Survival impact of post-operative immunotherapy in resected stage III cutaneous melanomas in the checkpoint era

BACKGROUND

Checkpoint inhibitors have shown improvement in recurrence-free survival in the post-operative setting for node-positive melanoma and were first approved in late 2015. However, single-agent checkpoint therapies have yet to show benefit to overall survival (OS) for lower-risk stage III cancers. We evaluated the OS benefit of post-operative immunotherapy in the National Cancer Database (NCDB).

PATIENTS AND METHODS

Patient cases were selected from the NCDB 2020 Participant Use File. Patients diagnosed with stage III cutaneous melanoma between 2016 and 2019 who underwent definitive resection for their melanoma were included. OS between those who received post-operative immunotherapy within 84 days of surgery and those who did not was analyzed by the Kaplan-Meier method. Demographic and clinical characteristics between the two groups were compared via Cox proportional hazard models.

RESULTS

14 978 patients with stage III melanoma were included. Of those, 34.9% (n = 5234) received post-operative immunotherapy and 65.1% (n = 9744) did not. Using the American Joint Committee on Cancer version 8 (AJCCv8) staging, 36-month survival was significantly higher in patients who received post-operative immunotherapy compared to no post-operative systemic therapy in those diagnosed with stage IIIB (88.0% versus 84.7%, P = 0.011), IIIC (75.6% versus 68.1%, P < 0.001), or IIID (59.2% versus 48.4%, P = 0.002). No significant improvement in 36-month survival was seen in patients who received post-operative immunotherapy in patients with stage IIIA disease (93.0% versus 92.2%, P = 0.218).

CONCLUSIONS

Post-operative immunotherapy had an OS benefit in patients with AJCCv8 stage IIIB, IIIC, and IIID disease, but had no significant survival benefit for patients with stage IIIA melanomas.

Separation of antithrombin III variants by micellar electrokinetic chromatography

The characterisation of proteins is still one of the most challenging analytical tasks in modern bioanalysis. Due to the complex structure of proteins, several analytical techniques are often required to get sufficient information. Antithrombin III (AT III), a high-molecular-mass plasma glycoprotein which is an important protease inhibitor and the main modulator of thrombin activity, circulates in plasma in two isoforms, the so-called AT III-alpha (90-95%) and -beta (5-10%). Micellar electrokinetic chromatography was used to analytically separate these AT III variants, which differ in their affinity to the polysaccharide heparin.

Group therapy program for African-American veterans with posttraumatic stress disorder

A Vet Center's group therapy treatment program for African-American veterans with posttraumatic stress disorder (PTSD) has met regularly and expanded since it was established in 1984. Program attributes described by participants as particularly helpful include facilitating open communication of thoughts and feelings among African-American men; providing support for coping with the intrapsychic, social, and economic effects of racism; increasing knowledge about the causes, consequences, and treatment of PTSD; and decreasing emotional and social isolation. The program appears to be a useful treatment for African-American veterans with PTSD.

Immunization of Aotus monkeys with recombinant Plasmodium falciparum hybrid proteins does not reproducibly result in protection from malaria infection

Plasmodium falciparum antigens SERP, HRPII, MSAI, and 41-3 have shown promise as vaccine components. This study aimed at reproducing and extending previous results using three hybrid molecules. Antibody responses were reproduced in Aotus monkeys, but solid protection from a P. falciparum blood-stage challenge that showed an unintendedly enhanced pathogenicity was not observed.

A strategy for the mapping of N-glycans by high-performance capillary electrophoresis

We have evaluated high-performance capillary electrophoresis (HPCE) with respect to its suitability for use in establishing a carbohydrate-mapping database that would enable a carbohydrate structural analysis by mere comparison of migration times. The suitability of HPCE for carbohydrate structural assignments was ascertained by validation experiments. The migration times of distinct N-glycans, prepared and measured on different days, were shown to be highly reproducible, with a coefficient of variation of usually less than 0.20%, requiring only femtomoles of N-glycan per injection for reliable measurements. By including mesityl oxide and sialic acid as internal standards and a triple-correction method, HPCE fulfills the analytical requirements with respect to accuracy, precision, reproducibility, and sensitivity. The N-glycan-mapping database was established using a newly developed and optimized buffer system containing 1,5-diaminopentane as an organic modifier. Approximately 80 different sialylated N-glycans of known structure, which have thus far been measured and characterized, have been entered into our Lotus 1-2-3 mapping database. The database for structural determinations was tested using the N-linked carbohydrates released from recombinant human urinary erythropoietin (baby hamster kidney) by PNGase F treatment and from bovine serum fetuin and alpha 1-acid glycoprotein by automated and manual (large-scale) hydrazinolysis, respectively. The efficiency of the database and of the triple-correction method was further confirmed by HPCE measurements performed in a different laboratory and by a different analyst who used the HPCE system of a different manufacturer.

