Stage 3 N2 Lung Cancer: A Multidisciplinary Therapeutic Conundrum.

PURPOSE OF REVIEW: The treatment of stage III N2 non-small cell lung cancer (NSCLC) remains debated. There is an absence of a universally agreed definition of resectability for this heterogeneous group and a lack of trial data. RECENT FINDINGS: We reviewed and compared current international guidelines and evidence surrounding management of stage III N2 NSCLC. The Irish and Australian guidelines advise subcategorising N2 disease into N2a (may be resectable) and N2b (never resectable). On the contrary, American and British guidelines avoid subcategorising N2 disease, emphasising importance of local MDT decisions. It is suggested that evidence for resection of stage III tumours is relatively weak, but that stage IIIA should generally be considered for resection, and stage IIIB is not recommended for resection. For resectable disease, surgery may be combined with neoadjuvant chemoimmunotherapy, or adjuvant chemotherapy followed by immunotherapy and radiotherapy in selected patients. There is some evidence that technically resectable disease can be treated solely with radiotherapy with similar outcomes to resection. In the event of unresectable disease, chemoradiotherapy has been the traditional management option. However, recent studies with chemoradiotherapy alongside immunotherapy appear promising. There are many factors that influence the treatment pathway offered to patients with stage III N2 NSCLC, including patient factors, team expertise, and local resources. Therefore, the role of MDTs in defining resectability and formulating an individualised treatment plan is crucial.

Indolethylamine N-methyltransferase (INMT) is not essential for endogenous tryptamine-dependent methylation activity in rats.

Indolethylamine N-methyltransferase (INMT) is a transmethylation enzyme that utilizes the methyl donor S-adenosyl-L-methionine to transfer methyl groups to amino groups of small molecule acceptor compounds. INMT is best known for its role in the biosynthesis of N,N-Dimethyltryptamine (DMT), a psychedelic compound found in mammalian brain and other tissues. In mammals, biosynthesis of DMT is thought to occur via the double methylation of tryptamine, where INMT first catalyzes the biosynthesis of N-methyltryptamine (NMT) and then DMT. However, it is unknown whether INMT is necessary for the biosynthesis of endogenous DMT. To test this, we generated a novel INMT-knockout rat model and studied tryptamine methylation using radiometric enzyme assays, thin-layer chromatography, and ultra-high-performance liquid chromatography tandem mass spectrometry. We also studied tryptamine methylation in recombinant rat, rabbit, and human INMT. We report that brain and lung tissues from both wild type and INMT-knockout rats show equal levels of tryptamine-dependent activity, but that the enzymatic products are neither NMT nor DMT. In addition, rat INMT was not sufficient for NMT or DMT biosynthesis. These results suggest an alternative enzymatic pathway for DMT biosynthesis in rats. This work motivates the investigation of novel pathways for endogenous DMT biosynthesis in mammals.