The tripeptide thiol antioxidant glutathione (GSH) has multiple physiological functions. Female mice lacking the modifier subunit of glutamate cysteine ligase (GCLM), the rate-limiting enzyme in GSH synthesis, have decreased GSH concentrations, ovarian oxidative stress, preimplantation embryonic mortality, and accelerated age-related decline in ovarian follicles. We hypothesized that supplementation with thiol antioxidants, N-acetyl cysteine (NAC), or α-lipoic acid (ALA) will rescue this phenotype. Gclm-/- and Gclm+/+ females received 0 or 80 mM NAC in drinking water from postnatal day (PND) 21-30; follicle growth was induced with equine chorionic gonadotropin (eCG) on PND 27, followed by an ovulatory dose of human CG and mating with a wild type male on PND 29 and zygote harvest 20 h after hCG. N-acetyl cysteine supplementation failed to rescue the low rate of second pronucleus formation in zygotes from Gclm-/- versus Gclm+/+ females. In the second study, Gclm-/- and Gclm+/+ females received diet containing 0, 150, or 600 mg/kg ALA beginning at weaning and were mated with wild type males from 8 to 20 weeks of age. α-Lipoic acid failed to rescue the decreased offspring production of Gclm-/- females. However, 150 mg/kg diet ALA partially rescued the accelerated decline in primordial follicles, as well as the increased recruitment of follicles into the growing pool and the increased percentages of follicles with γH2AX positive oocytes or granulosa cells of Gclm-/- females. We conclude that ovarian oxidative stress is the cause of accelerated primordial follicle decline, while GSH deficiency per se may be responsible for preimplantation embryonic mortality in Gclm-/- females.

Objective

To review overall survival (OS), recurrence patterns, and prognostic factors of de novo sinonasal squamous cell carcinoma (DN-SCC).

Data sources

PubMed, Scopus, OVID Medline, and Cochrane databases from 2006 to December 23, 2020.

Review methods

The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Articles were required to report either recurrence patterns or survival outcomes of adults with DN-SCC. Case reports, books, reviews, meta-analyses, and database studies were all excluded.

Results

Forty-one studies reported on survival or recurrence outcomes. The aggregate 5-year OS was 54.5% (range, 18%-75%) from 35 studies (n = 1903). Patients undergoing open surgery were more likely to receive radiation therapy and present at an advanced stage compared to those receiving endoscopic surgery (all P < .001). Advanced T stage, presence of cervical nodal metastases, maxillary sinus primary site, and negative human papillomavirus (HPV) status were all correlated with significantly worse 5-year OS. Direct meta-analysis of 8 studies demonstrated patients with surgery were more likely to be alive at 5 years compared to those who did not receive surgery (odds ratio, 2.26; 95% CI, 1.48-3.47; P < .001). Recurrence was reported in 628 of 1471 patients from 26 studies (42.7%) with an aggregate 5-year locoregional control rate of 67.1% (range, 50.4%-93.3%).

Conclusion

This systematic review and meta-analysis suggests that the 5-year OS rate for DN-SCC may approach 54.5% and recurrence rate approaches 42.7%. In addition, various tumor characteristics including advanced T stage, positive nodal status, maxillary sinus origin, and negative HPV status are all associated with decreased survival.