Atypical meningiomas (AMs) and malignant meningiomas (MMs) are tumors with a lower incidence and poorer prognosis than benign meningiomas. The role of radiotherapy as an adjuvant to surgical resection, especially for AMs, is incompletely defined. In this study, the English-language literature was systematically reviewed for studies that reported tumor characteristics, treatment parameters, and clinical outcomes after adjuvant radiotherapy for AM and MM, including overall survival, progression-free survival, and/or time to recurrence or mortality. Clinical outcomes were further assessed in the context of resection status, timing of administration, and radiation dose. Outcomes after stereotactic radiosurgery were also examined. Treatment toxicity and other potential prognostic or confounding factors were appraised. Ten and 11 studies for AM and MM, respectively, met the inclusion criteria. The median 5-year progression-free survival and overall survival after adjuvant radiotherapy were 54.2% and 67.5%, respectively, for AM and 48% and 55.6% for MM. The complication rates were 11.1% for AM and 5.1% for MM. Incomplete resection and radiation dose <50 Gy conferred significantly poorer 5-year progression-free survival. Most studies were unable to demonstrate a statistically significant prognostic benefit for adjuvant radiotherapy in AM. In conclusion, adjuvant radiotherapy significantly improved local control of AMs and MMs, especially after subtotal resection. Study limitations, including inadequate statistical power, may underlie the studies' inability to demonstrate a statistically significant benefit for adjuvant radiotherapy in AM. Because these tumors preferentially recur within 5 years of surgical resection, future studies should define whether early adjuvant therapy should become part of the standard treatment paradigm for completely excised tumors.

Eph/ephrins drive cell segregation and boundary formation. O’Neill et al. discover that segregation is driven by unidirectional kinase-dependent EphB signaling. Unidirectional signaling generates a cortical actin differential between ephrin-B1– and EphB2-expressing cells and requires ROCK activity for cell segregation.

Objective In small (≤2 cm) oral tongue squamous cell carcinoma (OTSCC), we sought to clarify the contribution of pathologic features including perineural invasion (PNI), lymphovascular invasion (LVI), and worst pattern of invasion‐5 (WPOI‐5) to clinical outcomes relative to tumor depth of invasion (DOI) of > or ≤ 4 mm. Methods Cases of ≤2 cm OTSCC treated surgically between 2000 and 2017 at an academic cancer center were reviewed, with retrospective pathologic slide review of DOI, LVI, PNI, and WPOI‐5. Primary outcome measures included occult nodal positivity, 2‐year locoregional recurrence (LRR), disease‐specific survival (DSS), and overall survival (OS). Results One hundred tumors were included in analyses; 50 had DOI ≤ 4 mm, while 50 had DOI > 4 mm. When DOI was ≤4 mm, the presence of PNI, LVI, or WPOI‐5 was not associated with higher rates of occult cervical metastasis, LRR, or OS. When DOI was >4 mm, there was no difference in rates of occult cervical metastasis or LRR with each feature. On multivariate analysis, only the presence of two or more adverse features was associated with higher LRR (OR 5.7, P = .01) and worse DSS (HR 6.5, P = .02). Conclusion The rate of occult cervical metastases in small (≤2 cm) OTSCC when DOI is ≤4 mm is very low even when PNI, LVI, or WPOI‐5 is present, and 2‐year LRR is no different. When DOI is >4 mm, the strongest predictor of recurrence and survival on multivariate analysis is the presence of two or more features in the tumor. Level of Evidence 4 Laryngoscope, 130:1715–1720, 2020