC-free survival (p = .032). A meta-analysis of four relevant studies demonstrated significant statistical difference in clinical improvement with RP plus ADT over ADT alone in OS survival (p < .001; hazard ratio [HR] = 0.51; 95% confidence interval [CI] = 0.38-0.69) instead of CRPC-free survival (p = .42; HR = 0.86; 95% CI = 0.59-1.24).

CONCLUSION

The addition of RP to ADT for the treatment of oligometastatic PCa was associated with an improved OS instead of CRPC-free survival.

Tumor biology and multidisciplinary strategies of oligometastasis in gastrointestinal cancers

More than 70% of gastrointestinal (GI) cancers are diagnosed with metastases, leading to poor prognosis. For some cancer patients with limited sites of metastatic tumors, the term oligometastatic disease (OMD) has been coined as opposed to systemic polymetastasis (PMD) disease. Stephan Paget first described an organ-specific pattern of metastasis in 1889, now known as the "seed and soil" theory where distinct cancer types are found to metastasize to different tumor-specific sites. Our understanding of the biology of tumor metastasis and specifically the molecular mechanisms driving their formation are still limited, in particular, as it relates to the genesis of oligometastasis. In the following review, we discuss recent advances in general understanding of this metastatic behavior including the role of specific signaling pathways, various molecular features and biomarkers, as well as the interaction of carcinoma cells with their tissue microenvironments (both primary and metastatic niches). The unique features that underlie OMD provide potential targets for localized therapy. As it relates to clinical practice, OMD is emerging as treatable with surgical resection and/or other local therapy options. Strategies currently being applied in the clinical management of OMD will be discussed including surgical, radiation-based therapy, ablation procedures, and the results of emerging clinical trials involving immunotherapy.

Lung-Seeking Metastases

Metastases from different cancer types most often affect the lung parenchyma. Moreover, the lungs are among the most frequent sites of growth of metastatic masses of uncertain/unknown lineage of origin. Thus, with regards to pulmonary neoplastic parenchymal nodules, the critical issue is to determine if they are IN the lung or OF the lung. In this review, we highlight the clinical, instrumental and molecular features which characterize lung metastases, mainly focusing on recently advancing and emerging concepts regarding the metastatic niche, inflammation, angiogenesis, immune modulation and gene expression. A novel issue is related to the analysis of biomechanical forces which cooperate in the expansion of tumor masses in the lungs. We here aim to analyze the biological, genetic and pathological features of metastatic lesions to the lungs, here referred to as site of metastatic growth. This point should be a crucial part of the algorithm for a proper diagnostic and therapeutic approach in the era of personalized medicine.