[Nasopharyngeal adenoid cystic carcinoma, a rare but highly challenging disease with unmet therapeutic needs: A case-report and review of the literature]

Nasopharyngeal adenoid cystic carcinoma presenting with exophthalmos: A case report

Adenoid cystic carcinoma is a malignant tumor involving the salivary glands, rarely developing in the nasopharynx. It is a slowly evolving entity with strong local aggressiveness and a high tendency to recurrence. We report the case of 23-year-old patient with adenoid cystic carcinoma of the nasopharynx presenting with exophthalmos in which radiation therapy is the sole therapeutic option.

Adenoid Cystic Carcinoma of the Skull Base: Response to Radiation Therapy and Outcomes in a Retrospective Case Series

Objectives  The main purpose of this article is to examine a single-center cohort of patients with nasopharyngeal adenoid cystic carcinoma (ACC) for pathologic features, skull base invasion, overall survival, and disease-free survival, with a focus on response to proton beam radiation therapy. Design, Setting, and Participants  Single-center institutional cancer registry was used to retrospectively identify and analyze outcomes for 12 patients treated for ACC of the nasopharynx from 2000 to 2016. Main Outcomes and Measures  Primary outcomes included 5-year overall survival and locoregional control. Statistical analysis was performed using STATA 12.0 (STATACorp, College Station, Texas, United States). Spearman's rank order correlation was used for ordinal, monotonic variables with p -values <0.05 considered statistically significant. Survival analysis was performed by Kaplan-Meier method; comparison between groups was performed using log-rank test. Results  Twelve patients with ACC of the nasopharynx were included. All patients presented with advanced disease and were treated with primary radiation therapy, typically proton beam therapy. Only two underwent a surgical attempt at resection. A majority of cases had a cribriform growth pattern. The 5-year survival was 75% and rate of locoregional control rate at 5 years was 50%, comparable to other ACC cohort studies that included earlier stage tumors in various subsites that were surgically resected. Conclusions  Although ACC is traditionally noted to be radioresistant, ACC of the nasopharynx was responsive to radiotherapy in our cohort, despite advanced stage and skull base invasion. Reasons for this improved survival are unclear and suggest the need for further pathologic and genetic characterization of nasopharyngeal ACC.

Three-year results after radiotherapy for locally advanced sinonasal adenoid cystic carcinoma, using highly conformational radiotherapy techniques proton therapy and/or Tomotherapy

PURPOSE

We report the patient outcomes of a treatment combining proton therapy and Tomotherapy in sinonasal adenoid cystic carcinoma involving skull base.

MATERIALS AND METHODS

We included patients treated at Curie Institute, Paris, France, between March 2010 and February 2014 for an advanced adenoid cystic carcinoma involving skull base. Patients received Tomotherapy, proton therapy or both. We evaluated treatment toxicity (according to CTCAE V4), local control, distant metastasis-free survival and overall survival.

RESULTS

Thirteen patients were included, with a median follow-up of 34 months. Radiation therapy followed surgery for 77% of the patients and margins were positive in all those cases. Median dose was 73.8Gy. Local control, distant metastasis-free survival and overall survival at 3 years were respectively 60%, 48% and 60%. One-sided grade 3 hearing impairment occurred in 46% of the patients.

CONCLUSION

Combining high-dose proton therapy and Tomotherapy is effective and has moderate toxicity in the treatment of T4 sinonasal adenoid cystic carcinoma involving skull base.

Emerging Opportunities for Target Discovery in Rare Cancers

Rare cancers pose unique challenges to research due to their low incidence. Barriers include a scarcity of tissue and experimental models to enable basic research and insufficient patient accrual for clinical studies. Consequently, an understanding of the genetic and cellular features of many rare cancer types and their associated vulnerabilities has been lacking. However, new opportunities are emerging to facilitate discovery of therapeutic targets in rare cancers. Online platforms are allowing patients with rare cancers to organize on an unprecedented scale, tumor genome sequencing is now routinely performed in research and clinical settings, and the efficiency of patient-derived model generation has improved. New CRISPR/Cas9 and small-molecule libraries permit cancer dependency discovery in a rapid and systematic fashion. In parallel, large-scale studies of common cancers now provide reference datasets to help interpret rare cancer profiling data. Together, these advances motivate consideration of new research frameworks to accelerate rare cancer target discovery.