The mapping by high-pH anion-exchange chromatography with pulsed amperometric detection and capillary electrophoresis of the carbohydrate moieties of human plasma alpha 1-acid glycoprotein

The reducing oligosaccharides released from alpha 1-acid glycoprotein (AGP) by conventional hydrazinolysis have been analyzed by two different mapping techniques, using high-pH anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD) and capillary electrophoresis (CE) with uv detection at 190 nm. The CE measurements proved about 4000 times more sensitive than the measurements by HPAE-PAD. The N-glycan pool was fractionated by Mono Q anion-exchange chromatography, and individual fractions so obtained were desialylated using Vibrio cholerae neuraminidase. The resulting asialo-N-glycans were further analyzed by HPAE-PAD, revealing 2 major, 4 intermediate, and 4 small peaks and at least 3 spikes, which counted for at least 13 different asialo-N-glycans. The carbohydrate structures were tentatively assigned by comparison of the Mono Q-separated N-glycans with the known AGP carbohydrate structures and known structures contained in a mapping database that allows structural assignment of N-glycans by mere comparison of retention times. In addition to the hitherto known AGP carbohydrate structures, we have tentatively identified a number of sulfated N-glycans that are currently being analyzed in more detail. We have also compared the glycan pools recovered from AGP using hydrazinolysis and glycopeptidase F (PNGase F). Approximately 40 distinct peaks could be detected in the hydrazinolysis-derived N-glycan pool by either technique (HPAE-PAD and CE), while about 30 distinct peaks were detected in the N-glycan pool derived by PNGase F digestion of the tryptic AGP digest of the same batch of AGP. These differences were attributed to an increased desialylation (approximately 3 mol%) during hydrazinolysis, based on the detection by HPAE-PAD and CE of free sialic acid and monosialylated oligosaccharides in the glycan pool derived by conventional hydrazinolysis. The integrity of the N-glycans' chitobiose core was examined by 500-MHz 1H NMR spectoscopy. The hydrazinolysis procedure could be optimized such that the hydrazinolysis-derived N-glycan pool was chromatographically essentially identical to the PNGase F-derived N-glycan pool. Hydrazinolysis proved best, with practically no loss of N-acetlylneuraminic acid and the closest resemblance to the PNGase F-derived N-glycan pool, using an automated apparatus. Notably, it was recognized that, in our hands, PNGase F digestion in the presence of sodium dodecyl sulfate resulted in partial desialylation of the liberated N-glycans.

Human basement membrane collagen (type IV). The amino acid sequence of the alpha 2(IV) chain and its comparison with the alpha 1(IV) chain reveals deletions in the alpha 1(IV) chain

The cDNA and protein sequences of the N-terminal 60% of the alpha 2(IV) chain of human basement membrane collagen have been determined. By repeated primer extension with synthetic oligodeoxynucleotides and mRNA from either HT1080 cells or human placenta overlapping clones were obtained which cover 3414 bp. The derived protein sequence allows for the first time a comparison and alignment of both alpha chains of type IV collagen from the N terminus. This alignment reveals an additional 43 amino acid residues in the alpha 2(IV) chain as compared to the alpha 1(IV) chain. 21 of these additional residues form a disulfide-bridged loop within the triple helix which is unique among all known collagens.

Completion of the amino acid sequence of the alpha 1 chain of human basement membrane collagen (type IV) reveals 21 non-triplet interruptions located within the collagenous domain

The cDNA and protein sequences of the N-terminal half of human basement membrane collagen (type IV) have been determined. Overlapping cDNA clones were constructed by repeated primer extension with synthetic oligonucleotides. They cover 2953 bp, beginning at the 5' end of the corresponding mRNA. At the protein level, the sequence of the cyanogen bromide peptide CB6 adjacent to the 7S domain has been additionally elucidated. The data presented here complete the protein sequence and nearly the entire cDNA sequence of the human alpha 1(IV) chain. The amino-terminal half of the alpha 1(IV) chain contains 8 cysteine residues involved in intramolecular and intermolecular cross-links. The entire triple-helical domain of alpha 1(IV) is interrupted by 21 non-triplet regions.